JP2007238106A - Composite spout, and injection molding device for molding the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composite spout capable of easily fitting a sleeve to a core of a male die, and reliably sticking a spout body to an adhesive surface of the sleeve. <P>SOLUTION: The composite spout 1 is formed in a manner in which a cylindrical sleeve 10 is embedded in an inner peripheral surface of a spout body 2 substantially only with its inner peripheral surface being exposed thereto by injection-molding the spout body 2 while the cylindrical sleeve 10 with a functional resin layer being arranged thereon as an intermediate layer is fitted to a core member of an injection molding die as a core. One end of the inner peripheral surface of the spout body 2 constituting a base end of the spout body 2 forms an inclined surface 28 which is inclined outwardly in the radial direction from one end to a front end side of the spout body 2, and covers an end face of the sleeve 10. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a composite spout in which a sleeve attached to a spout body at the time of manufacture can be easily set in a molding die at the time of injection molding, and an injection molding apparatus for forming a composite spout.

  In recent years, in high-function foods and other containers such as pouches with spouts and paper containers that are poured out from the pouring tool (hereinafter referred to as spout) 1 shown in FIG. Therefore, it is required that the oxygen permeation amount is extremely small not only for the main body of a container such as a pouch or a paper container but also for the spout. Therefore, there has been proposed a composite spout 1 in which a sleeve 10 as a blocking body having an excellent gas barrier property or oxygen absorption property is attached to the inner wall of the spout.

The sleeve 10 shown in FIG. 7 is mounted by insert molding inside the spout body 2 of the composite spout 1. The sleeve 10 is composed of multiple layers, and an inner layer 10b is disposed on the inner side and an outer layer 10c is disposed on the outer side with the functional resin layer 10a in between, and these are disposed between the functional resin layer 10a and the inner layer 10b and the functionality. The resin layer 10a and the outer layer 10c are bonded with an adhesive layer 10d interposed therebetween.
Examples of the functional resin include a gas barrier material and an oxygen-absorbing material. Examples of the gas barrier material include a resin material such as an ethylene-vinyl alcohol copolymer. The oxygen-absorbing material may be obtained by adding an oxygen absorbent to the gas-barrier resin, or the gas-barrier resin itself may have an oxygen-absorbing structure. Examples of the oxygen-absorbing material include polybutadiene and polyisoprene which are oxidizing organic materials. As a material of the inner layer 10b and the outer layer 10c, for example, an olefin resin that is a thermoplastic resin is used.

FIG. 8 shows a molding method of the composite spout 1 having the sleeve 10 by the injection molding apparatus.
As shown in FIG. 8A, the spout is formed by a male mold 21 and a female mold 31, and the male mold 21 is provided with a cylindrical core 22 formed with the same diameter from the proximal end side to the distal end side. The sleeve 10 is mounted around the core 22. The female mold 31 is a split mold that opens to the left and right, and has an inner peripheral surface formed in a shape corresponding to the outer peripheral surface of the spout body 2 shown in FIG.
As shown in FIG. 8B, a gate 33 through which molten resin is injected from an injection molding machine (not shown) is connected to one female right mold 31b.

With such a configuration, the core 22 of the male mold 21 is inserted into the female mold 31 to close the mold, and the molten resin is injected from the gate 33 into the cavity 32 as shown in FIG. The part which becomes the spout body 2 is formed, and the composite spout 1 having the sleeve 10 provided inside the spout body 2 is formed. The spout body 2 and the sleeve 10 are bonded together by heat welding of the molten resin, which is the material of the spout body 2, by heat.
JP 2001-213455 A

