A method and apparatus for producing highly-oriented polyester sheet comprises a two-stage drawing process. The first drawing stage is performed within a zero-gap milling and stretching roller assembly comprising a pair of opposed rollers defining a nip therebetween and wherein the rollers are rotated in opposite directions at different lineal surface velocities such that a predetermined draw ratio is defined therebetween. Amorphous polyester sheet is conducted through the nip of the opposed rollers, and as a result of the simultaneous milling and stretching of the polyester sheet, the amorphous polyester is transformed into crystalline polyester as a result of orientation-induced crystallization. The crystalline polyester sheet is heated above the glass transition temperature (Tg) immediately downstream of the nip defined between the pair of opposed rollers, and an exit bridle assembly is disposed downstream of the pair of opposed rollers. The rollers of the bridle assembly are rotated at lineal surface velocities which are greater than the lineal surface velocity of the downstream one of the pair of opposed rollers such that a second draw ratio is defined with respect to such downstream one of the pair of opposed rollers. The heating of the crystalline polyester sheet facilitates the additional stretching thereof within the second drawing stage of the apparatus, the overall drawing ratio being approximately 6:1. Highly oriented polyester, having tensile strength values of approximately 100,000 psi, and modulus values of approximately 3,000,000-5,000,000, is achieved.
This patent application is a Continuation-In-Part (CIP) patent application of U.S. patent application Ser. No. 08/353,721 filed on Dec. 12, 1994 by Donald L. Van Erden et al. and entitled METHOD AND APPARATUS FOR PRODUCING ORIENTED PLASTIC STRAP, AND STRAP PRODUCED THEREBY and now U.S. Pat. No. 5,525,287 which issued on Jun. 11, 1996, which, in turn, is a Continuation-In-Part (CIP) patent application of U.S. patent application Ser. No. 07/958,803 filed on Oct. 9, 1992 by Donald L. Van Erden et al. and entitled METHOD AND APPARATUS FOR PRODUCING ORIENTED PLASTIC STRAP, now U.S. Pat. No. 5,387,388.
The present invention relates generally to a method and apparatus for producing an oriented plastic sheet, and more particularly to a method and apparatus for producing a highly oriented polyester sheet which exhibits enhanced tensile strength and modulus characteristics, parameters, or values.
In accordance with a typical prior art stretching process, such as, for example, the SIGNODE process, a cast sheet of thermoplastic material, such as, for example, polypropylene, is first reduced in size, that is, the thickness dimension thereof, by rolling the sheet through a pair of closely spaced milling rollers or cylinders which rotate in opposite directions. After the thickness of the sheet has been reduced, the sheet is then drawn and stretched out from the milling rollers by means of a series of orienting rollers or a bridle assembly so as to achieve its finalized desired size or thickness.
Another prior art process or method that is commonly used in connection with the fabrication of stretched sheet materials is a process known as or called the short-gap method and is generally comprised of an entry bridle, a stretching assembly, and an exit bridle. In accordance with this process, a slow speed, heated entry bridle assembly advances a cast sheet of material, usually film, to a stretching assembly which comprises a pair of rollers or cylinders which are set a predetermined distance apart. The first roller rotates at the same speed as that of the entry bridle, whereas the second roller rotates at a speed which is greater than that of the first roller and which is equal to the rotary speed of the exit bridle. Thus, as the film passes through the entire assembly, it is stretched to its finalized desired size or thickness dimension.
These prior art methods or processes have presented several disadvantages. For example, the properties of the straps produced by these methods or processes provide or exhibit limited increases in strength without significant decreases in other desired properties. In addition, substantial necking of the sheets occur as the sheets are stretched over the distance or space defined between the rollers.
U.S. patent application Ser. No. 07/958,803, now U.S. Pat. No. 5,387,388, disclosed a novel process and apparatus for achieving the simultaneous milling and stretching of such sheets whereby the aforenoted problems were minimized, however, other operational problems with such process and apparatus were discovered which likewise required rectification in order to achieve simultaneously milled and stretched sheets of thermoplastic material which exhibited other desirable properties. For example, one operational problem or deficiency which was discovered in connection with the fabrication or manufacture of the simultaneously milled and stretched sheets of thermoplastic material in accordance with the zero-gap process and apparatus set forth and described within U.S. Pat. No. 5,387,388 is that when the thermoplastic sheet is ready to be worked, that is, simultaneously milled and stretched, by being conducted through the nip defined between the oppositely rotating rollers of the zero-gap assembly, it was found that the opposite surfaces of the thermoplastic sheet exhibited different surface temperature values. The reason for this is that as the thermoplastic sheet is routed about the first or upstream roller of the zero-gap roller assembly, the inside surface of the thermoplastic sheet, that is, the surface of the sheet which is disposed in direct contact with the first or upstream roller of the roller assembly, will be heated by the first or upstream roller, or at least have its surface effectively prevented from being cooled by the ambient air because such surface is disposed in direct contact with the first or upstream roller and not exposed directly to the ambient air. On the contrary, the outer or exterior surface of the thermoplastic sheet, that is, the surface of the sheet which is not disposed in direct contact with the first or upstream roller, is effectively cooled as a result of being exposed to the ambient air. Such temperature differential between the aforenoted surfaces of the thermoplastic sheet leads to density differentials throughout the thermoplastic sheet which adversely affects the various properties of the processed sheet, such as, for example, the tensile strength, weldability and associated properties, and split resistance.
Another problem or deficiency which was discovered in connection with the aforenoted zero-gap simultaneous milling and stretching apparatus and method was that as a result of the processing of the thermoplastic sheet, the opposite edge portions of the sheet became thickened, or in other words, the sheet did not exhibit a uniform thickness or flatness profile across the width thereof. Consequently, when the processed sheet was to be subsequently processed into thermoplastic strapping, the thickened edge portions could not be used to fabricate such straps unless further processing was performed upon the sheet so as to effectively reduce the thickness dimensions of the edge portions of the sheet to desired thickness dimensions characteristic of useable strapping.
Accordingly, the invention embodied and disclosed within U.S. patent application Ser. No. 08/352,721 was directed toward an apparatus and method for producing an oriented thermoplastic strap was which simultaneously milled and stretched as a result of a thermoplastic sheet workpiece being passed through a nip defined between the oppositely rotating rollers of the zero-gap assembly, and wherein further, in order to overcome the aforenoted deficiencies of the zero-gap simultaneous milling and stretching apparatus and method with respect to the density differentials and thickened edge portions of the milled and stretched sheet, various heating techniques were employed in connection with the milled and stretched sheet, as more particularly disclosed within the aforenoted patent application Ser. No. 08/352,721, which disclosure is hereby incorporated herein by reference, whereby the aforenoted deficiencies were overcome.
Additional studies and analysis of the existing zero-gap technology as noted hereinabove, as disclosed and described within both U.S. Pat. No. 5,387,388 and U.S. patent application Ser. No. 08/353,721, now U.S. Pat. No. 5,525,287, have revealed, however, that when such technology is applied or utilized in connection with the fabrication or manufacture of polyester sheets or straps, particularly in connection with the fabrication or manufacture of such sheets or straps from polyethylene terephthalate, the resulting sheets or straps do not exhibit high tensile strength and high modulus characteristics, parameters, or values.
A need therefore exists for the development of apparatus, and a concomitant method, for producing highly oriented polyester sheets or straps wherein the apparatus, and the concomitant method, employs special or unique orientation, stretching, or drawing techniques in conjunction with special or unique heating techniques whereby the produced or manufactured polyester sheets or straps exhibit enhanced tensile strength and modulus values, characteristics, or parameters.
Accordingly, it is an object of the present invention to provide a new and improved method and apparatus for producing highly oriented polyester sheets or straps.
Another object of the present invention is to provide a new and improved method and apparatus for producing highly oriented polyester straps or sheets which overcomes the various deficiencies, drawbacks, disadvantages, and problems of the prior art processes and apparatus.
Yet another object of the present invention is to provide a new and improved method and apparatus for producing highly oriented polyester sheets or straps which is capable of producing such straps or sheets by simultaneously milling and stretching sheet workpieces into such straps or sheets, having a predetermined thickness dimension, as a result of the sheet workpieces being conducted in a single pass through a nip defined between a pair of zero-gap rollers.
Still another object of the present invention is to provide a new and improved method and apparatus for producing highly oriented polyester sheets or straps wherein the sheets or straps produced thereby exhibit significantly higher tensile strength and modulus values when compared to straps or sheets produced by heretofore known prior art methods and apparatus.
A further object of the present invention is to provide a new and improved method and apparatus for producing highly oriented polyester sheets or straps wherein improved uniform thickness and flatness characteristics are imparted to the finalized milled and stretched strap or sheet as a result of various heating, rolling, and extrusion techniques being imparted to the original sheet workpiece or material.
Briefly, the foregoing and other objects are achieved in accordance with the present invention through the provision of a method and apparatus for producing highly oriented polyester sheets or straps which will have a predetermined desired thickness for use in strapping packages and the like, wherein the strap, having the noted predetermined desired thickness, is simultaneously milled and stretched as a result of a polyester sheet workpiece being passed through a nip defined between a pair of rollers or cylinders which are spaced closely together with respect to each other. The nip has a space dimension which is substantially less than the original thickness dimension of the sheet workpiece, and the rollers are rotated in opposite directions and at substantially different lineal surface velocities.
