JPH0768629A - Molding method for bottles with handles - Google Patents

Abstract

(57) [Summary] [Structure] The temperature of the mold dies 3a, 3b is 80 ° C or higher 2
The temperature of the bottom die 4 is set to 00 ° C. or less, the temperature of the bottom die 4 is set to 50 ° C. or more and 150 ° C. or less, and the bottom die 4 having the directional and substantially line-symmetrical concave-convex shapes 41, 42, 43 is formed by Set so that it has an inclination of 20 to 70 degrees with respect to the vertical plane 22 including the center of the handle 2 and the center axis of the bottle, blow mold it, and bring it into contact with the mold for a few seconds to heat-treat, then cool and take it out. Is characterized by. [Effect] The bottle bottom portion 11 can be reinforced by the rib structure of the directional uneven shape to improve the heat resistance of the bottom portion, and at the same time, the fitting strength of the handle fitting portion 21 does not deteriorate and the mounting strength does not decrease. It is possible to suppress the deformation of 11 and the like, and it is possible to correct the deviation of the core of the bottom portion due to the handle 2 and suppress the occurrence of uneven thickness.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for forming a bottle with a handle having a bottle body having a handle and a bottle bottom having a directional uneven rib.

[0002]

2. Description of the Related Art Conventionally, FIG. 1 is a front view of a cross section of a mold, and FIG.
As shown in the II-II sectional view of FIG. 1, in order to mold the plastic bottle 1 having the handle 2, a pair of barrel molds 3a and 3b for forming a bottle barrel and a bottle bottom are formed. And a mouth die 5 for holding the preform 6, and the body dies 3a, 3b are provided with portions 31a, 31 on which the preformed handle 2 is arranged.
The mold provided with b was used.

When the plastic bottle 1 is blow-molded using the mold having the above structure, after the preform 6 held by the handle 2 and the mouth mold 5 and heated to the molding temperature is placed in the divided mold. , Closing the body molds 3a, 3b and the bottom mold 4,
High-pressure blow air is blown into the preform 6 to form the plastic bottle 1 along the inner surface of the mold, and the wall of the preform 6 is wound around the fitting portion 21 of the handle 2 to attach the handle 2. The bottom mold 4 is pulled out below the bottle, and the body molds 3a and 3b are opened in the lateral direction of the bottle to take out the plastic bottle 1.

[0004]

According to the above conventional method, 6
In order to mold a bottle that can withstand high temperature filling of 5 ° C or higher, it is conceivable to raise the mold temperature or perform an annealing treatment in a heating furnace after molding, but in both cases, the handle fitting part 21 is deformed. However, there is a drawback that the grip attachment strength is reduced.

Particularly, in the case of providing a plurality of linear ribs which are directional and arranged substantially in line symmetry in order to improve the strength by increasing the draw ratio of the bottom of the bottle, the handle 2 is provided for the directional property. Toward the direction of, the deviation of the core, that is, the deviation of the center of the preform bottom and the center of the bottle bottom easily occurs, so that the vicinity of the bottom on the side opposite to the handle tends to be thin,
Further, there is a problem that the bottle grounding surface is deformed due to the directionality of the linear ribs.

Therefore, the present invention provides a plastic bottle having a structure capable of preventing the deterioration of the grip attachment strength, the misalignment of the core, the uneven thickness, the deformation, etc. while improving the heat resistance of the bottle and the strength of the bottom of the bottle. Has an aim.

[0007]

Means for Solving the Problems The present invention is intended to achieve the above-mentioned object, and provides a preform heated to 70 ° C or higher and 130 ° C or lower in a mold in which a handle having a fitting portion is inserted in advance. In the method of biaxially stretch-blow molding and winding the wall of the preform around the fitting portion to form a bottle with a handle, the temperature of the body of the mold is 80 ° C. or higher 2
The temperature of the bottom mold is set to 00 ° C. or less, the temperature of the bottom mold is set to 50 ° C. or more and 150 ° C. or less, and the bottom mold having a directional and substantially line-symmetrical concavo-convex shape has the axis of symmetry including the handle center and bottle center axis. It is characterized in that it is set so as to have an inclination of 20 to 70 degrees with respect to the vertical plane, blow-molded, brought into close contact with a mold for several seconds for heat treatment, and then cooled and taken out.

[0008]

The bottle with a handle obtained by the above process is 65
It has heat resistance to withstand high temperature filling of ℃ or more, deformation of the grip fitting part does not reduce the mounting strength, deformation of the bottom part can be suppressed, and core misalignment of the bottom part due to the grip Can be modified.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in more detail below with reference to the embodiments shown in the drawings. 1 is a front view of a cross section of a mold used in the method for forming a bottle with a handle of the present invention, and FIG.
II-II sectional view of FIG. 3, FIG. 3 is a plan view of the bottom mold, FIG. 4 is IV of FIG.
-IV is an end view.

