JPH03243570A - Semirigid hollow cylindrical core and adhesive tape roll and their manufacture - Google Patents

Abstract

PURPOSE: To suppress the telescopic phenomenon by forming a core so that its diameter can be reduced. CONSTITUTION: A thin and long missing part having free ends 50 is formed stretching in the longitudinal direction of a cylindrical core 10, and the free ends 50 adjoin with a certain spacing reserved in between such that the ends touch each other caused by diametric shrinkage of the core 10 at the time of stress restorage. By the use of the diametrically shrinkable core 10, an adhesive tape 20 cut by a knife 30 and overlaid roll 40 and wound on the core 10 sustains a stress restorage, which causes extrusion of the core, and the stress restoring phenomenon will cause the core to make diametric shrinkage and deformation. Thus, the telescopic phenomenon is either removed or reduced at least to the allowable range substantially.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to adhesive tape roll manufacturing technology, and more particularly to a core or hollow cylindrical member around which adhesive tape is conventionally wound.

BACKGROUND ART A plurality of adhesive tapes are - numerically formed from one sheet. That is, it is formed from a tape that is significantly wider than the width of the final tape and is passed through a cutting operation to produce rolls of a predetermined width, such as 3/4, 1, 2 inches, etc.

The tape is formed by first applying an adhesive layer to a desired substrate to create an adhesive coated substrate, the adhesive coated substrate having a width, e.g. Measures 30 to 50 inches by 70 yards or more.

Following application of the adhesive layer, the finished tape is typically wound onto a master or oversized roll and transported to the cutting operation.

There are basically two different cutting methods to form a tape roll of a given width. The first and most common process is referred to as 'baloney slicing', in which the desired length of tab is formed into one core of the same width as the tape drawn from the supply roll for the cutting operation. rolled on top and further slicing ba
It is cut into individual rolls of a predetermined width, so-called loney'. Typically, this cutting is accomplished by passing a core wrapped with a length of adhesive tape through a cutting process that includes a plurality of knives spaced apart. It is arranged. The cutting results in a plurality of individualized rolls of a predetermined width.

In a second method, which is more desirable from an industrial production point of view, the web of tape drawn from the master supply roll is first cut to a predetermined width and then wound onto a core therein. This core is for packaging and shipping.

In either case, a manufacturing problem known as "telescopic" occurs (see Figure 3). Basically, telescopic is when the overlapping portion of the tape rolls protrudes beyond the width of the core around which the tape is wound. Rolls exhibiting telescopic phenomena are rejected during manufacturing quality control inspections, requiring the roll to be discarded or re-rolled.

The so-called balonyli cutting in tape production
eing) method, this is not a very serious problem. This is because the narrow cutting tape is not stretched before being wound around the core.

Briefly stated, the problem of the present invention is to elucidate the cause of the problem known as telescoping. Then, from a commercial manufacturing standpoint, it is a matter of finding solutions to cost efficiency and other development issues.

SUMMARY OF THE INVENTION In accordance with the present invention, it has been discovered that the cause of the problem is the stress recovery experienced by the tape after it has been cut and wound onto the core (discussed in more detail below). Also,
Said problem is eliminated by using what is defined as a "reduced core". This causes the stress recovery phenomenon to become telescopic, ie, rather than causing the tape to slide out of the core, the core contracts in diameter.

As previously mentioned, conventional methods of roll tape production begin with a coating operation in which an adhesive layer is applied to at least one side of a suitable substrate material, e.g. by calendering, extrusion coating, etc. , casting, etc., whereby a long web having a substrate coated with an adhesive is created. This web is
The web is wound onto a roll forming a supply roll for the cutting operation, in which the web is cut to the desired width, i.e. 3
It is cut widthwise to make tapes of 74 inches, 1 inch, 2 inches, etc. The web can also be cut to desired lengths and wound around a core to form commercially available tape rolls.

Generally, two alternative cutting processes are known. That is, the so-called 'baloneyslicin'
g" (baloney slicing) technique and the shear cutting technique. In the former, a tape of the desired length is wound onto a core whose width is approximately the same as the width of the adhesive web. The resulting tape The extension roll is then cut into multiple rolls of predetermined widths and sent to a packaging and distribution station.The cutting is typically carried out by a series of spaced, parallel cutting knives to provide the desired width. In contrast, this is done in a single step of passing the roll tape.