In order to improve the various properties of the simultaneously milled and stretched strap, that is, for example, the tensile strength and modulus or stiffness of the fabricated oriented sheets or straps, the solid sheet or strap, in accordance with the teachings of the present invention, is subjected to a unique orientation sequence and a unique heating sequence. In particular, the orientation sequence is, in effect, a two-stage drawing sequence wherein the first drawing operation is effectively performed within the zero-gap roller assembly, while the second drawing operation is performed by means of an exit bridle assembly in cooperation with the downstream roller of the zero-gap roller assembly. Concomitantly therewith, the heating sequence comprises a predetermined mode of heating, for example, the upstream and downstream rollers of the zero-gap roller assembly, which indirectly heat the solid polyester sheet or strap, as well as directly heating the solid polyester strap or sheet at a particular location with respect to the upstream roller of the zero-gap roller assembly so as to accurately and consistently control and predetermine the orientation of the polyester sheet or strap. In addition, the mechanical work imparted to or impressed upon the polyester sheet or strap as the same is conducted through the nip of the rollers of the zero-gap roller assembly also contributes to additional heating of the strap or sheet so as to facilitate the stretching of the sheet or strap and the resulting orientation thereof.
In order to improve the flatness of the resultant simultaneously milled and stretched polyester sheet such that an increased volume of strapping can be produced from such sheeting, thinner edge portions can be initially imparted to the polyester sheet workpiece either upstream of or prior to entry of the sheet workpiece into the nip defined between the zero-gap milling rollers, or within the nip defined between the zero-gap milling rollers. In view of the tendency of the edge portions of the workpiece to become thickened as a result of the simultaneous milling and stretching of the sheet workpiece within the zero-gap roller assembly, the resulting edge portions, in accordance with the processing techniques of the present invention, will exhibit thickness dimensions which will be commensurate with the thickness dimension of the central portion of the sheet workpiece, as viewed transversely across the width of the sheet workpiece, when the sheet workpiece is simultaneously milled and stretched. Production of the thinner edge portions of the sheet workpiece can be produced, for example, by means of specially contoured milling rollers employed within the zero-gap roller assembly defining the nip through which the sheet workpiece is forced to pass, the zero-gap milling rollers effectively defining a nip therebetween which has a trapezoidal cross-sectional configuration. In a similar but alternative manner, and in accordance with a second means or mode for producing such thinner edge portions upon the resulting workpiece, specially contoured extrusion dies and casting rollers can be employed so as to similarly provide the extruded and cast sheet workpiece with a substantially trapezoidal configuration such that the edge portions of the sheet workpiece are tapered. As a result of the simultaneous milling and stretching of the sheet workpiece, the tapered edge portions thereof will experience increased thickening whereby, as a result, the thickness dimensions of the edge portions will become similar to the thickness dimension of the central portion of the sheet workpiece.
FIG. 9 is a front view of casting rolls used in conjunction with the extrusion dies of FIGS. 8A and 8B for casting and further forming the sheet workpiece extruded from the extrusion dies of FIGS. 8A and 8B such that the sheet workpiece can be conducted downstream toward the zero-gap milling and stretching assembly.
Referring now to the drawings, and more particularly to FIG. 1 thereof, there is schematically illustrated a zero-gap roller assembly, generally indicated by the reference character 20, for simultaneously milling and stretching or elongating a sheet workpiece 22 into a thin strap stock material. The present invention is discussed and illustrated with only a single sheet workpiece 22 being conducted through the assembly 20, however, it is to be understood that more than one sheet or workpiece 22 may be simultaneously passed through the assembly 20. It is to be further understood that the phrase or terminology "zero-gap" as will be used throughout this patent specification refers to the concept of substantially eliminating any gap between the step of milling the sheet workpiece and the step of stretching or elongating the sheet workpiece. Considered in an alternative manner, the steps of milling and stretching or elongating of the sheet workpiece are accomplished substantially simultaneously. In addition, it is noted, as disclosed in FIG. 1, that the zero-gap assembly 20 is located between a sheet or workpiece feeding assembly 24 and an exit bridle assembly 26 which are located or mounted upon a frame or support 28.
The feeding assembly 24 may take any one of several forms, and as shown in FIG. 1, comprises an extruding machine 30 for extruding a sheet or workpiece 22 of stock material, and an entry bridle assembly 32. The extruding machine 30 produces a sheet workpiece 22 from a suitable material, such as, for example, polypropylene, a polyester, such as, for example, polyethylene terephthalate (PET), or the like, and the sheet workpiece 22 is conducted into the entry bridle assembly 32 which, in turn, feeds the sheet workpiece into the zero-gap roller assembly 20. The sheet workpiece 22 may be heated during its passage through the entry bridle assembly 32 so as to in effect be pre-heated upon entry into the zero-gap roller assembly 20 in order to enhance the working properties, stretching or elongating, and orientation properties and resulting characteristics of the material comprising the sheet workpiece 22, and this heating technique will be more fully discussed in connection with the fabrication of highly-oriented polyester sheeting or strapping when the system or apparatus of FIGS. 5 and 6 is discussed hereinafter.
The entry bridle assembly 32 is seen to comprise a plurality of rollers or cylinders 34, 36, 38, and 40 which are mounted by suitable means, such as, for example, shafts, not shown, upon the frame or support 28. The rollers 34, 36, 38, and 40 may be either solid or hollow, and in the preferred embodiment, as illustrated in FIG. 1, the rollers 34, 36, 38, and 40 are essentially only used to properly deliver or feed the sheet workpiece 22 into the zero-gap assembly 20, and they do not substantially contribute to any stretching or milling of the sheet workpiece 22. A different number of rollers may be employed than that shown in FIG. 1, and it is seen that rollers 34, 36, 38, and 40 are arranged within two vertically spaced rows with the bottom row rollers 36 and 40 being located between or offset with respect to the top row rollers 34 and 38. Rollers 34 and 38 are also mounted for rotation in the clockwise direction while rollers 36 and 40 are mounted for rotation in the counterclockwise direction, whereby when the sheet workpiece 22 is wound around or routed through the entry bridle assembly 32, it travels through the rollers 34, 36, 38, and 40 in the proper mode or direction with respect to the directions of rotation of the rollers 34, 36, 38, and 40. Each one of the rollers 34, 36, 38, and 40 is rotated at a uniform speed by suitable means, not shown, such as, for example, a motor and shaft drive assembly, and all of the rollers 34, 36, 38, and 40 rotate at substantially the same speed or lineal surface velocity as the top roller 42 of the zero-gap assembly 20, which will be discussed in greater detail hereinafter.
Continuing further, after the sheet workpiece 22 passes through the feeding assembly 24, it advances toward the zero-gap assembly 20 for simultaneous milling and stretching into a finished sheet 22 which has a predetermined desired thickness. The zero-gap assembly 20 comprises a pair of rollers or cylinders 42 and 44 that are rotatably mounted in an opposing relationship. The nip 46, that is, the distance defined between the rollers 42 and 44, can be substantially varied depending upon the desired finished thickness of the finished sheet 22. The zero-gap rollers 42 and 44 may either be solid or hollow, and may be heated by any well-known means, not shown, such as, for example, circulating a heated fluid through the rollers 42 and 44, in order to enhance the stretching properties of the sheet material. The zero-gap rollers 42 and 44 may also be flat, as shown in FIGS. 1-4, or may be contoured as will be illustrated and described more particularly hereinafter in order to change the shape of the sheet workpiece 22 as it passes through the rollers 42 and 44 of the zero-gap assembly 20 and provide the finalized sheet workpiece product with predetermined thickness profile characteristics.
As best shown in FIG. 2, the upper roller 42 of the zero-gap roller assembly 20 is driven in the clockwise direction, as is shown by means of its associated arrow, while the bottom or lower roller 44 of the assembly 20 is driven in the counterclockwise direction as similarly shown or designated by means of its associated arrow. Thus, the sheet workpiece 22 is first routed around a major circumferential portion of the top or upper milling roller 42, the workpiece 22 is then conducted through the nip 46 defined between the milling rollers 42 and 44, and is then conducted around a major circumferential portion of the bottom or lower roller 44. More particularly, it is to be appreciated that the sheet workpiece 22 is disposed in surface contact with each one of the zero-gap assembly rollers 42 and 44 over a circumferential extent which is greater than one-half of each one of the circumferential extents of each one of the rollers 42 and 44, and it is further noted that as a result of this particular routing of the sheet workpiece 22 through the nip 46 defined between the zero-gap milling rollers 42 and 44, and about the outer circumferential or peripheral surfaces of the rollers 42 and 44, each roller 42 and 44 is disposed in contact with an opposite surface or side of the sheet workpiece 22.