The method for forming a bottle with a handle according to the present invention is as shown in FIG.
As shown in FIGS. 4 to 4, the preform 6 heated to 70 ° C. or higher and 130 ° C. or lower is biaxially stretch-blow molded in a mold into which the handle 2 having the fitting portion 21 is inserted, and the fitting portion 21 is formed. In the method for winding the wall of the preform 6 into the bottle 1 with a handle, the temperature of the mold dies 3a, 3b is set to 80 ° C or higher and 200 ° C or lower, and the temperature of the bottom mold 4 is set to 5 ° C.
The bottom die 4 having a directional and substantially line-symmetrical concavo-convex shape 41, 42, 43 is provided on the vertical plane including the center of the handle 2 and the center axis of the bottle while keeping the temperature from 0 ° C to 150 ° C. It is characterized in that it is set so as to have an inclination of 20 ° to 70 ° with respect to 22, blow-molded, brought into close contact with a mold for a few seconds to be heat-treated, and then cooled and taken out.

As a material for the preform 6, a polyester resin such as polyethylene terephthalate is particularly preferable because the heat resistance can be improved by heating. Preform 6
Needs to be heated in advance to a stretching temperature range of 70 ° C. or higher and 130 ° C. or lower.

As shown in FIG. 1, the preform 6 is preferably preheated at least near the top surface of the plug portion 61, preferably up to the neck ring portion 62, to be crystallized for whitening. As a result, the spout 61 at the time of high temperature filling
It is possible to prevent the contents from leaking and the invasion of air due to the deformation.

The blow mold dies 3a and 3b shown in FIGS. 1 and 2 are heated to a temperature of 80.degree.
Temperature in the range of 50 ° C to 150 ° C, preferably 9
Keep at 0 ° C to 120 ° C. The temperature of the body molds 3a, 3b is 8
If the temperature is lower than 0 ° C, heat resistance is not imparted to the molded bottle body and deformation occurs during high temperature filling. On the other hand, when the temperature exceeds 200 ° C., the winding failure occurs in the handle fitting portion 21 and the cloudiness around this occurs. If the temperature of the bottom mold 4 is less than 50 ° C, the heat resistance of the bottom portion 11 of the obtained bottle is poor, and
If it exceeds 0 ° C, it will be deformed during molding.

The body dies 3a and 3b are kept warm by hot water pipes or the like provided therein, and the molded plastic bottle 1 is contacted for 2 to 10 seconds for annealing to improve heat resistance. I have to.

The shape of the bottom die 4 has uneven shapes 41, 42, 43 as shown in FIGS. 3 and 4, and these uneven shapes have directionality and are formed line-symmetrically with respect to the first rib 41. The axis of symmetry 44 has an angle α of 20 to 70 degrees, preferably 40 to 50 degrees with respect to the surface 22 including the handle 2.

If the angle α is less than 20 degrees, the effect of preventing deformation and displacement of the core is small, and if it exceeds 70 degrees, the displacement of the core is small but deformation of the grounding surface is likely to occur.

Bottle 1 with a handle obtained by this
Linear ribs corresponding to the concavo-convex shapes 41, 42, 43 are formed on the bottom portion 11 of the to improve the strength of the bottom portion and prevent deformation during filling. The bottom portion 11 of the bottle 1 can be prevented from being deformed and the like, the smoothness of the grounding portion can be improved, the stability of the bottle can be increased, and the misalignment of the core of the bottom portion 11 can be suppressed.

The concavo-convex shape of the bottom mold 4 shown in FIGS. 3 and 4 is
It has a linear first rib 41 passing through the center, and substantially fan-shaped second ribs 42 and third ribs 43 provided line-symmetrically with respect to the first rib 41.

The ribs 41, 42 and 43 are formed so as to have a main direction in the direction of the symmetry axis 44 as a whole in a horizontal plane, and the direction of the symmetry axis 44 is the surface 22 including the handle, that is, the bottle. It is formed so as to form an angle α of about 45 degrees with respect to the direction in the horizontal plane of the parting line remaining on the body.

Since it is difficult to sufficiently spread hot water pipes and the like at the portion where the divided surfaces of the barrel dies 3a and 3b and the bottom die 4 intersect, the heating effect of this portion is different from other portions.

