TAPE ROLL AND ITS WIND-UP CORE AND METHOD FOR PRODUCING TAPE ROLL

Abstract: A tape roll comprises: an annular wind-up core comprising a wind-up core sheet, wherein the wind-up core sheet comprises a first edge and a second edge, and the first and second edges are opposed to each other and not fixed to each other when the wind-up core sheet defines the annular wind-up core; and an annular tape roll comprising an inner peripheral tape face, wherein the wind-up core is closely contacted to the inner peripheral tape face.

Description: DESCRIPTION TAPE ROLL AND ITS WIND-UP CORE AND METHOD FOR PRODUCING TAPE ROLL TECHNICAL FIELD This invention relates to a tape roll and its wind-up core, and a method for producing a tape roll. BACKGROUND ART A tape roll normally includes a tape that is wound on a wind-up core and is set to reuse as required. In this case, an annular plastic or paper product that is hard and strong is usually employed as such a wind-up core. Such a strong annular plastic product as mentioned above has been obtained by cutting a plastic extruded annular tube in round slices or plastic injection molding. In order to form the strong annular paper product, a paper sheet is formed into a paper roll to make a strong paper tube by hardening the paper layers therebetween with an pressure-sensitive adhesive whereby to cut the paper sheet in round slices. In order to produce the tape roll according to the invention, a plastic or paper core tube is fitted into the mandrel to securely connect the mandrel to the core tube, and then rewind the raw tape on the wind-up core by rotating the mandrel or paper core tube. Then the raw tape and the wind-up core are cut in round slices as required and the mandrel is removed further. In a conventional tape roll having a strong wind-up core sheet, tape-width contraction originating from roll tightening or residual stress is prevented, so that the tape roll side tends to become tapered. When the wind-up core with the used tape is disposed, moreover, the wind-up core is hardly collapsible to pieces and this makes it disadvantageous to prevent an increase in the amount of waste. In this case, any attempt to reduce wind-up cores into pieces by cutting needs tools for slicing the wind-up cores, thus increasing the recycling cost. DISCLOSURE OF THE INVENTION An object of the present invention is to provide a tape roll which can be held in a stable rolled condition by making its wind-up core follow the contraction of the tape in width and when the tape roll is used up, its residual parts are readily disposable or recyclable. One tape roll according to the invention is characterized in that a wind-up core sheet is bound to the inner peripheral tape face of an annular tape roll in such a state that both edges of the wind-up core sheet remain uncoupled together. Here, the "uncoupled" edges means that the edges of the wind-up core sheet are opposed to each other and not fixed to each other when the wind-up core sheet define an annular wind-up core. When the tape is a pressure-sensitive adhesive tape, the wind-up core sheet and the inner peripheral tape face which form a contacted interface are bound together by utilizing the pressure-sensitive adhesive of the pressure-sensitive adhesive tape itself. Another tape roll according to the invention is characterized in that a wind-up core sheet is bound to the inner peripheral tape face of an annular tape roll in such a state that both edges of the wind-up core sheet remain uncoupled together. When the tape is a pressure-sensitive adhesive tape, the wind-up core sheet and the inner peripheral tape face which form a contacted interface are bound together by utilizing the pressure-sensitive adhesive of the pressure-sensitive adhesive tape itself. A method for producing a tape roll according to the invention comprises the steps of winding up one wind-up core sheet layer on a mandrel by butt-winding or gap-winding, rewinding a raw tape on the wind-up core sheet while rotating the mandrel and then taking the raw tape out of the mandrel or otherwise cutting the raw tape in round slices and then taking the sliced raw tapes out of the mandrel, so that the raw tape on the binder pressure-sensitive adhesive film is rewindable on the binder pressure-sensitive adhesive film after winding the binder pressure-sensitive adhesive film on the wind-up core sheet. Here, the "butt-winding" means that the uncouples edges of the wind-up core sheet are brought in contact with each other, and the "gap-winding" means that the uncoupled edges are opposed to each other with a gap. BRIEF EXPLANATION OF DRAWINGS Fig. 1 represents a diagram showing an example of an apparatus for manufacturing tape rolls according to the invention. Fig. 2 represents a diagram showing a mechanism for expanding and contracting the diameter of a mandrel in the apparatus of Fig. 1. Figs. 3A to 3C each represents a diagram showing another example of an annular wind-up core sheet for use according to the invention. Fig. 4 represents a diagram showing an example of an annular body with a pressure-sensitive adhesive film for use according to the invention. Figs. 5A to 5B each represents a diagram explanatory of the effect of a tape roll according to the invention. BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will now be described with reference to the drawings Fig. 1 shows an example of an apparatus for manufacturing tape rolls according to the invention. As shown in Fig. 1, one end of an