Abstract:
A process for manufacturing easily portable and multi-layered adhesive tape roll is described. The flat piece of easily portable and multi-layered adhesive tape is formed by compressing the adhesive tape roll having circular shape or other shapes. The adhesive tape roll is compressed and cohered during the compressing step. A stiff interfacial layer, for example, having adhesion by adhering two innermost adhesive surfaces, by providing a stronger adhesion material, by inserting a stiff and solid material, or a stiff and solid material coated with a strong adhesion material, is applied to the symmetry plane of the adhesive tape during the compressing step. The preferential material of the high adhesion material is a cyanoacrylate adhesive or an epoxy adhesive.

Description:
This application is a continuation-in-part of Ser. No. 09/276,782 filed Mar. 25, 1999, now U.S. Pat. No. 6,224,705. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates in general to special process for manufacturing a multi-layered adhesive tape roll, wherein the flat piece of multi-layered adhesive tape is easily portable adhesive tape capable of saving space for convenient carrying. 
     2. Description of the Related Art 
     Conventional adhesive tapes usually are designed with circular inner core, such as paper core, plastic core or similar core. Recent developments have led to the flat adhesive tapes  12 . Hollow orthogonal flat plastic tubes are made by ejection molding or hollow square flat paper tubes are designed by bending card board, as reference number  10  shows in FIG.  1 . Adhesive tape is then unwounded out from jumbo roll and slitted into a desired tape. The tubes  10  are individually winded up into the flat adhesive tapes  12 . However, such a manufacturing method requires a long working time and higher cost. Moreover, this kind of flat adhesive tape cannot provide necessary special physical properties, for example, super-transparence and coherence, due to the occurrence of trapped bubbles when the adhesive tapes are individually winded up. 
     If the conventional adhesive tapes are compressed directly to become the flat adhesive tape, the inner tubes are distorted and the outside surface of the adhesive tapes is deformed by applied stress. Moreover, a strong rebound force remains in the distorted material, for example, the tube and tape. The more distortion occurs in a short time, the more rebound force there is. Besides, due to intrinsic properties such as visco-elasticity and memory of the substrate and adhesive layer of the adhesive tape structure, after the compression stress is removed the relaxation of the structure accompanied by a rebound force drive the adhesive tape to a stable state. The rebound force drives the adhesive tape to regain the tape&#39;s original shape. The strength of the rebound force depends on the deformation degree on the each position of the adhesive tape. The strength of the rebound force further depends on the thickness of the substrate, mechanical strength of the substrate, physical properties of the adhesive layer, adhesion, total length, central length of the symmetric plane (internal diameter before performing the compression step), and the winding up tension of the adhesive tape. 
     SUMMARY OF THE INVENTION 
     The manufacturing process of the easily portable and multi-layered adhesive tape of the present invention is suitable for flatting any adhesive tape roll and capable of automatic production and manufacturing a high quality flat adhesive tape. 
     The flat piece of easily portable and multi-layered adhesive tape, that is a flat adhesive tape, of the present invention is mainly made by flatting the non-flat and multi-layered adhesive tape roll having a circular shape or other shapes. During the flatting process, the non-flat and multi-layered adhesive tape roll is compressed and cohered symmetrically, or a stiff interfacial layer having or lacking high adhesion property is provided before the non-flat and multi-layered adhesive tape is compressed. The existence of the stiff interfacial layer produces an extending force along the symmetric plane of the easily portable flat adhesive tape. This extending force partially diminishes the rebound force, which causes the deformation of the flat adhesive tape. If the total length of the flat adhesive tape is not very long, the rebound force is not very large, either. Therefore, the non-flat