JP4453399B2 - Resin spout with 1-point gate - Google Patents

Description

  The present invention has a ring shape with a through-hole in the center position, and even if injection molding is performed with a single point gate, the generation of weld lines (melted resin fusion parts), bubbles and sink marks (shrinkage dents) is extremely small. This relates to a ring shape with good moldability.

Conventionally, in a ring-shaped molded product, for example, molding by a single point gate of a spout (outlet tool) of a liquid paper container plug, it is impossible to prevent the generation of weld lines, bubbles and sink marks. Bubbles and sink marks significantly deteriorated the appearance and physical properties of the molded product. Therefore, weld lines, bubbles, and sink marks are unlikely to occur. For example, molding using a ring gate (G ₂ ) shown in FIG. 3 or molding using a disk-shaped punching molding (270) shown in FIG. 4 is performed. It was.

However, in the molding by the ring gate (G ₂ ) shown in FIG. 3 described above, the molten resin is cavities (female type and male type) by the ring gate from the entire inner circumference of the lower end of the spout (260) of the spout (200). When the mold is opened after the molding is completed, a ring-shaped chipping may occur on the entire inner circumference of the lower end of the spout pipe, or it may be cut into the mold. There were cases where problems such as adhesion of dust or clogging of ring gates occurred. In addition, the cost of producing a mold is higher than that of a one-point gate mold.

  In the molding using the disk-shaped punching molding (270) shown in FIG. 4, when the disk-shaped punching molding is punched from the spout (200) after molding, the spout pipe ( 260), a small return generated by punching occurs around the entire inner periphery of the lower end of the lower end of 260), and troubles such as sticking of the scraps to the inner surface of the spout due to static electricity may occur. In addition, a punching process is required after the molding process, and the number of processes is increased in the manufacturing process, and the cost of manufacturing the mold is higher than that of a one-point gate mold. In addition, as shown in FIG. 4, the punching position of the disk-shaped punching molded product is provided with an annular cut (271) on the outer peripheral upper surface of the disk-shaped punching molded product (270). This is performed at the position where is formed.

  The present invention solves the problems in the conventional ring-shaped molding described above, and provides a ring shape with good moldability by a one-point gate with very few weld lines, bubbles and sink marks.

  That is, the first invention of the present invention is an annular shape comprising, in order from the center to the outside, an annular through hole, a narrow inner annular portion, an intermediate annular portion, and a wide outer annular portion of a molding main body, A gate position is provided at one position of the narrow inner annular portion, and the intermediate annular portion is formed by connecting a narrow inner annular portion and a wide outer annular portion with center lines at equal intervals in the circumferential direction around the gate position. A plurality of thick connection portions connected radially, a plurality of thin connection portions provided between the plurality of thick connection portions, the narrow inner annular portion and the wide outer annular portion; And a width of the plurality of thick connection portions is increased as the distance from the gate position is increased, and a thickness of the plurality of thin flat portions is increased as the distance from the gate position is increased. Ring shape with good moldability.

The second invention of the present invention is characterized in that the plurality of thick connection portions are 4 or more and 32 or less, and the plurality of thin flat portions are 4 or more and 32 or less. The ring shape with good formability by the one-point gate according to claim 1.

Flow in the cavity of molten resin during molding of moldability good annular shape by one point gate of the present invention, an inner annular molten resin from one point gate (G ₁₎ is shown in FIG. 1 (a) and (b) When injected into the portion (130), first, the molten resin is filled into the inner annular portion, and then flows out from the entire outer periphery to the intermediate annular portion (120) to fill the inside of the intermediate annular portion. The intermediate annular portion is provided between a plurality of thick connection portions (121) having a center line at equal intervals in the circumferential direction around the gate position and widening as the distance from the gate position increases. A plurality of thin flat portions (122) that become thicker as they move away from the gate position to be formed, and by this action, the outer annular shape in which the molten resin becomes a molding subject almost simultaneously from the entire outer periphery of the intermediate annular portion. The molten resin is filled into the outer annular portion without generating a weld line. In addition, bubbles that could not escape in the molten resin and sink marks of the molded product due to insufficient molten resin pressure are absorbed by the thick connecting part of the intermediate annular part and the thin flat part around the thick connecting part. Generation of weld lines, bubbles and sink marks is extremely reduced in the outer annular portion as a main body.

  Next, an embodiment of an annular shape with good formability by a one-point gate of the present invention will be described in detail with reference to the drawings.

FIGS. 1A and 1B show an annulus shape having good formability by a one-point gate of Embodiment 1, FIG. 1A is a plan view, FIG. 1B is a bottom view, and FIG. 1C is AA ′. It is line sectional drawing. FIG.
It is explanatory drawing which shows the gate position of the spout of the stopper for liquid paper containers of Embodiment 2 using the ring shape with good moldability by the one-point gate of the present invention.

As shown in FIG. 1 (a), the ring-shaped shape (100) with good formability by the one-point gate of the first embodiment has an annular through hole (140) and a narrow inner annular portion (130) in order from the center to the outside. ), An intermediate annular portion (120) and a wide outer annular portion (110) which is a main molding body, and as shown in FIGS. 1 (b) and (c), a narrow inner annular portion (130). A one-point gate (G ₁ ) is provided at one place on the back surface of the substrate. As shown in FIGS. 1 (a) and 1 (b), the intermediate annular portion (120) has a narrow inner annular portion (with a center line at equal intervals in the circumferential direction around the position of the one-point gate (G ₁ )) ( 130) and the wide outer annular portion (110) and eight thick connection portions (121a, 121b, 121c, 121d, 121e, 121d, 121c, 121b) connected radially, and the eight thicknesses Eight thin flat surfaces (122a, 122b, 122c, 122d, 121d, 121c, 121b, 121a) are provided between the meat connecting portion, the narrow inner annular portion, and the wide outer annular portion. Then, the widths of the eight thick connection portions are increased as the distance from the one-point gate position is increased, and the thicknesses of the eight thin plane portions are increased as the distance from the gate position is increased. That is, the width of the thick connection portion is 121e>121d>121c>121b> 121a, and the thickness of the thin flat portion is 122d>122c>122b> 122a.

