JP3032821U - Synthetic resin packages that are molded with high quality characteristics - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To obtain a high-quality product by uniformizing the flow nonuniformity due to the uneven thickness of the thinning synthetic resin. [Structure] A thin flat plate portion and two upper and lower sheets having a rising portion on the periphery with a thick portion 10b interposed therebetween and having a thin portion 10a in the entire region except for the periphery are rotatably pivotally supported to form a storage chamber. A square member A that can be formed, and has a gate mark 40 at the central portion of the thin portion 10a near the rising portion 30 of the flat plate portion 10 and the back surface of the flat plate portion 10 and the rising portion 3
Synthetic resin packages that are molded with high quality characteristics by forming a meat steal portion 50 along the inside corner of 0.

Description

[Detailed description of the invention]

[0001]

[Technical field to which the invention belongs]

 The present invention relates to a package made of synthetic resin having high-quality characteristics without quality defects such as weld lines.

[0002]

[Prior art]

 Conventionally known packages of this kind are widely used for MO, MD, MFD, CD and even audio tape, and generally have a thin shape and are made of two upper and lower synthetic resin members. It is formed so that it can be opened and closed by pivotally supporting. Since it is necessary to form a storage chamber, these members have rising portions formed along the edges of four or three sides.

By the way, when a pair of upper and lower rectangular members are formed by resin, as shown in FIGS. 4 to 7, the corners 2 or the side edges of the flat plate portion 1 are formed by leaving the peripheral edge of the rectangular member a as a thin portion 1a. Many are injection-molded with the gate position at the central portion 3. That is, the gate trace 4 can be recognized in the thick portion 1b at the periphery of the flat plate portion 1 above the rising portion 4.

[0004]

[Problems to be solved by the invention]

 In the case of the synthetic resin rectangular member a injection-molded as described above, the flow state of the molten resin in the cavity is common when the gate position is located at the corner 2 or the side edge central portion 3. 6 (submarine gate trace) or FIG. 7 (pin gate trace), the resin flows faster from the thick wall portion 1b of the rectangular member a toward the rising portion 3, so that the flow to the thin flat plate portion 1 is delayed. However, there is a disadvantage in that a stepwise flow occurs due to the delay, and uneven and wavy weld lines 1 are derived in multiple stages as shown in the figure.

[0007] In the molding process of synthetic resin packages of this type, which are becoming thinner and thinner, uneven flow of resin due to uneven thickness at the portion where the flat plate portion and the rising portion contact each other hinders high-quality molding. It was

The present invention was made by paying attention to the above-mentioned points, and it is formed with a novel high-quality characteristic in which a gate mark is provided so as not to cause a flow delay due to uneven thickness during molding. The purpose is to provide resin packages.

[0007]

[Means for Solving the Problems]

 This invention is composed of a flat plate portion having a thin portion in the entire area except the peripheral edge and an upper and lower two sheets having a rising portion with a thick portion at the peripheral edge, and is pivotally supported rotatably to form a storage chamber. A rectangular member having a gate trace at the central portion of the thin portion near the rising portion of the flat plate portion, and a meat steal portion formed along the back surface of the flat plate portion and the inside corner of the rising portion. This relates to synthetic resin packages molded with quality characteristics.

[0008]

[Embodiment of the invention]

 FIGS. 1 to 3 show an example of one rectangular member of the synthetic resin package according to the present invention, and like the conventional example, a flat plate portion 10 having a thin portion 10a over the entire region with a peripheral edge left. , The adjacent rising portions 30 are provided along the side edges of the three sides through the thick portion 10b, and one square member A can be configured as a whole.

Reference numeral 40 denotes a gate mark, which is provided at a central portion of the flat plate portion 10 in the thin portion 10 a and at a position near the peripheral thick portion 10 b.

Reference numeral 50 denotes a meat stealing portion, which is formed along the back surface of the flat plate portion 10 and the inside corner of the rising portion 30 so as to extend over the entire area of the rising portion 30 on one side.

Reference numerals 6 and 6 denote projections projecting on the inner sides of both ends of the rising portion 30 of the rectangular member A, which have the same structure as that of the other rectangular member A (not shown), that is, the flat plate portion and the three-sided peripheral edge. It is capable of forming various kinds of discs, cassettes, etc. by forming a storage chamber by being detachably locked and rotatably coupled with a rectangular member made of synthetic resin having a rising portion.

Due to the above structure, the resin discharged from the gate corresponding to the gate mark 40 at the time of injection molding is blocked by the structure of the meat steal portion 50, and the resin toward the thick portion 10b is blocked. Since the resin toward the thin wall portion 10a and the resin toward the rising portion 30 are evenly distributed and the resin is uniformly flowed into the cavity, uneven flow due to poor resin flow or slow speed is eliminated, and the flow balance is improved. As shown by the waveform line L in the figure, it is kept evenly on the left and right around the gate. As a result, weld lines are derived from the product, gas removal defects occur, filling defects, resin burning, etc. High-quality synthetic resin packages with excellent moldability can be obtained.

[0013]

[Effect of the invention]

 In this invention, as described above, in order to eliminate the uneven thickness structure due to the thinning of the molded product, a thick-walled portion is formed at a portion corresponding to the thick-walled portion and the thick-walled portion is made thin so that the resin In addition to making the flow uniform, there is a gate mark at the center of the flat plate, so the flow of resin to the left and right can be made more even, and it can be widely applied to various packages to obtain high-quality molded products. be able to.

[Brief description of the drawings]

1A and 1B show an embodiment of a synthetic resin package according to the present invention, in which (A) is a rear view and (B) is (A).
Central cross-sectional view, (C) is a front view

FIG. 2 is an enlarged sectional view of a main part.

FIG. 3 is an explanatory view showing a flow state of resin.

FIG. 4 is a surface view showing a conventional example.

FIG. 5 is an enlarged cross-sectional view of the same as above.

FIG. 6 is an explanatory diagram showing a gate trace and a flow state of the resin.

FIG. 7 is an explanatory view showing other gate marks and the flow state of the resin.

[Explanation of symbols]

 1a, 10a Thin part 1b, 10b Thick part 1,10 Flat plate part 3,30 Rising part 4,40 Gate mark 50 Meat steal part a, A Square member

Claims (1)

[Utility model registration claims] 1. A storage chamber is formed by a flat plate portion having a thin portion in the entire area except the peripheral edge and an upper and lower two sheets having a rising portion with a thick portion in the peripheral edge, and being rotatably pivotally supported. A rectangular member that can be formed and has a gate trace at the central portion of the thin wall portion near the rising portion of the flat plate portion, and a meat steal portion is formed along the back surface of the flat plate portion and the inside corner of the rising portion. Synthetic resin packages that are molded with quality characteristics.