However, at the time of molding the composite spout, as shown in FIG. 8A, the inner surface of the sleeve 10 is exposed on the inner peripheral surface of the composite spout 1. A gap is not formed between the inner peripheral surface of each other. Therefore, there is a problem that it is difficult to attach the sleeve 10 to the core 22.
Moreover, since the end part by the side of the discharge opening 6 of the formed composite spout 1 is thin and has a small capacity, only a small amount of molten resin is filled. Therefore, the heat of the molten resin is not sufficiently transmitted to the sleeve 10, and the welded state between the sleeve 10 and the spout body 2 may be deteriorated. As shown by an imaginary line 10 h in FIG. 6, one end of the sleeve 10 is formed from the spout body 2. There is a possibility that the tip of the portion 10e is peeled off. When the sleeve 10 is peeled off, the contents in the container wrap around between the spout body 2 and the sleeve 10. Further, when the end surface 10g of the sleeve 10 is exposed in the container, the functional resin may not work efficiently due to deterioration of the gas barrier material from the functional resin layer 10a and elution of a material such as an oxygen absorbent. is there.
Further, when the cross section of the core 22 has the same diameter from the proximal end side to the distal end side of the core 22, depending on the material of the sleeve 10, the friction coefficient, the size of the inner diameter, etc., as shown in FIG. The sleeve 10 may be displaced toward the axial base end side of the core 22 by using the core 22 as a guide material due to the flow pressure of the resin injected from the injection molding machine. As described above, when the sleeve 10 abuts against the surface of the base 23 of the core 22, the end face 10g of the sleeve 10 is exposed inside the composite spout 1, and as described above, oxygen is released from the functional resin layer 10a. Materials such as absorbents may be eluted and the functional resin may not work efficiently.
The present invention has been made in view of such circumstances. A composite spout and a composite spout that can easily attach the sleeve to the male core and can securely bond the adhesive surface of the spout body and the sleeve. It is an object of the present invention to provide an injection molding apparatus for molding a mold.

In order to achieve the above object, the composite spout of the present invention has a spout body in a state of being fitted to an injection mold core member with a cylindrical sleeve having a functional resin layer disposed as an intermediate layer as a core. By injection molding, a composite spout is formed in a form in which the cylindrical sleeve is embedded in the inner peripheral surface of the spout body so that only the inner peripheral surface is exposed, and the base end portion of the spout is formed. The end portion of the inner peripheral surface of the spout body to be formed is an inclined surface that is inclined radially inward toward the opening end of the base end portion.
In the composite spout, one end side of the inclined surface can cover the inner peripheral surface on one end side of the cylindrical sleeve.
In the composite spout, an additional portion that covers the inner peripheral surface on the other end side of the cylindrical sleeve can be formed on the spout body at the tip of the spout body that constitutes the discharge end of the spout.
Further, in the composite spout, at the tip end of the spout body constituting the discharge end portion of the spout, the inner peripheral surface of the spout body is in front of the other end side end of the cylindrical sleeve from the tip of the spout body. A seal region having a predetermined length extending up to can be formed.
The injection molding apparatus of the present invention includes a convex core member in which a cylindrical sleeve having a functional resin layer disposed as an intermediate layer is fitted as a core, and the cylindrical sleeve is fitted. The composite spout is provided in a state in which the cylindrical sleeve is embedded in the inner peripheral surface of the spout body so that only the inner peripheral surface is exposed. In the injection molding apparatus for forming, the distal end portion of the core member is formed by a surface that smoothly tapers radially inward from the proximal end portion side to the distal end portion side of the core member.
In the injection molding apparatus, the tapered surface of the core member can extend from the inner peripheral surface on one end side of the cylindrical sleeve to a position protruding from the one end portion of the cylindrical sleeve.
In the injection molding device, the base end portion of the core member extends from the inner peripheral surface of the cylindrical sleeve to the axially outer side of the cylindrical sleeve on the distal end side of the cylindrical sleeve. A concave portion that is recessed inward in the radial direction from the inner peripheral surface of the cylindrical sleeve can be formed.

In the composite spout of the present invention, the end portion of the inner peripheral surface of the spout body constituting the base end portion of the spout is an inclined surface inclined inward in the radial direction toward the opening end of the base end portion. Since one end side of the inclined surface covers the inner peripheral surface of one end side of the cylindrical sleeve, both end portions of the sleeve can be reliably covered. As a result, deterioration and elution of the gas barrier material can be prevented from the functional resin layer of the sleeve.
In the injection molding apparatus of the present invention, an inclined surface that is inclined inward in the radial direction is formed at the distal end portion of the male core member from the proximal end portion side to the distal end portion side of the core member. The sleeve can be easily attached to the core.

