JPS6037783B2 - Multilayer stretch blow molding machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a multilayer stretch blow molding machine for manufacturing multilayer resin bottles.

Conventionally, this type of multilayer stretch blow molding machine has a rotary type in which the core mold is sequentially passed through the primary injection, secondary injection, stretch blow, and discharge stations arranged on a circle. In this case, the first layer of injection parison does not have enough time to cool down, and the first layer of parison at the injection port is torn or becomes thinner due to the second layer injection, so the molding cycle has to be slowed down. First, there is a problem that mass production of bottles is not possible.

There is also a method in which the outer layer is blow-molded and the inner layer is further blow-molded therein, but this has the problem that a layer of air is interposed between the inner and outer layers, making it impossible to bond the layers. The present invention was devised to solve the above-mentioned conventional problems, and consists of a plurality of injection molds placed next to each other at appropriate intervals on a rotary table, and an injection mold made of these injection molds. The rotary table is capable of intermittent rotation at intervals of the injection molding parts, and each injection molding part of the injection molding part is placed at a predetermined stop position of the injection molding part of the rotary table. An injection machine corresponding to the mold is provided to enable injection molding, and a preforming means is provided at a stop position of the injection molding section in front of the position, and a transfer device for sequentially transporting the core mold to the next injection mold. , the preform ejected from the final mold is transferred to the next heating, stretching, and blowing station by the transfer device of the means, so that the parison of each layer has sufficient cooling time and the space between the layers is The object of the present invention is to provide a multilayer stretch blow molding machine suitable for mass production, which can efficiently produce preformed products with good adhesion and high quality.

Hereinafter, the present invention will be explained with reference to the illustrated embodiment. In the figure, reference numeral 1 denotes a rotary table that rotates by 1200 degrees and then stops;
On top of that are primary molds AI, A2, A3 and secondary mold B1,
B2 and B3 are provided alternately shifted by 1200 in the rotation direction (arrow direction), and the neck mold 2 and the core mold 3
are provided in combination in each mold to form a cavity (space).

Further, the rotary table 1 is provided with a window hole 5 on the back side thereof through which the sublue 4 of each mold is exposed. 6 is 1
The secondary injection machine 7 is a secondary injection machine, which is placed around the table so as to correspond to the primary mold A and the secondary mold B, respectively, when the rotating tape is stopped, and the corresponding mold and the neck mold 2 Molten resin is filled into a cavity composed of a core mold 3 and a core mold 3 through hot runners 8 and 9 passed through a window hole 5, and parisons 10 and 11 can be molded, respectively.

Reference numeral 12 denotes a transfer device that can sequentially transfer the core mold 3 from the primary mold A to the secondary mold B, and from the secondary mold B to the primary mold A before the injection molding. It is placed around the table in front of the injection molding position.

Although not shown, the two-layer parison 13 with integrated inner and outer layers is extracted from the core mold 3 extracted from the secondary mold B by the transfer device 12, heated outside the rotating tape, and heated.
A transport device is provided for transporting it to a drawing and blowing station. Next, its effect will be explained.

(i) In the state shown in Fig. 1, the cavity consisting of the primary mold AI, neck mold 2, and core mold 3 is filled with molten resin by the primary injection machine 6 to form the inner layer as shown in Fig. 4. A parison 10 is formed.

'. } Next, rotate the rotary table 1 1200 times to rotate the second
The parison 10 is cooled in the state shown in the figure. Furthermore, the rotary table 1 is rotated 1200 times to bring it into the state shown in FIG. In the state shown in FIG. 6, it is extracted from the primary mold AI and transferred to the secondary mold BI, and then the neck mold 2 is closed. 8 In this state, turn the rotary table 1 to 12
After 00 rotations, the state shown in FIG. 1 is returned to the state shown in FIG. 1, but the parison 10 is in the secondary mold BI, and a cavity is formed between the parison 10, the neck mold 2, and the core mold 3 as shown in FIG. Since this cavity is filled with molten resin by the secondary injection machine 7, the outer layer parison 11 is formed, and the parison 10' is bonded to the cavity.

