JPS60171116A - Forming tool of plastic cap - Google Patents

Abstract

PURPOSE:To prevent a bridge section from breaking when the male mold is removed after forming a plastic part with a pilferproof band by using an external mold with a specified engaging member. CONSTITUTION:After a formed cap 1 is hardened, a die 16 is dropped, a guide member 18 is elevated and a top force 10 is elevated with the upper plunger 11. A wing 5 is drawn out of the hole section 10a of the top force and the wing 5 is bent in the circumferential direction to draw out a bottom force 9. The elevating force given by the bottom force 9 to a pilferproof band 3 is accepted by a pushing member 17 and does not act on a bridge section 4.

Description

[Detailed description of the invention] ゛ The present invention relates to a molding tool for a glass cap,
More specifically, the present invention relates to a molding tool for a plastic cap, which includes a pilfer-proof band that is connected to a skirt portion through a pleated portion and has a protrusion formed on its inner surface.

For example, a relatively easy-to-deform container that tightly engages the opposing outer circumferential surface of the container mouth so that when the skirt portion is turned during opening, the printern portion is severed to prove that the container has been opened. A plastic cap is known that includes a pilfer-proof band in which a large number of protrusions in the shape of triangular pieces (see 5 in FIG. 1) are formed on the inner surface.

When this type of plastic cap is formed by compression molding using conventional male and female molds, when the male T-cap is pulled out, the protrusion engages with the male mold and the Billfasol roof IZ is pulled. Since the shaft was raised, the thin bridge part was cut off, making it impossible to obtain a satisfactory character 76. Therefore, conventionally, for example, JP-A-58-51
As described in Publication No. 116, this type of key y
When molding the bridge, without forming the bridge part,
After molding so that the skirt part and the pilfa proof band are continuous and extracting the male mold, the boundary part between the skirt part and the pilfa proof band ° is cut discontinuously with a cutter to form the bridge part. The method was adopted. In this case, there is a problem in that a step of cutting is required after molding.

The present invention has been made in view of the problems of the prior art described above, and the present invention provides that even if a pre-shaped portion is formed during molding of this type of cap, the bridge portion will not be cut when removing the male mold. The purpose is to provide forming tools.

In order to achieve all of the above objects, the present invention provides a plastic cap forming tool comprising a pilfer-proof band connected to a skirt portion through a plurality of bridge portions and having a protrusion formed on the inner surface, the tool comprising an inner mold and a pilfer-proof band. The outer mold has an annular surface that defines the entire end surface of the skirt portion, and a reservoir that forms a retaining portion on the outer peripheral surface of the pilfer-proof band when the inner mold is extracted from the cap. The present invention provides a plastic cap forming tool characterized by comprising an engaging member having an inner circumferential surface with a recess formed therein.

The present invention will be described below with reference to the drawings which are examples.

Reference numeral 1 in FIGS. 1, 2, and 3 shows an example of a plastic cap manufactured by the tool of the present invention, in which the skirt portion 2. The skirt part 2 is provided with a pilfa glue and a flap 3 connected to the skirt part 2 via a plurality of pre-tipped parts 4. Along the inner circumferential surface of the Pilfasol-7 pan 3, a large number of triangular protruding wings 5 which are relatively easy to bend are integrally formed.

The angle O (Fig. 1) formed between the wing 5 and the inner surface of the pilfer-proof band 3 is an acute angle (preferably 60 to 85 degrees), and the cap 1 is attached to the mouth of the container (not shown) in the direction in which the right-hand thread advances. When the container is sealed by turning, there is little frictional resistance between the parts of the container opening that are in contact with the wings 5, so the bridge portion 4 can be opened without breaking by turning in the direction in which the cloth screw retreats. When the container is capped, the frictional resistance increases, the bridge portion 4 breaks, and the pilfer-proof band 3 remains at the mouth of the container, proving that the container has been opened. 6 is a presser flank described later, and 7 is a threaded portion.

FIGS. 4 and 5 show a male tool according to a first embodiment of the present invention. The male mold 8 includes a lower mold 9 in which a screw hole 9a having a shape corresponding to the screw portion 7 is formed.
and a hole 10 a in the shape corresponding to the wing 5 on the side.
Furthermore, the upper mold 10 is provided with four parts 10b'i formed at the bottom of the mold, each having a shape corresponding to the shoulder part 9c of the lower mold.

The upper mold 10I'i (not shown) is fixed to the lower surface of the upper planter 11 connected to a drive device (for example, a hydraulic cylinder). It is attached to the upper part 11 so as to be able to slide along it. The lower mold 9 is biased by a coil spring 12 built into the upper planter 11, and is normally lowered to the position set by the pin 13, as shown in FIG.
c is spaced apart from the upper die 10 by a predetermined distance. However, during molding, although the upper plunger 11 descends as described later,
The lower mold 9 is lowered by the lower silane gloss 19 (see Figure 6-a).
Therefore, the lower die 9 and the upper die 10 approach each other, and the shoulder portion 9c and the recessed portion 10b come into contact with each other, as shown in FIG.