expandable-contractible rotary mandrel 1 is supported by a bearing 10 in a cantilever way. In order to make the diameter of the mandrel 1 expandable and contractible, one pair of opposed segments 11 and 13 out of the divided segments 11 - 14 are respectively supported by extensible-contractible hydraulic lugs 21 and 23, whereas the other pair of opposed segments 12 and 14 are respectively supported by extensible-contractible hydraulic lugs 22 and 24. In other words, the other pair of hydraulic lugs 22 and 24 are extended or contracted after the one pair of hydraulic lugs 21 and 23 are extended or contracted. A hydraulic inlet 3a (3b) is provided to the hydraulic lugs 21 and 23 (22 and 24) . A movable bearing 101 capable of moving back and forth is provided to the other end of the mandrel 1. There are also installed a motor 41, a reduction gear 42 and a transmission belt 43. A cutting tool 5 is fitted to a traverse trestle so that the cutting tool 5 may be moved in both directions of X and Y. In order to manufacture a tape roll according to the invention, the diameter of the mandrel 1 is expanded first and a sacrifice tape is wound on the mandrel 1 that is being rotated. Further, only one layer of wind-up core sheet is wound on the sacrifice tape spirally in a butt-winding or gap-winding condition. Instead of the spiral butt-winding or gap-winding (as shown in Fig. 3A) , one layer of wind-up core sheet A may be wound on the sacrifice tape by butt-winding (like Japanese rolled sushi, for example) as shown in Fig. 3B or otherwise one layer of the wind-up core sheet may be wound thereon by butt-winding with the wave shape (i.e., butt-winding where the opposing edges of the core sheet extend obliquely with respect to the axis of the wind-up core) added thereto as shown in Fig. 3C. A raw pressure-sensitive adhesive tape (a base before being cut in predetermined tape widths) is gradually wound by rotating the mandrel after the one layer of the wind-up core sheet is thus wound on the sacrifice tape by butt-winding. When the raw tape reaches a predetermined roll amount, the cutting tool 5 is moved in the direction of Y at a predetermined position in the direction of X, and simultaneously the mandrel 1 is rotated so as to cut the raw tape roll together with the butt-wrapped wind-up core sheet in predetermined tape widths. In this case, the edge of the cutting tool is so controlled that even when it reaches the sacrifice tape layer, it may not touch the rotating mandrel to ensure that the cutting is effected up to the butt-wrapped wind-up core sheet. Then the cutting tool 5 is moved repeatedly in the direction of X corresponding to the width of a tape roll to be cut in round slices. Further, the sacrifice tape is removed from the inner surface of each sliced tape roll to obtain tape rolls according to the invention. A non-tacky raw tape without any coating of pressure- sensitive adhesive may be employed according to aforementioned embodiment of the invention. In this case, one winding start end of the raw tape is fixed to the butt-wrapped wind-up core sheet with a double-sided pressure-sensitive adhesive tape and then the non-tacky raw tape is wound by rotating the mandrel likewise. When the raw tape reaches a predetermined roll amount, the cutting tool is moved in the direction of Y at a predetermined position in the direction of X, and simultaneously the mandrel is rotated to cut the raw tape roll together with the butt-wrapped wind-up core sheet in predetermined tape widths. This cutting operation is repeated to obtain tape rolls according to the invention. After the one layer of the wind-up core sheet is thus wound on the sacrifice tape by butt-winding or gap-winding according to the aforementioned embodiment of the invention, a thin pressure-sensitive adhesive film is pressed against the surface thereof whereby to rewind the adhesive raw tape or non-tacky raw tape on the rotating mandrel. When the predetermined raw tape roll amount is reached thereby, the cutting tool is moved in the direction of Y at the predetermined position in the direction of X, and simultaneously the mandrel is rotated to cut the raw tape roll together with the butt-wrapped wind-up core sheet in predetermined tape widths. This cutting operation is repeated by moving the cutting tool in the direction of X to obtain tape rolls cut in width as predetermined. The invention may be implemented though through the steps of spirally winding the wind-up core on the rotating mandrel by butt-winding or gap-winding, spirally winding a pressure- sensitive adhesive film thereon to pre-produce an annular material with the pressure-sensitive adhesive film as shown in Fig. 4 (A refers to a wind-up core sheet, while . refers to a pressure-sensitive adhesive film) , fixedly inserting the annular material with the pressure-sensitive adhesive film, then winding the raw tape on the mandrel in the same manner as mentioned above, and cutting the raw tape in predetermined widths by rotating the cutting tool in the direction of Y at the predetermined position of X together with rotating the mandrel to cut the raw tape in predetermined widths when the predetermined raw tape roll amount is reached thereby. In that case of manufacturing annular materials each having the pressure-sensitive adhesive films, it may be possible to make the extrusion process continuous to the steps of extrusion- forming wind-up core sheets using an extruder, spirally winding each of the wind-up core