In accordance with the illustrated zero-gap roller assembly embodiment of the present invention, as shown in FIGS. 1-4 and as has been described in detail in conjunction with such drawing figures, the milling and stretching rollers 42 and 44 of the zero-gap roller assembly 20 are disposed in a top-bottom or upper-lower arrangement with respect to each other, however, it is to be appreciated that the rollers 42 and 44 may alternatively be disposed in a side-by-side arrangement in which case the top or upper roller 42 will be disposed toward the left of the bottom or lower roller 44 such that the roller 42 will be the first or upstream roller that the sheet workpiece 22 contacts or encounters, while the bottom or lower roller 44, which is now, in effect, the right roller, will be the second or downstream roller that the sheet workpiece 22 will contact or encounter. As best seen in FIG. 2, the rollers 42 and 44 are respectively mounted upon rotary shafts or axles 52 and 54.
With particular reference now being made to FIG. 4, the drive system for the rollers 42 and 44 is disclosed therein, and it is seen that the axles or shafts 52 and 54 of the rollers 42 and 44 are operatively connected, through means of bearings 69 and 68, to driven shafts 48 and 50. Suitable drive means 56 and 58, such as, for example, electric motors, are mounted upon the support 28 and drive the rollers 42 and 44, respectively, through means of drive shafts 60 and 62 which are connected to the shafts 48 and 50 by means of suitable couplings 64 and 66, coupling 66 preferably comprising a universal coupling for reasons to become apparent shortly. The bottom or lower roller 44 is connected to the support 28 through means of bearings 68 and 70, and the coupling 66, and bearings 68 and 70, permit the bottom or lower roller 44 to move with respect to the support 28 by means of actuators 72 and 74. In this manner, the bottom or lower roller 44 is able to be moved toward or away from the stationary top or upper roller 42 so as to desirably change the size of nip 46 defined between the rollers 42 and 44. Each one of the driven shafts 48 and 50 is independently driven by its separate drive means 56 and 58, and the bottom or lower roller 44 is driven at a speed greater than that of the top or upper roller 42. In particular, in accordance with the teachings of the present invention, the lower or bottom roller 44 is driven in such a manner that its lineal surface velocity is preferably within the range of seven to twelve (7-12) times greater than the lineal surface velocity of the top or upper roller 42 when, for example, the sheet workpiece 22 being processed comprises polypropylene. However, as will be more fully explained and disclosed hereinafter, when the sheet workpiece 22 being processed is polyester, such as, for example, and preferably, polyethylene terephthalate (PET), the lineal surface velocity or draw ratio of the lower or bottom roller 44 is within the range of four to five (4-5) times greater than the lineal surface velocity of the top or upper roller 42.
In view of the foregoing, it can be appreciated that as the sheet workpiece 22 is passed through the nip 46 defined between the upper and lower rollers 42 and 44 of the zero-gap roller assembly 20, the top or upper roller 44 effectively operates as a brake, and the mill reduction operation per se may also effectively operate as a brake, upon the lower surface of the sheet workpiece 22, that is, the surface disposed in contact with the upper roller 42, while the bottom or lower roller 44 pulls and accelerates the sheet workpiece 22, the roller 44 effectively operating upon the upper surface of the sheet workpiece 22, that is, the surface thereof which is disposed in contact with the roller 44. As the sheet workpiece accelerates through the nip 46 defined between the rollers 42 and 44, it is simultaneously milled and stretched to its final predetermined thickness which may in fact be less than the space dimension of the nip 46 as defined between the rollers 42 and 44. In particular, the thickness of the finished sheet 22 depends upon the lineal surface velocity differential or draw ratio defined between the top roller 42 and the bottom roller 44, that is, the faster the bottom or lower roller 44 rotates relative to the top or upper roller 42, the thinner the finished sheet 22 will be. It is also to be noted that some stretching may occur slightly before or slightly after the nip 46 defined between the pair of rollers 42 and 44 depending, again, upon the surface velocity differential defined between the rollers 42 and 44. Thus, as has been noted hereinabove, there is essentially a zero gap, space, or time frame between the milling and stretching functions or operations performed in connection with the sheet workpiece 22 and the processing thereof into the finalized or finished sheet 22. As a result of such simultaneous milling and stretching processing, it has been noted that there is substantially less necking of the sheet width as compared to the parameters of sheets which have undergone stretching or drawing processing in accordance with prior art processes or techniques wherein the sheet is stretched only after the milling step has been performed and completed.
After the finished sheet 22 exits from the zero-gap roller assembly 20, it is conducted through the exit bridle assembly 26. The exit bridle assembly 26 may take any one of several different forms, and as shown in FIG. 1, the assembly preferably comprises a plurality of rollers or cylinders 76, 78, 80, 82, 84, and 86 which are mounted by suitable means, such as, for example, shafts or axles, not shown, upon the support 28. The assembly 26, and in particular, the rollers 76-86, are used to pull the finished sheet 22 out from the zero-gap assembly 20. The rollers 76, 78, 80, 82, 84, and 86 may be solid or hollow, and more or fewer rollers than those disclosed may be used. The rollers 76, 78, 80, 82, 84, and 86 do not, in this embodiment, substantially contribute to any stretching of the finished sheet 22, however, as will become apparent hereinafter, when the system of FIG. 1 is modified so as to fabricate highly-oriented polyester sheets, the rollers of the exit bridle assembly of such modified apparatus or system will perform a critically important stretching, elongating, or drawing function in connection with the fabrication of such polyester sheets so as to achieve polyester sheets which exhibit desired high tensile strength and modulus parameters. Referring back to the embodiment of FIG. 1, it is seen that the rollers 76, 78, 80, 82, 84, and 86 are arranged in two vertically spaced rows with the bottom or lower row rollers 78, 82, and 86 also being spaced between the top or upper row rollers 76, 80, and 84 as considered in the transverse direction. The upper rollers 76, 80, and 84 all rotate in the clockwise direction, while the lower rollers 78, 82, and 86 all rotate in the counterclockwise direction such that the finished sheet 22 can be properly conducted through the exit bridle assembly 26. The rollers 76, 78, 80, 82, 84, and 86 are rotated at a uniform rate of speed by suitable drive means, not shown, such as, for example, a motor and shaft assembly, and the speed of the rollers 76, 78, 80, 82, 84, and 86 is such that, in accordance with this embodiment of the present invention, the lineal surface velocities thereof are essentially the same as that of the bottom or lower roller 44 of the zero-gap roller assembly 20.
It is to be appreciated that in accordance with further teachings of the present invention, another stretching process, and apparatus for implementing the same, such as, for example, a short gap stretching apparatus, system, or assembly, may be used either before or after the zero-gap assembly 20 so as to further modify or enhance the characteristics of the finished sheet 22, and as has been alluded to hereinbefore, such an additional apparatus or system, and the concomitant stretching techniques thereof, will be more fully disclosed hereinafter with respect to the special processing or fabrication of highly oriented polyester sheets.
Having now disclosed the specifics of the apparatus comprising the first embodiment of the present invention, the method to be practiced by means of such apparatus and in accordance with the present invention will now be described. More particularly, the sheet workpiece 22 is fed from the extruding machine 30 to the entry bridle assembly 32 and is wound around the entry bridle assembly rollers 34, 36, 38, and 40 so as to be, in turn, properly conducted into the zero-gap assembly 20. The sheet workpiece 22 is then fed around the top or upper roller 42 of the zero-gap assembly 20, the top or upper roller 42 of the roller assembly 20 being driven at the same lineal surface velocity as that of the entry bridle rollers 34, 36, 38, and 40. As the sheet workpiece 22 enters the zero-gap assembly 20, it travels around the outer peripheral surface of the top or upper roller 42 until it reaches the nip 46 defined between the top or upper roller 42 and the bottom or lower roller 44. As previously noted, the faster rotating bottom or lower roller 44 pulls the sheet workpiece 22 through the nip 46 while the slower rotating top or upper roller 42, as well as the mill reduction process per se, effectively acts as a brake upon the lower surface of the sheet workpiece 22, that is, the surface of the workpiece 22 which is disposed in contact with the upper or top roller 42. Thus, the sheet workpiece 22 accelerates through the nip 46 defined between the rollers 42 and 44, and is simultaneously milled and stretched to its finalized predetermined thickness dimension as the same passes through the nip 46. The exit bridle assembly 26 subsequently pulls the finished sheet 22 off from the bottom or lower roller 44 of the zero-gap assembly 20, and it is therefore appreciated that in accordance with the method of the present invention, there is able to be achieved the production of a thin, flat, oriented sheet 22 which is ready to be surface treated and/or heat treated as desired, and sliced into thin straps as required or desired for use in strapping packages and the like in accordance with well-known procedures.
As can be appreciated from the table noted above, the zero gap method produces strapping which exhibits higher tensile strength, and a stronger and higher percentage weld. Furthermore, splitting of the strapping has been essentially eliminated while still achieving high tensile strength, whereas in accordance with known or prior art manufacturing techniques and processes, as the tensile strength is increased, increased splitting occurs and the percent of weld strength decreases. Still further, since the tensile strength of the strapping produced in accordance with the zero-gap process is approximately 1.47 times the tensile strength of conventionally produced strapping, and since the elongation of such strapping of the present invention is approximately one-half that of the conventional strapping, better creep performance is achieved. Such results present several marketing advantages in connection with polypropylene or polyethylene terephthalate (PET) polyester straps. More particularly, if the break strength of the strapping is a controlling factor in connection with the particular application or use of the strapping, then the higher tensile strength of the material will permit the use or substitution of a strap which comprises only approximately seventy percent (70%) of currently used material or strapping. Similarly, if stiffness is a controlling factor, characteristic, or attribute, the strapping produced in accordance with the present invention is such as to be readily capable of being reliably fed into a strapping machine by being pushed around a guide chute of the strapping machine. Still yet further, if weld strength of the strapping is a controlling factor or characteristic, then strapping comprising less than one-half of the currently or conventionally used raw material will produce the equivalent joint strength.