The lower die 9 has a short cylindrical annular protuberance 9d connected to the lower end of the shoulder part 9c. Located at the bottom level. Then, in cooperation with the female mold 8 during molding,
The annular raised portion 9d forms the bottom portion 4 and the lower portion 3b 2 of the pilfer-proof band 3, while the upper mold 10 forms the upper portion 3a including the wings 5 of the pilfer-proof band 3.

As shown in FIG. 6-a, the female mold 15 according to the first embodiment of the present invention has a cavity 16ai having a cross-sectional shape corresponding to the outer peripheral surface of the skirt portion 2, and is moved up and down by a drive device (not shown). The die 16 to be moved, the annular presser member 17 placed on the upper surface of the die 16, and the presser member 17
The upper sylanger 11 includes a guide member 18 having a guide hole 18a'z that is slidable along the inner surface of the upper sylanger. Further, a lower plunger 19 is provided in the cavity 16a, and the upper surface 19a has a shape corresponding to the outer surface of the top portion la of the cap 10 (see FIG. 6-b) to be formed.

As shown in FIGS. 7 and 8, the presser member 17
In cooperation with the annular raised part 9d, the bulge part 4 and the lower part 3b of the pilfer-proof band 3 are formed. The lower end 17a of the presser member 17 is attached to the skirt portion 2 during molding.
The end face 2ai extends radially inward above the cavity 16a, and in the portion where the bridge portion 4 is not formed, as shown in FIG. As shown in FIG. 8, the pre-pressing member 1
The lower part 3 of the building fasol roof gundo 3 on the inner peripheral surface of 7
The portion corresponding to b is formed as an annular four part 17b having a sawtooth cross section and having an annular horizontal step part 17bli. A presser flange 6 is formed on the outer surface of the lower portion 3b of the pilfer-proof band 3 by the sawtooth recess 17b.

The cap 1 is formed using the above tools in the following manner.

First, as shown in FIG. 6-a, the upper surface 16b of the die 16
With the die 16 raised until the lower plunger 19 is at a slightly higher level than the upper surface 19a, and with the upper plunger 11 pulled out above the guide member 18 (not shown), extrusion (not shown) is performed. A predetermined amount of molten plastic mass 20 (e.g.
ff IJ Made of ethylene or polypropylene, preferably with a slightly higher melting point (
(within 30° C.) is dropped through the guide hole tSa and placed on the lower layer 19.

Immediately, with the lower planter 19 fixed,
The upper plunger 11 is lowered (Fig. 6-a), and the male die 8 and the lower plunger 19 remove the plastic lump 20t.
Press. At this stage, the shoulder portion 9c of the lower mold 9 of the male mold 8 comes into contact with the upper mold 10.

Subsequently, when the die 16 is raised, the presser member 17 and the guide member 18 are also raised, and the plastic material extending from between the lower mold 9 and the lower desinger 19 is
Lower mold 9. The mold moves upward along the gap between the upper mold 10 and the female mold 8, and as shown in FIG. As the plastic material rises along the inner surface of the presser member 17 corresponding to the bulge part 4, the complex-shaped bilfasorf band 3 having the burr nose part 4 and the wings 5 is removed from the missing part. It is formed to have a precise profile without causing any turbulence.

After the cap 1 is solidified, the die 16 is lowered and the guide member 18t is raised, as shown in FIG. 6-c. Therefore, the outside of the upper part 3a of the male alpha-proof node becomes free. Then, with the end surface 2a of the skirt portion and the bottom end 17a' of the presser member in contact with each other, the horizontal step portion 17b1 of the presser member 17 and the presser flange 6 of the cap 1 are kept engaged, and the upper part is raised together with the upper glossy 11. When the mold 10 is raised, the first wing 5 passes through the recess 10b of the upper mold, as shown in FIG. Since it is free, it opens outward, and the wings 5 also bend in the circumferential direction, so that the lower mold 9 can be easily extracted from the cap 1.

At this time, the end surface 2a of the skirt portion 2 is held down by the lower end 17a of the holding portion, so that the skirt portion 2 does not rise. Further, the upward force applied to the pilfer-proof band 3 from the lower die 9 is received by the pressing member 17 due to the above-mentioned engagement, and does not act on the bulge portion 4. Therefore, there is no risk that the pre-shaped portion 4 will break.

Figures 9, 10, 11, and 12 show the main parts of the process of extracting a male mold from a cap molded using a tool according to a second embodiment of the present invention. Parts with the same reference numerals as in FIGS. 7 and 8 indicate similar parts.

In this case, the structure of the male mold 8 is similar to that of the first embodiment, and includes a lower mold 9 and an upper mold lo. The presser member 27 of the female mold 25 is the presser member 17 of the first embodiment.
This tool differs from the tool of the first embodiment only in that it is integrated with the guide member 18't-1.

Figure 9 shows the state immediately after the molding of the character f1 is completed, and shows the molding method and the molded character f1.
1 is similar to that of the first embodiment. 1st
In Figure 0, the die 16 and the lower syranger are lowered, the upper granger begins to rise, the lower mold 9 still remains in its original position, only the upper mold 10 rises, and the wing 5 is released from the upper mold 10. Indicates the condition.