In the shear cutting technique, the web is first cut to predetermined widths and lengths and wound into individualized cores for packaging and distribution.

In both methods, the core member around which the tape is wound is a continuous cylindrical core made of semi-rigid material such as cardboard, plastic, paper, or composites thereof. be.

Irrespective of the cutting technique utilized, the telescopic problems mentioned above often arise, thereby affecting manufacturing costs.

As mentioned above, this problem is not as severe in the baloney cutting process. However, the above-mentioned cutting process is a very serious problem. Therefore, although this cutting process has certain industrial advantages in terms of cost advantages over baloney cutting, telescopic problems preclude its use in large scale industrial production.

(Example) The telescopic problem to be solved by the present invention will be better understood by referring to FIGS. 1 to 3 of the accompanying drawings.

FIG. 2 schematically illustrates the shear cutting technique, in which a web of adhesive tape 20 drawn from a master roll (not shown) is cut with a plurality of cutting knives and a polymerized roller. , passing between. Here, knife 30
Only one of the rollers 40 and 40 is shown. tape 20
The exact lengths are shown in FIG. 1 for an understanding of the invention (as can be seen, they are wound onto discrete semi-rigid cores that are predefined as continuous or endless cylinders).

In this operation, the tip of the tape web is wound around the plurality of cores, and this winding is performed by a driving operation of a shaft on which the plurality of cores are installed, and by driving this shaft, the web is Moving through the cutting knife 30.

The drive action of pulling the tape web through the knife and polymerization roll creates tension, or in other words, involves a pulling action that creates stress or elongation forces as the cut tape is wound around the core.

Tapes are variously flexible and have elastic memory capabilities. Therefore, after being wrapped around the core, the tape resists stress recovery, and this is the stress recovery force that is believed to be responsible for extruding the core. And this stress is the third
As shown in the figure, it is called telescopic. It is known that when telescopicity occurs, it is directly proportional to the ambient temperature, and increasing ambient temperature generates and/or enhances the roll telescopic phenomenon.

An early measure to prevent this roll telescopic phenomenon was in the present invention, when the tape was pulled through the knife,
The aim was to reduce stress and tension when the core is wound.However, at least some tension is present from the beginning in industrial processes, and even when minimal tension is used, roll telescopic phenomena can occur. was still observed. Therefore, another means had to be found to eliminate the roll telescopic phenomenon.

According to the invention, the telescopic phenomenon problem can be eliminated or at least substantially reduced to an acceptable range. This is accomplished by using what is described as a retractable core. If the core is collapsible, the stress recovery phenomenon will result in the core collapsing and deforming rather than the tape pushing or sliding out of the core.

A fourth preferred method for making the retractable core 10 of the present invention
It is shown in the figure. As shown in FIG. 4, an elongated notch is formed along the longitudinal direction of the cylindrical core 10, and has two free ends 50.50, which are adjacent to each other with a space between them. Such objects are defined as discrete cylindrical cores.

While the removed portion is shown to be substantially perpendicular to the ends, preferably the removed portion is formed by cutting at an angle.

Generally, the spacing between the free ends 50,50 should be such that upon stress recovery, the core 10 will contract and the ends will abut each other. If the distance is too large, the ends will not touch, resulting in a deformed (discontinuous) core. On the other hand, if the removal is too small (the spacing is too small) it cannot be accompanied by enough deformation of the core to prevent the tape from pushing it out, so some telescopic phenomenon still occurs.

The exact amount of spacing provided by tightening a portion of the core will depend, at least in part, on the degree of tape stress relaxation. This depends on the elasticity and stress of the special tape, that is, the magnitude of the tension generated during the manufacturing process.

Therefore, the spacing between the ends 50.50 of the discontinuous core of the present invention varies somewhat depending on the tape and/or the amount of tension applied to the tape. For this reason, it is not possible to define a definite number for the above-mentioned spacing.

However, as shown, in commercially available tapes tested by Applicant, spacing of 1/3 to 1/4 inch width gave optimal results.

