JPH01275122A - Injection blow molding machine for multilayer vessel - Google Patents

Abstract

PURPOSE:To injection-mold many uniform multilayer preforms by a method in which the hot runners of the resin molding the main part and the intermediate layer of the preform are provided in a hot runner block, and an injection device is nozzle-touched to the resin feeding cylinder of a distributor. CONSTITUTION:The bottom forces 6 are set with hot runner blocks 12 on the lower mold-clamping platen of a mold clamping mechanism 8, and the first hot runner 14 of the resin molding the main part of a preform and the second hot runner 15 of the resin molding an intermediate layer, are provided in said block 12. A resin path 17 is arranged in the first hot runner 14 adjacent to a first resin-distributor 16 between the blocks 12, and a resin-feeding cylinder 18 is connected to the distributor 16 through the outer block 12. The resin- feeding cylinder 19 of the second hot runner 15 is positioned on the outer surface of the block 12, and two first resin-injection devices and four second resin- injection devices are nozzle-touched to the resin-feeding cylinders 18, 19. Consequently, many uniform multilayer preforms may be molded in one operation.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] This invention relates to an injection blow molding machine used for collapsing multilayer containers such as biaxially oriented bottles having an intermediate layer.

[Prior art] A transfer plate is provided above the machine base so as to be able to rotate horizontally and intermittently, and a predetermined number of injection molds each having a plurality of lip molds are arranged in two rows, inside and outside, along the periphery on the lower surface of the transfer plate. Prepare at regular intervals,
The lower injection mold at the injection station where the upper injection mold stops and the blow mold at the stretch blowing station are arranged in two rows, one inside and one outside, corresponding to the upper injection mold. A method of continuous stretch-blow molding of a container is already known from Japanese Patent Publication No. 53-22096.

[Problem to be solved by the invention] Using such a molding machine, a multilayer preform having an internal layer that provides a gas barrier or heat resistance is molded, and the preform is stretch blow molded. It is possible to continuously mold multilayer horizontal bottles, etc., but in order to increase the number of molded products, it is possible to increase the number of cavities and inject resin into those cavities through a hot runner. There is a difference in filling depending on the position of the hollow 1-runner, and a preform is likely to be filled with an insufficient amount of resin forming the intermediate layer. For this reason, the injection molding of the preform and the stretch blow molding of the container are performed continuously.
The molding machine described in F is limited in the number of multilayer containers that can be produced in one molding cycle, and further improvements are required to prevent uneven molding of preforms when used as a mass production machine.

This invention was devised in order to solve the above problems, and its purpose is to reduce the amount of resin filling in each cavity even if the number of cavities in the 01 dispensing mold is increased.
An object of the present invention is to provide a new multilayer container blow molding machine that can continuously injection mold a large number of homogeneous multilayer preforms with no difference in quality.

[Problems to be Solved by the Invention] This invention according to the above object has a transfer plate horizontally and intermittently rotatable above the machine base, and a predetermined number of injection molds having a small number of lip molds on the lower surface of the transfer plate. The upper mold is placed in two rows of inner and outer rows along the periphery at regular intervals. In a molding machine that is installed in rows and successively performs injection molding of a large number of preforms and stretch blow molding of containers of a desired shape, a lower mold board with a mold clamping structure installed vertically in an injection station is used. above,
A lower injection mold having a large number of cavities is arranged along with a lower hot runner block in two rows, inside and outside, in a direction transverse to the plane of the machine, and the main part of the preform is formed in each hot runner block. A first hot runner made of resin and a second hot runner made of resin forming an intermediate layer are provided separately on the left and right for each required number of cavities,
A first resin distributor is provided in the center between each of the inner and outer hot runner blocks, and a resin passage is provided between the distributors and the adjacent inner and outer first hot runner blocks, and a resin passage is provided between the inner and outer hot runner blocks. - through the block,
A resin supply cylinder is connected to the distributor, and the resin supply cylinder of the second hot runner is protruded from the outer surface of each hot runner block and positioned on the side of the machine, and the resin supply cylinder of the second hot runner is positioned on the side of the machine. injection devices are arranged side by side on the rock stand, and four second resin injection devices are arranged in pairs on the side of the punching side, each having its nozzle touched to the resin supply tube.

[Embodiment] In the figure, reference numeral 1 denotes a machine base having a rectangular plane, which is installed horizontally with a base 2 above supporting the periphery and the center.

A circular transfer plate 3 (see FIG. 3) is provided below this base with its central portion supported on a shaft so that it can rotate freely intermittently.

As shown in FIG. 3, on the lower surface of the transfer 5183, a predetermined number of injection molds 5 having a plurality of lip molds 4 are attached along the circumference in two rows, inside and outside, at regular intervals. The lower injection mold 6 of the injection station where the upper injection mold 5 stops and the blowing mold 7 of the stretch blowing station (see Figure 1) are provided in two rows, inside and outside, corresponding to the lower injection mold 5. This allows injection molding of a large number of preforms and stretch blow molding of a container of a desired shape to be performed successively.