FIG. 11 shows the state in which the lower die 9 has also started to rise and the annular protrusion 9d is passing along the pilfer-proof band 3. The end face of the skirt part 2 is held down by the lower end 27a of the presser part 27, so that when the lower mold 9 rises with its threaded hole part 9a passing over the threaded part 7 of the skirt part 2, ．． The rising force applied to the skirt portion 2 is suppressed, and the skirt portion 2 does not rise.

When the annular protrusion 9d contacts the wing 5, the wing 5
falls sideways, and wing 5 lifts roof band 3.
The lower mold 9 is pulled out from the cap 1 while in contact with the inner surface of the cap. At this time, the frictional force between the outer peripheral surfaces of the wing 5 and the lower die 9 is considerably large, so the pilfer-proof band 3
A fairly large upward force acts on the However, since the annular horizontal step portion 27bl of the serrated recess 27b of the presser member 27 and the presser foot 7 runno 6 of the pilfer-proof band 3 are engaged, the above-mentioned rise is suppressed, and the burr and ji portion 4 break. There is no risk of it happening. After the lower mold is extracted, as shown in FIG. is ejected, the cap f1vi is lowered, and the cap lf is removed from the holding member 27.

The present invention is not limited to the above embodiments,
For example, it can also be applied to a type of cap 31 formed on the inner surface of the upper part 33m of the wing 5 margin DK1 circumferential direction as shown in FIG. 13. It is. As shown in the figure, the raised portions 35 may be continuous along the entire circumference, or may be provided in plural numbers.

In the capped state, the raised portion 35 engages with the lower jaw of an annular protrusion (usually called a locking ring) provided below the threaded portion of the container opening (not shown), and when the cap is opened. This makes it easier to break the bridge portion 34.

In addition, 36 is a presser flange, and functions similarly to the presser flange 6 of the cap 1 when extracting the male mold from the formed character 7'31.

Furthermore, in the above example, the die 16 was fixed to the lower planter 19 and raised during molding, but conversely, the die 16
may be fixed, and the lower sylanger 19 may be lowered as the upper granger 11 is lowered.

In addition, the tool of the present invention is a cap 1 manufactured by Aketsune's compression molding method using a female mold in which a die and a lower plunger are integrated.
．． Cage 1.3 by molding of 31 etc. and injection molding
It can also be applied to first-class molding. However, in the case of these molding methods, better fluidity of the plastic material is required than in the case of the molding method of the above-mentioned example, so a stiffer cap with a higher melt flow index is used. (and in the case of polyolefins, it is difficult to obtain a cap of sufficient strength).

According to the present invention, after molding a plastic cap having a pilfer-proof band formed with a protruding portion on the inner surface and connected to a skirt portion through a bridge portion, the bridge portion does not break when the male enamel is completely pulled out. This effect is achieved.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a first example of a plastic cap manufactured by the tool of the present invention; FIGS. 2 and 3 respectively show the pilfer-proof band of the cap of FIG. 4 and 5 are front views of the male die of the tool according to the embodiment of the present invention, and FIG. 4 shows a state in which the upper die and the lower die are separated from each other. FIG. 5 is a drawing showing a state in which the upper mold and lower mold are in contact with each other.
Figures 6-a, 6-b, 6-a, and 6-d are
A vertical cross-sectional view showing the process of manufacturing the character ffz shown in FIG. 1 using the tool according to the first embodiment of the present invention, and FIGS. 7 and 8 are enlarged views of part A in FIG. 6-b. FIG. 7 is a longitudinal sectional view along the portion between the silicon portions, FIG. 8 is a longitudinal sectional view along the prismatic portion, and FIGS. A of FIG. 6-b shows the main part of the process of manufacturing the cap of FIG. 1 using the tool of Example 2.
Figure 13 is an enlarged longitudinal sectional view of the part corresponding to the section 1.3.
1...Glass cap, 2.32...Skirt portion, 2 a * 32 a... End surface, 3, 33...
・Pilfasol roof band, 4.34...Print part, 5...Wing (protruding part), 6.36...Press flange) (retaining part), 35... Protruding part (protruding part) part), 8
... Male type (inner type), 15... Female type (outer type), 19.
... Lower flange (outer mold), 17... Pressing member (retaining member), 17m..., Lower surface tip (3Il-shaped surface), 1
7b... Serrated recess (recess), 25... Female mold (outer mold), 27... Pressing member, 27a'... Lower surface tip (annular surface), 27b... Serrated recess (recess) ). Patent Applicant Sho Kishimoto 1 Figure 4 Figure 5 Figure 6-0 Figure 6-C Figure 6-d Figure 7 Figure 9 Figure 27 Figure 10

Claims (1)

[Claims] (Connected to the skirt part via multiple pre-tipped parts,
A molding tool for a plastic cap having a pilfer-proof band formed with a protrusion on the inner surface, the tool having an inner mold and an outer mold, the outer mold having an annular surface defining an end surface of the skirt portion. , and an engaging member having an inner circumferential surface with a recess formed therein for forming an engaging portion on the outer circumferential surface of the pilfer-proof band when the inner mold is extracted from the cap. A molding tool for plastic caps.