Hereinafter, a composite spout and an injection molding apparatus for forming the composite spout in an embodiment of the present invention will be described with reference to the drawings.
Since the sleeve 10 described in the conventional example is a multi-layered sleeve 10 including an adhesive layer having the same structure as the sleeve 10 of the present embodiment as shown in FIG. 7, detailed description thereof is omitted. To do. Moreover, about the composite spout 1, let the discharge | emission opening 6 side be a front-end | tip part.

1 is a composite spout 1 according to the present invention, in which A in FIG. 1 is a front view, B in FIG. 1 is a sectional view seen from the front direction, C in FIG. 1 is a sectional view seen from the side direction, FIG. FIG. 3 is a cross-sectional view seen from the front direction in a state where a sealing cap is put on the composite spout.
As shown in the figure, the composite spout 1 is composed of a spout body 2 and a sleeve 10. The composite spout 1 is formed of a spout main body 2 and a sleeve 10, and has a substantially cylindrical conduit hole 3 through which contents flow in and out on the inner peripheral surface side, and a discharge opening 6 is formed at the upper end thereof. Yes.
On the outer peripheral surface side of the spout body 2, a male screw 7 to which the female screw 4 a of the sealing cap 4 shown in FIG. 2 is screwed is formed on the end side of the discharge opening 6. An engaging portion 15 of the cap 4 with the tamper-evident band 4b and a flange 16 are formed at a distance from the engaging portion 15. The flange 16 plays a functional role such as holding and supporting the composite spout 1 during conveyance. An attachment portion 17 for attaching a pouch is formed at the lower portion of the flange 16, and the sealing performance of the connection portion between the pouch and the composite spout 1 is maintained by the attachment portion 17 located on the base end side of the spout body 2.

A sleeve 10 is attached to the inner peripheral surface of the spout body 2. The sleeve 10 has the same thickness from one end side 10 e to the other end side 10 f in the axial direction, and the outer peripheral surface of the sleeve 10 is in close contact with the inner peripheral surface of the inner hole of the spout body 2. On the other end side 10 f of the sleeve 10 located on the end side of the discharge opening 6 of the spout body 2, a projection 8 that has a triangular cross section and protrudes toward the center side of the conduit hole 3 is formed annularly in the circumferential direction of the conduit hole 3. is doing.
As shown in FIG. 3A, the protrusion 8 includes a regulating surface 8a intersecting at right angles to the axial direction of the conduit hole 3 and an inclined surface (trapezoidal conical surface or tapered surface) 8b facing the discharge opening 6, that is, discharge. An inclined surface 8b extending toward the opening 6 is formed.

An additional portion 9 extending continuously from the inclined surface 8b is formed on the inner peripheral surface of the other end side 10f of the sleeve 10. The additional portion 9 is formed so as to protrude inward in the radial direction of the sleeve 10 from the inner peripheral surface of the sleeve 10, and is formed in the same cross-sectional shape in the entire circumferential direction of the sleeve 10. The position where the additional portion 9 is formed is the inner peripheral surface on the end portion side of the other end side 10 f of the sleeve 10.
Thus, the other end side 10f and the end face 10g of the sleeve 10 are covered in a bag shape with the conduit hole 3, the protrusion 8 and the additional portion 9 of the spout body 2, and the functional resin layer 10a of the sleeve 10 is It is formed so as not to be exposed to the internal space of the hole 3.
At the upper part of the conduit hole 3, an inner peripheral seal surface 5 is formed on the inner peripheral surface side where the seal portion 4 e of the sealing cap 4 abuts. The inner peripheral seal surface 5 is located at the tip end of the spout body 2 that forms the discharge opening 6 of the composite spout 1, and the inner peripheral surface of the spout body 2 extends from the tip of the spout body 2 to the end of the other end side 10 f of the sleeve 10. A protrusion 8 is interposed between the seal surface 5 and the sleeve 10.
The sealing cap 4 is formed with a seal portion 4e on the inner side of the top surface wall 4c of the cap with a space from the skirt portion 4d, and the outer peripheral surface of the seal portion 4e comes into contact with the seal surface 5 to be sealed. The

The spout body 2 located on one end side 10e of the sleeve 10 is formed with a covering portion 26 integrally therewith. As shown in B of FIG. 3, the covering portion 26 is formed from the inner peripheral surface on one end side 10 e of the sleeve 10 to the opening end 27 on the attachment portion 17 side of the spout body 2. The covering portion 26 covers the one end side 10e of the sleeve 10 in a bag shape, and the inner peripheral surface of the covering portion 26 decreases toward the opening end 27 toward the radially inner side of the spout body 2 and has a truncated cone-shaped inclined surface 26a. Is forming.
Thus, the sleeve 10 is mounted on the inner peripheral surface of the inner hole of the spout body 2, and the functional resin layer 10 a of the sleeve 10 is configured not to be exposed to the inner space of the conduit hole 3.

