JP5375136B2 - Molding method of plug with pull ring - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To make a melting resin difficult to dwell while easy to flow in both the directions of the mold of an upturned supporting post in a pull ring and the mold of horizontal annular incision (half-cut section), the melting resin being poured in from the center-gate section of a mold in the injection molding of a bung with a pull ring to be spread in a concentric fashion from the center of the mold of the bung for packing. <P>SOLUTION: The bung A with a pull ring is equipped with a blocking plate 5 sealing the bung within the interior of the annulus of a plinth section 2, an annular incision section 6 on the blocking plate 5 along the inner circumference of the plinth section, and a pull ring 8, located inside the annulus of the annular incision section, for opening the bung via the supporting post 7 erected on the upper surface of the blocking plate in the vicinity of the incision section. In this bung A, an annular thick-walled part 9 is provided, on the upper surface of the blocking plate 5, along the vicinity of the incision section within the interior of the annulus of the annular incision section. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a spout for use in liquid dispensing such as a soft packaging container for liquid packaging and a paper packaging container by welding with an ultrasonic heating seal or the like, and more particularly to a plug with a pull ring.

  As shown in FIG. 5 (a), a conventional mouthpiece with a pull ring for liquid pouring is provided with a flange 1 on the outer periphery of the lower end of the annular pedestal 2, and a male screw 3a on the outer periphery of the upper end of the pedestal 2. This is a spigot A ′ in which a screwed cylinder 3 is erected and a sealing plate 5 in which the inner ring 4 is sealed is provided in the inner ring 4 of the pedestal portion 2.

  The sealing plate 5 is provided with an annular cut portion 6 (half cut portion) for cutting the sealing plate 5 from the pedestal portion 2 along the inner ring circumference 2 a of the pedestal portion 2. On the upper surface of the sealing plate 5 in the vicinity of the notch 6, a support column 7 is erected at a height lower than the height of the cylindrical body 3, and a pull ring for opening the plug in the horizontal direction via the support column 7. 8 is provided.

  The plug A ′ with pull ring is formed by projecting the pedestal 2 and the cylindrical body 3 from the container wall of the liquid packaging container, and superposing the lower surface or upper surface of the flange 1 on the outer surface or the inner surface of the container wall, and ultrasonic heating sealing Used by welding to the container body. FIG. 5B shows a state in which the lid B is screwed onto the cylindrical body 3 of the stopper A ′.

  Such a plug with a pull ring is generally molded by injecting and filling a plastic molten resin R into a mold in injection molding. 6A is an example of a mold C used for injection molding, and FIG. 6B shows a flow state (arrow) of the molten resin R injected into the mold C in the mold. FIG.

  In the injection molding of the plug with a pull ring using the mold C as described above, the molten resin R is injected from the center gate portion G (the upper or lower center gate portions G1, G2) of the mold C. At the time of molding, the flow of the resin R spreads concentrically from the center of the mold stopper A ′ and is filled. However, since the column 7 of the pull ring 8 is provided, the annular cut portion 6 (half cut portion) is formed. It does not flow in the direction of the mold, and it tends to flow upward in the middle of the mold in the direction of the mold of the support column 7.

  At this time, the resin R tends to stay in front of the half-cut portion 6, and when the resin R exceeds the mold of the annular half-cut portion 6, the flow timing is shifted, and the base portion of the column 7 of the pull ring 8 Then, the resin R is cooled and hardly flows, and only the portion of the annular half-cut portion 6 is configured with the other half-cut portion 6 and the skin layer (the resin thickness of the half-cut portion 6). Changes, a skin layer having a non-uniform thickness in the annular direction is formed in the annular half-cut portion 6, the support column 7 and the pull ring 8 are torn off from the sealing plate 5 during use, and the half-cut portion 6 is whitened. There is a problem that.

  Further, the plug A ′ with a pull link used for a container plug for liquid packaging is formed by cutting the pull ring 8, the support column 7 and the sealing plate 5 through a thin cut portion 6 (half cut portion). When the stopper A ′ is opened, the pull ring 8, the column 7 and the sealing plate 5 become unnecessary portions. Therefore, as a resource saving and energy saving measure, it is desirable to reduce the amount of resin used for forming the pull ring 8, the column 7 and the sealing plate 5 as much as possible and to reduce the thickness of the sealing plate 5 as much as possible. However, in order to take such measures, the above problems become more prominent.