sheets on the rotating mandrel by butt-winding or gap-winding, and spirally and superimposedly a pressure-sensitive adhesive film thereon. Even in the case of winding the raw tape without cutting it in round slices according to the aforementioned embodiment of the invention, the invention may also be applicable to that case. According to this embodiment of the invention, use can also be made of a sacrifice tape bearing a brand name so that the sacrifice tape may be left unremoved. Instead of the sacrifice tape, moreover, an auxiliary core or a thin paper tube displaying a brand name, for example, may be used in such a state that the paper tube is not adhering to the inner periphery of the annular body. As the tape rolls manufactured according to the invention employ the wind-up cores such that both edges of the wind-up core sheets are not coupled together, each wind-up core readily contracts toward the inner diameter as the tape base of the tape roll contracts. Consequently, even when the tape base of such as a polyvinyl pressure-sensitive adhesive tape contracts because of roll tightening or residual stress, it is possible to hold the tape roll in good order by preventing the tape roll side from being tapered (like a bamboo shoot) . This effect can be fully anticipated because the film rigidity is practically ignored even in the case of an annular material with a pressure-sensitive adhesive film. This effect is particularly conspicuous as the wind-up core is easily contracted by butt-winding in a case where there is an edge-to-edge gap between both edges of the wind-up core sheet. In a case where the wind-up core sticks out of the tape roll side, moreover, it can readily be corrected by butt-winding. Further, the above effect can be ensured as the outside wind-up core slides and contracts with respect to the auxiliary wind-up core even in the case where the auxiliary wind-up core is internally furnished. Fig. 5A is a side view of the tape roll produced according to the invention wherein the wind-up core sheet A is made to adhere to the inner surface of an annular tape roll B by butt-winding. As shown in Fig. 5B, no foreign matter is allowed to enter and stay in a gap e_ between both edges of the wind-up core sheet A because there exists no gap therebetween. Particularly when the annular tape roll is a pressure-sensitive adhesive tape roll, a pressure-sensitive adhesive flowing from the innermost peripheral edge of the pressure-sensitive adhesive tape is prevented from forming an adhesive bump therein. Therefore, the wind-up core sheet is set free from creating the adhesive bump after the tape is used up with only such a wind-up core sheet being left, so that the wind-up core sheet can be treated as a recyclable material of high purity. According to the aforementioned embodiment of the invention, a material for use in the wind-up core sheet A is not limited to any specific kind but may be what is made of plastics such as polyethylene, polypropylene and a mixture of them, or paper or any other plastic waste product, for example, any one recycled from plastics containing different kinds of adhesives. Such a wind-up core sheet may normally be about 2,000 μm to 500 μm. As the pressure-sensitive adhesive film a, there is used an extremely thin film capable of substantially eliminating a gap allowing the entry and adhesion of the foreign matter therein and resulting in creating the adhesive bump despite of butt- winding . According to the aforementioned embodiment of the invention, the annular tape roll B is not limited to any specific kind but may be what is made of plastics such as polyethylene, polypropylene and polyvinyl chloride, or paper, metal foil and their laminates or any other product with one of these bases coated with an ordinary pressure-sensitive adhesive. INDUSTRIAL APPLICABILITY The tape roll produced according to the invention are such that the inner diameter of each wind-up core readily contracts as it follows the contraction of the tape base of the tape roll. Consequently, even when the tape base contracts because of roll tightening or residual stress, it is possible to hold the tape roll in good order by preventing the tape roll side from being tapered (like a bamboo shoot) . Moreover, only the annular body of the wind-up core sheet remaining uncoupled together is left after the tape is used up and since the annular body can easily be expanded into a soft planar material before being disposed. Further, the annular wind-up core sheet formed by butt-winding is set free from a gap with respect to the annular tape roll and also an adhesive bump, whereby the wind-up core sheet without the pressure-sensitive adhesive can be treated as a recyclable material of high purity. Even in the case of the annular wind-up core sheet with the pressure-sensitive adhesive film formed by butt-winding, the wind-up core sheet can also be treated as a recyclable material of high purity without lingering paste. The separated pressure-sensitive adhesive film is disposable too after being brought into a compact lump. The tape roll produced according to the invention may easily be formed into a hard-to-tumble shape, for example, a triangle, a square, an elliptic or the like, so that it is prevented from being lost by tumbling. According to the invention, the residual parts after tape rolls are used up are therefore readily disposable or recyclable and further tape rolls practically stable in posture can be provided as before.