Another embodiment of the invention is a form fform) 60(
By wrapping the outer surface of the core 10 with a material (see Fig. 5), a diameter reduction effect is brought about. Note that the outer surface of the core 10 is not exact. For purposes of illustration, but not limitation, the following flexible foam materials may be used. namely polyurethane, rubber latex, polyethylene and vinyl polymers. The foam is integrated with said core by adhesive means known per se, for example a pressure sensitive adhesive.

The selection of the particular foam material and its thickness will depend on the expected amount of restoring stress. Therefore, a tape that would be assumed by those skilled in the art to have sufficient recovery would require a foam material with comparable flexibility to prevent telescopic phenomena.

As can be seen from the figure, the polyurethane foam is
The thickness will be ~3o+m.

If the core 10 shown in FIG. 4 is moderately reduced in diameter, it will exhibit desirable aesthetic results, as shown in FIG. As shown, the ends of the tape are uniform without telescopic effects and the free ends 50,50 are sufficiently adjacent that the core 10 is substantially cylindrical in appearance.

The core material used in the practice of the present invention may be any conventional semi-rigid material used in the roll tape industry - for boat fishing. Such a material has the rigidity and dimensional stability to maintain its shape under the weight of the wound adhesive material, but under the stress restoring force mentioned above, it resists slight diameter contraction. Fully flexible. Typically, such cores are formed from cardboard or other laminates based on paper materials. In any event, the selection of the particular core material itself does not form part of the invention (and is therefore merely a matter of choice within the discretion of a person skilled in the art).

Similarly, for the purpose of the present invention, the tape is 1! The adhesive and substrate used for the preparation are not critical.

Typically, pressure-sensitive adhesives, such as acrylic or rubber-based adhesives, are comprised of at least one natural or synthetic rubber elastomer and one or more tackifying resins. , coated on polyolefins, such as polyethylene, and other plastic sheet materials. So-called double-sided tapes, which have adhesive layers on both sides, can be considered as duct tapes, etc., which have a reinforcing fabric disposed between the base material and the adhesive layer. While pressure sensitive adhesive rolls are most common, it will be appreciated that the invention applies equally to other types of adhesives, such as heat-activated or water-activated adhesive tapes.

Typical tapes that may be considered for use in the present invention are characterized by being comprised of a flexible polymeric film with delayed stress recovery.

It will also be appreciated that the width and length of the tape are not critical. However, normal rolls have a width of 0.75 to 2.5
inches and ranges in length from about 15 feet to about 60 feet.

The following specific examples are not intended to limit the practice of the invention.

(Specific example) The above-mentioned cutting device has 12 cutting knives, and these 1
The two knives are placed side by side and spaced apart to create a 3/4 inch tape. The above cutting device is
It is used in conjunction with a 3/4 inch core to make two 3-high inch tables. Section 2.4.6.8.10.
The 12-point core is a conventional continuous cardboard core while the 1.3.5.7.9.
The core at point 11 was a discontinuous core according to the invention with a 1/4 inch gap between the free ends of the core. A web of commercially available butyl, rubber based pressure sensitive adhesive on a plastic substrate was used to form 12 tape rolls on a 3 by 4 inch core. The finished tape was measured from one end of the roll to the other to determine the maximum width. (Theoretically, the maximum width should be approximately 374 inches of tape and core.) Of the 6 consecutive (control) cores, the core at point 4.6.10.12 is increased by 15 inches. This was measured and showed a severe telescopic phenomenon that was more than twice the width of the core.

A fairly small telescopic phenomenon was observed in the continuous core at the second point, and no telescopic phenomenon was observed in the continuous core at the sixth or central point, although this cannot be explained.

Among the six discontinuous tapes (for experimental use), the width of each is [
1,07,O,[+8.0.07,0.05,0.06
, 0.03 inches, and these tapes were acceptable tape rolls as being sufficiently free of telescopic effects from a commercial standpoint. For tape wound on a reduced diameter core, the gap between the ends of the core does not close perfectly, leaving a gap on average, thus indicating that smaller gaps can be used. Even with this remaining elongated gap, the roll is sufficiently cylindrical, aesthetically pleasing, and acceptable.