Thus, the uneven shape 4 formed on the bottom mold 4
1, 42, 43 are formed so as to have directionality and line symmetry in the horizontal plane, and the symmetry axis 44 is formed so as to form a specific angle α with respect to the surface 22 including the handle 2, thereby forming the unevenness. The directionality of the shape array itself and the difference in heating effect on the surface 22 including the handle 2, that is, the divided surface portion of each mold cancel each other out to suppress deformation and the like, and the misalignment of the core in the handle direction can be eliminated. It is considered that it is possible to prevent the vicinity of the bottom portion on the side opposite to the handle from being thin.

After blow molding and heat treatment, it is necessary to cool, but for example, blow air is exhausted and 20 to 40 kg / cm is passed through the hole 71 from the hollow drawing rod 7.
^It is preferable to send high-pressure cooling air ( ² ) to cool the bottle from the inner surface. At that time, by making the size of the hole 71 of the stretch rod 7 large especially near the fitting portion 21 of the handle 2, the fitting portion 21 and the preform wall 6 near the fitting portion 21.
It is preferable to be able to cool quickly.

By cooling the mold from the inside, it is not necessary to cool the mold itself as described above. Therefore, the bottle can be efficiently cooled even if heat treatment is performed by the heated mold, and the handle fitting portion 21 is Since it can be prevented from being deformed by heat, sufficient heat resistance can be imparted.

The bottle with a handle made in the above process is
It is possible to prevent deformation of the bottom portion and the like, and to correct misalignment of the core of the bottom portion due to the handle, without deformation of the handle fitting portion and reduction in mounting strength.

For example, 7 in a bottle 1 having a capacity of 1.8 liters.
After filling with 0 ° C warm water, put a cap on it and place it in a cardboard box.
Fully packed and left in an atmosphere of 65 ° C for 24 hours, then
After naturally cooling in a room temperature atmosphere for one day, the entire bottle and
In particular, as a result of visually observing the appearance near the handle fitting portion, no remarkable deformation is observed.

In this embodiment, a plastic bottle with a handle has been described as an example, but a similar effect can be obtained with a plastic bottle without a handle. It can be appropriately set depending on the shape of the bottom portion, and the material of the bottle body is not particularly limited.

[0027]

As described above, according to the present invention, the preform heated to 70 ° C. or higher and 130 ° C. or lower is pre-heated in a mold having a handle having a fitting portion, and the preform is biaxially stretch blow molded to obtain In the method of winding the wall of the preform around the fitting portion to form a bottle with a handle, the temperature of the body of the mold is set to 80 ° C or higher and 200 ° C or lower, and the temperature of the bottom mold is set to 50 ° C.
The temperature is not lower than 150 ° C. and not higher than 150 ° C., and a bottom die having a directional and substantially line-symmetrical uneven shape is provided with respect to a vertical plane in which the axis of symmetry includes the handle center and the bottle center axis.
Since it is a molding method for a bottle with a handle, which is characterized in that it is set so as to have an inclination of 0 to 70 degrees, blow-molded, brought into close contact with a mold for a few seconds, heat-treated, and then cooled and taken out. The bottom of the bottle can be reinforced by the rib structure of the directional uneven shape to improve the heat resistance of the bottom.
The grip fitting portion will not be deformed and the mounting strength will not be reduced, deformation of the bottom part, etc. can be suppressed, and deviation of the core of the bottom part due to the grip can be corrected and uneven thickness can be suppressed. is there.

[Brief description of drawings]

FIG. 1 is a front view of a cross section of a mold used in a method for molding a bottle with a handle according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a plan view of the bottom mold.

4 is an end view of IV-IV of FIG.

[Explanation of symbols]

 1 Plastic bottle 2 Handle 21 Fitting part 22 Vertical surface including handle center and bottle center axis 3a, 3b Body type 4 Bottom type 41, 42, 43 Concavo-convex shape 44 Symmetric axis 5 Mouth type 6 Preform

Claims (1)

[Claims] 1. A biaxial stretch blow molding of a preform heated to 70 ° C. or higher and 130 ° C. or lower in a mold in which a handle having a fitting portion is inserted in advance, and a wall of the preform is fitted to the fitting portion. In the method of wrapping and making it into a bottle with a handle, the temperature of the body of the mold is set to 80 ° C or higher and 200 ° C or lower, and the temperature of the bottom mold is set to 50 ° C or higher and 150 ° C or lower. The bottom mold having the uneven shape formed in the above is set so that the symmetry axis has an inclination of 20 to 70 degrees with respect to a vertical plane including the handle center and the bottle center axis, and blow molding is performed. A method for forming a bottle with a handle, which comprises contacting for 2 seconds, heat-treating, and then cooling and taking out.