JPH05305934A - Plastic bottle which is hard to crush and manufacture thereof - Google Patents

Abstract

PURPOSE:To make it possible to recover used bottles stacked by a method wherein nearly one half of the periphery of the body part of a plastic bottle is formed to be thin and the rest is formed to be thick, and the mouth is eccentric to the longitudinal axis of the body part. CONSTITUTION:A bottle main body 1 is formed by drawing-blowing molding using polyethylene terephthalate, etc. In this case, nearly one half of the peripheral part 3 is thin and the other half is thick. The thickness is this case is determined by the pressure strength, and the pressure strength of the thin part of approximately 0.2mm-0.6mm is appropriate. Then, a pouring port 4 is formed at a location which is eccentric to the longitudinal axis of the body part. The shape of the body part is not limited to a cylindrical shape, and it can be a polygonal cylindrical shape, etc. Also, an exterior member made of a film is attached to reinforce the body part. This bottle can be easily crushed, and can be recovered being stacked.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a crushable plastic bottle and a method for producing the same. More specifically, when the plastic bottle is discarded or collected after use, it is easily crushed to reduce the volume of the bottle,
The present invention relates to a plastic bottle capable of stacking and collecting and a manufacturing method thereof.

[0002]

2. Description of the Related Art In recent years, as a container for storing liquids such as soft drinks and alcoholic drinks, P is used instead of glass bottles and cans
Plastic bottles such as ET bottles are often used.
However, most of the bottles of this type are disposable one-way type, and are not collected for reuse after use, and are actually disposed of as waste. Unlike the porcelain and glass bottles, this type of bottle cannot be easily crushed and is bulky, so if it is discarded as it is, it often occupies space in the collection site and is inconvenient for handling during transportation. .. In addition, even if they are collected and incinerated, high costs are required, which is not preferable in terms of environmental hygiene and is a major social problem. Therefore, we reduce the amount of such plastic waste,
In addition, how to efficiently collect and recycle those wastes as recycled resources is an important need today.

In view of such circumstances, recently, a protruding concave groove directed outward or inward is provided in a body portion of a plastic bottle at a symmetrical position with respect to a generatrix direction thereof, and a shoulder portion and a shoulder portion are formed following the protruding concave groove. Japanese Utility Model Publication No. 4-1050 discloses an easily crushable plastic bottle having a structure in which arcuate projecting concave grooves passing through a lower portion or a bottom portion of a body portion are continuously provided.

[0004]

However, as in the above-mentioned conventional example, the protruding groove is locally provided only at a limited position of the bottle body, and the shoulder and the body are connected to the protruding groove. It is not technically easy to manufacture a plastic bottle in which arc-shaped protruding grooves are connected to the bottom or bottom of the product by the blow molding method, and the mold used is also special, so it is an economical problem. There is. In addition, since the protruding groove portion and the bottle body are not thin, there is a drawback that they cannot be easily crushed by the force of a child after use.

Here, the present invention can be manufactured by a relatively simple method using the stretch blow molding method, has strength at the time of use, and is easily disposed of after use by easily disposing the body of the bottle with fingers. It proposes a plastic bottle that can be crushed to reduce the volume of the bottle so that it can be stacked and collected.

[0006]

In order to solve the above-mentioned problems, the bottle of the present invention has a wall thickness of a plastic bottle in the transverse direction of the body, in which approximately half the circumference of the body is thin and the remaining half circumference is It is characterized in that it is formed thicker than the thin portion.

Further, in the method for producing a plastic bottle according to the present invention, the bottomed parison is attached so as to maintain an eccentric positional relationship with respect to the central longitudinal axis of the blow mold during stretch blow molding, and then the parison is axially formed. After stretching, blow compressed air into this to make the thickness of the molded product in the transverse direction of the body of the molded product approximately half the circumference of the body thin, and the remaining half of the circumference from the thin part. The feature is that it is cooled and demolded after it is thickly formed.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the structure of a plastic bottle which is easy to be crushed, which is an embodiment of the present invention, and its manufacturing method will be specifically described with reference to the drawings. In the following description, PET (polyethylene terephthalate) was mentioned as a specific example of the material resin used for molding the bottle body, but other than PET, for example, PAN (polyacrylonitrile-based resin), PEN (polyethylene naphthalate), etc. Can be used. However, the present invention is not limited to these resins, of course, and resins conventionally known as synthetic resins for stretch blow molding can be used.

FIG. 1 is a perspective view of a bottle of the present invention stretch-blow-molded using PET as an example, and FIG. 2 is a cross-sectional view of the same bottle. In the figure, reference numeral 1 is a bottle body, and the bottle body has the following thickness in the transverse direction of the body portion a. That is, the substantially half-circumferential portion 2 of the body portion is formed thin, and the remaining half-circumferential portion 3 is formed thicker than the thin portion. The wall thickness of the bottle is set according to the pressure resistance of the bottle required for use, but generally, the thickness of the thin portion is set to an appropriate thickness within the range of 0.2 mm to 0.6 mm. Good to do. Reference numeral 4 denotes a spout connected to the shoulder b so as to maintain an eccentric positional relationship with respect to the longitudinal axis L of the body. The bottle body a can be formed in a polygonal cylinder shape other than the right cylinder shape shown in the embodiment, or in other shapes.

