JPS6253329B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method and apparatus for manufacturing a blow molded product, and particularly to a method for manufacturing a blow molded product and an apparatus for the same, particularly when blow molding a plurality of hollow molded products at the same time by placing two parisons in parallel. The present invention relates to a method and apparatus for preventing thermal deformation due to mutual contact between molded articles.

Conventionally, when blow-molding a synthetic resin hollow molded product, surplus parts called "bits" are formed at the upper and lower parts of the molded product, for example, due to the insertion of blow pins and the like into the parison. In some cases, this bit can be removed by rotating the calibration of the blow pin to cut out the bit and the disposable bag, or by removing the bit by using a pick-up device or the like. However, in recent years, with the diversification of this type of hollow molded products, especially hollow containers, etc., for example, tube containers and other squeeze containers that are difficult to sit, and multi-layer containers that are easy to cut, etc. If the material is made of poor material, the above-mentioned processing or equipment cannot be used, and the material is removed from the mold with the bits still attached and then processed.

However, since this bit part is generally allowed to cool naturally, the temperature is still high when the molded product is taken out, and if the bit comes into contact with another molded product, the heat of the bit can be transferred to other molded parts. This was often transmitted to objects, damaging their appearance and shape, resulting in defective products. This drawback is particularly noticeable when a large number of hollow molded products are simultaneously molded by using two parisons in parallel. For this purpose, a forced cooling device as shown in FIG.
Although air is forcedly cooled by blowing air into the bits by surrounding them with thin tubes 35, 35, which have air outlets 36, 36..., cooling is not sufficient. Moreover, in order to achieve sufficient cooling, the cooling time must be increased, which reduces the molding cycle and significantly reduces manufacturing efficiency.

This invention was proposed in view of the above-mentioned current situation, and its purpose is to prevent the appearance of defective products due to mutual contact between molded products, without affecting the cooling time or molding cycle in any way. It is. The details of the present invention will be explained below with reference to the accompanying drawings.

FIG. 1 shows a perspective view of a molded product 10 of a tube container after blow molding and before finishing.
1, and respective bit parts 12 and 13 are integrally formed at the head and tail parts thereof.

Figures 2 to 4 relate to an embodiment of the method and apparatus of the present invention, in which Figure 2 is a sectional view of the mold 20 during blow molding, and Figure 3 is a front view showing the state of removal after blow molding. , and FIG. 4 show their plan views.

That is, the feature of the method for manufacturing a hollow molded article according to the present invention is that a plurality of hollow molded articles are simultaneously blow-molded by placing two parisons in parallel,
As the specific example is shown in FIG.
After blow molding, compressed air is blown in two directions from an intermediate position between the two parallel molded products 10, 10, and is blown onto the sides of each of the parallel molded products, so that each of the parallel molded products 10, 10 is blown in different directions. By taking it out at the same time, contact between the two was prevented.
Further, the apparatus for manufacturing a hollow molded product according to the second invention is 2.
In an apparatus for simultaneously blow-molding a plurality of hollow molded products by arranging book parisons in parallel, at an intermediate position between both cavities of a split mold that clamps the parisons,
The apparatus for producing a hollow molded product is characterized in that a blowing nozzle for blowing compressed air in two directions so as to blow against the side surface of each molded product is provided. The details will be explained below while explaining an example of the device.

First, the mold 20 for blow molding a tube container is
It is a split mold, and has two molding cavities 21a and 21b on the left and right sides of which hold two parisons. In the embodiment shown in FIG. 2, one product is molded from one parison, but in some cases, the cavity 21 may be configured so that two or more products can be molded from one parison. Sometimes. And both cavities 21 of the mold 20
A compressed air blowing nozzle 2 is located between a and 21b.
A cavity 22 is formed so that 5 can be installed.

Each molded product 1 after blow molding is inserted into the blow nozzle 25.
Two air outlets 2 are provided so that the air can be taken out (blown out) in different directions.
6 and 26 are provided. This air outlet 26 is
As shown in FIG. 4, it is generally provided parallel to the split surface of the mold 20. In the embodiment, a cavity 22 for mounting the air nozzle 25 is formed in the mold, but this cavity 22 is not necessary when the air nozzle is embedded or integrally mounted within the mold.

Next, the operation of the present invention will be explained with reference to the drawings. First, in FIG. 2, two parisons supplied in a predetermined amount are clamped into each cavity 21a, 21b of the mold, and a blow pin 30 is inserted from the top of the mold 20.
a and 30b descend to blow air into the parison to expand and shape it into a cavity shape. In this case, burrs occur along the split surfaces of the mold at the top and bottom of the shaped molded product, and so-called burrs flow out.

After a certain molding time has elapsed, the mold 20 is opened and the blow pins 30a, 30b are removed from the mold 20. In this case, as shown in FIG. 3, the molded product 10 is pulled up while remaining attached to the blow pins 30a, 30b, so a removal plate 31 is provided to remove the blow pins. 32 is a pull-out hole. At the same time, compressed air is fed into the blow-off nozzle 25 installed in the central cavity 22 of the mold 20, and air is blown out from the blow-off ports 26, 26. Molded products 10 and 1 from which blow pins 30a and 30b have been pulled out
The 0s fall downward as they are, but are blown off in different directions (left and right in the figure) by the compressed air blown out from the outlet of the air nozzle 25 and taken out.

As shown in FIG. 4, each molded product 10, 1
A belt conveyor 34 or the like is installed at the dropping point of 0, and each molded product is sent to the next process while being naturally cooled.

As described above, according to the present invention, two molded products simultaneously molded by two parisons are separated and taken out in different directions, so that even if they are taken out at the same time, their edges do not touch each other. Therefore, the occurrence of defective products due to such contact can be completely prevented. Further, according to the present invention, there is no need to provide a forced cooling device for the tooth portion as described above, and there is no need to take cooling time for that purpose, and it is possible to prevent the molding shot cycle from decreasing. Further, according to the present invention, it is possible to feed the product to a predetermined take-out position, for example, the conveyor position in the embodiment, thereby eliminating the need for not only a cooling device but also a special pick-up device. As described above, according to the present invention, a blow molded product can be obtained extremely efficiently and economically by simply blowing compressed air from the intermediate portion of both molded products.

[Brief explanation of the drawing]

Fig. 1 is a perspective view showing a tube container molded product after blow molding, Fig. 2 is a sectional view of a mold during blow molding showing an embodiment of the present invention, and Fig. 3 is a molded product after blow molding. A front view showing the removal state of the
FIG. 4 is a plan view thereof, and FIG. 5 is a perspective view of a mold equipped with a conventional forced cooling device. DESCRIPTION OF SYMBOLS 10... Molded article, 12, 13... Bit, 20... Mold, 21... Molding cavity, 22... Blank space, 25...
Blowout nozzle, 26...Blowout port, 30...Blow pin,
31...Removal board.

Claims (1)

[Scope of Claims] 1. In a method of blow-molding two parisons in parallel and simultaneously blow-molding a plurality of hollow molded products, compressed air is blown in two directions from an intermediate position between both molded products arranged in parallel after blow-molding. A method for manufacturing a hollow molded product, characterized in that the side surfaces of each molded product are sprayed, and the molded products arranged in parallel are taken out in different directions. 2. In an apparatus for simultaneously blow-molding a plurality of hollow molded products by placing two parisons in parallel, a blower is placed at a midpoint between both cavities of a split mold that clamps the parisons, so as to blow against the sides of each molded product. A blow molded product manufacturing device characterized by being equipped with a blowing nozzle for blowing out compressed air in two directions.