JP 2004-99141 A

  An object of the present invention is to make it difficult to retain a molten resin that is injected from a center gate portion of a mold and spreads concentrically from the center of the mold stopper in injection molding of a stopper with a pull ring. The skin layer with a uniform thickness in the annular direction is formed in the annular cut portion by facilitating the flow in both the direction of the mold of the upward support column and the horizontal annular cut portion (half cut portion) of the die. Further, it is intended to eliminate the phenomenon that the support column and the pull ring are torn off from the sealing plate and the cut portion is whitened when the plug is opened.

The invention according to claim 1 of the present invention is
A method of injecting molten resin into a mold to mold a plug ,
This plug is a plug in which a cylindrical body in which a male screw is screwed on the outer periphery is erected on the upper end of an annular pedestal portion having a flange on the outer periphery of the lower end, and the plug is sealed inside the ring of the pedestal portion A sealing plate is provided, and an annular notch is provided on the sealing plate along the inner circumference of the pedestal, and the support is erected on the upper surface of the sealing plate in the ring in the vicinity of the notch. In the plug with a pull ring provided with a pull ring for opening the plug through a ring, a thick portion is provided on the upper surface of the sealing plate in a ring shape along the vicinity of the cut portion inside the ring cut portion. Yes ,
A method for forming a plug with a pull ring is characterized in that the molten resin is injected from the center gate portion to the center of the sealing plate and filled and formed concentrically from this position .

The invention according to claim 2 of the present invention, the thick portion 9, and characterized in that along the該切addition unit 6 near the ring inner annular notch portion 6 is provided on the continuous annular or discontinuous annular The method for forming a plug with a pull ring according to claim 1.

The invention according to claim 3 of the present invention, the upper surface of the blockade plate 5, the pull ring according to claim 1 or 2 wherein the thick portion 10 connected to the thick portion 9, characterized in that provided radially This is a method for forming a spigot.

  According to the plug with a pull ring of the present invention, on the upper surface of the sealing plate, annularly (circumferentially) along the vicinity of the incision portion inside the annular incision portion, including the base of the strut inside the incision portion, By providing the thick part (rib), the molten resin at the time of injection molding is provided with an annular (circumferential) thick part (rib). It becomes easy to flow in both directions of the mold of the mold and the mold of the annular cut portion (half cut section) in the horizontal direction.

  Furthermore, after the molten resin flows through the column to the pull ring and has been filled, the molten resin begins to flow beyond the cut portion, the filling balance is improved, and the annular cut portion of the molded plug with the pull ring is formed. In addition, a skin layer with a uniform thickness in the annular direction can be obtained, and the phenomenon that the struts and pull rings are torn off from the sealing plate and the cut portion is whitened when the plug is opened is used. it can.

  Further, according to the plug with a pull ring of the present invention, the base of the column is formed on the upper surface of the sealing plate in a ring shape (circumferential shape) along the vicinity of the cut portion inside the ring cut portion, and on the inner side of the cut portion. In addition, by providing thick parts (ribs) and radially providing thick parts (ribs) connected to the thick parts (ribs) on the upper surface of the sealing plate, the molten resin at the time of injection molding is injection molded. Sometimes, it tends to flow in both directions of the mold of the upward support column in the pull ring and the mold of the horizontal annular cut portion (half cut portion).

  Furthermore, after the molten resin flows through the column to the pull ring and has been filled, the molten resin begins to flow beyond the cut portion, the filling balance is improved, and the annular cut portion of the molded plug with the pull ring is formed. In addition, a skin layer with a uniform thickness in the annular direction can be obtained, and the phenomenon that the struts and pull rings are torn off from the sealing plate and the cut portion is whitened when the plug is opened is used. it can.

The whole sectional side view explaining the structure of the stopper with a pull ring of this invention. The whole sectional side view explaining the state which applied the mouthpiece with a pull ring of the present invention. (A) is a top view explaining an example of the structure of the plug with a pull ring of this invention, (b) is a top view explaining another example. (A) is a sectional side view for explaining an example of a mold for injection-molding the plug with pull ring of the present invention, and (b) explains the flow state of the molten resin injected and filled in the mold. FIG. (A)-(b) is a whole sectional side view explaining the structure of the conventional stopper with a pull ring. (A) is a side sectional view for explaining an example of a mold for injection molding a stopper with a pull ring having a conventional structure, and (b) shows a flow state of molten resin injected and filled in the mold. Outline side sectional view to explain.