Next, the rotary table 1 is rotated 1200 times to bring it into the state shown in FIG. 2, and the outer layer portion of the parison 13, in which the inner and outer layers are integrated, is cooled.

The rotary table 1 was further rotated by 120 degrees to the state shown in FIG. It is pulled out from the secondary mold BI in the state shown in FIG.

Here, the parison 13 is extracted from the core mold 3 by the transfer device (not shown) and brought into the state shown in FIG.
Stretch and transfer to blowing station. Therefore, the core mold 3 transferred from the secondary mold BI to the primary mold AI is empty, and if the neck mold 2 is closed after the transfer, a cavity is formed again, so the rotary table 3 120
o If it rotates, it will be in the state shown in Figure 1 again, and parison 1
0 can be molded. The above operation is the primary mold A2
, an injection molding section consisting of secondary mold B2 and primary molds A3 and 2.
The injection molding section consisting of the next mold B3 is also carried out in parallel, although there is a time lag between them, and each injection molding section can produce a parison 13 at the rate of one ejection per two revolutions, so the parison 13 is a preformed product. No. 13 can be manufactured efficiently.

Although this embodiment has been described for manufacturing a two-layer parison 13, it can also be applied to manufacturing a multi-layer parison.

For example, for manufacturing a three-layer parison, three injection molding sections consisting of a primary mold A, a secondary mold B, and a tertiary mold C may be arranged as shown in FIG. Further, although each mold, neck mold, and core mold were made of one piece, it is also possible to make a plurality of pieces.

As described above, the present invention sequentially installs multiple injection molds on the same rotary table, and from the primary to the secondary mold,
The structure is equipped with a transfer device that transfers the core mold to the next stage of mold, such as from the secondary mold to the tertiary mold, and from the final mold to the primary mold, so it is easy to produce multilayer parisons as preformed products. Production can be carried out on a rotating table, and it can be easily connected to a pond station. In addition, it is possible to adjust the cooling time of the base layer before lamination to ensure sufficient cooling time, and it is also possible to bond each layer together without intervening an air layer between them.
The quality of preforms can be improved. Furthermore, since the structure includes two or more injection molding sections each having a plurality of stages of injection molds, the manufacturing base for preformed products can be appropriately increased, and manufacturing efficiency can be improved.

[Brief explanation of the drawing]

FIGS. 1, 2, and 3 are schematic diagrams showing the embodiments of the present invention in different operating states, and FIGS. 4 and 5 are cross-sectional views taken along lines W~ and V~ in FIG. 6, 7, and 8 are front views showing different situations in which the parison is extracted by the transfer device, and FIG. 9 is a schematic view showing another embodiment of the present invention. 1...Rotating table, AI, A2, A3...
・Primary mold, B1, B2, B3...Secondary mold,
C1, C2, C3... Tertiary mold, 2...
・Neck type, 3... Core type, 4... Sprue, 5... Window hole section, 6... Primary injection machine, 7...・Secondary injection machine, 8, 9... Hot runner, 10, 11, 13... Parison, 12...
...transfer device, 14...tertiary injection machine. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9

Claims (1)

[Claims] 1. On a rotary table, a plurality of injection molds are placed next to each other at appropriate intervals, and two or more injection molding parts made of these injection molds are arranged adjacent to each other at appropriate intervals, and the rotary table is The injection molding section is capable of intermittent rotation at intervals of the injection molding section, and an injection machine corresponding to each injection mold of the injection molding section is provided at a predetermined injection molding section stop position of the rotary table to enable injection molding. A preforming means is provided at a stop position of the injection molding section at the front, and is provided with a transfer device for sequentially transferring the core mold to the next injection mold, and the preform is extracted from the final mold by the transfer device of the means. A multilayer stretch blow molding machine, characterized in that it is configured to transfer the material to a subsequent heating, stretching, and blowing station.