JP2508572B2 - Manufacturing method of synthetic resin container with handle - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a synthetic resin container with a handle, and more specifically, to a heat treatment after molding at the handle mounting portion of the container body as well as other portions of the container body. The present invention relates to a method for producing a synthetic resin container with a handle which can be sufficiently fixed and has excellent heat resistance.

[0002]

2. Description of the Related Art A hollow container formed by biaxially stretch blow molding a thermoplastic polyester such as polyethylene terephthalate has transparency, gas barrier properties, light weight, impact resistance and appropriate rigidity, and has a liquid content. It is widely used as a packaging container for accommodating. Among the large-sized hollow containers, it is known that a handle formed separately from the container body is provided for easy handling.

In this synthetic resin container with a handle, a handle part is formed in advance, and the handle part is placed in a blow mold so as to be integrated with the container at the same time when the container forming preform is stretched. A method of integrating the handle with the container body in the axial stretch blow molding process or the injection molding process of the handle.
No. 36393). By the way, in any of the containers molded by any method, the polyester container has a drawback that it is inferior in heat resistance, and for the purpose of hot filling the contents, thermal deformation or shrinkage deformation of volume occurs. Therefore, heat fixing is performed after the biaxial stretch blow molding.

[0004]

However, in such a synthetic resin container with a handle, the handle is roughly composed of a mounting portion and a gripping portion, and has a shape adapted to the concave portion of the container body. Therefore, not only the mounting portion that actually plays a role of coupling with the container, but also the gripping portion is in close contact with the concave portion of the container main body and the upper surface and the lower surface that are extension lines of the container body. There is a problem in that the presence of heat inhibits heat conduction at the time of heat fixation, and that this part cannot be sufficiently heat fixed.

Therefore, it is an object of the present invention to provide a synthetic resin container with a handle, which is capable of reliably heat-fixing the handle mounting portion of the container body. .

[0006]

DISCLOSURE OF THE INVENTION The present invention has been proposed in order to solve the above-mentioned object, and the structure of the connecting portion between the container body and the handle portion has a specific shape, and the entire container body is It is characterized in that it can be heat-fixed uniformly. That is, according to the present invention, a synthetic resin preform is placed in a blow mold and biaxially stretch blow molded, and a neck portion, a body portion, and a closed bottom portion are provided, and the most recessed portion is a neck portion in a part of the body portion. A handle having a diameter that is substantially the same as or slightly larger than the neck and that is provided with a protrusion for engaging the handle is formed in the recess, and the grip and the attachment are integrally formed by injection molding of synthetic resin. In the method of manufacturing a synthetic resin container with a handle, the attaching part of the handle is configured as a ring having a shape similar to that of the protrusion, and the holding part is provided at least on the upper surface and the lower surface of the concave portion of the container body with a space therebetween. Provided is a method for producing a synthetic resin container with a handle, which is characterized in that it is attached to a recess and then heat-fixed.

Further, according to the present invention, the handle is inserted into a predetermined position in the blow mold, and the preform placed in the blow mold from above is biaxially stretch-blow molded so that the container body and the handle are There is provided a method for producing the synthetic resin container with a handle, which comprises:

[0008]

DETAILED DESCRIPTION OF THE INVENTION In the present invention, the handle to be attached to the container body is configured to be spaced apart from the concave portion of the container body except for the attachment portion, so that the mold is also brought into contact with this gap portion. An important technical feature is that the heat is evenly transferred to the entire concave portion which is the handle mounting portion when heat fixing. The heat fixing of the container is performed at the same time when the handle comes into contact with the inner surface of the mold after the handle is attached to the container body. Therefore, in the case where the container body and the handle part are in close contact with each other over a wide area, such as a conventional container made of synthetic resin with a handle, there are more parts that are not in contact with the mold surface, and this part is heat-set. Therefore, the properties such as heat resistance are inferior at that portion, and there is a problem that the container body is distorted due to shrinkage during hot filling.