adhesive tape without a paper core can be compressed and cohered directly through both innermost adhesive surfaces or a stiff and solid interfacial layer located in the innermost portion of the flat adhesive tape, so that a beautiful and easily portable flat piece of adhesive tape is formed. The stiff and solid interfacial layer is, for example, adhesive, cardboard, plastic plate, metal slice, or combination, or the like. When the strength of the flat adhesive tape is increased using, for example, increasing the thickness of the substrate with a high mechanical strength, increasing the total tape length, or reducing the inner diameter, the rebound force is also increased. Under such circumstances, a layer of high adhesion material can be applied to the symmetric plane of the adhesive tape. The layer of high adhesion material is, for example, high glass transition temperature polymeric materials, thermoset materials, hot melt materials, or ultra-violet curable adhesive materials for ensuring the symmetric cohesion of the innermost portion of the flat adhesive tape. The preferential material of the high adhesion material is a cyanoacrylate adhesive or an epoxy adhesive, having a high cross-linking density property after curing. After solidification for any mentioned adhesion material the high adhesion material not only provides adhesion functionality but also provides an extension force for sustaining the flat adhesive tape and partially offsetting the rebound force. Of course, if the high adhesion material is combined with the stiff interfacial layer, the rebound force is further offset, and the stability of the flat adhesive tape is therefore increased. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     Other objects, features, and advantages of the invention will become apparent from the following detailed description of the preferred but non-limiting embodiments. The description is made with reference to the accompanying drawings in which: 
     FIG. 1 is a schematic, cross-sectional view showing a conventional adhesive tape roll with a paper core and a plastic core having a hollow orthogonal shape; 
     FIG. 2A is a schematic, cross-sectional view showing an flat adhesive tape that has no paper core or plastic core according to a first preferred embodiment of the present invention; 
     FIG. 2B is a diagram showing a schematic, cross-sectional view of the flat adhesive tape showing in FIG. 2A; 
     FIG. 3 is a schematic, cross-sectional view showing the flat adhesive tape having a high-adhesion layer in the plane of symmetry the flat adhesive tape shown in FIG. 2; 
     FIG. 4 is a schematic, cross-sectional view showing the flat adhesive tape having a stiff layer in the plane of symmetry plane of the flat adhesive tape shown in FIG. 2; 
     FIG. 5 is a schematic, cross-sectional view showing the flat adhesive tape having a high-adhesion layer and a stiff layer on the symmetry plane of the flat adhesive tape showing in FIG. 2; 
     FIG. 6 is a schematic, cross-sectional view showing the flat adhesive tape having a paper or a plastic film, wherein there is a high-adhesion layer located in the plane of symmetry plane of the flat adhesive tape; 
     FIG. 7 is a schematic, cross-sectional view showing the flat adhesive tape having a high-adhesion layer and a stiff layer in the plane of symmetry of the flat adhesive tape shown in FIG. 6; 
     FIG. 8A is a schematic, cross-sectional view showing the flat adhesive tape having a stiff layer in the plane of symmetry of the flat adhesive tape shown in FIG. 6; 
     FIG. 8B is a schematic, side view showing the flat adhesive tapes roll with different width, wherein the flat adhesive tapes are arranged in a row; 
     FIG. 9 is a schematic, top view showing the flat adhesive tape having a stiff layer in the plane of symmetry of the flat adhesive tape, wherein the stiff layer is wider than the adhesive tape; 
     FIG. 10 is a schematic, top view showing the flat adhesive tape having perforations holes; 
     FIG. 11 is a schematic, top view showing the flat adhesive tape having a binder and a safe cutter; and 
     FIG. 12 is a schematic, side view showing the container for storing the flat adhesive tape. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     First Preferred Embodiment 
     FIGS. 2A to  2 B are schematic, cross-sectional views showing the flat adhesive tape of the first preferred embodiment of the present invention. 
