JPS6322621A - Synthetic resin bottle with handgrip and its preparation - Google Patents

Abstract

PURPOSE:To make a consideration on a positional relation of a handgrip in a mold unnecessary and to make a high speed and automatic operation easier, by molding integrally the handgrip by means of injection molding on a bottle main body prepared by means of blow molding. CONSTITUTION:A saturated polyester resin (PET) bottle is molded in a usual way by blow molding of a polyethylene terephthalate resin. Then, a handgrip is molded and set by means of injection molding. A mold 6 is a split-cavity mold having an inner cavity 11 whose shape roughly coincides with the outer shape of a bottle 6. A path of resin flow 12 making a round around the bottle neck is set in the inner cavity 11. Moreover, an extended path of resin flow 13 having a shape of the handgrip main body is continuously set from the path of resin flow 12. Temp. of the injected resin material is about 180-260 deg.C and the temp. of the bottle 6 is room temp. The injected resin is immediately welded to the bottle to become an integral body. The design of the attached part to hold a handle is so made that the area of the part connected with PET bottle will be minimum and that the thickness of the belt-shaped part is surely kept to increase the flow characteristic.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention particularly relates to a bottle with a handle made of saturated polyester resin and a method for manufacturing the same.

(Prior Art) In general, bottles made of saturated polyester resin (commonly known as PET bottles, hereinafter abbreviated) are suitable for large bottles because the mechanical strength of the bottles can be increased by biaxial stretching, and originally PET bottles It has excellent features such as no leaching of harmful substances such as solvents and no generation of harmful gases when incinerated after disposal, and is used in a wide range of applications.

However, such PET bottles tend to be larger in size, and in consideration of ease of handling, a handle part is desired.

Such handles are usually molded integrally with the bottle body during blow molding of large bottles, but it is particularly difficult to mold large bottles with handles. In other words, bottles made of saturated polyester resin tend to whiten due to crystallization and lose their strength.Also, in order to increase the strength of the bottle, biaxial stretching is usually performed during blow molding, but this method causes the handle to become white. It was extremely difficult to blow mold the bottle together with the bottle body. Therefore, a method has been proposed in which the handle is made separate in advance, placed in a blow molding mold, and then integrated during blow molding of a parison for bottle molding (for example, Japanese Patent Application Laid-Open No. 1983-1999-1). 64948
No. 56-64949 and No. 56-74438).

(Problems to be Solved by the Invention) However, in each of the above methods, the molded handles generally have a significantly irregular shape, and it is difficult to accurately arrange them in the blow molding mold, and continuous workability is difficult. often significantly impede

Furthermore, there are problems in that even a slight positioning error of the handle often results in a large number of defective final products, resulting in high costs. This invention attempts to solve such problems.

(Means for Solving the Problems) The present invention consists in integrally molding a handle onto a bottle body by injection molding.

That is, specifically, a means for molding a synthetic resin bottle body by a biaxial stretching method by a conventional blow molding method, a means for forming a synthetic resin bottle body by a biaxial stretching method, and a means for forming a synthetic resin bottle body, which has a lumen portion approximately equal to the outer shape including the neck attachment portion to the neck portion of the bottle body; A split mold for injection molding, in which a resin flow path corresponding to a mounting portion is recessed in the inner cavity and a resin flow path corresponding to a handle shape is extended outward from the neck mounting portion, is installed outside the bottle body. and means for injecting molten resin for the handle into the resin flow path.

(Function) This invention consists of a synthetic resin bottle body molded by biaxial stretching, a neck attachment part that surrounds the neck of the bottle body, and a handle part that integrally extends outward from the neck attachment part. Since the handle is integrally attached to the bottle body by injection molding, there is almost no need to consider the arrangement of the irregularly shaped handle in the mold. This is done by opening and closing the mold outside the bottle body, and as will be described in detail later, it is fast and does not interfere with automated work significantly.

(Example) An embodiment of the present invention will be described below with reference to the drawings.

First, the PET bottle is molded by blow molding polyethylene terephthalate resin in the usual manner.

Most specifically, for example, as schematically shown in Figures 1 a to 1e, material (1) is extruded and heat-melted using Jt (2) to form a parison (4) in a mold (3). (A in the same figure). Next, this parison (4) is heated and softened with a heater (h) (B in the same figure), and stretched to, for example, twice the length in a blow molding mold (5) (C in the same figure). Then, air is blown into the stretched parison to form a bottle (6) (d) in the same figure, and this is taken out (e).

