JP4876871B2 - Method for producing plastic molded article having rubber film on outer peripheral surface of peripheral wall - Google Patents

Description

  The present invention relates to a method for producing a molded article having a rubber film on the outer peripheral surface of the peripheral wall, which is formed on the peripheral wall by an insert injection molding method.

  Conventionally, plastic molded products such as caps and containers formed by injection molding have been widely used in foods, kitchen detergents, cosmetics, pharmaceuticals, chemicals, and the like. In some cases, these plastic molded products are covered with a rubber member as a grip for ease of use.

  However, as a container for storing cosmetics, there is no container in which the rubber member is covered as a grip in order to impair the appearance as a product, and there is no container in which the rubber member is limited to the outer peripheral surface of the peripheral wall.

  The present invention solves the above-mentioned problems as the conventional cosmetic container, and is limited to a necessary portion of the outer peripheral surface of the peripheral wall of the molded product body, and the rubber member is integrated with the molded product body as a product. The present invention provides a method for producing a molded article having a rubber film on the outer peripheral surface of the peripheral wall, which can be formed without impairing the properties.

  That is, the first invention of the present invention is a method of manufacturing a plastic molded product in which a rubber coating is welded to the outer peripheral surface of the peripheral wall by an insert injection molding method, and a female rubber coating of a mold of the plastic molded product is provided. The longitudinal dimension of the rubber film to be inserted is increased by 0.15 to 1.25 mm, compared with the longitudinal dimension of the peripheral wall cavity to be inserted. Molten resin injected into the mold so that molding resin does not leak into the parting line and more than two-thirds of the thickness of the rubber film to be inserted is held by the upper end surface of the peripheral wall cavity. So that the rubber film inserted in is not displaced, the outer diameter dimension of the rubber film is made smaller by 0.1 to 2.0 mm than the inner diameter dimension of the peripheral wall cavity, and the rubber film is inserted into the peripheral wall cavity. It is easy to insert a film, and the rubber film material contains a component that is welded to the molding resin, so that the rubber film is easily welded to the molding resin, and the draft angle between the inner surface of the peripheral wall cavity and the rubber film Is set to 0.5 ° or more so that the molded plastic molded product can be easily released from the female mold, and the stripper plate protrudes more than half of the thickness of the peripheral wall molded portion excluding the rubber film of the plastic molded product. Thus, the method for producing a plastic molded article having a rubber film on the outer peripheral surface of the peripheral wall, wherein the molded plastic molded article is completely released from the male mold.

  According to a second aspect of the present invention, the lower end of the peripheral wall of the plastic molded product is positioned below the lower end of the welded rubber film to improve feeder suitability. The manufacturing method of the plastic molded product which has a rubber film in the outer peripheral surface of a surrounding wall as described in above.

In the method for producing a plastic molded article having a rubber film on the outer peripheral surface of the peripheral wall of the present invention, the length of the rubber film to be inserted is larger than the longitudinal dimension of the peripheral wall cavity into which the rubber film of the mold of the plastic molded article is inserted. The length in the vertical direction is increased by 0.15 to 1.25 mm. For this reason,
When the mold is clamped and the molten resin is injected into the mold from the gate and molded, it can be prevented from leaking into the upper end of the rubber film to which the molten resin is inserted or into the parting line of the mold.

  Also, since more than two-thirds of the thickness of the rubber film to be inserted into the mold is pressed by the upper end surface of the peripheral wall cavity, the rubber injected into the mold and inserted by the molten resin It is possible to prevent the position of the film from shifting.

  Moreover, since the outer diameter dimension of the rubber film is about 0.1 to 2.0 mm smaller than the inner diameter dimension of the peripheral wall cavity, the rubber film can be easily inserted into the peripheral wall cavity.

  Further, since the rubber film material contains a component that is welded to the molding resin, the rubber film is sufficiently easily welded to the molding resin.