     Referring to  2 B, an adhesive tape  200  having a substrate  202 , a releasing layer  206  and an adhesive layer  204  is provided. The adhesive tape  200  described hereafter denotes an unwinded adhesive tape. The substrate  202  is composed of, for example, paper, synthetic paper, clothes, nonwoven, plastic film, embossed plastic film, or materials with similar property, wherein the plastic film is composed of, for example, Polypropylene (PP), Polyethylene Terephthalate (PET), Polyethylene (PE), Polyethylene Naphthalate (PEN), Polyimide (PI), Polyvinylchloride (PVC) or the like. In the present invention, the preferred substrate  202  can also be a metal foil, for example, copper foil, aluminum foil, a copper foil with silver plating on a single side or both sides thereof, or tin, chromium, nickel or gold plated copper foil. Furthermore, the substrate  202  can be a composite film consisting of above mentioned metal foils and plastic films. An adhesive layer  204  is formed on one side of the substrate  202 , and a releasing layer  206  is formed on the other side of the substrate  202 . The adhesive tape roll  200  is then winded up to be a semifinished, cordless and multi-layered adhesive tape with a given length and diameter. The semifinished, cordless and multi-layered adhesive tape is then cut into several multi-layered adhesive tapes with adequate width. These multi-layered adhesive tapes are then compressed into a flat shape. The letters TD indicate a transverse direction, which is perpendicular to the symmetric plane in the flat adhesive tape  220  which is multi-layered (hereafter the flat adhesive tape denotes a multi-layered flat adhesive tape). The letters PD indicate a parallel direction, which is parallel to the symmetric plane in the flat adhesive tape  220 . The symmetric flat adhesive tape  220  is formed by compressing and self-cohering the innermost surface of the adhesive layer on the symmetric plane  208 , as shown in FIG.  2 A. 
     Second Preferred Embodiment 
     A high-adhesion layer  224  is further placed in the symmetric plane  208  of the flat adhesive tape  220  without paper cores, as described in the first embodiment. The preferred material of the high-adhesion layer  224  is a high glass transition temperature polymeric material, a thermoset material, a hot melt material, and a ultra-violet curable adhesive material. The preferential material of the high adhesion material is a cyanoacrylate adhesive or an epoxy adhesive. The flat adhesive tape  230  is then formed after the compressing and cohering steps are performed, as shown in FIG.  3 . The “cyanoacrylate or epoxy adhesives on the symmetric plane can be easily cured and becomes a stiff interfacial layer  224 . This stiff interfacial layer  224  partially eliminates the rebound force causing the deformation. 
     Third Preferred Embodiment 
     The stiff interfacial layer  226  may be placed in the symmetric plane of the flat adhesive tape  220  without a paper core, as described in the first embodiment, before the compressing step is performed. The preferred interfacial layer  226  has a length equal to or a little longer than the half-length of the innermost circumference of the adhesive tape without paper core. The length of the interfacial layer  226  can be longer than the half-length of the innermost circumference of the adhesive tape because of the existing of the adhesive layer&#39;s coherent and extended properties. The flat adhesive tape  220  is formed, as shown in FIG. 4, after the compressing step is performed. The stiff interfacial layer  226  is a flat and solid layer, and is composed of, for example, Polyethylene, Polypropylene, Polystyrene, Polyester, Polycarbonate, Polyvinyl Chloride (PVC), Acrylonitrile-Butadiene-Styrene (ABS), metal etc. The preferred material of the interfacial layer  226  is plastic or metal having high surface energy and polarity. Therefore, the partial rebound force caused by deformation is diminished by making the innermost surface of the cordless adhesive tape adhere to opposite surfaces of the stiff interfacial layer. Since it is not easy to separate the innermost surface of the adhesive tape from the surfaces of the interfacial layer, the flat shape of the adhesive tape is maintained. 
     Fourth Preferred Embodiment 
     The stiff interfacial layer  226  having a high adhesion property on its outer surface may be placed in the symmetric plane of the flat adhesive tape  220  without a paper core, as described in the third preferred embodiment, before the compressing step is performed. For example, a layer of high adhesion material layer  224  is coated on the outer surface of the stiff interfacial layer  226  followed by placing the stiff interfacial layer  226  in the symmetric plane of the adhesive layer  224 . A flat adhesive tape  250  is then formed after a compressing step is performed on the adhesive layer, as shown in FIG.  5 . The high adhesion material layer  224  is composed of material, for example, a high glass transition temperature polymeric material, a thermoset material, a hot melt material, and a ultra-violet curable adhesive material. The preferential material of the high adhesion material is a cyanoacrylate adhesive or an epoxy adhesive, having a high cross-linking density property after curing. 
     Fifth Preferred Embodiment 
     FIG. 6 is a schematic, cross-sectional view showing the flat adhesive tape according the fifth preferred embodiment of the present invention. 