  The number of thick connection portions and thin flat portions provided in the intermediate annular portion is 4 or more and 32 or less, and if it is 4 or less, weld lines, bubbles and sink marks are generated in the wide outer annular portion of the molding body. If the number is 32 or more, it becomes difficult to manufacture the mold.

  Next, the spout of the spout for the liquid paper container of the second embodiment using an annular shape with good moldability by the one-point gate of the present invention will be described.

As shown in FIG. 2, the spout (200) of the spout (200) for a liquid paper container according to the second embodiment has a pedestal ring (230) standing on the inner peripheral edge of an annular flange (210). A pouring tube (260) having an external thread (261) on the outer peripheral surface is erected on the inner peripheral edge, and an annular through hole (240) is provided in the center. Then, an intermediate annular portion comprising a thick connection portion (221) and a thin flat portion (222) is provided at the inner peripheral lower end portion of the pedestal ring, and a narrow inner annular portion (230) is formed on the inner periphery of the intermediate annular portion. ) And a one-point gate (G ₁ ) is provided at one position on the lower surface of the inner annular portion.

As in the first embodiment, the intermediate annular portion composed of the thick connection portion (221) and the thin flat portion (222) shown in FIG. 2 is equally spaced in the circumferential direction around the position of the one-point gate (G ₁ ). Eight thick connection parts having a center line and radially connecting between the inner annular part (230) and the lower end of the inner periphery of the pedestal ring (260), and the eight thick connection parts and the narrow connection part Eight thin flat portions provided between the inner annular portion and the inner peripheral lower end portion of the pedestal ring are provided. Then, the widths of the eight thick connection portions are increased as the distance from the one-point gate position is increased, and the thicknesses of the eight thin plane portions are increased as the distance from the gate position is increased.

In the spout (200) of the liquid paper container cap of the second embodiment described above, the molten resin is fed from the one-point gate (G ₁ ) provided on the lower surface of the inner annular portion (230) shown in FIG. When injected into (230), first, the molten resin is filled in the inner annular portion, and then flows out from the entire outer periphery to the intermediate annular portion to fill the intermediate annular portion. The intermediate annular portion is provided between a plurality of thick connection portions (221) having a center line at equal intervals in the circumferential direction around the gate position and widening as the distance from the gate position increases. And a plurality of thin flat surface portions (222) that become thicker as they move away from the gate position, and by this function, the molten resin causes the pedestal ring (250) to almost simultaneously from the entire outer periphery of the intermediate annular portion. After that, it flows out into the flange (210) (corresponding to the outer annular portion of the first embodiment), and the molten resin is filled without generating a weld line in the pedestal ring, the dispensing cylinder (260), and the flange, In addition, bubbles that could not escape in the molten resin and sink marks of the molded product due to insufficient molten resin pressure are absorbed by the thick connecting portion of the intermediate annular portion and the thin flat portion around the thick connecting portion. The main portion, the spout of the weld line, air bubbles and no sink marks liquid feed container spout (200) is molded.

1 shows the shape of a ring-shaped embodiment 1 with good formability by a one-point gate of the present invention, (a) is a plan view thereof, (b) is a bottom view, and (c) is a bottom view. It is AA 'line sectional drawing. It is explanatory drawing which shows the gate position of the spout of the stopper for liquid paper containers of Embodiment 2 using the ring shape with good moldability by the one-point gate of the present invention. It is explanatory drawing which shows the spout gate position of the stopper for liquid paper containers using the ring gate of an example of the past. It is explanatory drawing which shows the disk position for punching of the spout of the spout of the stopper for liquid paper containers using the disk for punching of another example of the past.

Explanation of symbols

100 ... annular molded body 110 ... outer annular parts 120, 220 ... intermediate annular parts 121, 221 ... thick connection parts 122, 222 ... thin planar parts 130, 230 ... inner annular parts 140, 240 ... Annular through-hole 200 ... Spout 210 ... Flange 250 ... Pedestal ring 260 ... Pour cylinder 261 ... Male screw 270 ... Disc-like punching molded article 271 ... Annular cut 272 ... Annular thin weak line G ₁ …… Single gate G ₂ …… Ring gate

Claims (2)

A spout made of resin having an annular portion and injection-molded by injection molding with a one-point gate,
The ring-shaped part , in order from the center to the outside , consists of an annular through hole, a narrow inner annular part, an intermediate annular part, a wide outer annular part of the molding main body ,
A gate for injection molding is at a position corresponding to one place of the narrow inner annular portion;
The intermediate annular portion is a plurality of thick connection portions arranged at equal intervals in the circumferential direction, and is connected radially between the narrow inner annular portion and the wide outer annular portion. A plurality of thick connection portions, and a plurality of thin connection portions provided between the plurality of thick connection portions, the narrow inner annular portion and the wide outer annular portion,
The plurality according to the thickness width of the wall connection of箇away from the gate position wide no longer, and one point said plurality of thickness of the thin flat portion and wherein the have a thickness Kuna' as the distance from the gate position Resin spout by gate. 2. The resin by a one-point gate according to claim 1, wherein the plurality of thick connection portions are 4 or more and 32 or less, and the plurality of thin flat portions are 4 or more and 32 or less. Spout made of .

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