JPH0671645A - Preform having a thread part - Google Patents

Abstract

PURPOSE:To obtain a good appearance container which is strong in torque when a cap is attached or detached by a method wherein a recessed part or a projected part to which a barrel part molding wall is fitted when the barrel part and a bottom part are molded is provided to an inner wall of a neck part of a preform equipped with a preliminarily molding part for molding the barrel part and the bottom part on a roof face of the neck part having a thread part on its outer wall. CONSTITUTION:The preform is equipped with a barrel part and a bottom part- preliminarily molding part 12 on a roof surface of a neck part 11, an external thread 13 threaded with a cap on an outer wall, and vertical angular groove recessed parts 14 at equal intervals on an inner wall in the neck part 11. The preliminarily molded part 12 of the preform is heated, projected from above to downward in an inner side of the neck part 11 by a plug assist forming method, and further, a wide mouthed container 100 is prepared by an elongation and compression air molding method. Since a forming part 17 of the barrel part fits into the recess part 14 provided on the inner wall of the neck part 11 of the container 100 to reinforce the neck part 11, the cap is easily detached and attached.

Description

Detailed Description of the Invention

[0001]

The present invention relates to foods, cosmetics, detergents,
The present invention relates to a preform for molding a wide-mouth container such as a medicine.

[0002]

2. Description of the Related Art Conventionally, as a preform for molding a container having a screw-formed neck, it has been widely used for food containers such as fruit juice drinks and carbonated drinks and non-food containers such as kitchen detergents and shampoos. There is a preform made of polyethylene terephthalate for stretch hollow molding containers. In this preform, a body part and a bottom preforming part for molding a body part and a bottom part of a container are formed in a test tube in a lower part of a neck part where a screw part is formed. Unlike this, the preform according to the present invention has a body and a bottom preforming portion for molding the body and the bottom of the container formed on the top surface of the cylindrical neck portion formed with the screw portion in a flat shape. It is a thing. The molding method of the container using such a preform is still in the development stage, but the characteristics of this molding method include a stretch hollow molding method, a vacuum molding method, a method of molding the body and the bottom. It is possible to use various molding methods such as a pressure molding method and a plug assist molding method, and it is possible to select a molding method that suits the purpose of the container.
It is a suitable method for molding a wide-mouthed container. However, as shown in FIG. 4, the neck portion (41) formed with the screw portion (43)
When the container (400) is manufactured using the above-mentioned preform (40) consisting of the body and the bottom preform (42), the inner wall of the neck and the outer wall of the body (45) except the upper end are
Because it is not connected (in Fig. 4, it is widely written to make it easier to understand the gap (44) between the inner wall of the neck and the body forming wall as compared to the other figures), so when the cap is screwed onto the neck, Depending on the tightening or opening torque (rotational force) of the generated cap,
Sometimes the lower part of the neck was deformed and the cap was not attached or removed properly. Therefore, in the specification of Japanese Patent Application No. 4-89773, the applicant of the present invention, as shown in FIG. 5, has a neck portion (51) having a screw portion (53), a body portion and a bottom preforming portion (52). It was proposed that a preform (50) consisting of (1) and (2) be partially provided with a recess (54) which fits the molding wall of the body (55) (FIG. 5 shows five recesses).

[0003]

However, in the method described in Japanese Patent Application No. 4-89773, the lower end of the neck portion having the threaded portion is fitted to the wall of the body portion, which occurs when the cap is attached or detached. However, due to the fitting between the recess at the lower end of the neck and the body wall, the shoulder is uneven (in FIG. 5, the shoulder where the body wall is fitted in the recess is shown). The part (57) is projected to the other shoulder part (58)), and the appearance of the container (500) is impaired. Therefore, the present inventors have completed the present invention as a result of further improvement in order to obtain a container having a strong torque when mounting or removing the cap and having a good appearance.

[0004]

The first aspect of the present invention, as shown in FIG. 1, has a body (15) on the top surface of a cylindrical neck (11) having a thread (13) on an outer wall. And bottom (16)
A preform having a body portion and a bottom preforming portion (12) for forming a body, wherein a convex portion or a recess portion (1) into which the body portion forming wall is fitted to the inner wall of the neck portion when forming the body portion and the bottom portion.
4) is a preform (10) having a threaded portion, wherein the second aspect of the present invention, as shown in FIG. 2, is the upper portion of the body and bottom preform of the preform of the first aspect of the present invention. A preform (20) having a screw part in which a laminated film layer (28) is formed on the preform (20) according to the third aspect of the present invention, as shown in FIG. And a functional resin layer (38) in the molding wall layer.
It is a preform (30) having a threaded portion formed with.

The screw portion provided on the outer wall of the neck portion is
It is a male screw that is screwed into the female screw of the cap to be mounted.

The protrusions or recesses provided on the inner wall of the neck are
There is no restriction on shape, height, or depth, and any shape, height,
It may have a depth, and normally, a plurality of depths are provided at equal intervals.

The base material of the preform is formed by injection molding using a material such as polyethylene, polypropylene, polystyrene, polyester resin, polyacrylonitrile, or polycarbonate.