     The adhesive structure in FIG. 6 is the same as FIG. 2B, so the description of the adhesive structure is omitted. The adhesive tape is multi-layer winded to a predetermined length and diameter, and a semi-finished product having one layer of material  227  on the innermost surface of the adhesive tape is obtained. The layer of material  227  can be a paper, synthetic paper, clothes, nonwoven, plastic, embossed plastic, metal etc. The semi-finished product is then cut into an adhesive tape  200   a  with a predetermined width. A layer of high-adhesion material or double-sided adhesive tape is then placed on between the surface of the paper layers or one plastic layers before the compressing step is performed on the semi-finished product. The preferred high-adhesion material is the adhesive material, selected from a high glass transition temperature polymeric material, a thermoset material, a hot melt material, and a ultra-violet curable adhesive material. The preferential material of the high adhesion material is a cyanoacrylate adhesive or an epoxy adhesive, having a high cross-linking density property after curing. The adhesive tape roll having a circular or non-circular shape is then compressed into flat adhesive tape  260  with flat piece shape. 
     Furthermore, a layer of interfacial layer having high adhesion, for example, a stiff interfacial layer  226  coated by a layer of high adhesion material  224 , can also be placed on the symmetric plane of adhesive tape  260  before the compressing step is performed. The flat adhesive tape  270 , as shown in FIG. 7, is formed after the compressing step is performed. The interfacial layer  226  without coating with high adhesion material can be used instead of the interfacial layer coating with high adhesion material. The interfacial layer  226  can extend and flatten the adhesive tape along the plane of symmetry. This makes the adhesive tape roll become the flat adhesive tape  280 , wherein the interfacial layer  226  has a length longer than or equal to the half-length of the innermost circumference of the adhesive tape roll, as shown in FIG.  8 A. 
     Moreover, several adhesive tapes with different width could be arranged in a row before the adhesive tapes are compressed. A stiff interfacial layer  296  is applied to the central space, that is the plane of symmetry, within all the adhesive tapes, wherein the stiff interfacial layer  296  is, for example, coated with a layer of high adhesion material  294 . The adhesive tapes are then compressed for forming the easily portable adhesive tapes  290 , wherein the adhesive tapes  290  are arranged in a row, as shown in FIG.  8 B. 
     Furthermore, a stiff interfacial layer  228  wider than the width of the adhesive tape roll can be utilized in the symmetry plane of the adhesive tape roll for adding the Trademark of the company or product on the flat adhesive tape, especial on the opaque adhesive tape roll. The Trademark of the company or product is marked on the extension portion of the stiff interfacial layer  228 , which protrudes from the adhesive tape roll. If the stiff interfacial layer  228  is not coated with adhesive material, then the length of the stiff interfacial layer  228  should be longer than or equal to the half-length of the innermost circumference of the adhesive tape roll, as shown in FIG.  9 . Of course, an adhesive layer (not shown) can be applied to the outside surface of the stiff interfacial layer  228  for diminishing partial rebound force, which caused the deformation of the flat adhesive tape  230 . 
     For easy use, perforations  232  can be drilled along the width, the first to fifth preferred embodiments. This makes the flat adhesive tape become a flat adhesive tape  300  with easy tearing off property, as shown in FIG. 10. A binder  302  with a safe cutter  304  can be used, instead of the perforations, on the adhesive tapes  400  for easy removal, as shown in FIG.  11 . Furthermore, the flat adhesive tape as described can be placed into a flat, rectangular container  500 , as shown in FIG.  12 . 
     If the flat adhesive tape is a transparent adhesive tape, then the Trademark of the company or the product can be applied to the surface of the interfacial layer  226 . Furthermore, if the adhesive tape roll has the stiff interfacial layer, for example, a polyester or metal foil layer, no deformation of the adhesive tape will occur even when the flat adhesive tape is almost used up. Therefore, the flat adhesive tape can still be easily used. 
     Furthermore, the adhesive surface of the adhesive tape roll can be placed inwardly or outwardly, and is not limited to the embodiments. If the adhesive surface of the adhesive tape is outwardly placed, then the flat adhesive tape can be used to remove lint and dust from clothes or a carpet. The flat adhesive tape also has other benefits; for example, it is easy to find the starting point of the flat adhesive tape due to the adhesion. 
     Other embodiments of the invention will appear to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.