The various properties resulting from the process of the present invention give significant flexibility of design to the strapping which may then be used in connection with a variety of applications. It is believed, for example, that the strapping produced by means of the process of the present invention exhibits a stronger bond across the grain, while still being relatively easy to tear the strap across the grain. Furthermore, the strap produced by means of the zero-gap process of the present invention does not exhibit structural delamination as is often characteristic of most prior art strapping. Since the strap of the present invention does not exhibit structural delamination, higher weld strength is also obtained. As has also been noted hereinbefore, if a prestretch step is performed between the entry bridle assembly and the zero-gap assembly, or if a post-stretch step is performed between the zero-gap assembly and the exit bridle assembly, the same overall characteristics are achieved as are achieved in accordance with the embodiment of the invention as described in connection with the system and process of FIGS. 1-4. It is noted, however, that if a pre-stretch process step is performed upon the sheet workpiece 22, a higher tensile modulus can be achieved, whereas if a post-stretch process step is performed upon the finished sheeting 22, the material comprising the sheeting has a somewhat greater tendency toward fibrillation.
With reference again being made to the apparatus or system of FIG. 1, it has been discovered that when the sheet workpiece 22 is conducted through the entry bridle assembly 32, and particularly as the workpiece 22 approaches the upper milling and stretching roller 42 of the zero-gap assembly 20, the upper or outer surface of the sheet workpiece 22, that is, the surface thereof which is not disposed in contact with the peripheral surface of the upper or top roller 42 of the zero-gap assembly 20, will tend to cool at a faster rate than the lower or inner surface of the sheet workpiece 22 which is disposed in contact with the peripheral surface of the upper or top roller 42 of the zero-gap assembly 20 in view of the fact that the upper or outer surface of the sheet workpiece 22 is directly exposed to the ambient air. As a result of such uneven or unequal cooling of the workpiece surfaces, or as a result of the development of such a temperature differential between the noted surfaces of the sheet workpiece 22, the sheet workpiece 22 exhibits density differentials throughout the thickness thereof whereby such density differentials adversely affect some of the properties or characteristics of the sheet workpiece. Consequently, in order to rectify, resolve, or eliminate such problem, an improved pre-heating system or apparatus, as more particularly disclosed within the aforenoted pending patent application, Ser. No. 08/353,721, now U.S. Pat. No. 5,525,287, has been developed. In view of the fact that such an improved system or apparatus does not comprise the subject matter of this particular patent application, a detailed description of such system or apparatus is not actually disclosed herein but is hereby incorporated herein by reference.
Continuing further, it is also known that during processing of the sheet workpiece 22, that is, by means of the aforenoted milling and stretching thereof, the side edge portions of the sheet workpiece 22 will tend to be thicker than the more centrally located portions of the sheet workpiece 22. The reasons for this phenomenon are explained within co-pending U.S. patent application Ser. No. 08/474,355, filed on the same date as the present patent application, and entitled METHOD AND APPARATUS FOR PRODUCING ORIENTED PLASTIC STRAP, AND STRAP PRODUCED THEREBY, and the solution to such problem has been the provision of edge heaters along the side edge portions of the sheet workpiece 22 at positions immediately upstream of the nip 46 defined between the pair of milling rollers 42 and 44. Still further, despite the employment of such edge heaters, it has been additionally determined that concavities and transitional bump regions are nevertheless present within the sheet profile, and in accordance with further teachings of the aforenoted co-pending patent application, Ser. No. 08/474,355, additional strip heaters are also employed in conjunction with the aforenoted edge heaters. Again, in view of the fact that such sheet edge heating apparatus and techniques do not comprise the subject matter of this particular patent application, a detailed description of such apparatus and techniques is omitted herefrom but is hereby incorporated herein by reference. It is still yet further noted that in accordance with the particular teachings of the present invention, additional non-heating, structural apparatus and associated techniques for reducing thickened side edge portions of the fabricated sheeting will be disclosed hereinafter.
Continuing further, while the zero-gap milling and stretching system of FIGS. 1-4 has of course been very satisfactory and commercially successful in connection with the commercial fabrication of polypropylene and polyester sheeting and strapping, particularly as modified by means of the various improvements disclosed within patent application Ser. No. 08/353,721, now U.S. Pat. No. 5,525,287, filed Dec. 12, 1994, and patent application Ser. No. 08/474,355, filed on the same date as the present patent application, additional studies performed in connection with the fabricated sheeting or strapping comprising polyester, particularly polyethylene terephthalate (PET), have demonstrated that the apparatus or system of FIGS. 1-4 in and of itself, and operated in accordance with the previously disclosed method and mode, cannot produce highly-oriented polyester sheets or straps, that is, sheeting or strapping which exhibit, for example, a tensile strength value of 100,000 psi and a modulus value which is within the range of 3,000,000 to 5,000,000 psi. Accordingly, apparatus and a mode of operation, similar to those of FIGS. 1-4 but modified accordingly in accordance with the particular teachings of the present invention, will now be described in connection with the fabrication of such highly-oriented polyester sheets or straps which will exhibit a tensile strength value of 100,000 psi and a modulus value of 3,000,000-5,000,000 psi.
Polyester exists in two different states as a solid, that is, either as amorphous polyester, or crystalline polyester. The present invention is directed toward the fabrication of commercial sheeting or strapping comprising crystalline polyester as derived from amorphous polyester. Amorphous polyester can be changed into crystalline polyester, or crystallized, by means of either heat-induced crystallization or orientation-induced crystallization. Heat-induced crystallization of polyester is disclosed, for example, within U.S. Pat. No. 4,022,863 which issued to Thomas J. Karass et al. on May 10, 1977, however, the fabricated polyester strap is milky-white in appearance and does not exhibit satisfactory split resistance properties. The present invention is therefore directed toward the fabrication of crystalline polyester sheeting by means of orientation-induced crystallization of amorphous polyester employing a modified zero-gap milling and stretching system.
More particularly, with reference now being made to FIGS. 5 and 6, a modified polyester roller assembly or apparatus system is generally indicated by the reference character 100 and is seen to comprise the zero-gap roller assembly 120 comprising upper and lower rollers 142 and 144, an entry bridle arrangement or system 132 comprising rollers 134,136,138, and 140, and an exit bridle arrangement or system 126 which comprises rollers 178, 180,182, and 184. An idler roller 141 is interposed between roller 140 of the entry bridle system 132 and the upper roller 142 of the zero-gap roller assembly 120, and similarly, an idler roller 177 is interposed between the lower roller 144 of the zero-gap roller assembly 120 and the roller 178 of the exit bridle arrangement or system 126.
In order to prevent heat-induced crystallization of the polyester sheet 122 conducted through the entry bridle arrangement 132 and toward the zero-gap milling and stretching assembly 120, until, of course, crystallization has been induced as a result of the orientation of the sheet 122 by means of the sheet 122 having passed through the nip 146 defined between the milling rollers 142 and 144, the temperature of the sheet 122 must be maintained below the glass transition temperature (Tg) of approximately 80° C. for any substantial period of time. If the polyester sheet 122 is heated to a temperature level above the glass transition temperature (Tg) for any substantial period of time, the sheet 122 will crystallize, become sticky or tacky, and the sheet 122 will not be able to be properly conducted along its conveyance path through the entry bridle assembly 132 and the zero-gap roller assembly 120. Consequently, in accordance with the teachings of the present invention, all of the entry bridle assembly rollers 134, 136, 138, and 140, as well as the idler roller 141 and the upper roller 142 of the zero-gap roller assembly 120 are heated to and maintained at a temperature level of 75° C.
