JPH08108473A - Manufacture of synthetic resin case for outer packaging - Google Patents

Abstract

PURPOSE: To prevent printed parts from peeling and falling by forming design displaying parts and folding lines based on difference in rough face finish at predetermined positions of a synthetic resin sheet simultaneously with a seating process. CONSTITUTION: A melting material of a synthetic resin, for example, a polypropylene is rolled by a pair of embossing rolls, cooled and fixed so as to form an outer surface 11b having rough face. At the same time that a predetermined number of smooth design displaying parts 12 are formed at fixed positions, folding lines 14 are formed. A predetermined number of sheets, for example, six sheets of small pieces 13 are stamped from the rolled material in a stamping process. Thereafter, jointing pieces 15 are folded inward with boundaries at the folding lines 14. These jointing pieces 15 are superposed and jointed by, for example, ultrasonic machining so as to assemble a case 16 for facing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a synthetic resin exterior case such as a VTR cassette tape protective case, a book case, or a cosmetic design case.

[0002]

2. Description of the Related Art In recent years, along with the diversification of products, various designs are printed on the exterior case of the product in addition to characters such as brand name and quality required for identification, and the function of simply packaging and protecting. In addition to the above, the case has come to take a form capable of responding to the taste of the user or the demand for high-end products. The above-mentioned exterior cases include those made of paper and those made of synthetic resin. For example, the latter case is used as a protective case for cassette tapes for VTRs and a design case for cosmetics in order to make it higher quality. In general, more recently, bookcases made of synthetic resin have been widely used. And, these synthetic resin outer case,
Generally, a synthetic resin sheet is punched out and assembled from the viewpoint of manufacturing cost.

Many conventional cases of this type are made of polypropylene, for example, because of their good processability. For example, the case described above is processed according to the processing sequence shown in FIG. .

In FIG. 2, reference numeral 1 is a plain synthetic resin sheet whose surface is roughened if necessary, and this synthetic resin sheet is cut into a predetermined length during sheeting to form a large rectangular shape. Has been formed. Next, the synthetic resin sheet 1 is printed, for example, by offset printing at a predetermined position with a design display portion 2 including a predetermined number of brand names, product name identification characters, and the like, and is punched into small pieces 3 of the same shape and a predetermined number.

Next, each small piece 3 is pushed by a streak,
That is, ruled line processing for forming the polygonal line 4 is performed by thermal processing or the like. Then, it is bent according to the polygonal line 4,
The joining pieces 5 formed with the fold line 4 as a boundary are overlapped with each other, and necessary portions are welded by ultrasonic machining or the like to assemble the case 6. The design display portion 2 is printed on the synthetic resin sheet 1 so as to be located at a predetermined position of the assembled case 6.

[0006]

However, in such a conventional exterior case, since the design display portion is printed in a separate step during processing, the broken line is also a stripe in a separate step. Since it is formed by pressing, there is a problem that the manufacturing cost of the case increases. In particular, of the series of processing steps described above, the printing process occupies the highest cost, and since it has to be done in a specialized printing plant, the transfer cost is also added, which is a major factor that further increases the manufacturing cost of the outer case. Was there.

Further, for example, in the case of a protective case of a cassette tape for VTR, price competition in the cassette tape market is fierce, and not only the cost of the cassette tape itself but also the cost of the protective case can be reduced as much as possible. , Has become a major issue for cassette tape manufacturers. Moreover, since the cost of the synthetic resin case is generally higher than that of the paper case, the tape manufacturer is eager to reduce the cost of the protective case.

When the outer case is made of a synthetic resin having poor adhesion to printing ink such as polypropylene, the design display portion is printed by silk screen printing or offset printing. However, even with these printing techniques, the adhesion of the ink is still insufficient, and the printed portion often peels off during the distribution stage or during use. Therefore, there is a problem in that the quality of a product that uses the exterior case as a packaging material is deteriorated and is subject to user complaints.