FIG. 3 shows an example of an openable / closable blow mold 10 used in the manufacturing method of the present invention. The blow mold 10 shown in the figure includes body dies 11a and 11b that can be divided in the left-right direction,
A bottom mold 1 that is vertically movable so as to contact the lower part of the body mold
1c and. Also, on the upper part of the body,
A fitting portion 12 on which a neck ring for holding a bottomed parison can be set is formed. The bottomed parison 13 for molding a bottle is injection-molded using a resin which has been heated and fluidized, and then held by the neck ring 14 and set in the blow mold 10. The parison is integrally molded with the bottle injection port 4 by a conventionally well-known injection molding method, then held by the neck ring and introduced into the barrel mold, and after being axially stretched by using the stretching rod 15, compressed air is used. Stretch blow molding is performed laterally in the mold. This stretch blow molding method itself is a method conventionally used for manufacturing PET bottles.

In this case, the bottle manufacturing method according to the present invention is characterized in that the bottomed parison 13 is attached to a position having an eccentric positional relationship with respect to the central longitudinal axis L of the blow mold 10 during stretch blow molding. Especially.
With such an attachment relationship, when compressed air is blown into the parison 13 from the air outlet of the stretch rod 15, the parison having the same thickness in the cross-sectional direction has molding conditions such as resin temperature, thickness, and blow pressure. However, as it expands in the blow mold so as to be in close contact with the cavity 16, it becomes thinner as the distance between the mounting axis M of the parison and the bottom of the cavity increases (see FIG. 4). In this way, approximately half the circumference of the body of the bottle body is formed thin, and the remaining half is formed thicker than the thin part. When the molding is finished, the molded product is cooled and demolded to obtain a product (plastic bottle) as shown in FIG.

FIG. 5 is a perspective view of a bottle in which a hard exterior member 5 made of paper or film is wound around the body portion a of the bottle, and FIG. 6 is a sectional view thereof. In this way, when the hard exterior member 5 such as a paper box or a paper cylinder is attached to the outer peripheral surface of the bottle body, the thin-walled portion having weak strength is reinforced, and the strength required when filling the contents can be maintained. In addition, it is less likely to be damaged in normal use, and at the same time, it exerts an effect of preventing deterioration of the contents of the bottle due to sunlight. It is also possible to partially attach the paper or film exterior member 5 as described above to only the thin portion to reinforce it.

In the above-mentioned bottle, the body can be easily crushed by fingers for disposal after use.
That is, when the thin portion 2 of the bottle body is pressed inward, the thin portion 2 is folded inward and the volume of the bottle is reduced as shown in FIGS. It can be collected in a lump without.

[0014]

As described above, in the bottle of the present invention, the wall thickness in the transverse direction of the body is such that approximately half the circumference of the body is thin, and the remaining half circumference is thicker than the thin part. Therefore, since the bottle can be easily crushed after use to reduce its volume, handling at the time of disposal or collection becomes easy. Further, according to the present production method, a plastic bottle which is easy to be crushed can be produced easily and inexpensively both technically and economically.

[Brief description of drawings]

FIG. 1 is a perspective view of a plastic bottle of the present invention.

FIG. 2 is a transverse sectional view of the bottle taken along line AA of FIG.

FIG. 3 is a cross-sectional view showing an example of a blow mold used in the manufacturing method of the present invention.

FIG. 4 is an explanatory view of the same manufacturing method, showing a process in which the parison swells in the blow mold.

FIG. 5 is a perspective view in which an exterior material is wrapped around the body of a bottle.

FIG. 6 is a sectional view of the same.

FIG. 7 is a perspective view showing a state in which a body portion is crushed.

8 is a cross-sectional view taken along the line BB of FIG.

[Explanation of symbols]

 1 Bottle Main Body 2 Half Circumference Part 3 Half Circumference Part 4 Pouring Outlet 5 Exterior Member 10 Blow Mold 11a Body Mold 11b Body Mold 11c Bottom Mold 12 Fitting Part 13 Bottomed Parison 14 Neck Ring 15 Stretched Rod

Claims (4)

[Claims] 1. A pressing method according to claim 1, wherein the plastic bottle is formed such that the thickness of the plastic bottle in the transverse direction of the body is formed such that substantially half of the circumference of the body is thin, and the remaining half of the circumference is thicker than the thin portion. A crushable plastic bottle. 2. The spout is provided so as to maintain an eccentric positional relationship with respect to the longitudinal axis of the body.
Easy-to-crush plastic bottle described. 3. The exterior member made of paper or film is attached to the periphery of the body portion.
Easy-to-crush plastic bottle described. 4. A bottomed parison at the time of stretch blow molding,
The blow mold is attached so as to maintain an eccentric positional relationship with respect to the central longitudinal axis of the blow mold, and then the parison is stretched in the axial direction, and then compressed air is blown into the parison to blow the parison in the transverse direction of the body of the molded product. The wall thickness of the plastic bottle is characterized in that the body half portion is formed to be thin, and the remaining half portion is formed thicker than the thin portion, and then the molded product is cooled and released from the mold. Manufacturing method.