In order to properly process the polyester sheet 122, that is, in order to obtain consistently oriented polyester sheeting which will, in turn, consistently exhibit the desired tensile strength, modulus, creep resistance, split resistance, and other characteristics or parameters, it is necessary to facilitate commencement of the orientation of the sheet workpiece 122 at a precise location along its conveyance path through the system. Since molecular orientation, and therefore crystallization, of the polyester sheeting occurs within the nip 146 defined between the upper and lower rollers 142,144 of the zero-gap assembly 120, the most advantageous location at which the orientation can be commenced and controlled is at a location which immediately precedes the nip 146 defined between the rollers 142,144. From an operational viewpoint, and with reference to FIG. 5, if the end view of the upper roller 142 was considered to the face of a clock, then orientation of the sheet 122 would desirably be commenced within the lower right quadrant of such clock face, or in other words, anywhere within the range from the two o'clock position to the six o'clock position. It might be difficult to achieve such orientation commencement at the six o'clock position since such position comprises the location of the nip 146 defined between the rollers 142,144, so consequently, it is preferred to commence orientation at a position which is effectively as close to the six o'clock position as is possible. Accordingly, in accordance with the present invention, infrared heaters 143 are disposed exteriorly of the upper roller 142 so as to heat the sheet workpiece 122. Such heating changes the tensile strength of the sheet workpiece 122 at such location, elongation of the sheet workpiece 122 becomes easier at such location, and consequently, orientation of the sheet workpiece 122 is controlled or forced to commence at such location. As illustrated in FIGS. 5 and 6, the infrared heaters 143 are disposed at, in effect, a five-thirty (5:30) clockface position, although they may be placed anywhere within the aforenoted range of two o'clock to five-thirty. In addition, the heaters 143 may have a length extending continuously from the two o'clock to five-thirty position so as to extend the heating region of the workpiece 122 depending upon the speed of the workpiece 122 through the assembly 120. While the infrared heaters 143 will raise the temperature of the workpiece 122 at such location to a temperature value which is greater than the glass transition temperature (Tg), due to the closeness of such location to the nip 146 defined between the upper and lower rollers 142 and 144, within which orientation-induced crystallization of the polyester sheet occurs, heat-induced crystallization is minimized. Due to the elevation of the temperature of the sheet workpiece 122 to a temperature level which may be greater than the glass transition temperature (Tg), the sheet workpiece 122 may exhibit some tendency to stick to the upper zero-gap roller 142. Consequently, in order to prevent such sticking of the sheet 122 to the upper roller 142, a water-soluble, water-based emulsion, comprising water, air, and 1-2% by weight oil, is applied as a spray, from spraying means 145, onto the lower surface of the sheet workpiece 122 at a conveyance position which is disposed upstream, for example, of the entry bridle idler roller 141. As can be appreciated from FIGS. 5 and 6, the lower surface of the sheet workpiece 122 becomes the inner surface with respect to the upper roller 142 of the zero-gap assembly 120, and consequently, such emulsion will prevent any sticking from occurring between the sheet workpiece 122 and the upper roller 142 of the zero-gap assembly 120. Sticking of the oriented sheet 122 upon the lower roller 144 of the zero-gap assembly 120 is not a problem because once the polyester sheet 122 undergoes its orientation within the nip 146 defined between the rollers 142 and 144 of the zero-gap assembly 120, the amorphous polyester is converted into crystalline polyester which does not exhibit sticky or tacky properties.
In order to properly orient the sheet workpiece 122 within the nip 146 defined between the upper and lower rollers 142 and 144 of the zero-gap assembly 120, the lower zero-gap roller 144 is rotated at a rotational speed such that the lineal surface velocity of such roller 144 is substantially greater than the rotational speed and effective lineal surface velocity of the upper zero-gap roller 142. In particular, in accordance with the present invention, the lineal surface velocity of the lower zero-gap roller 144 is set to be approximately 4-5 times that of the lineal surface velocity of the upper zero-gap roller 142 such that the draw ratio impressed upon the sheet workpiece is likewise within the range of 4-5:1. In a similar manner, the exit bridle assembly rollers 178, 180, 182, and 184 are rotated at a rotational speed which is greater than that of the lower zero-gap roller 144 such that the lineal surface velocity, and therefore, the draw ratio, of the exit bridle assembly rollers 178, 180, 182, and 184 are a multiple of the lineal surface velocity of the lower zero-gap roller 144. In particular, in accordance with the present invention, the lineal surface velocity of the exit bridle rollers 178, 180, 182, and 184 is set to be approximately 1.1-1.5 times that of the lineal surface velocity of the lower zero-gap roller 144 such that the draw ratio impressed upon the sheet workpiece is likewise within the range of 1.1-1.5:1. As can therefore be appreciated, the present invention comprises a two-step drawing process within an overall drawing ratio of approximately 6:1 being impressed upon the sheet workpiece 122. For example, if the lower zero-gap roller 144 is rotated at a rotational speed such that the lineal surface velocity thereof is 4.5 times the lineal surface velocity of the upper zero-gap roller 142, and the exit bridle rollers 178,180,182, and 184 are rotated at a rotational speed such that the lineal surface velocities thereof are 1.34 times the lineal surface velocity of the lower zero-gap roller 144, then an overall or resultant drawing ratio of 6.03 would be achieved and impressed upon the sheet workpiece 122. Alternatively, for example, the lineal surface velocity differential or drawing ratio between the lower zero-gap roller 144 and the upper zero-gap roller 142 could be 5.0 or 5:1, respectively, while the lineal surface velocity differential or drawing ratio defined between the exit bridle assembly rollers 178-184 and the lower zero-gap roller 144 could be 1.2 or 1.2:1, respectively, whereby, again, the overall drawing ratio would be 6:1. In order to facilitate the secondary or second-stage stretching and orientation of the sheet workpiece 122 as developed between the lower zero-gap roller 144 and the exit bridle assembly rollers 178-184, the lower zero-gap roller 144 is heated to a temperature level of 150° C. while the exit bridle assembly rollers 178-184 may be maintained at room temperature (RT). After undergoing the secondary or second-stage stretching and orientation, the resultant polyester sheeting exhibits tensile strength values of 100,000 psi and modulus values of between 3,000,000 psi and 5,000,000 psi.
As has been noted hereinbefore, during the fabrication of oriented sheet workpieces within the zero-gap apparatus or system characteristic of the present invention, the fabricated sheet workpieces tend to exhibit thickened edge portions or regions. Accordingly, it has been further noted hereinabove that the provision of suitably disclosed edge heaters and strips heaters, as more fully disclosed within co-pending U.S. patent application Ser. No. 08/474,355, rectifies or substantially eliminates such problem such that an increased volume of useable sheeting or strapping may in fact be produced for the ultimate fabrication of package strapping. Increased flatness or increased amounts of uniformly flat finished sheets across the width dimensions thereof can also be achieved in accordance with other non-heating, structurally based manufacturing techniques. For example, with reference being made to FIGS. 7A and 7B, there is shown, in effect, front view profiles of two differently contoured mill rollers which may be incorporated within the zero-gap assembly 120 of the system of FIGS. 5 and 6 in conjunction with the fabrication of the highly oriented polyester sheeting. As can be appreciated from the contoured mill rollers 204 and 206 of FIGS. 7A and 7B, respectively, the central portions of the rollers 204 and 206 are effectively concave as seen at 208 and 209, respectively, while the lateral side edge portions 211 and 213 have straight or horizontal configurations or contours. In this manner, when the sheet workpiece 122 is milled and stretched within the nip 146, the edge portions of the sheet workpiece 122 will be worked to a greater degree than the central portions of the sheet workpiece 122 whereby the edge portions of the sheet workpiece 122 will be rendered thinner. Upon being processed within the nip 46 or 146, the edge portions of the sheet workpiece 122 will also undergo thickening to some extent as described hereinbefore, whereby the finalized edge regions of the sheet workpiece 122 or finished sheet 122 will have the desired degree of thinness and uniformity of flatness as may be similarly achieved by means of the aforenoted edge and strip heating techniques. As can be further appreciated from FIGS. 7A and 7B, the primary difference between the contours or configurations of the miller rollers 204 and 206 resides in the fact that in the case of the roller 204 of FIG. 7A, the central portion thereof has a cylindrical contour as at 215 while the adjacent axial portions thereof have tapered or frustoconical configurations as at 217. Finally, the outermost end or edge portions are cylindrical as at 219, the diametrical extent of cylindrical portions 219 being, however, greater than the diametrical extent of central cylindrical portion 215. Similarly, in the case of the roller 206 of FIG. 7B, the central portion 209 has a concave arcuate configuration while the outermost end portions 221 are cylindrical and have diametrical extents which are greater than that of the central portion 209.
With reference lastly being made to FIGS. 8A, 8B, and 9, another manufacturing technique which may be employed in order to achieve increased flatness or increased amounts of uniformly flat finished sheets across the width dimensions thereof involves the extrusion of the sheet workpiece 122 from particularly configured extrusion dies 223 and 225 which are respectively shown in FIGS. 8A and 8B. As can be appreciated from such figures, each one of the dies 223 and 225 has, in effect, a die mouth 227 and 229 which has a trapezoidal configuration which therefore produces polyester sheet workpieces 122 which likewise have trapezoidal cross-sectional configurations, or in other words, the edge portions 231 and 233 will be substantially thinner than the central portions of the sheet workpieces 122. In this manner, when such trapezoidal configured sheet workpieces 122 are milled and stretched, their edge portions will have thickness dimensions which are substantially the same as that of the central portion of the sheet workpiece 122 such that a substantially uniform thickness dimension is achieved across substantially the entire width of the sheet workpiece 122, except, of course, at the very outermost edge regions as has been noted hereinbefore. It is further appreciated that the only significant difference between the dies 223 and 225 is that die 223 produces a sheet workpiece 122 which has a greater thickness dimension than a similar workpiece 122 that may be produced by means of die 225.