On the other hand, Japanese Patent Application Laid-Open No. 58-22126 proposes a technique of covering a sheet surface with a masking film and using an elastic roller having fine irregularities on the surface to partially roughen the surface. ing. In this way,
The design display part can be formed by partially roughening the surface, and the problem of the printing part peeling off and falling off is solved, but before performing the rough surface finishing work, Is covered with a masking film, and the masking film is peeled off after finishing the rough surface, which is not suitable for manufacturing the external case of VTR cassette tape that produces the same product in large quantities, and realizes a sufficient cost reduction. It was something I couldn't do. In addition, this method is limited to design display only on the portion to be roughened and not to be roughened, and the change is scarce, and it is not possible to meet the preference of the user or the desire for high-quality products. Further, in this proposal, even if the printing process can be omitted, the streaking must be performed in a separate process, and the sheeting, the design display part formation, and the polygonal line formation are performed in one process. There is no suggestion of a method for manufacturing an outer case that can be carried out in 1.

The present invention has been made against the background of the above-mentioned conventional technical problems. The printing step and the streak pushing step of the design display portion are omitted, and the printed portion is prevented from peeling and falling off, thereby making it possible to form an exterior case. It is an object of the present invention to provide an exterior case that reduces the manufacturing cost and further eliminates the decrease in the commercial value of a product that uses the case as a packaging material.

[0011]

SUMMARY OF THE INVENTION According to the present invention, at least one of the inner and outer surfaces of a synthetic resin sheet is provided with a difference in unevenness for rough surface finishing at a predetermined position and a polygonal line is formed at a predetermined position. Process of embossing with an embossing roll provided with ridges for forming ruled lines and simultaneously forming a design display part and a polygonal line based on the difference in rough surface finish at a predetermined position on the surface, a synthetic resin on which a design display part and a polygonal line are formed And a step of assembling an outer case by bending a synthetic resin sheet punched into a desired shape along a fold line, and a step of assembling the outer case. It is a thing.

[0012]

According to the manufacturing method of the present invention, in the substantially same step as the conventional sheeting step, the design display portion and the polygonal line are formed almost simultaneously based on the difference between the sheeting and the rough surface finish, and then the rough surface is formed. Design display part based on the difference in finish and a synthetic resin sheet on which a polygonal line is formed are punched into a desired shape, then bent, joined with joining pieces, etc. The case is assembled. In the present invention, since the exterior case having the design display portion formed in this manner is assembled without the printing process and the streaking process, the manufacturing cost of the case is significantly reduced while exhibiting the same design effect as printing. Moreover, it is possible to eliminate the decrease in the commercial value of the product in which the case is used as the packaging material due to the peeling or dropping of the printing portion.

[0013]

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited to the embodiments shown below. In this embodiment, a case for protecting a cassette tape for VTR is used as an outer case.

FIG. 1 is a diagram showing an embodiment of the present invention. First, this configuration will be described. In FIG. 1, reference numeral 1
Reference numeral 1 denotes a transparent synthetic resin sheet, an outer surface 11b of which has a roughened surface finish with a grain pattern and a polygonal line 14, and an inner surface 11a of which is smoothed. The rough surface finishing and the polygonal line formation are simultaneously performed by a sheeting technique in which a continuously supplied melt of a synthetic resin such as polypropylene is rolled by a pair of embossing rolls (not shown) and cooled and solidified.

On the surface of the embossing roll which is brought into contact with the outer surface area 11b and is rolled, a smooth portion having no irregularities forming a grain pattern is provided at a predetermined position, and a ridge for forming a ruled line is provided. On the outer surface 11b of 11, a design display portion 12 based on the presence or absence of the grain pattern, the polygonal line 14 and the grain pattern, that is, the difference in the rough surface finish is formed simultaneously with the sheeting.

Reference numeral 13 is a small piece of the synthetic resin sheet 11 having the design display portion 12 and the polygonal line 14 formed on the basis of the difference in the rough surface finish, which is punched into a predetermined number by the punching device (not shown), six pieces in this embodiment. The small piece 13 is bent with the fold line 14 as a boundary, the joining pieces 15 are superposed on each other, and joined by ultrasonic processing, for example, and assembled into the protective case 16 of the VTR cassette case.