Next, an injection mold for molding the composite spout 1 will be described.
FIG. 4 shows a male mold 21 of an injection mold, and a cylindrical core 22 is formed on a base 23 of the male mold 21. The core 22 is positioned on the base end side of the base 22 on the base 23 side (note that the composite spout 1 and the core 22 are positioned on the tip side opposite to each other), and the core 22 is positioned on the tip end side of the core 22. A small-diameter portion 22b, a trapezoidal conical inclined surface 22c formed between the large-diameter portion 22a and the small-diameter portion 22b, and an additional portion-forming concave portion 25. The inclined surface 22c is inclined so as to extend inward in the radial direction toward the distal end side of the core 22.

In this embodiment, the outer diameter of the large diameter portion 22a of the core 22 is equal to the outer diameter of the sleeve 10, the outer diameter of the small diameter portion 22b is equal to the inner diameter of the sleeve 10, and the position of the inclined surface 22c on the inner end side is It is preferable that the sleeve 10 is located inward from the inner peripheral surface of the sleeve 10.
The additional portion forming concave portion 25 is a portion where the additional portion 9 of the spout body 2 is formed, and is continuously formed on the inclined surface 22c. Further, the additional portion forming recess 25 is formed so as to be confined to the inner side in the radial direction of the core 22 than the inner diameter of the sleeve 10 and the outer diameter of the small diameter portion 22b.
When the sleeve 10 is attached to the core 22, it is arranged on the inner peripheral side of the sleeve 10, and the shape of the additional portion forming concave portion 25 is an arc shape, a triangular shape, and the like so that the core 22 can be smoothly cut out. It is preferable to form in the shape.
A truncated cone-shaped inclined surface 28 is formed at the tip of the small-diameter portion 22 b of the core 22. The inclined surface 28 is formed so as to be inclined radially inward toward the tip of the core 22, and in relation to the one end side 10 e of the sleeve 10, the end position of the one end side 10 e of the sleeve 10 is the axis of the sleeve 10. It arrange | positions so that it may respond | correspond to the middle of the inclined surface 22c with respect to a direction.
The length of the core 22 in the axial direction is longer than the length of the sleeve 10 in the axial direction, and the tip of the inclined surface 28 protrudes from the end of the one end 10 e of the sleeve 10.

  5A shows a female mold 31. The female mold 31 is formed of a left female mold 31a and a right female mold 31b so that the female mold 31 can be divided into right and left, and a cavity 32 is formed inside the female mold 31. The shape of the inner peripheral surface 31 is the same as the outer peripheral shape of the spout body 2. As shown in C of FIG. 5, one right female die 31 b is provided with a gate 33 that communicates with an injection port of an injection molding machine (not shown) toward the cavity 32. The male mold 21 described above is configured to be capable of moving forward and backward so that the core 22 can be taken in and out of the cavity 32 of the female mold 31.

Next, the molding process of the composite spout 1 will be described.
The composite spout 1 is molded by an injection molding apparatus having an injection molding machine and a molding die. As shown in FIG. 4, the sleeve 10 is mounted on the core 22 of the male mold 21, and the other end side 10 f of the sleeve 10 is inserted to the vicinity of the boundary between the inclined surface 22 c and the additional portion forming recess 25, and the sleeve 10 is slightly Between the end of the other end side 10f and the inclined surface 22c, a gap into which the molten resin at the time of molding enters is formed. When the sleeve 10 is inserted into the core 22, the truncated cone-shaped inclined surface 28 is formed at the tip of the core 22, so that the sleeve 10 can be easily inserted into the core 22, and the mounting operation of the sleeve 10 is facilitated.