That is, in FIGS. 1 and 2 showing a mold used for heat-fixing a synthetic resin container in which a handle is integrated, FIG. 1 shows a synthetic resin container to which a handle is attached. It is a reference drawing of the metal mold | die 1 used for the conventional system fixed. On the other hand, FIG. 2 is a reference view of the mold 1 used in the method of the present invention for thermally fixing the synthetic resin container 10 to which the handle 11 is attached. As is clear from comparing FIGS. 1 and 2, the conventional heat setting method shown in FIG.
A portion of the die 1 to which the handle is attached, that is, an upper curvature portion 4 and a lower curvature portion 5 of the die 1 to which the handle is attached.
In, the handle is in contact with the container body when heat-fixed,
The mold 1 (hatched portion) is not in direct contact with this portion.
On the other hand, in the method of the present invention shown in FIG. 2, the protruding pieces 2 and 3 provided on the mold 1 come into contact with the upper surface 17 and the lower surface 19 of the container body concave portion 16, respectively, and the upper curved portion 2 of the handle 11 is brought into contact therewith.
4 and the lower curvature portion 25, and any of these portions are in direct contact with the mold 1, so that sufficient heat treatment can be performed, and heat fixing can be reliably performed.

In the present invention, the handle is manufactured in advance by injection molding, and the handle is inserted into the blow mold,
Moreover, a method of fixing the handle to the container body by biaxially stretch blow molding the container body preform in a blow mold (insert blow molding method) is preferably adopted. Alternatively, or in advance, in a blow mold, the container body preform is biaxially stretch blow molded to mold the container body,
A method of inserting this container body into an injection mold and injecting a handle resin (insert injection molding method) to fix the handle to the container body can also be adopted. In either method, stretching of the container body is conventionally known (Japanese Patent Publication No.
Stretching can be carried out in the range of Japanese Patent No. 36939).
Generally, it is preferable that the blow temperature is 80 to 130 ° C. and the blow ratio (length × width) is about 6 to 12 times. In any of the above methods according to the present invention, it is important that the container body and the handle are formed so as to have a space in the concave portion of the container body and to be in contact only with the protrusion and the mounting portion of the handle.

Next, the container to which the handle is attached is so-called one-mold method in which heat is fixed in a mold common to biaxially stretch blow molding, and so-called one in which a mold different from biaxial stretch blow molding is heat-fixed. It can be heat set by the two-mold method. That is, in the case of the one-mold method in which the same mold is used for biaxial stretch blow molding and heat setting, when the container body is stretched, the blow mold is a heated mold of 100 to 180 ° C., preferably 125 to 155 ° C. At the same time as the outside of the wall of the blown container comes into contact with the inner surface of the mold, heat treatment is performed. After a predetermined heat treatment time, the blowing fluid is switched to the internal cooling fluid to start cooling the inside.
The heat treatment time varies depending on the thickness and temperature of the blow-molded product, but is generally 2 to 15 seconds, especially 3 to 5 seconds.
Seconds are preferred. The cooling time also varies depending on the heat treatment temperature and the type of the cooling fluid, but is generally 2 to 10 seconds, preferably about 3 to 5 seconds.

When heat setting is carried out by the two-mold method, the stretch-blow molded container with a handle is taken out without cooling, the container with a handle is put into a second mold, and this mold is Heat fixing is performed inside. This heat setting can also be performed according to the one-mold method.

3 to 5 showing a synthetic resin container with a handle obtained by the method of the present invention, FIG. 3 is a side view of the synthetic resin container with a handle as seen from the side of the handle, and FIG. 4 is A in FIG. FIG. 5 is a side view of the synthetic resin container with a handle as seen from the direction of the handle, respectively showing a view from the direction of arrow A, a view from the direction of arrow BB, and a view from the direction of arrow CC.

The synthetic resin container with a handle obtained by the method of the present invention has a container body generally designated by 10 and a total of 11
It consists of a handle and a handle. The container body 10 has a neck 1
2, consisting of a tubular body 13 and a closed bottom 14,
A frustoconical shoulder 15 exists between the neck 12 and the body 13. A recess 16 is provided below the frustoconical shoulder 15. When viewed from the side, this recess 16 is composed of an upper surface 17 extending slightly inclined toward the center of the container, a side surface 18 extending substantially vertically, and a lower surface 19 extending slightly inclined toward the body side surface. . The recess side surface 18 has a horizontal cross section (B
As is clear from FIGS. 4A and 4B showing the (B cross section), the most recessed portion is provided so as to have a diameter substantially the same as the neck portion 12 or larger than the neck portion.