The design display portion 12 provided on the outer surface 11b of the synthetic resin sheet 11 is assembled to the protection case 16 of the VTR cassette case, as in the case of the conventional protection case having the design display portion formed by printing. It is formed so as to come to a predetermined position when it is pressed. Further, the positions where the design display portion 12 and the polygonal lines 14 are provided on the outer surface 11b of the synthetic resin sheet 11 need to be sufficiently calculated and designed in consideration of shrinkage of the synthetic resin such as polypropylene after cooling. Further, the design display unit 12 may display only the brand name, for example, and the quality display may be displayed on the cassette tape housed in the protective case 16.

Next, the operation will be described. In FIG. 1, a synthetic resin, for example, a melt of polypropylene is rolled, cooled, and solidified by a pair of embossing rolls (not shown) to roughen the outer surface 11b, and a predetermined number of smooth design display portions are provided at fixed positions. At the same time that 12 is formed, the polygonal line 14 is formed. Next, in a punching process, a predetermined number of pieces, in this embodiment, six pieces 13 are punched out, and the joining piece 15 is bent inward at the folding line 14, and these joining pieces 15 are superposed, for example, ultrasonically processed. And the protective case 16 is assembled.

At this time, the design display portion 12 is located at a fixed position of the protective case 16 and has an appearance as if the design display portion 12 was printed at a fixed position of the plain sheet, and a design effect equivalent to printing is obtained. Can be demonstrated. Further, since the design display portion 12 is not printed, it is possible to eliminate the peeling and dropping during the distribution process or the use, and as long as the protective case 16 is not exposed to severe conditions such as melting. The display unit 12 does not fall off.

The outer surface of the protective case 16 corresponds to the outer surface 11b of the sheet-shaped molded product 11 and becomes a rough surface with a grain pattern, which provides the convenience that the user can easily write notes on the protective case 15. .

As described above, in this embodiment, since the design display portion 12 and the polygonal line 14 based on the difference in the rough surface finish are formed at the fixed positions of the synthetic resin sheet 11 in the sheeting process, the protection case 16 is printed. It is possible to omit the step and the line pushing step, and to eliminate the peeling and dropping of the printing portion. As a result, it is possible to significantly reduce the manufacturing cost of the protective case 16 while exhibiting a design effect equivalent to that of printing, and it is possible to eliminate the decrease in the commercial value of the VTR cassette tape housed in the protective case 16.
Further, by reducing the number of manufacturing steps by two, it is possible to shorten the delivery time of the product and further reduce the distribution cost.

In this embodiment, the design display portion 12 is formed only on the outer surface 11b based on the difference in the rough surface processing. However, the design display portion 12 is formed on only the inner surface 11a or both surfaces. be able to. In addition, the protective case 16
The synthetic resin sheet 11 constituting the above is not limited to a transparent one, and may be an opaque one containing a pigment, a filler and the like. Furthermore, the synthetic resin sheet 11 that constitutes the protective case 16 is not limited to a single layer, and may be a multi-layered structure in which a plurality of layers are laminated.

[0023]

According to the present invention, the design display portion and the polygonal line based on the difference in the rough surface finish are formed at the predetermined positions of the synthetic resin sheet at the same time as the sheeting step. It is possible to eliminate the steps and eliminate the peeling and dropping of the printing portion. Therefore, while exhibiting a design effect equivalent to that of printing, it is possible to significantly reduce the manufacturing cost of the outer case, and to eliminate the decrease in the commercial value of the product using the case as a packaging material.

[Brief description of drawings]

FIG. 1 is a diagram showing an example of a process of manufacturing an exterior case from a sheet-shaped molded product according to the present invention.

FIG. 2 is a diagram showing a process of manufacturing an exterior case from a conventional sheet-shaped molded product.

[Explanation of symbols]

 11 Synthetic Resin Sheet 11a Inner Surface 11b Outer Surface 12 Design Display 14 Line

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Claims (1)

[Claims] 1. A ridge for forming a ruled line for forming a broken line is provided at a predetermined position on at least one of the inner and outer surfaces of a synthetic resin sheet, with a difference in unevenness for roughening the surface at a predetermined position. Performing embossing with an embossing roll and simultaneously forming a design display portion and a polygonal line based on the difference in rough surface finish at a predetermined position on the surface, a step of punching a synthetic resin sheet having the design display portion and the polygonal line into a desired shape, A method of manufacturing a synthetic resin outer case, comprising the steps of bending a synthetic resin sheet punched into a desired shape along a fold line, and assembling the outer case.