5A, with the sleeve 10 inserted into the core 22, the core 22 is disposed in the cavity 32 of the female mold 31, and as shown in FIG. 31 is closed.
Next, as shown in C of FIG. 5, the resin that has been stirred and melted by the injection molding machine is injected from the gate 33 into the cavity 32. Since a gap is formed between the end portion of the other end side 10 f of the sleeve 10 and the inclined surface 22 c, the molten resin easily wraps around the additional formation concave portion 25 of the core 22. Further, even when the sleeve 10 receives the flow pressure of the molten resin and moves toward the large diameter portion 22 a on the proximal end side of the core 22, the sleeve 10 moves more than a certain amount by the inclined surface 22 c of the core 22. Is regulated.
When the end of one end 10e of the sleeve 10 moves to the vicinity of the inclined surface 22c of the core 22, the end of the other end 10f of the sleeve 10 corresponds to the inclined surface 28 on the front end side of the core 22. It is necessary to set the length of the sleeve 10 so that the

Thus, the spout body 2 is formed by filling the molten resin between the female mold 31 and the core 22 of the male mold 21 by the injection molding machine. A triangular gap is formed between the other end side 10f of the sleeve 10 and the inclined surface 22c formed on the core 22, and the protrusion 8 of the spout body 2 is formed by filling the gap with molten resin. Is done. The protrusion 8 is formed as a regulating surface 8a at a portion that contacts the end surface 10g on the other end side 10f of the sleeve 10, and a surface at which the protrusion 8 contacts the inclined surface 22c of the core 22 as an inclined surface 8b (see FIG. 5 see Y and Z).
Also, molten resin is filled between the one end side 10 e of the sleeve 10 and the additional portion forming recess 25 between the core 22, and the additional portion 9 is formed on the inner peripheral surface of the sleeve 10, and the other end of the sleeve 10 is formed. The end portion of the side 10f is covered in a bag shape by the additional portion 9, and the other end side 10f of the sleeve 10 is prevented from being peeled from the spout body 2.
At this time, the inner and outer surfaces of the end portion of the other end side 10f of the sleeve 10 are firmly bonded, and peeling is prevented.

At one end side 10 e of the sleeve 10, molten resin is filled between the end portion and the inclined surface 28 to form the covering portion 26, and the end surface 10 i on the one end side 10 e of the sleeve 10 is connected to the mounting portion and the covering portion 26. Covered with a bag.
In addition, since there is the attachment portion 17 on the one end side 10e of the sleeve 10, the outer peripheral surface of the spout body 2 and the sleeve 10 is caused by the heat stored in the molten resin in the attachment portion 17 or in the vicinity of the injection gate 33. Although it is easily welded, there is an effect of preventing peeling when a welding failure occurs. In this way, the end surfaces of the one end side 10e and the other end side 10f of the sleeve 10 are integrally covered with the spout body 2.

The composite spout 1 is formed by the molten resin being cooled and solidified. The solidified spout body 2 can take out the composite spout 1 by opening the female die 31. Since the sleeve 10 does not form a gap between the sleeve 10 and the small diameter portion 22 b of the core 22, molten resin does not enter between the sleeve 10 and the inner peripheral surface of the sleeve 10 on the inner peripheral surface of the composite spout 1. The surface can be exposed.
In the present embodiment, even when the welded portion between the spout body 2 and the sleeve 10 is in the thin portion of the spout body 2 during injection molding, the heat of the additional portion 9 is generated by forming the additional portion 9. Since it is sufficient for welding, the contact surface of the spout body 2 and the sleeve 10 can be more reliably welded.
Further, even if the sleeve 10 moves in the axial direction of the core 22 due to the flow pressure of the molten resin, the composite spout 1 can be formed without exposing both end faces of the sleeve 10 after the spout body 2 is formed. Become. Therefore, after the composite spout 1 is completed, it is possible to prevent the material such as the oxygen barrier material from being eluted from the functional resin layer 10a of the sleeve 10.

While the embodiments of the present invention have been described above, the present invention can of course be modified or changed in various ways based on the technical idea of the present invention.
For example, in the above-described embodiment, the shape of the tip of the core 22 of the male mold 21 is the truncated cone-shaped inclined surface 28. However, the inclined surface 28 may be changed to a polygonal pyramid shape or a hemispherical shape. It is only necessary that the distal end portion is tapered with a smooth shape having no step at least on the distal end side of the small diameter portion 22b.
In the composite spout 1 shown in FIG. 1 described in the above embodiment, the protrusion 8, the additional portion 9 and the covering portion 26 are continuously formed on the inner peripheral surface of the sleeve 10. About the shape of the part 9 and the coating | coated part 26, although formed cyclically | annularly, you may form at intervals, without forming them continuously.