Variations that do not depart from the scope of the invention are included in the invention, and all content contained in the above description and accompanying drawings should be understood not as a limitation (but as an illustration). be.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a general core for adhesive rolls, Fig. 2 is a schematic diagram showing a general cutting process and tape roll forming process, and Fig. 3M is a conventional tape roll. FIG. 4 is a perspective view of a diameter-reducing roll according to the present invention, and FIG. 5 is a perspective view of a diameter-reducing core according to another embodiment of the present invention. FIG. 6 is a perspective view of a tape roll provided with a reduced diameter core of the present invention. lO...core 20...adhesive tape 30...knife 50...free end 60...engraving of one side of the form (no change in content) Figure 1 Figure 2 Figure 3 Figure 4 Procedure (How to write an amendment) % formula % Name of the invention Half-sized hollow cylindrical core and adhesive tape roll and its manufacturing method 3゜Relationship with the case of the person making the amendment Patent applicant address Name Name Zarkendor φ Company 4, Agent address Shin-Otemachi Building 206, 2-2-1 Otemachi, Chiyoda-ku, Tokyo Telephone: 3270-6641-6646 6. Subject to correction

Claims (16)

[Claims] (1) A semi-rigid hollow cylindrical core used for winding an adhesive tape to provide an adhesive tape roll having substantially the same width as the core, the core having a diameter that can be reduced. A semi-rigid hollow cylindrical core which suppresses the telescopic phenomenon in which the overlapping portion of the wound tape protrudes beyond the width of the core. (2) a semi-rigid hollow core used for winding adhesive tape, the core having a cylindrical shape to provide an adhesive tape roll having substantially the same width as the core; an adhesive tape that is sometimes subjected to stress and can undergo stress recovery immediately after winding the adhesive tape around the core to cause a telescopic phenomenon in which the polymerized portion of the wound tape jumps out from the core; The core is discontinuous and has two free ends that are spaced apart and brought together under pressure created by the stress recovery of the wound adhesive tape, causing the core to shrink. An adhesive tape roll characterized in that the two free ends are substantially in contact with each other to suppress the telescopic phenomenon of the adhesive tape. (3) Claim (2), wherein the distance between the two free ends of the core is approximately 1/1 inch.
8 to about 1/4. (4) In claim (1), the core is provided with a foam material on its outer periphery. (5) In claim (4), The foam material is an elastic porous plastic. (6) According to claim (5), the elastic porous plastic is selected from the group consisting of polyurethane, rubber latex, polyethylene, and vinyl polymer. (7) an adhesive tape wound around a semi-rigid, generally cylindrical core of substantially the same width as the adhesive tape; and a foam layer on the outer surface around which the adhesive tape is wound. and a core, the adhesive tape is subjected to stress while being wound around the core, and the stress is restored immediately after the winding is completed, and the core is initially allowed to contract in diameter, The adhesive tape roll is configured to reduce in diameter under the stress restoration, thereby suppressing a telescopic phenomenon in which the overlapping portion of the wound adhesive tape protrudes beyond the core. (8) In claim (7), The adhesive tape is a pressure-sensitive adhesive tape. (9) According to claim (8), the pressure-sensitive adhesive tape is made of an acrylic or rubber paste adhesive applied to a plastic sheet material. (10) In claim (9), the plastic sheet material is made of polyolefin. (11) In claim (7), the foam material is made of flexible foam plastic. (12) In claim (11), the flexible foam plastic is selected from the group consisting of polyurethane, rubber latex, polyethylene, and vinyl polymer. (13) A cutting step of cutting a piece of adhesive tape pulled out from a master roll in its longitudinal direction to form a plurality of independent tapes narrower than the tape of the master roll, and after the cutting step, a winding step of winding at least one of the cut tapes around a cylindrical semi-rigid core having substantially the same width as the tape under tension; A method of manufacturing an adhesive tape, wherein the tape has flexible and elastic memory performance, and the tape undergoes stress recovery after being wound while being under tension on the core, wherein the core is A method for producing an adhesive tape comprising a core whose diameter can be reduced as defined by (14) In claim (13), the core that can be reduced in diameter consists of a discontinuous core defined in claim (2). (15) The device according to claim 13, further comprising the step of wrapping the core with a flexible foam material. (16) The flexible foam material according to claim 15 is selected from the group consisting of polyurethane, rubber latex, polyethylene, and vinyl polymer.