JPH066354U - Plastic core - Google Patents

Abstract

(57) [Abstract] [Purpose] To realize an inexpensive and simple plastic core capable of preventing the deformation of the tape by well dispersing / releasing the stress strain generated when the tape material is slit or wound. [Structure] A plastic core 1 in which a tape material having an adhesive layer is wound around the outer periphery in a roll shape, and a rubber layer 3 is adhered and formed on an outer peripheral surface of a core material 2 to cause tape deformation. Make it harder.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a plastic core around which a tape material is wound in a roll.

[0002]

[Prior art]

 A so-called adhesive tape is generally constructed by winding a long tape material having an adhesive layer on one surface in a roll shape and multiply-wrapping it around the outer circumference of a paper-made cylindrical core (core material). From the viewpoint of increasing value, diversifying products, and eliminating inconveniences related to manufacturing (eliminating dust generated during manufacturing), there is a movement to change to a plastic core.

[0003]

[Problems to be solved by the device]

 However, when the core is made of plastic, the change in the shape of the tape immediately after winding the tape material and with time becomes a serious problem. That is, stress strains that occur during slitting and winding are inevitably latent inside the tape material, and especially in the case of an adhesive tape such as a tape material having an adhesive layer, the tape winding tension is large. The more prominent it is.

In the case of a conventional paper core, since the core itself appropriately absorbs and relaxes stress and strain, there has been almost no problem, but in the case of a plastic core, it is elastic. Since it cannot be absorbed or dispersed, the so-called bamboo shoot phenomenon (a phenomenon in which the entire tape is transformed into a bamboo shoot on one side, which significantly destroys the commercial value), etc. are likely to occur.

Therefore, in the present invention, it is an object of the present invention to provide an inexpensive and simple plastic core capable of reducing or avoiding the above-mentioned inconvenience which may be caused and guaranteeing a tape quality equal to or higher than the conventional one. And

[0006]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention is a plastic core in which a tape material is wound in a roll shape on the outer periphery, and has an elastic material layer on the outer peripheral surface of the core. Further, in the present invention, preferably, the tape material has an adhesive layer, and the elastic material layer is made of a rubber material.

[0007]

[Action]

 The elastic material layer on the outer peripheral surface of the core disperses and relaxes the strains of the tape material wound in a roll on it, which makes it difficult for the tape to deform even when the winding tension of the tape is large.

[0008]

【Example】

 Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a sectional side view of an embodiment of a plastic core according to the present invention. Referring to the figure, the core 1 of this embodiment basically comprises a cylindrical polypropylene core material 2 having circumferential grooves on both sides, and a synthetic rubber (elastomer) layer 3 on the outer peripheral surface thereof. Formed and deposited uniformly. The specifications of this synthetic rubber (synthetic rubber layer 3) will be described later. As the plastic material forming the core material 2, styrene, an acrylic resin, an ABS resin, a polyester resin, a glass-reinforced resin thereof, or the like can be used in addition to polypropylene.

Although not shown, on the outer periphery of the core 1, the same tape material as one product (Scotch (registered trademark) Mending Tape No. 810) which the applicant (Sumitomo 3M Ltd.) holds is It is wound in multiple layers in a roll. This tape material is made of acetate as a base material, and one surface of which is coated with an acrylic adhesive (adhesive layer). In terms of quality, it has excellent moisture resistance and little expansion / contraction.

In the present embodiment, the tape material is not directly wound on the plastic core material 2 but is wound with the synthetic rubber layer 3 sandwiched therebetween, so that the bamboo shoot phenomenon as described above almost occurs. There is no. That is, for example, when the tape material is wound directly on the plastic core material 2, although the tape quality is excellent, it is inevitably generated at the time of slitting or winding. The stress strain remaining (latent) inside the material is not dispersed (transmitted) or absorbed because the core material 2 itself does not have elasticity (elasticity). Therefore, depending on the case, immediately after winding or with time. Then, the adhesive creeps, and as a result, the entire tape is deformed (distorted) into a bamboo shoot shape as described above.