The body portion and the bottom preforming portion formed on the top surface of the neck portion are usually formed in a flat shape, but their shape and thickness are determined by the shape of the body portion and the bottom portion of the container to be molded. It is what is done.

The laminated film layer for imparting characteristics to the container provided on the upper portion of the body portion and the bottom preforming portion of the second aspect of the present invention is composed of polyvinylidene chloride, ethylene
It has a so-called functional resin layer of vinyl acetate alcohol copolymer, polyester, polyarylate, polyacrylonitrile or the like.

The preform molded by the multi-layer injection molding method of the third aspect of the present invention also has polyvinylidene chloride, an ethylene-vinyl acetate alcohol copolymer, in the formed layer.
It has a so-called functional resin layer of polyethylene terephthalate, polyarylate, polyacrylonitrile or the like.

The forming method for forming the body and the bottom from the preform having the threaded portion of the present invention is a stretch hollow forming method, a vacuum forming method, a pressure forming method, or a plug assist forming method according to the shape of the container and the purpose of use. The method is used.

[0012]

When a container is molded by using the preform having the threaded portion of the present invention, the body molding wall is formed into a shape fitting with the convex portion or the concave portion provided on the inner wall of the neck portion at the time of molding the body portion and the bottom portion. Since it is cooled and solidified in its original shape, the tightening or opening torque of the cap that occurs when the cap is screwed onto the neck of the container is not affected by the neck of the container and the body wall fitted to the inner wall of the neck. Due to the catch, the deformation of the neck cap due to the torque is extremely small.

Further, the deformation of the body forming wall for reinforcement against the tightening or opening torque of the cap of the neck portion occurs on the inner wall surface of the neck portion which cannot be seen from the outside of the container, so that the appearance of the container is not changed by the reinforcement.

[0014]

【Example】

<Example 1> First, a preform having a threaded portion according to this example was produced by injection molding using polyethylene terephthalate. As shown in FIGS. 1 (a) and 1 (b), this preform is provided with a body part and a bottom preforming part (12) on the top surface of a neck part (11),
Further, in the neck portion, male screws (13) for screwing with the cap are formed on the outer wall, and vertical corner groove-shaped recesses (14) are provided on the inner wall at five locations at equal intervals on the circumference. It is a thing.

Next, the prepared preform of this embodiment is heated from the upper part of the body and the bottom part thereof, and then is protruded from above the upper part of the body part and the lower part of the bottom part by plug assist molding to the inside of the neck. Further, the wide mouth container (100) of FIG. 1 (c) was produced by the stretching and pressure forming method.

As shown in FIG. 1 (c), the molding wall (17) of the body is fitted into the vertical rectangular groove-shaped recess (14) provided on the inner wall of the neck of the produced wide-mouthed container. I tried to put on and take off the cap because the neck was reinforced, but it was not difficult to put on and take off the cap because the neck was deformed.

Further, when there is a preformed portion of the body portion at the lower end of the screw portion, the effect due to the stretchability cannot be exerted on the screw portion, but like the present embodiment, the body portion is formed at the upper end of the screw portion. If there is a preformed portion of the portion, the effect due to the stretchability can be brought to the threaded portion as well. In addition, compared to the case where the lower end of the screw part is preformed with the body part, the stretching ratio can be made higher, so it is more effective (gas barrier property) for the resin (polyethylene terephthalate, etc.) whose functionality is improved by stretching. , Aroma blocking property, etc.) can be exhibited.

Example 2 First, a laminated film for imparting gas barrier property to a container was produced. This is a dry lamination method in which a polyvinylidene chloride film having a thickness of 30 μm is laminated on a biaxially stretched polyester film having a thickness of 25 μm with a urethane adhesive, and further, the ethylene / vinyl alcohol copolymer film surface is subjected to a dry lamination method. An unstretched polypropylene film having a thickness of 30 μm is laminated with a urethane adhesive to prepare a laminated film having a polyester layer / ethylene / vinyl alcohol copolymer resin layer / polypropylene layer structure, which is punched into a disc shape.

Next, in order to manufacture the preform having the threaded portion of this embodiment, the disk-shaped laminated film prepared was mounted in an injection molding die, and polypropylene was used to form the laminated film by an injection molding method. Figure 1
The preform (20) of this example shown in (a) was produced. This preform includes (a) and (b) of FIG.
As shown in FIG. 2, a body part having a laminated film (28) and a bottom preforming part (22) are provided on the top surface of the neck part (21), and the neck part further has a cap on the outer wall. Male threads (23) to be screwed together are formed, and vertical semicircular gutter-shaped recesses (24) are formed on the inner wall at five locations evenly spaced on the circumference.
Is provided.

Next, the produced preform of this embodiment was heated from the upper portion of the body and the bottom preforming portion, and then protruded from the upper portion of the body portion and the lower portion of the bottom preforming portion to the lower inside of the neck portion by the plug assist molding method. Further, the wide-mouth container (100) of FIG. 2 (c) was produced by the pressure molding method.