In FIG. 9, a set of casting rollers 235, 237, and 239 are disclosed as being arranged in a vertical array. The upper and lower rollers 235 and 239 each have configurations which are somewhat similar to those of mill rollers 204 and 206, while the central casting roller 237 has a cylindrical configuration. Consequently, it can be appreciated that the spaces 241 and 243 defined respectively between the casting rollers 235 and 237, and 237 and 239, have, in effect, trapezoidal configurations such that when the sheet workpiece 122 is extruded from the die mouths 227 or 229, the workpiece 122 is initially routed about the casting rollers so as to be inserted into the space 241, wrapped around the roller 237, and withdrawn from the space 243. Consequently, it is seen that the trapezoidal configuration of space 243 is, in effect, upside-down with respect to the trapezoidal configuration of space 241. As an alternative means of creating or defining the trapezoidal spaces 241 and 243, rollers 235 and 239 may be cylindrical while roller 237 has a configuration similar to that of roller 204 or 206. After passing through such spaces 241 and 243, the sheet workpiece 122 may be conveyed further toward the zero-gap assembly 120 for processing in accordance with the techniques of the present invention as previously described.
Thus, it may be seen that in accordance with the foregoing, and particularly the manufacturing techniques and apparatus developed in accordance with the principles of the present invention, finished milled and stretched sheet comprising highly-oriented polyester exhibit enhanced tensile strength and modulus characteristics. In addition, the sheets also exhibit improved degrees or uniformity of flatness whereby increased volumes of polyester strapping may be produced or derived therefrom.
Obviously, many modifications and variations of the present invention are possible in light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the present invention may be practiced otherwise than as specifically described and set forth herein.
means for driving said at least one additional roller at a sufficiently different lineal surface velocity with respect to said lineal surface velocity of said downstream one of said pair of opposed rollers so as to additionally stretch said milled and stretched sheet workpiece in accordance with a predetermined second draw ratio.
said polyester sheet workpieces comprises polyethylene terephthalate.
said at least one additional roller comprises a set of rollers forming an exit bridle assembly for said milled and stretched workpiece with respect to said pair of opposed rollers.
whereby the overall draw ratio impressed upon said polyester sheet workpiece is approximately 6:1, and said highly-oriented polyester sheeting exhibits tensile strength values of approximately 100,000 psi and modulus values within the range of approximately 3,000,000-5,000,000 psi.
means for heating said downstream one of said pair of rollers to a temperature level which is substantially above said glass transition temperature (Tg) of said sheet workpiece so as to facilitate said additional stretching of said crystalline polyester sheet workpiece.
means for supplying a lubricant to a surface of said polyester sheet at a position upstream of said nip defined between said pair of opposed rollers so as to prevent any sticking of said polyester sheet to said upstream one of said pair of opposed rollers when said polyester sheet workpiece is heated to said temperature level greater than said glass transition temperature (Tg).
said pair of opposed rollers each has a configuration comprising a concave central portion and cylindrical end portions so as to provide said sheet workpiece with thinner edge portions than said central portion when said sheet workpiece is conducted through said nip defined between said pair of opposed rollers such that an increased degree of flatness of said simultaneously milled and stretched sheet workpiece, across the width of said simultaneously milled and stretched sheet workpiece after said simultaneously milled and stretched sheet workpiece has passed through said nip defined between said pair of opposed rollers, is achieved.
said central portions of said pair of opposed rollers are arcuate in configuration.
said central portions of said pair of opposed rollers have a trapezoidal configuration.
die means for extruding said sheet workpiece wherein said die means has a predetermined cross-sectional configuration such that said extruded sheet workpiece has thinner edge portions than central portions such that an increased degree of flatness of said simultaneously milled and stretched sheet workpiece, across the width of said simultaneously milled and stretched sheet workpiece after said simultaneously milled and stretched sheet workpiece has passed through said nip defined between said pair of opposed rollers, is achieved.
said predetermined cross-sectional configuration of said die means comprises a trapezoid.
a plurality of casting rolls disposed within a vertical array and defining spaces therebetween which have a trapezoidal configuration for accommodating trapezoidal-configured sheet workpieces produced by said die means.
driving said at least one additional roller at a sufficiently different lineal surface velocity with respect to said lineal surface velocity of said downstream one of said pair of opposed rollers so as to additionally stretch said milled and stretched sheet workpiece in accordance with a predetermined second draw ratio.
said polyester sheet workpiece is fabricated from polyethylene terephthalate.
all of said rollers of said set of rollers defining said exit bridle assembly are driven at a rotational speed so as to define with said downstream one of said pair of opposed rollers said second draw ratio.
heating said downstream one of said pair of rollers to a temperature level which is substantially above said glass transition temperature (Tg) of said sheet workpiece so as to facilitate said additional stretching of said crystalline polyester sheet workpiece.
supplying a lubricant to a surface of said polyester sheet which will be disposed in contact with said upstream one of said pair of opposed rollers and at a position upstream of said nip defined between said pair of opposed rollers so as to prevent any sticking of said polyester sheet to said upstream one of said pair of opposed rollers when said polyester sheet workpiece is heated to said temperature level which is greater than said glass transition temperature (Tg).
providing said pair of opposed rollers with a configuration which comprises a concave central portion and cylindrical end portions so as to provide said sheet workpiece with thinner edge portions than said central portion when said sheet workpiece is conducted through said nip defined between said pair of opposed rollers such that an increased degree of flatness of said simultaneously milled and stretched sheet workpiece, across the width of said simultaneously milled and stretched sheet workpiece after said simultaneously milled and stretched workpiece has passed through said nip defined between said pair of opposed rollers, is achieved.
providing die means for extruding said sheet workpiece wherein said die means has a predetermined cross-sectional configuration such that said extruded sheet workpiece has thinner edge portions than central portions such that an increased degree of flatness of said simultaneously milled and stretched sheet workpiece, across the width of said simultaneously milled and stretched sheet workpiece after said simultaneously milled and stretched sheet workpiece has passed through said nip defined between said pair of opposed rollers, is achieved.
providing a plurality of casting rolls disposed within a vertical array and defining spaces therebetween which have a trapezoidal configuration for accommodating trapezoidal-configured sheet workpieces produced by said die means.
TR96/00409A TR199600409A2 (en) 1995-06-07 1996-05-17 Coke routed to produce a polyester layer on the method and apparatus.
MX9602229A MX9602229A (en) 1995-06-07 1996-06-06 Method and apparatus for producing highly oriented polyester sheet.
Principles of Polymer Processing, Tadmor and Gogos, pp. 363-372; 442-447; 661-663 (1979).
NL8103400A (en) 1981-12-01 A method for forming sleeves of thermoplastic material.


Devoto Orchard Cider from Sebastopol (CA) is proud to announce the release of their 2013 "Save The Gravenstein" hard cider, handcrafted from organic apples grown on the Devoto family farm in Sonoma County. "Save The Gravenstein" is a standout amongst craft ciders – a semi-dry, locally grown and produced, food-friendly cider with an elegant modern visual brand appeal.
"Devoto Orchards Cider is amazingly crisp, with a lovely fresh Gravenstein tartness, complemented by a great dry finish. Definitely worth grabbing one, or two…" stated Shawn Riley, Beer Buyer for Oliver's Markets in Sonoma County.
Founders Jolie Devoto-Wade and Hunter Wade are second generation apple farmers, who were inspired to start a hard cider company after laying down roots at the Devoto family farm. They began with 6,500 apple trees in 1976 and have grown nearly 100 varieties of heirloom and cider apples including the centuries-old Gravenstein [that has limited availability in Sonoma County due to the replacement of orchards with vineyards]. Today, they tend to 50+ heirloom apple varieties on 26 acres. Devoto Orchards is a small family farm and cidery, but the largest cidery in California that uses exclusively California-grown certified organic apples.
"Save The Gravenstein" is made of 95% Gravenstein and a 5% blend of Akane, Burgundy, Hubbardston Nonesuch, Pink Blush and Pink Pearl apples. In August, when the Gravenstein apples are at the peak of their ripeness, the apples are picked, pressed and poured. The result is a 6.9% ABV cider that pairs well with seafood, pork and sharp cheeses.
"Our 'Save The Gravenstein' cider is a gorgeous expression of our land, our apples, and our story. Craft cider will help us continue farming apples for generations to come," states Jolie Devoto-Wade, Director of Sales and Marketing.
If you would like to get your hands on a bottle, you can find 750mL bottles retailed at $12.99 throughout the Sonoma, Santa Cruz and San Francisco counties. Visit DevotoCider.com for additional information on "Save The Gravenstein" and other Devoto ciders. All photos by Kimberley Hasselbrink courtesy of Devoto Orchards Cider.
Blake's Orchard and Cider Mill announced the opening of The Ciderhouse and Winery, serving a brand new line of hard cider made from Blake's apples. The Ciderhouse officially opened in October to serve through the holiday season.
Blake's Orchard and Cider Mill has been family owned and operated since 1946, providing local products including apples, berries, and pumpkins amongst other things. In the fall season, the farm also provides family fun and entertainment including hayrides, corn field mazes and more. This fall season is the first that Blake's served its new line of original hard cider.
The hard cider will feature four varieties all made with Blake's apples: Original, Gentlemen's Dry, Semi-Sweet, and Autumn Apple. Average ABV for the ciders will be approximately 6.4%. All varieties are gluten-free. The Ciderhouse and Winery will serve the hard cider along with seven varieties of fruit wines, ciderkin (non-alcoholic sparkling cider) and s nacks.