BRIEF DESCRIPTION OF THE DRAWINGS It is the composite spout by embodiment of this invention, Comprising: A is a front view of a composite spout, B is sectional drawing seen from the front direction, C is sectional drawing seen from the side direction. It is sectional drawing seen from the front direction of the state which covered the sealing cap on the composite spout shown in FIG. A is an enlarged sectional view in a circle indicated by an arrow X in B of FIG. 1, and B is an enlarged sectional view in a circle indicated by an arrow Y in B of FIG. 1. It is sectional drawing of the male type | mold of the injection molding apparatus which forms the composite spout of FIG. 1 shows a molding process of the composite spout injection molding apparatus of FIG. 1, wherein A is a cross-sectional view of a male core with a sleeve mounted thereon, B is a cross-sectional view of a male and female molds closed, and C is from a gate Sectional drawing of the state which filled the mold with molten resin, D is sectional drawing of the state which took out the composite spout from the metal mold | die. It is sectional drawing of the composite spout by a prior art example. It is a perspective view of the sleeve of the composite spout by this invention and a prior art example. The molding process by the injection molding apparatus of the conventional composite spout is shown, A is a sectional view in a state where a sleeve is mounted on a male core, B is a sectional view in a state in which a male mold and a female mold are closed, and C is a gold from a gate. Sectional drawing of the state which filled the mold with molten resin, D is sectional drawing of the state which shifted | deviated the composite spout to the axial direction of the core.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Composite spout 2 Spout main body 8 Protrusion part 8b Inclined surface 9 Additional part 10 Sleeve 10e One end side 10f The other end side 21 Male type 22 Core 22a Large diameter part 22b Small diameter part 22c Inclined surface 25 Additional part formation recessed part 26 Cover part 26a Inclined surface 31 female

Claims (7)

By injection-molding the spout body with the cylindrical sleeve having the functional resin layer disposed as an intermediate layer as a core and being fitted onto the core member of the injection mold, the spout body is formed on the inner peripheral surface of the spout body. In the composite spout formed into a form in which the cylindrical sleeve is embedded by exposing only its inner peripheral surface,
The composite spout is characterized in that an inner peripheral surface end portion of the spout body constituting the base end portion of the spout is formed of an inclined surface inclined inward in the radial direction toward the opening end of the base end portion.   The composite spout according to claim 1, wherein one end side of the inclined surface covers an inner peripheral surface of one end side of the cylindrical sleeve.   The tip portion of the spout body constituting the discharge end portion of the spout has an additional portion formed on the spout body covering the inner peripheral surface of the other end side of the cylindrical sleeve. The composite spout as described.   In the tip of the spout body constituting the discharge end of the spout, a seal having a predetermined length extending from the tip of the spout body to the front of the other end of the cylindrical sleeve from the tip of the spout body 4. The composite spout of claim 3 forming a region. A convex core member in which a cylindrical sleeve having a functional resin layer disposed as an intermediate layer is fitted as a core, and a space surrounding the core member in which the cylindrical sleeve is fitted. In an injection molding apparatus for forming a composite spout in a state in which the cylindrical sleeve is embedded in the inner peripheral surface of the spout body so as to substantially expose only the inner peripheral surface thereof.
An injection molding apparatus, wherein the core member is formed at a distal end portion thereof with a smoothly tapered surface radially inward from the proximal end portion side to the distal end portion side of the core member.   The injection molding apparatus according to claim 5, wherein a tapered surface of the core member extends from an inner peripheral surface on one end side of the cylindrical sleeve and extends to a position protruding from the one end portion of the cylindrical sleeve.   The proximal end portion of the core member has an inner periphery of the cylindrical sleeve extending from the inner peripheral surface of the cylindrical sleeve to a portion corresponding to the axially outer side of the cylindrical sleeve on the distal end side of the cylindrical sleeve. The injection molding apparatus according to claim 5 or 6, wherein a recess that is recessed radially inward from the surface is formed.

Images