A protrusion 20 is provided substantially in the center of the recess 16, and the protrusion 20 is integrally formed by blow molding with the recess 16 and other parts of the container body. As is clear from FIG. 4B, the flange portion 21 is provided so that the handle is firmly fixed.

The handle 11 is composed of a grip portion 22 and an attachment portion 23 which are integrally molded by injection molding of synthetic resin.
The grip portion 22 includes an upper curvature portion 24 and a lower curvature portion 25.
And is continuous with the mounting portion 23 through these curved portions 24 and 25, and forms a ring as a whole. The mounting portion 23 forms a ring, and the ring of the mounting portion 23 has a shape similar to that of the container body protruding portion 20 and has an inner peripheral dimension substantially equal to the outer peripheral dimension of the protruding portion 20.

In the present invention, a space is provided between the upper curved portion 24 of the handle and the upper surface 17 of the container body recess 16 and between the lower curved portion 25 of the handle and the lower surface 19 of the container body recess 16. There is. The distance between these can be appropriately determined depending on the size of the container, the size of the recessed portion to be provided, and the like. The shape of the handle is not limited to that shown in the figure, and various shapes can be adopted as long as this condition is satisfied. In addition, the side and bottom of the container may be provided with irregularities to improve the strength of the container. Similarly, the handle may be provided with ribs to improve the strength of the handle, or the vertical part for easier gripping. Of course, unevenness may be provided.

In the method of the present invention, as the resin used for forming the container body, polyethylene terephthalate,
Thermoplastic polyesters such as polybutylene terephthalate; polycarbonates; polyacrylonitrile, polyethylene terephthalate and the like can be used. As the resin used for forming the handle, the same resin as that used for forming the container body can be used. In addition to this resin, polypropylene, low-, medium-, high-density polyethylene, ethylene-propylene can be used. A polyolefin such as a copolymer, a styrene-butadiene thermoplastic elastomer, or the like can be used. If necessary, various colorants, fillers and the like may be added to the handle forming resin.

[0019]

According to the method of the present invention, the handle is attached to the concave portion of the container body so as not to come into contact with anything other than the attachment portion, so that the area where the mold does not come into contact with the container body at the time of heat fixing is as small as possible. Since it has become possible to reduce the number of parts, the part of the container body that corresponds to the handle can be sufficiently heat-treated like other parts of the container body, and a synthetic resin container with a handle with excellent heat resistance. Can be manufactured.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a heat setting process of a conventional synthetic resin container with a handle.

FIG. 2 is a view for explaining a heat setting step of the synthetic resin container with a handle of the present invention.

FIG. 3 is a side view of an example of a synthetic resin container with a handle obtained by the method of the present invention viewed from the side of the handle.

FIG. 4 is a view showing an AA arrow view to a CC arrow view of FIG. 3;

FIG. 5 is a side view of an example of a synthetic resin container with a handle obtained by the method of the present invention viewed from the handle direction.

[Description of sign]

 1 Mold 2, 3 Projecting Piece 4 Upper Curvature Part 5 Lower Curvature Part 10 Container Main Body 11 Handle 16 Recess 20 Protrusion 22 Grasping 23 Attachment

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Claims (2)

(57) [Claims] 1. A synthetic resin preform is placed in a blow mold and is biaxially stretch blow molded to have a neck portion, a body portion, and a closed bottom portion, and whether the most recessed portion is partly the same as the neck portion. Alternatively, a recess having a diameter slightly larger than that of the neck and provided with a protrusion for engaging the grip is formed, and the grip having the grip and the mounting part integrally formed by injection molding of synthetic resin is fixed to the recess. In the method for manufacturing a container made of synthetic resin with a handle, the attachment part of the handle is configured as a ring similar in shape to the projection part, and the grip part is attached to the recess at least at the upper surface and the lower surface of the recess of the container body. A process for producing a synthetic resin container with a handle, which is characterized by being heat-fixed. 2. The container main body and the handle are fixed by inserting the handle at a predetermined position in a blow mold and biaxially stretch-blow molding a preform put in the blow mold from above, Next, heat setting is performed.
A method for producing a synthetic resin container with a handle as described.