The Ciderhouse is located at Blake's Orchard and Cider Mill in Armada (MI). The new ciderhouse is made out of all natural woods, repurposed metals, and presents a rustic family-friendly tasting room. The Ciderhouse will be open through December during the afternoons and evenings, with future plans for remaining open all year.
Blake's hard cider is only available at The Ciderhouse currently. However, the orchard and cider mill has hopes to distribute early next year. To learn more about Blake's Orchard and Cider Mill, and specifically The Ciderhouse and Winery, please visit BlakeFarms.com or BlakesHardCider.com. Photos provided by Blake's Farm.
America's best-tasting hard ciders are produced by Ciderboys Cider Co., according to Chicago's Beverage Testing Institute (BTI).
The BTI's expert judges taste-tested hard ciders from North America and Europe during October and bestowed four gold medals – the most for any cider maker – on Ciderboys' Peach County, Raspberry Smash, Magic Apple and Cranberry Road hard ciders, which blend unexpected fresh fruit flavors with the crisp taste of apple. Ciderboys First Press Traditional Hard Cider earned a silver award.
The BTI's hard-cider judging, part of the institute's ongoing World Beer Championships quality rankings, was the very first beverage competition Ciderboys Cider Co. has entered. The results are available online at www.tastings.com and will be published in All About Beer magazine in early 2014.
Grizzly Ciderworks proudly announced the release of its first selection of craft hard ciders brewed and kegged from the company's headquarters in Woodinville, Washington. Since its inception, Grizzly has set its sights on bridging the gap between beer and cider.
With an abudance of sweet ciders on the market, Grizzly set out to expand cider's reach by introducing beer drinkers to the world of dry cider. Grizzly wants to be known for its specialty dry-hopped ciders (DHCs'), which contain apples from Washington State along with hops and other ingredients sourced from the Northwest. The resulting beverages are aimed at beer drinkers who are looking for a new twist on old tastes, cider drinkers who are looking for a full-bodied step-up in the market, along with drinkers who are sensitive to gluten.
Endowed with the nation's largest supply of apples and hops, Washington State is an epicenter of the nation's growing cider movement. "The world is rediscovering cider, and the Pacific Northwest has established itself as one of America's leading cider regions. The explosion in the number of cider drinkers and the places where it can be enjoyed are a sure sign cider culture has found a home. We are excited to welcome Grizzly Ciderworks as the newest member of our Northwest cidermaking family," said David White, President of the Northwest Cider Association and Co-Owner of Whitewood Cider C ompany of Olympia, Washington.
Grizzly's path to craft took an interesting turn earlier this year when it crossed paths with Vessel Wines, a Northwest producer of kegged wines which shares the same commitment to local sourcing and production. A unique partnership was born, with the two sharing resources to target new markets. Thanks to Vessel's state-of-the-art kegging equipment, Grizzly is already on tap in bars and restaurants across the Seattle metro area, and they have plans to hit retail markets early next year.
Grizzly and Vessel's shared facilities are located in Woodinville. They include a tank room and mezzanine taproom, both of which are frequently filled with interesting people, music, and other live events. Grizzly is poured nightly in the taproom from Thursday through Saturday.
The Ridge and Bruin are already available but Hopclaw and RazzBear are to be released.
For more information about Grizzly Ciderworks or their ciders, please visit GrizzlyCider.com.
Now, in their third year of production and first full release of hard ciders to the public, Bull Run Cider has made a name within the community of Northwest cider enthusiasts and is pleased to be expanding their reach into new restaurant and retail channels with the recent release of all new half barrels and sixth barrels of their popular Bramble Berry Cider, Powerhouse Dry Cider and all new Cranberry Perry.
As a limited release seasonal perry, Bull Run is pleased to introduce the Cranberry Perry to its line of premium products. In partnership with Mt. Hood Organic Farms, this semi-sweet perry is made from organic pears and finished with a touch of cranberry. The mellow sweetness of the 5.5% ABV perry is perfectly offset by the tartness of the cranberry to create this well-balanced, delicious beverage.
The Cranberry Perry, along with Bull Run's signature Bramble Berry and Powerhouse ciders can be found at local retailers and restaurants in the Oregon market including Whole Foods, Zupan's, New Seasons, Bushwackers, Belmont Station and Made In Oregon along with other high quality retailers throughout the state. Creekside Cranberry Perry is sold in 500mL bottles for a recommended $6.00 per bottle.
Bull Run will also be expanding their distribution to include California and Washington and are expected to begin rolling out product in these new markets within the fourth quarter. Furthermore, Bull Run's co-owners are actively seeking new distribution channels to expand the company's reach to the Mid-West, East and South.
For more information, visit BullRunCider.com.
This Thanksgiving, "think outside of the box" as you select the recipes you will make for your meal. Perhaps that means substituting water for cider… Perhaps it means drinking (more) cider versus wine or beer… However you may interpret the phrase – "think outside of the box" – your challenge this holiday is to include hard cider in your cornucopia and on your Thanksgiving table.
As you find recipes including hard cider and make them, please consider sharing them with Hard Cider News. "Post/Message" your recipe(s) along with a photo of the dish to our Facebook page, Hard Cider News. We'll feature some of our favorites in future e-newsletters!


Suneva Medical, an aesthetic medical device company, has presented interim results from the prospective, open-label, five-year safety study on Artefill for nasolabial fold (NLF) correction.
Suneva Medical said that the oral presentations took place at the American Society of Aesthetic Plastic Surgery's Aesthetic Meeting 2010 in Washington, DC and the American Academy of Facial Plastic & Reconstructive Surgery's International Symposium in Hollywood, FL, respectively.
According to Suneva Medical, the 23-center, prospective, open-label study consists of 1,008 patients who had no recent history of nasolabial fold correction. Patients received an initial treatment with Artefill, and up to two touch-ups after 30 and 60 days, until full correction was achieved. Potential adverse events and satisfaction data are reported by all patients at 2, 6, 12, 18, 24, 36, 48 and 60 months to assess the presence of or absence of adverse events, patient satisfaction, and any changes in health.
Potential subject-reported adverse events (AEs) were followed up on and changes thought to be granulomas were biopsied and confirmed or ruled out by histology. All study patients will complete a final in-office visit at 60-months.


as she stepped down from the train.
she didn't even know her name.
she would take a chance to win it all.
Help me, help me, hear my s.o.s.
like the words she used to say.
give me love and give me tenderness.
Even now the war is over, she recalls it every day.
In the darkness she was crying.
maybe even dead and gone.


text:
Walgreens Boots Alliance to Acquire Rite Aid for $17.2 Billion in All-Cash Transaction
Acquisition furthers Walgreens Boots Alliance's commitment to accessible, affordable, quality healthcare in the U.S. and advances consumer access to pharmacy-led health and wellbeing
Acquisition underscores Walgreens Boots Alliance's global approach to growth opportunities
Rite Aid shareholders to receive $9.00 per share in cash, a premium of 48 percent to the closing price on 26 October 2015
Transaction expected to be accretive to Walgreens Boots Alliance's adjusted earnings per share in its first full year after completion
October 27, 2015 05:15 PM Eastern Daylight Time
DEERFIELD, Ill. & CAMP HILL, Pa.--(BUSINESS WIRE)--Walgreens Boots Alliance, Inc. (Nasdaq: WBA) and Rite Aid Corporation (NYSE: RAD) today announced that they have entered into a definitive agreement under which Walgreens Boots Alliance will acquire all outstanding shares of Rite Aid, a U.S. retail pharmacy chain, for $9.00 per share in cash, for a total enterprise value of approximately $17.2 billion, including acquired net debt. The purchase price represents a premium of 48 percent to the closing price per share on 26 October 2015, the day before the agreement was signed. The combination of Walgreens Boots Alliance and Rite Aid creates a further opportunity to deliver a high-quality retail pharmacy choice for U.S. consumers in an evolving and increasingly personalized healthcare environment.
Walgreens Boots Alliance is highly focused on building a differentiated in-store experience for health, wellness and beauty, and this combination will help accelerate Rite Aid's own efforts toward that end. Once the acquisition closes, Walgreens Boots Alliance plans to further transform Rite Aid's stores to better meet consumer needs.
"Today's announcement is another step in Walgreens Boots Alliance's global development and continues our profitable growth strategy. In both mature and newer markets across the world, our approach is to advance and broaden the delivery of retail health, wellbeing and beauty products and services," said Walgreens Boots Alliance Executive Vice Chairman and CEO Stefano Pessina. "This combination will further strengthen our commitment to making quality healthcare accessible to more customers and patients. Our complementary retail pharmacy footprints in the U.S. will create an even better network, with more health and wellness solutions available in stores and online. Walgreens Boots Alliance will provide to Rite Aid its global expertise and resources to accelerate the delivery of integrated frontline care, and to offer innovative solutions for providers, payers and other entities in the U.S. healthcare system. Finally, this combination will generate a stronger base for sustainable growth and investment into Rite Aid stores, while realizing synergies over time."