On the other hand, in the structure of this embodiment in which the outer peripheral surface of the core material 2 has a uniform synthetic rubber layer 3 having a predetermined hardness, and the tape material is wound on the synthetic rubber layer 3, it is effective to reduce the strain. Since the dispersion is moderated, the occurrence of such an unfavorable situation can be reduced or eliminated. In addition, in this embodiment, in addition to the above-described actions and effects, since the plastic core 1 (core material 2) can be adopted, dust and the like are not generated unlike the paper core during the manufacturing process. It is preferable in terms of work environment. Therefore, the present invention should be applied not only to adhesive tape but also to other tapes, for example, cores such as magnetic tapes that are extremely reluctant to produce dust, etc. You can also Further, there is an advantage that the production range of the tape winding tension is widened and the production efficiency is remarkably improved.

Next, a method of manufacturing the core structure of this embodiment will be described. In general, it is not easy to reasonably coat a plastic product with rubber on a commercial basis, but in this embodiment, as an example, an insertion molding method will be briefly described below to explain its basic process. To adopt. That is, a large number of core materials that have been previously formed into a single predetermined shape are juxtaposed in a mold having a gap of a predetermined rubber component, and the rubber component is injected between the gaps so that the entire outer peripheral surface of the core is predetermined. The rubber component of is uniformly applied and then subjected to a predetermined cooling treatment. As a result, it is possible to manufacture a core having excellent dimensional and hardness accuracy (uniformity) of the synthetic rubber layer at a relatively low cost and in a large amount. Before cutting into a single piece, use the same method to apply rubber to a long cylindrical cylindrical core material, and then change the process so that the core is manufactured by cutting it individually. You can also

Finally, various specifications such as the material of the synthetic rubber layer (elastic body layer) 3 formed on the outer periphery of the core material will be briefly described. First, as the material of the synthetic rubber (layer), the following can be mentioned. For example, crosslinked rubbers such as NBR, SBR, isobrene, chloroprene and butadiene, and rubbers having no crosslinking such as SBS and SIS. Alternatively, a composite rubber containing a foaming agent and having a sponge-like form can be used. Incidentally, these rubber materials may appropriately contain an ultraviolet absorber, carbon black, a cross-linking agent, an antioxidant and the like. In addition, natural rubber can be used (partly or wholly) because it is cheaper.

Next, if the thickness of the synthetic rubber layer (elastic layer) 3 is less than 0.5 mm, the effect of the present invention is poor, and if it exceeds 3 mm, the tape diameter becomes too large and manufacturing becomes difficult. It is recognized that the practical size is about 5 mm to 3.0 mm. The hardness of the synthetic rubber layer (elastic layer) 3 is in the range of 25 to 70 degrees in Vickers hardness as can be well understood from FIG. 2 showing the experimental correlation between the rubber hardness and the deformation amount of the tape material. More practically, it is preferable to use a rubber material having a hardness in the range of 30 to 50 degrees.

The experimental data shows that two different winding tensions (larger (8.5 g / m ² ) A and smaller (4.5 g / m ² ) were applied to various cores having different rubber hardness. ) Is indicated by B, and the larger the number is, the higher the winding tension is), and the experimental tape wound with the tape material (polyacetal adhesive tape) is used at a temperature of 50 ° C. and a humidity of 90% RH for 3 days. The amount of deformation of the tape was measured by leaving it for one day. To measure the amount of tape deformation, place the experimental tape horizontally on a surface plate, measure the maximum displacement (deformation) of the tape using a height gauge, and use the difference from the original width of the tape as the maximum amount of deformation. . In practical use, the allowable range of tape deformation is 4 mm or less.

[0016]

[Effect of device]

 As described above, according to the present invention, the above-mentioned inconveniences that may be caused can be reduced or avoided, and even if the winding tension is large, an inexpensive and simple plastic core that can guarantee a tape quality equal to or higher than the conventional one Can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional side view of an embodiment of a plastic core according to the present invention.

FIG. 2 is a diagram showing an experimental correlation between rubber hardness and a tape material deformation amount.

[Explanation of symbols]

 1 ... Core 2 ... Core material 3 ... Rubber layer

Claims (3)

[Scope of utility model registration request] 1. A plastic core around which a tape material is wound in a roll shape, the plastic core having an elastic material layer on the outer peripheral surface of the core. 2. The plastic core according to claim 1, wherein the tape material has an adhesive layer. 3. The plastic core according to claim 1, wherein the elastic material layer comprises a rubber material.