The present invention relates to pressure sensitive stamps, and more particularly to a pressure sensitive stamp design which makes practicable rolling the stamps into a coil without providing a backing or liner on the entire coil by providing a primer layer.
It has long been known to roll a strip of stamps into a coil to save space and to provide a convenient mechanism for detaching one or more stamps from a plurality of others. However, such a coil configuration has heretofore been limited to traditionally known stamps which required moistening on the glue side before being adhered to an envelope.
More recently, so-called xe2x80x9cself adhesivexe2x80x9d stamps have been becoming more and more popular. These stamps do not have to be moistened, but rather are provided with a pressure sensitive adhesive layer which is adhered to the envelope. The pressure sensitive adhesive layer is typically covered with a protective backing, or liner, consisting of a strip of non-adhesive material, generally of the same width as or wider than the strip of stamps, which is peeled away before the stamp is adhered to the envelope in order to expose the adhesive layer.
It has been proposed to roll such self-adhesive stamps into a coil in order to enjoy the convenience and space-saving characteristics associated therewith. However, when using known pressure sensitive adhesive stamp designs, doing so requires that the entire coil of stamps have a strip of protective liner backing the adhesive layer. This is true because if the liner layer were not present, the stamps, once rolled into a coil, would tightly adhere to themselves, thereby preventing the stamps from being unrolled. The cause of this undesirable phenomenon is described in more detail below.
Providing a liner for the entire coil of stamps, however, is undesirable for several reasons. One such reason relates to environmental concerns. The liner strip comprises unnecessary waste, which adversely impacts the environment. Moreover, the liner increases the material costs associated with manufacturing the stamps. Furthermore, when a liner is used, one is required to unroll a stamp off the coil, remove the stamp from the liner, and detach it from the next following stamp before adhering the stamp to the envelope. It would be easier for the user if the stamp could simply be unrolled, detached from the following stamp, and adhered to the envelope without having to remove a liner layer.
What is desired, therefore, is a stamp, a strip of which can be rolled into a coil, which includes a pressure sensitive adhesive layer for being adhered to an envelope, and which, when coiled, does not require a liner layer over the entire strip of stamps comprising the coil.
Accordingly, it is an object of the present invention to provide a stamp, a strip of which can be rolled into a coil.
Another object of the present invention is to provide a stamp having the above characteristics and which includes a pressure sensitive adhesive layer for being adhered to an envelope.
A further object of the present invention is to provide a stamp having the above characteristics and which when coiled, does not require a liner layer over the entire strip of stamps comprising the coil.
These and other objects of the present invention are achieved by provision of a coil of stamps formed from a plurality of self-adhesive stamps detachably connected to each other end-to-end to form a continuous strip of stamps. The strip is wound about itself in spiral-like fashion, and includes an inner end and an outer end. The strip of stamps includes a portion adjacent to the inner end of the strip having a piece of liner material disposed thereon, and a portion having no liner material thereon, whereby the portion having no liner material thereon allows the strip to be wound directly onto itself. Preferably, the strip of stamps also includes a portion adjacent to the outer end of the strip having a piece of liner material disposed thereon in order to facilitate removal of the first stamp or group of stamps from the strip of stamps.
Each of the plurality of self-adhesive stamps preferably comprises a paper layer having a first surface and an opposing second surface, a pressure sensitive adhesive layer adhered to the first surface of the paper layer, an ink layer disposed on at least portions of the second surface of the paper layer, a primer layer disposed on the ink layer and on any portions of the second surface of the paper layer not having the ink layer disposed thereon, and a silicone layer disposed on the primer layer. Most preferably, each of the plurality of self-adhesive stamps also includes a starch layer disposed between the first surface of the paper layer and the pressure sensitive adhesive layer. The primer layer is preferably at least partially absorbed by any portions of the second surface of the paper layer upon which the primer layer is disposed, whereby the paper layer is sealed, and preferably substantially none of the silicone layer is absorbed by the paper layer.
In another aspect, the present invention is directed to a system for packaging stamps, and is particularly well-suited for packaging the coils of stamps described above. The system is comprised of a plurality of coils of stamps aligned end-to-end along a longitudinal common axis, and a tube formed from a shrink-wrap material. The tube, which is shrink-wrapped around the plurality of coils of stamps, has a plurality of circumferential perforations therein, which perforations are located substantially adjacent to mating surfaces of adjacent coils of stamps for allowing coils of stamps to be separated from each other without removing the shrink-wrap material therefrom. The tube also includes at least one, and preferably two, longitudinal perforation for facilitating removal of the shrink-wrap material from the coils of stamps.
The invention and its particular features and advantages will become more apparent from the following detailed description considered with reference to the accompanying drawings.