Next, a handle is attached to the bottle (6) blow-molded as described above by injection molding, and the molds (1 to 1) are shown in FIG.

The mold (6) is a split mold having a mold lumen (11) having a shape that substantially matches the outer shape of the bottle (6).

As shown in the figure, the resin channel (l) surrounds the neck of the bottle and goes around.
A is recessed in the inner cavity (11).

Further, an extended resin flow path (one extension) extending from the resin flow path and having the shape of the handle body is provided continuously.

In the actual injection molding of the handle, the injection mold (1
υ), and select an appropriate position of the extended resin flow # flll that forms the handle part as described in detail later, and pour the molten resin into the flow path 11.
2) [The injection handle (7) is integrally molded into 1'J.

The temperature of this injected resin material varies depending on the resin used, but is approximately 180 to 260°C. In contrast to this high-temperature resin, the bottle (6) is at room temperature, and the injected resin is immediately welded and integrated with the bottle.

In addition, the injection molding mold 011 is used as a bottle (6) as in the above example.
) It is not necessary to surround the entire circumference (it may be sufficient to minimally surround the handle (7) and its attachment to the bottle (6)).

Next, an example of an actual continuous molding operation of a bottle with a handle will be schematically explained.

FIG. 3 schematically shows this, and st to stV indicate respective parts that operate synchronously in a cyclical manner to perform the molding operations described below.

First, in stl, the above-mentioned bottle parison is molded by the injection unit (U8), and it is heated in st[.

Next, stl [ is the above bottle (
6) is molded.

Next, at st (st), an injection mold surrounding the bottle (6) is placed, and the handle is injected by the injection unit (U2). St■ is the take-out part of the bottle with handle formed by the above operations.

In a specific example, when HDPE was used as the handle material, the injection pressure was 100 to 120 kg/ca (a good bottle with a handle was obtained, but of course the outer surface of the bottle (6) and the recessed resin channel Due to factors such as flow resistance in space due to (12, 13), it is desirable to take the following considerations.

A hot runner is also used to prevent the flow of the resin from finishing at the gate 62. A portion of this hot runner is installed inside the blow mold with air insulation or heat insulating material around the periphery.

(11) The runner structure is set according to the material used for the handle, taking into account the flow characteristics of the resin.

If we assume that the above-mentioned viscous flow follows Newton's law, it is well known that the flow velocity in a tubular runner becomes a so-called parabolic shape, with zero at the tube wall and MAX at the center. . The attachment design minimizes the area of contact with the PET bottle to hold the handle, and ensures a strip-like thickness to increase flow characteristics.

Gvl width and thickness are determined according to experimental examples/X When the handle material is HDPE (effects of the invention) As detailed above, in this invention, a synthetic resin bottle body formed by biaxial stretching, and a handle consisting of a neck attachment part and a handle part integrally extending outward from the attachment part, and the handle is integrally molded and attached to the bottle body by injection molding, so that the above-mentioned irregular-shaped handle There is almost no need to consider the arrangement within the mold; in other words, this is done by opening and closing the mold outside the bottle body of a normal injection mold, which significantly impedes high-speed and automated work as detailed above. This has the effect of eliminating the above-mentioned problems.

[Brief explanation of drawings]

FIG. 1 is a schematic explanatory diagram of the bottle body molding process of the present invention, FIG. 2 is a cross-sectional view of the handle injection mold, and FIG. 3 is a schematic explanatory diagram of an apparatus for carrying out the method of the present invention. 3... Blow mold, 6 ・Bottle, 7... Handle, 1
0... Injection mold, 11... Mold lumen, 12.13
・Resin flow path. Figure 1 Figure 3

Claims (2)

[Claims] (1) A synthetic resin bottle body formed by biaxial stretching,
The bottle includes a neck attachment part that surrounds the neck of the bottle body, and a handle that integrally extends outward from the neck attachment part, and the handle is integrally molded and attached to the bottle body by injection molding. A synthetic resin bottle with a handle. (2) Means for forming a synthetic resin bottle body by a biaxial stretching method by conventional blow molding, having an inner cavity approximately equal to the outer shape of the neck of the bottle body including the neck attachment portion, A split mold for injection molding is arranged on the outside of the bottle body, in which a corresponding resin flow path is recessed in the inner cavity, and a resin flow path corresponding to the shape of the handle is extended outward from the neck attachment portion. A method for manufacturing a synthetic resin bottle with a handle, comprising: a means for injecting a molten resin for a handle into the resin flow path.