"Joining together with Walgreens Boots Alliance will enhance our ability to meet the health and wellness needs of Rite Aid's customers while also delivering significant value to our shareholders," said Rite Aid Chairman and CEO John Standley. "This transaction is a testament to the hard work of all our associates to deliver a higher level of care to the patients and communities we serve. Together with Walgreens Boots Alliance, the Rite Aid team can continue to build upon this great work through access to increased capital that will enhance our store base and expand opportunities as part of the first global pharmacy-led, health and wellbeing enterprise."
The boards of directors of both companies have approved the transaction, which is subject to approval by the holders of Rite Aid's common stock, the expiration or termination of applicable waiting periods under the Hart-Scott-Rodino Antitrust Improvements Act of 1976, as amended, and other customary closing conditions. The transaction is expected to close in the second half of calendar 2016.
The transaction is expected to be accretive to Walgreens Boots Alliance's adjusted earnings per share in its first full year after completion. Additionally, Walgreens Boots Alliance expects to realize synergies in excess of $1 billion.
Upon completion of the merger, Rite Aid will be a wholly owned subsidiary of Walgreens Boots Alliance, and is expected to initially operate under its existing brand name. Working together, decisions will be made over time regarding the integration of the two companies, ultimately creating a fully harmonized portfolio of stores and infrastructure.
Walgreens Boots Alliance expects to finance the transaction through a combination of existing cash, assumption of existing Rite Aid debt and issuance of new debt.
Citi acted as Rite Aid's exclusive financial adviser, with Skadden, Arps, Slate, Meagher & Flom LLP acting as its legal counsel on transaction legal matters and Jones Day acting as its legal counsel on antitrust regulatory matters.
UBS Investment Bank acted as Walgreens Boots Alliance's financial adviser and provided a fairness opinion to the board of directors of Walgreens Boots Alliance, with Simpson Thacher & Bartlett LLP acting as its legal counsel on transaction legal matters and Weil, Gotshal & Manges LLP acting as its legal counsel on antitrust regulatory matters. UBS Investment Bank will be the sole arranger on the bridge financing to Walgreens Boots Alliance.
Walgreens Boots Alliance will hold a one-hour conference call to discuss its fourth quarter results and today's acquisition announcement beginning at 8:30 a.m. Eastern time tomorrow, 28 October 2015. The conference call will be simulcast through the Walgreens Boots Alliance investor relations website at: http://investor.walgreensbootsalliance.com. A replay of the conference call will be archived on the website for 12 months after the call.
The replay also will be available from 11:30 a.m. Eastern time, 28 October 2015 through 4 November 2015, by calling 855-859-2056 within the USA and Canada, or 404-537-3406 outside the USA and Canada, using replay code 42212047.
About Walgreens Boots Alliance
Walgreens Boots Alliance (Nasdaq: WBA) is the first global pharmacy-led, health and wellbeing enterprise.
The company was created through the combination of Walgreens and Alliance Boots in December 2014, bringing together two leading companies with iconic brands, complementary geographic footprints, shared values and a heritage of trusted health care services through pharmaceutical wholesaling and community pharmacy care, dating back more than 100 years.
The company employs more than 370,000* people and has a presence in more than 25* countries; it is the largest retail pharmacy, health and daily living destination in the USA and Europe. Including its equity method investments, Walgreens Boots Alliance is a global leader in pharmacy-led, health and wellbeing retail with over 13,100* stores in 11* countries. The company includes one of the largest global pharmaceutical wholesale and distribution networks with over 350* distribution centers delivering to more than 200,000** pharmacies, doctors, health centers and hospitals each year in 19* countries. In addition, Walgreens Boots Alliance is one of the world's largest purchasers of prescription drugs and many other health and wellbeing products.
Its portfolio of retail and business brands includes Walgreens, Duane Reade, Boots and Alliance Healthcare, as well as increasingly global health and beauty product brands, such as No7, Botanics, Liz Earle and Soap & Glory. More company information is available at www.walgreensbootsalliance.com.
* As at 31 August 2015 including equity method investments
** For 12 months ended 31 August 2015 including equity method investments
About Rite Aid
Rite Aid Corporation (NYSE: RAD) is one of the nation's leading drugstore chains with nearly 4,600 stores in 31 states and the District of Columbia and fiscal 2015 annual revenues of $26.5 billion. Information about Rite Aid, including corporate background and press releases, is available through the company's website at www.riteaid.com.
Cautionary Note Regarding Forward Looking Statements
Certain statements in this press release may constitute "forward-looking statements" within the meaning of the Private Securities Litigation Reform Act of 1995. Words such as "anticipate," "believe," "continue," "could," "estimate," "expect," "intend," "may," "plan," "predict," "project," "should," and "will" and variations of such words and similar expressions are intended to identify such forward-looking statements. These forward-looking statements are not guarantees of future performance and involve risks, assumptions and uncertainties, including, but not limited to, risks related to the satisfaction of the conditions to closing the acquisition in the anticipated timeframe or at all, including risks related to the failure to obtain necessary regulatory and Rite Aid stockholder approvals and the possibility that the acquisition does not close, including in circumstances in which Rite Aid would be obligated to pay Walgreens Boots Alliance a termination fee or other expenses and vice versa; risks related to the ability to realize the anticipated benefits of the acquisition, including the possibility that the expected synergies from the proposed acquisition will not be realized or will not be realized within the expected time period; the risk that the businesses will not be integrated successfully; risks associated with the financing of the transaction; disruption from the transaction making it more difficult to maintain business and operational relationships; negative effects of this announcement or the consummation of the proposed acquisition on the market price of Walgreens Boots Alliance's common stock; significant transaction costs; unknown liabilities; the risk of litigation and/or regulatory actions related to the proposed acquisition; other business effects, including the effects of industry, market, economic, political or regulatory conditions; future exchange or interest rates or credit ratings; changes in tax laws, regulations, rates and policies; competitive developments; and risks and uncertainties discussed in the reports that Walgreens Boots Alliance and Rite Aid have filed with the Securities and Exchange Commission (the ("SEC"). Should one or more of these risks or uncertainties materialize, or should underlying assumptions prove incorrect, actual results may vary materially from those indicated or anticipated by such forward-looking statements. Accordingly, you are cautioned not to place undue reliance on these forward-looking statements, which speak only as of the date they are made. Walgreens Boots Alliance and Rite Aid expressly disclaim any current intention to update publicly any forward-looking statement after the distribution of this release, whether as a result of new information, future events, changes in assumptions or otherwise. A further list and description of risks and uncertainties can be found in Rite Aid's Annual Report on Form 10-K for the fiscal year ended February 28, 2015 and its reports on Form 10-Q and Form 8-K as well as Walgreens Boots Alliance's most recent Form 10-K and its reports on Form 10-Q and Form 8-K. This release does not constitute an offer of any securities for sale.
Additional Information and Where to Find It
In connection with the proposed transaction, Rite Aid will file with the SEC and mail or otherwise provide to its stockholders a proxy statement regarding the proposed transaction. BEFORE MAKING ANY VOTING DECISION, RITE AID'S STOCKHOLDERS ARE URGED TO READ THE PROXY STATEMENT IN ITS ENTIRETY WHEN IT BECOMES AVAILABLE AND ANY OTHER DOCUMENTS FILED WITH THE SEC IN CONNECTION WITH THE PROPOSED MERGER OR INCORPORATED BY REFERENCE THEREIN BECAUSE THEY WILL CONTAIN IMPORTANT INFORMATION ABOUT THE PROPOSED TRANSACTION AND THE PARTIES TO THE PROPOSED TRANSACTION. Investors and security holders may obtain a free copy of the proxy statement and other documents that Rite Aid files with the SEC (when available) from the SEC's website at www.sec.gov and Rite Aid's website at www.riteaid.com.
Participants in Solicitation
Rite Aid and its directors, executive officers and employees may be deemed, under SEC rules, to be participants in the solicitation of proxies from Rite Aid's stockholders with respect to the proposed acquisition. Information regarding the interests of such individuals in the proposed acquisition of Rite Aid by Walgreens Boots Alliance will be included in the proxy statement relating to such acquisition when it is filed with the SEC. You may obtain information about Rite Aid's executive officers and directors in Rite Aid's definitive proxy statement for its 2016 annual meeting of stockholders, which was filed with the SEC on May 15, 2015. These documents may be obtained free of charge from the SEC's website at www.sec.gov and Rite Aid's website at www.riteaid.com.
Walgreens Boots Alliance, Inc.
USA / Michael Polzin, +1 847 315 2935
International / Laura Vergani, +44 (0)207 980 8585
Gerald Gradwell and Ashish Kohli, +1 847 315 2922
Rite Aid Corporation
Ashley Flower, +1 717 975 5718
Matt Schroeder, +1 717 214 8867
Walgreens Boots Alliance will acquire Rite Aid for $17.2 billion in an all-cash transaction for a total enterprise value of approximately $17.2 billion, including acquired net debt.

redpajama_set_name: RedPajamaCommonCrawl


"A faith without some doubts is like a human body without any antibodies in it. People who blithely go through life too busy or indifferent to ask hard questions about why they believe as they do will find themselves defenceless against either the experience of tragedy or the probing questions of a smart sceptic. A person's faith can collapse almost overnight if she has failed over the years to listen patiently to her own doubts, which should only be discarded after long reflection.
Tim Keller, The Reason for God (Hodder 2008), pages xvi-xvii.


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