Claims: CLAIMS 1. A tape roll comprising: an annular wind-up core comprising a wind-up core sheet, wherein the wind-up core sheet comprises a first edge and a second edge, and the first and second edges are opposed to each other and not fixed to each other when the wind-up core sheet defines the annular wind-up core; and an annular tape roll comprising an inner peripheral tape face, wherein the wind-up core is closely contacted to the inner peripheral tape face. 2. The tape roll as claimed in claim 1, wherein the first and second edges are opposed to each other with a gap. 3. The tape roll as claimed in claim 1, wherein the first and second edges are brought into contact with each other. 4. The tape roll as claimed in claim 1, wherein the first and second edges define helices around the axis of the wind- up core. 5. The tape roll as claimed in claim 1, wherein the first and second edges substantially extend in parallel with the axis of the wind-up core. 6. The tape roll as claimed in claim 1, wherein the tube is a cylinder. 7. The tape roll as claimed in claim 1, wherein the tape is a pressure-sensitive adhesive tape, and the wind-up core sheet and the inner peripheral tape face which define a contacted interface are adhered together with a pressure-sensitive adhesive of a pressure-sensitive adhesive tape itself. 8. A tape roll comprising: an annular body with a pressure-sensitive film, wherein the annular body comprises a wind-up core sheet, the wind-up core sheet comprises a first edge and a second edge, the first and second edges are opposed to each other and not fixed to each other when the wind-up core sheet defines a tube, and the annular body has an outer surface bound with the pressure-sensitive film; and an annular tape roll comprising an inner peripheral tape face, wherein the annular body with the pressure-sensitive film is closely contacted to the inner peripheral tape face. 9. The tape roll as claimed in claim 8, wherein the first and second edges are opposed to each other with a gap. 10. The tape roll as claimed in claim 8, wherein the first and second edges are brought into contact with each other. 11. The tape roll as claimed in claim 8, wherein the tape is a pressure-sensitive adhesive tape, and the annular body with the pressure-sensitive adhesive film and the inner peripheral tape face which define a contacted interface are adhered together with an pressure-sensitive adhesive of a pressure-sensitive adhesive tape itself. 12. A method for producing a tape roll, which comprises the steps of: winding up a wind-up core sheet on a mandrel to form one layer, by one of butt-winding and gap-winding; rewinding a raw tape on the wind-up core sheet while rotating the mandrel; and taking the raw tape out of the mandrel. 13. A method for producing a tape roll, which comprises the steps of: winding up a wind-up core sheet on a mandrel to form one layer, by one of butt-winding and gap-winding; rewinding a raw tape on the wind-up core sheet while rotating the mandrel ; cutting the raw tape in round slices; and taking the sliced raw tapes out of the mandrel. 14. The method for producing a tape roll as claimed in claim 12, which comprising the steps of: winding a binder pressure-sensitive adhesive film, on a butt-winding or gap-winding wind-up core sheet; and rewinding a raw tape on the binder pressure-sensitive adhesive film. 15. A wind-up core for a tape roll, which comprises an annular body comprising a wind-up core sheet, wherein the wind-up core sheet comprises a first edge and a second edge, and the first and second edges are opposed to each other and not fixed to each other when the wind-up core sheet defines the annular body. 16. The wind-up core for a tape roll as claimed in claim 15, which further comprises a pressure-sensitive adhesive film covering an outer surface of the annular body. 17. The wind-up core for a tape roll as claimed in claim 15, wherein an auxiliary core is provided to the inner periphery of the annular body in a non-adhered state. 18. The wind-up core for a tape-roll as claimed in claim 16, wherein an auxiliary core is provided to the inner periphery of the annular body in a non-adhered state. 19. The wind-up core for a tape-roll as claimed in claim 17, wherein the auxiliary core is a paper core. 20. The wind-up core for a tape-roll as claimed in claim 18, wherein the auxiliary core is a paper core.

Inventors: HOSOI MOTOYUKI, MAMIYA MASATOSHI, YONEMORI YOSHIHISA, HOSOI, MOTOYUKI, MAMIYA, MASATOSHI, YONEMORI, YOSHIHISA
Applicants: HOSOI MOTOYUKI, MAMIYA MASATOSHI, NITTO DENKO CORP, YONEMORI YOSHIHISA, HOSOI, MOTOYUKI, MAMIYA, MASATOSHI, NITTO DENKO CORPORATION, YONEMORI, YOSHIHISA
Application year: 2000
Main classification: B65H75
IPC codes: B65H75