Textiles are used in web or sheet form to cover and protect a large variety of items. In the construction of such items as awnings, convertible tops for motor vehicles, garments, geotextiles and tents, it is common to sew or stitch sections together to form larger sheets.
Tarpaulins are used in marine, military and recreation (circuses, picnics and the like) applications and in transportation (truck, train, freight covers) many of which are formed by splicing together roll goods of textiles resulting in many seams due to the large areas involved.
A disadvantage of stitched or sewn seams is that they can leak and over time the stitches can deteriorate and fail.
Further, many of these textiles are handled as roll goods and it is important to be able to splice textiles together on the fly in an automated process at high machine operating speeds without the bond severing or breaking.
A number of patents deal with the splicing of sheet materials together.
U.S. Pat. No. 4,699,824 to Pufahl discloses a pressure sensitive adhesive tape of particular utility as a flying slice; composed of a frangible substrate formed of a ply of a cured thermoset resinous aldehyde condensate (or fibrous cellulose web impregnated with said condensate) and an elastomeric pressure sensitive adhesive (PSA) on at least one side of the substrate.
U.S. Pat. No. 4,410,575 to Obayashi recites a lap welding method for textile fabrics wherein a piece of synthetic bonding tape is interposed between the superposed two end portions and a high frequency wave treatment is applied (or heat) and pressure to melt the tape. Claim 1 specifically recites “wherein at least one side edge portion of said interposed bonding tape extends outwardly over a corresponding edge of one of said end portions . . . and remains unmelted.” This is to prevent edge peeling. Said bonding tape (claim 6) consists essentially of at least one member selected from the group of polyvinyl chlorides, polyurethanes, polyesters, polyamides, vinyl chloride-vinyl acetate copolymers, and ethylene-vinyl acetate copolymers.
U.S. Pat. No. 4,094,721 to Sturm recites the use of a linear saturated crystalline polyester (of specific moieties) useful in securing textile substance to a substrate. Claim 17 recites “In a process for securing one substrate to another by disposing between said substrates a heat fusible material and maintaining the substrates in sufficient juxtaposition until said material has fused and bond one of said substrates to the other, the improvement which comprises employing a heat fusible material of the polyester in claim 1.
U.S. Pat. No. 4,093,492 to Raabe claims “a process for heat-sealing together surfaces of materials comprising applying to at least one of the surfaces to be sealed a composition comprising a copolyamide having a melting range below about 110° C.” and a specific chemical structure.
U.S. Pat. No. 4,310,373 to Schuhmacher relates to a method of heat sealing the opposing surfaces of planar textile materials which comprises applying a heat-seal adhesive to at least one of the opposing surfaces, and then pressing them together under heat and pressure. The heat-seal adhesive employed is a low melting polyurethane of specific molecular weight. The adhesive is in the form of a spun-bonded fabric.
U.S. Pat. No. 5,368,923 to Tippett recites the use of a bonding interlayer which includes a non-fluoro plastic carrier element coated with a fluoroplastic which melts under heat and pressure.
U.S. Pat. No. 6,060,408 to Monica discloses a double sided adhesive element for securing an article of clothing comprising a flexible support member having a first side coated with an adhesive and a second side coated with an adhesive, said support member comprising cloth, and said adhesive an acrylic adhesive.
U.S. Pat. No. 4,740,416 to DeCoste, Jr. discloses novel adhesive tapes consisting of a layer comprising glass or resin microspheres disposed in a polymer matrix, a cloth screen or reinforcing fabric and a layer of adhesive, preferably a PSA. These products are useful as duct tapes.
U.S. Pat. No. 4,091,150 to Roelofs discloses a splicing tape for abutted ends formed of an adhesively coated support film which comprises a biaxially oriented, heat set, co-extruded laminate formed from a layer of crystalline polyester material and a layer of less crystalline polyester material, with the thermosetting adhesive coating the surface of the latter layer. The support film is preferably PEN, PCDT or PET.
However, each of these references is directed to a specific bonding process or chemical polymer type.