A mold clamping mechanism 8 is vertically arranged in the injection station,
Four hot runner blocks 12 are installed at four locations on the inside, outside, left and right sides of a seat plate 11 provided on the lower mold board 10 of the mold clamping mechanism. The lower injection mold 6, which has two cavities 13 arranged in a row at equal intervals, is fixed. In each hot runner block, a first hot runner 14 made of resin forming the main part of the preform and a second hot runner 15 made of resin forming the intermediate layer are connected to the double nozzle 9. Each hot runner block 12 inside and outside
．． A first resin distributor 16 is provided in the center between each of the first resin distributors 12 .

Those distributors 16 and the adjacent inner and outer hot runners
The first hot runners 14, 14 of the block 12.12 communicate with each other by a resin passage 17 arranged therein, and the distributor 16 is connected to the outer hot runner block 12 by a gate. The resin supply cylinder 18 having the resin supply cylinder 18 is connected.

The resin supply tube 19 having the gate of the second pot runner 15 is provided to protrude in parallel from the outer surface of each hot runner block 12 and is positioned on the side of the machine.

Reference numeral 20 denotes a first resin injection device, two of which are arranged side by side on the machine stand 1 so that the nozzles touch the gates 1 to 1 of the resin supply cylinder 18.

21 is the second resin injection device, and the four injection molding machines are 2
Each unit is provided in parallel on both sides of the machine stand 1, and the nozzle touches the gate of the resin supply cylinder 19. Of these, the injection device located on the operating side of the machine is placed on a movable pedestal 22 and installed on the side of the machine so as not to interfere with mold replacement.

In such a molding machine, the first resin injected from the injection device 20 flows from the resin supply cylinder 18 through the distributor 16 and the resin passage 17 into the hot runner 14, and then from the outer passage of the double nozzle 9. , flows into the cavity 13.

Further, the second resin injected from the first output device 21 flows directly from the resin supply cylinder 19 to the hot runner 15 and flows into the cavity 13 from the inner passage of the double nozzle 9.

The above two resins are injected at the same time, but it is preferable to inject a small amount of the first resin first, so that the second resin is incorporated into the first resin in the cavity and forms the intermediate layer. Form.

[Effects of the Invention] Since the present invention is constituted by an injection blow molding machine as described above, even if the number of cavities is increased, the injection of the first and second resins is performed for each small number of cavities. Setting the injection pressure and speed is easier than when targeting multiple cavities, and the resin filling condition is better.
A large number of uniform multilayer preforms can be molded in one molding operation.

[Brief explanation of the drawing]

The drawings show one embodiment of the injection blow molding machine for multilayer containers according to the present invention, and FIG. 1 is a side view, FIG. 2 is a partially cutaway plan view, and FIG. 3 is a schematic diagram of an injection molding station. 1 is a sectional view, and FIG. 4 is a plan view of the injection mold portion. 1... Machine base 2...
Base 3... Rotation 5184... Lip mold 5... Injection top mold 6...
Injection lower mold 8... Mold clamping mechanism 11.
... Seat plate 12 ... Hot runner block 13 ... Cavity 14 ... First hot runner 15 ... Second hot runner 16...Distributor 17...
・Resin passage 18.19...Resin supply path

Claims (1)

[Claims] A transfer plate is provided above the machine base so as to be able to rotate horizontally and intermittently, and a predetermined number of injection molds each having a plurality of lip molds are arranged on the lower side of the transfer plate in two rows, inside and outside, along the periphery. Prepare at regular intervals,
The lower injection mold at the injection station where the upper injection mold stops and the blow mold at the stretch blowing station are arranged in two rows, one inside and one outside, corresponding to the upper injection mold, and are capable of injection molding a large number of preforms and stretching containers of a desired shape. In a molding machine that performs continuous blow molding, an injection lower mold with a large number of cavities is placed on a lower mold clamping plate of a mold clamping mechanism installed vertically in an injection station, together with a lower hot runner block. A first hot runner made of resin forming the main part of the preform and a second hot runner made of resin forming an intermediate layer are arranged in two rows, inside and outside in the transverse direction with respect to the plane of the machine, in each hot runner block. , the cavities are divided into left and right according to the required number of cavities, and a first resin distributor is provided in the center between each of the inner and outer hot runner blocks, and the first resin distributors are connected to the adjacent inner and outer first hot runners. At the same time as placing a resin passage across the entire area, it also penetrates the outer hot runner block.
A resin supply cylinder is connected to the distributor, and the resin supply cylinder of the second hot runner is protruded from the outer surface of each hot runner block and positioned on the side of the machine base, and the two first resins are injected. The apparatuses are arranged in parallel on the machine stand, and four second resin injection apparatuses are arranged in pairs on the side of the machine stand, each having its nozzle touching the resin supply tube. Injection blow molding machine for multilayer containers.