  Further, since the draft angle between the inner surface of the peripheral wall cavity and the rubber film is 0.5 ° or more, the molded plastic molded product can be easily released from the female mold.

  Further, since the stripper plate protrudes more than half of the thickness of the peripheral wall molding portion excluding the rubber film of the plastic molded product, the molded plastic molded product can be completely released from the male mold.

  Moreover, feeder suitability improves if the lower end of the peripheral wall of the plastic molded product is positioned lower than the lower end of the welded rubber film, if necessary.

  Next, an embodiment of a method for producing a molded product having a rubber film on the outer peripheral surface of the peripheral wall of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a cross-sectional view of a cap and a container according to the manufacturing method of the present invention, and FIG. 2 is a vertical length dimension of a peripheral wall cavity and a rubber when a rubber film is inserted into a female mold of an insert injection mold. Fig. 3 shows the difference in the vertical length of the coating. Fig. 3 shows the relationship between the upper end surface of the peripheral wall cavity and the upper end surface of the inserted rubber coating. Fig. 4 shows the stopper plate covering the lower end surface of the peripheral wall of the cap. FIG. 5 shows the difference between the lower end position of the rubber film and the lower end position of the peripheral wall of the cap.

  As shown in FIG. 1, the embodiment of the manufacturing method of the present invention has a rubber coating (310, 320) on the outer peripheral surface such as the peripheral wall (110) of the cap (100) and the outer peripheral wall (230) of the jar container (200). ) By an insert injection molding method. As shown in FIG. 1, the cap of the embodiment includes a top plate (120) and a peripheral wall (110), and an inner ring (121), a contact ring (122), and an outer ring (123) are suspended from the bottom surface of the top plate. The inner wall of the peripheral wall (110) has a female screw (111) that is screwed with the male screw of the container, and a rubber coating (310) is integrally formed on the outer peripheral surface of the peripheral wall to provide a grip feeling during use. is there. In addition, the jar container (200) of the embodiment includes a mouth neck portion, a peripheral wall, and a bottom plate, and, as shown in FIG. The peripheral wall is composed of an inner peripheral wall (220) and an outer peripheral wall (230), and a rubber film (320) is integrally formed on the outer peripheral surface of the outer peripheral wall to provide a grip feeling during use.

In this manufacturing method, in order to prevent the molding resin from leaking into the upper end portion of the rubber coating (310) or the parting line (PL) of the mold, as shown in FIG. ) Of the peripheral wall cavity (411) to which the rubber film (310) is inserted is made longer than the vertical dimension of the rubber film to be inserted. The difference (E) between the length dimension of the rubber film and the length dimension in the longitudinal direction of the rubber coating is 0.15 to 1.25 mm
It is intended to be in the range. If it is smaller than 0.15 mm, molding resin may leak into the upper end of the rubber film or the parting line part of the mold, and if it is larger than 1.25 mm, wrinkles will appear on the rubber film welded to the outer peripheral surface of the peripheral wall when molded. May occur.

  Further, in order to prevent the rubber film (310) inserted with the molten resin injected into the mold from being displaced, as shown in FIG. 3, the thickness of the rubber film (B) to be inserted is 3 minutes. 2 or more are to be held by the upper end surface (412) of the peripheral wall cavity (411). When the width of the upper end surface of the peripheral wall cavity is A and the thickness of the rubber film is B, A> B × 2 / 3.

  In order to facilitate the insertion of the rubber film into the peripheral wall cavity, the outer diameter of the rubber film is made smaller by about 0.1 to 2.0 mm than the inner diameter of the peripheral wall cavity.

  In order to facilitate the welding of the rubber film to the molding resin, the rubber film material contains a component that is welded to the molding resin. For example, when the molding resin is polypropylene, ethylene / propylene rubber, ethylene・ Propylene / diene terpolymer is included.

  Further, in order to make it easy to release a plastic molded product that forms a rubber film on the outer peripheral surface of the molded peripheral wall from the female mold, the draft of the inner surface of the peripheral wall cavity and the rubber film is set to 0.5 ° or more.