  The structure of the plug with a pull ring according to the present invention will be described below in detail with reference to the side sectional views of FIGS. 1 and 2. The plug A includes an annular pedestal portion 2 and an outer periphery of the lower end of the pedestal portion 2. A cylindrical body 3 having a male screw 3a on the outer periphery thereof is provided upright at the upper end of the pedestal portion. Inside the ring of the pedestal 2, a blocking plate 5 that seals the inside of the pedestal 2 (plug A) is provided.

  The sealing plate 5 is provided with an annular cut portion 6 along the inner circumference of the pedestal portion 2, inside the ring of the annular cut portion 6 and on the upper surface of the sealing plate 5 in the vicinity of the cut portion 6. 7 is erected, and a pull ring 8 for opening the plug is provided at the upper end of the column 7. In FIG. 1, L indicates an annular cutting line at the annular cut portion 6 (half cut portion).

  In the present invention, a thick portion 9 (rib) is provided on the upper surface of the sealing plate 5 in an annular (circumferential) shape in the ring inner side from the annular cut portion 6 and along the vicinity of the cut portion 6. ing.

  Moreover, in the plug with a pull ring of the present invention, the thick portion 9 is continuous along the vicinity of the annular incision 6 of the annular incision 6 as shown in the plan view of FIG. It may be provided in an annular shape (circumferential shape), or may be provided in an intermittent (not shown) annular shape (circumferential shape).

  Moreover, in the plug with a pull ring of this invention, as shown in the top view of FIG.3 (b), on the upper surface of the sealing board 5, the thick part 10 connected with the thick part 9 can be provided radially. .

FIG. 4A is a side sectional view showing an example of a mold C for injection molding a plug with a pull ring provided with the plug with a pull ring of the present invention, and FIG. It is a schematic diagram which shows the state (arrow) of the flow in the metal mold | die of the injected molten resin R. FIG.

  The injection molding of the plug with a pull ring according to the present invention will be described. First, the molten resin R is injected from the upper center gate G1 (or the lower center gate G2) of the mold C shown in FIG. Fill in the mold C.

  The molten resin R injected and filled in the mold C flows from the center gate G1 (or G2) into the mold of the sealing plate 5 as shown in FIG. The cut portion 6 is spread and filled in the mold direction and flows in the mold direction of the thick portion 9 on the upper surface of the sealing plate 5. Moreover, it flows in the direction of the mold of the radial thick portion 10 connected to the thick portion 9 on the upper surface of the blocking plate 5. As a result, the molten resin R easily flows in both directions of the mold of the upward support column 7 in the pull ring and the mold of the horizontal annular cut portion 6 (half cut portion).

  Also, the molten resin R flows through the support column 7 to the pull ring 8 and after filling is completed, the molten resin R flows in the horizontal direction beyond the cut portion 6, and the filling balance is improved and the molded pull ring is attached. A skin layer having a uniform thickness in the annular direction can be obtained at the annular cut portion of the plug. In addition, it eliminates the phenomenon that the struts and pull rings when the plug is opened are torn off from the sealing plate, and the cut portion is whitened.

A ... Mouth plug with a pull ring A '... Conventional plug with a pull ring B ... Lid C ... Mold 1 ... Flange 2 ... Annular base part 3 ... Cylindrical body 4 ... Ring inner surface 5 of the annular base part ... Sealing plate 6 ... Notches Part (half-cut part)
7 ... post 8 ... pull ring 9 ... annular thick part (rib)
10 ... Radial thick part (rib)

Claims (3)

A method of injecting molten resin into a mold to mold a plug ,
This plug is a plug in which a cylindrical body in which a male screw is screwed on the outer periphery is erected on the upper end of an annular pedestal portion having a flange on the outer periphery of the lower end, and the plug is sealed inside the ring of the pedestal portion A sealing plate is provided, and an annular notch is provided on the sealing plate along the inner circumference of the pedestal, and the support is erected on the upper surface of the sealing plate in the ring in the vicinity of the notch. In the plug with a pull ring provided with a pull ring for opening the plug through a ring, a thick portion is provided on the upper surface of the sealing plate in a ring shape along the vicinity of the cut portion inside the ring cut portion. Yes ,
A method of forming a plug with a pull ring, characterized in that the molten resin is injected from a center gate portion to the center of the sealing plate and filled and formed concentrically from this position . The method for forming a plug with a pull ring according to claim 1, wherein the thick portion is provided in a continuous ring shape or an intermittent ring shape along the vicinity of the cut portion inside the ring cut portion . The method for forming a plug with a pull ring according to claim 1 or 2, wherein a thick part connected to the thick part is radially provided on an upper surface of the sealing plate .

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