As shown in FIG. 2 (c), the molding wall (27) of the body is fitted into the vertical semicircular gutter-shaped recess (24) provided on the inner wall of the neck of the produced wide-mouthed container. Since the neck has been reinforced, the cap was attached and detached. However, the neck was not deformed and it was difficult to attach and detach the cap. In addition, since the molded container has a laminated film up to the top of the neck, it is possible to add gas barrier properties to the top of the neck, which was not possible with the two-stretch molding method using this type of preform. Became.

Example 3 First, the preform having a threaded portion of this example was prepared by a multilayer injection molding method using polypropylene, an ethylene-vinyl acetate alcohol copolymer and an adhesive resin (polypropylene and ethylene-vinyl acetate alcohol copolymer). And a resin which adheres to both the polymer and the polymer when melted. As shown in FIGS. 1 (a) and 1 (b), this preform has a gas barrier ethylene-vinyl acetate alcohol copolymer layer provided in the middle of a molding wall and has a neck (11). The top surface of the body is provided with a body part and a bottom preforming part (12), and the neck part is formed with a male screw (13) which is screwed with a cap on the outer wall, and is formed on the inner wall by 3
Vertical triangular prism-shaped protrusions (34) arranged at equal intervals are provided on two circumferences.

Next, the prepared preform of this embodiment is heated to the body and the bottom preforming portion, and then is protruded from above the body and the bottom preforming portion to the lower inside of the neck by the plug assist molding method. Further, the wide mouth container (100) of FIG. 1 (c) was produced by the stretching and pressure forming method.

As shown in FIG. 3 (c), the molding wall (37) of the body portion is fitted to the vertical triangular prism-shaped convex portion (34) provided on the inner wall of the neck of the produced wide-mouthed container. I tried to put on and take off the cap because the neck was reinforced, but it was not difficult to put on and take off the cap because the neck was deformed.

Generally, in the multi-layer injection molding method,
The gas barrier layer of the intermediate layer becomes harder to enter as it goes to the end of the molded product. Also in this example, the gas barrier layer of the intermediate layer was less likely to enter as it went to the end of the neck. However, when molding is performed using a preform having a body and a bottom preforming portion on the top of the neck as in the present example, a body forming wall having a gas barrier layer formed on the intermediate layer is formed along the inner wall of the neck. Since it is molded, the gas barrier property of the neck portion is improved when the cap is attached to the neck portion.

[0026]

When a container is molded using the preform having the threaded portion of the present invention, the convex portion or the concave portion provided on the inner wall of the neck portion and the body molding wall are fitted and reinforced, so that the container Very little deformation of the neck due to tightening or opening torque of the cap that occurs when the cap is screwed onto the neck,
The cap can be easily attached to and detached from the neck of the container.

The tightening or opening torque of the cap of the neck is reinforced by the inner wall surface of the neck which is invisible from the outside of the container, so that the appearance of the container does not change due to the reinforcement and the display effect of the product is not impaired when the product is distributed.

[Brief description of drawings]

FIG. 1 is a sectional view (a) of a preform, an AA ′ sectional view (b) thereof and a sectional view (c) of a container molded from the preform in Example 1 of the present invention.

FIG. 2 is a cross-sectional view (a) of a preform, a BB ′ cross-sectional view (b) thereof, and a cross-sectional view (c) of a container formed from the preform in Example 2 of the present invention.

FIG. 3 is a cross-sectional view (a) of a preform, a CC ′ cross-sectional view thereof (b) and a cross-sectional view (c) of a container molded from the preform in Example 3 of the present invention.

FIG. 4 is a sectional view (a) of a conventional preform and a sectional view (b) of a container molded from the preform.

FIG. 5 is a cross-sectional view (a) of a preform according to a conventional improvement method, a side view thereof (b), and a cross-sectional view (c) of a container molded from the preform.

[Explanation of symbols]

10, 20, 30, 40, 50 ... Preforms 11, 21, 31, 41, 51 ... Neck 12, 22, 32, 42, 52 ... Body and bottom preform 13, 23, 33, 43 , 53 ... Threaded part or male screw 14, 24, 34 ... Convex part or recessed part 17 ... Molding wall 15, 25, 35, 45, 55 ... Body part 16, 26, 36 ... Bottom part 17, 27, 37 ... Fitted forming wall 28 ... Laminated film 44 ... Gap 54 ... Recess 57, 58 ... Shoulder 100, 200, 300, 400, 500 ... Container

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification code Office reference number FI technical display location B29C 51/02 7421-4F // B29L 22:00 4F

Claims (3)

[Claims] 1. A preform in which a body and a bottom preforming portion for molding a body and a bottom are formed on a top surface of a cylindrical neck having a threaded portion on an outer wall, and the inner wall of the neck is formed. A preform having a screw portion, characterized in that a convex portion or a concave portion into which a body molding wall is fitted at the time of molding a body portion and a bottom portion is formed. 2. A preform having a threaded portion, characterized in that a laminated film layer is formed on an upper portion of a body portion and a bottom preforming portion of the preform according to claim 1. 3. A preform having a screw portion, characterized in that the preform according to claim 1 is molded by a multi-layer injection molding method, and a functional resin layer is formed in a molding wall layer.