  Further, in order to completely release the molded plastic molded product from the male mold, the stripper plate projects more than half of the thickness of the peripheral wall molded part excluding the rubber film of the plastic molded product. As shown in FIG. 4, when the thickness of the peripheral wall (110) of the molded product is C and the width of the male stripper plate (421) protruding from the lower end surface of the peripheral wall is D, D> C × 1/2.

  When the plastic molded product is a cap, in order to improve the cap feeder suitability on the filling machine, as shown in FIG. 5, the lower end of the peripheral wall (110) is placed from the lower end of the welded rubber film (310). The lower position is used to improve sliding.

It is sectional drawing of the cap and container by the manufacturing method of the molded article which has a rubber film in the peripheral wall outer peripheral surface of this invention. It is explanatory drawing which shows the difference of the vertical length dimension of a surrounding wall cavity, and the vertical length dimension of a rubber film when a rubber film is inserted in the female die of the insert injection mold in the manufacturing method of this invention. It is explanatory drawing which shows the relationship between the upper end surface of the surrounding wall cavity in the manufacturing method of this invention, and the upper end surface of the rubber film inserted. It is explanatory drawing which shows the width | variety which the stopper plate in the manufacturing method of this invention protrudes the surrounding wall lower end surface of a cap. It is explanatory drawing which shows the difference between the lower end position of the rubber membrane | film | coat in the manufacturing method of this invention, and the lower end position of the surrounding wall of a cap.

Explanation of symbols

100 ... cap 110 ... peripheral wall 111 ... female screw 120 ... top plate 121 ... inner ring 122 ... contact ring 123 ... outer ring 200 ... jar container 210 ... mouth and neck part 211 ... male screw 220 ... Inner peripheral wall 230 ... Outer peripheral wall 310, 320 ... Rubber coating 410 ... Female mold 411 ... Peripheral wall cavity 412 ... Upper end surface 420 ... Male mold 421 ... Stripper plate E ... Vertical length of the peripheral wall cavity Difference between dimension and longitudinal length of rubber coating A ... Width of upper end surface of peripheral wall cavity B ... Thickness of rubber coating C ... Thickness of peripheral wall D ... Width PL where stripper plate protrudes lower end surface of peripheral wall ...... Parting line

Claims (2)

  A method of manufacturing a plastic molded product in which a rubber film is welded to the outer peripheral surface of the peripheral wall by an insert injection molding method, and the longitudinal length of the peripheral wall cavity into which the female rubber film of the mold of the plastic molded product is inserted The vertical length of the rubber film to be inserted is larger by 0.15 to 1.25 mm than the dimensions so that the molding resin does not leak into the upper end of the rubber film or the parting line of the mold. The rubber film inserted by the molten resin injected into the mold is displaced so that more than two-thirds of the thickness of the rubber film to be inserted is held by the upper end surface of the peripheral wall cavity. The outer diameter of the rubber film is made smaller by 0.1 to 2.0 mm than the inner diameter of the peripheral wall cavity so that the rubber film can be easily inserted into the peripheral wall cavity. The rubber film is made to be easily welded to the molding resin by including a component that is welded to the molding resin in the material, and the inner wall of the peripheral wall cavity and the draft angle of the rubber film are set to 0.5 ° or more. The plastic molded article is molded so that the plastic molded article can be easily released from the female mold, and the stripper plate protrudes more than half the thickness of the peripheral wall molded portion excluding the rubber film of the plastic molded article. A method for producing a plastic molded article having a rubber film on the outer peripheral surface of a peripheral wall, wherein the mold is completely released from the male mold.   2. The plastic molding having a rubber coating on the outer peripheral surface of the peripheral wall according to claim 1, wherein the lower end of the peripheral wall of the plastic molded product is positioned below the lower end of the welded rubber coating to improve feeder suitability. Product manufacturing method.

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