JPS6054840A - Manufacture of double wall type plastic molded container - Google Patents

Abstract

PURPOSE:To equalize the conditions such as injection condition and the like between an inside and an outside shell bodies and consequently manufacture a molded part with favorable dimensional accuracy by a method wherein molten molding material is injected through a hot-runner manifold simultaneously into molds for inside sheel body and for outside shell body and molded. CONSTITUTION:After molds 1 and 2 are closed, molten molding material is simultaneously injected through a hot-runner manifold 4 and respective nozzles 16 and 16 into the mold cavity 7 of the mold 1 and into the mold cavity 8 of the mold 2 by touching the nozzle 6 of a molder to the nozzle touch 6' of the hot-runner manifold 4 of a movable platen 3 and molded. After the end of molding, the molds 1 and 2 are opened and the outside shell body 9 and the inside shell body 10 are taken out of the molds 1 and 2. The taken-out outside and inside shell bodies 9 and 10 are fitted to each other at shoulders 11 and 12 and at the same time said shoulders 11 and 12 are bonded with bonding adhesive. Thus, a double wall type homogeneous plastic molded container is molded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing container-type double-structured plastic molded products, such as hollow helmets, containers, tanks, etc., and particularly to a manufacturing method using injection molding.

Plastic molded products made by injection molding can have higher injection pressure than molded products made by blow molding, and have superior physical properties such as impact resistance.

Conventionally, the production of container-type double-layer plastic molded products using the injection molding method relies on a method of separately molding the inner shell body and outer shell body of the target molded product, and then joining the inner and outer shells. has been done.

According to this conventional method, since the inner and outer shell bodies are injection molded separately in a molding machine, the plasticization state of the inner shell body and the outer shell body during injection, injection pressure, and other molding results are seriously affected. However, the injection conditions that affect the performance are not the same, and high dimensional accuracy cannot be obtained, resulting in problems such as poor HP matching between the inner and outer shell bodies.

Therefore, the present invention eliminates the drawbacks of the prior art described above, and in the production of container-type double-layer plastic molded products using the injection molding method, the inner and outer shell bodies are molded under the same injection conditions, and the inner and outer shell bodies are molded under the same injection conditions. While ensuring no variation in physical properties and high dimensional accuracy.

The aim is to guarantee the yield of the outer shell body and to prevent defects in their joints.

The method for manufacturing a container-type double-structured plastic molded product of the present invention is to apply the molten molding material to a mold for forming an outer shell body and a mold for molding an inner shell body of the target molded product using a hot runner.
A method for manufacturing a container-type double-structure plastic molded product that is simultaneously made into an injection molded product through a manifold, characterized in that the outer shell body and the inner shell body have a joining shoulder portion that fits with each other, The chest portions of the inner and outer shell bodies may be joined by any appropriate means such as adhesive.

According to the present invention, the outer shell bodies of the target molded products are molded by simultaneously injecting the molten molding material into the mold through the pot runner manifold, so that the inner and outer shell bodies are plasticized. It is guaranteed that the injection conditions such as molding state and injection pressure are kept the same, and high dimensional accuracy is ensured with no variation in physical properties between 4I'J and no difference in shrinkage. In addition, in the present invention, the inner and outer shell bodies have joining shoulders that fit together, so while the front nails are simultaneously molded, by joining the outer shell bodies at the shoulders, the inner and outer shell bodies can be formed at the same time. , ensuring good bonding of the outer shell body.

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the mold device of the creation molding machine used to carry out the method of the present invention. In FIG. The body forming mold (32 is a movable platen having a hot runner manifold (4), the mold fil, (21 and a movable platen (3)
) is opened and closed by means of a hydraulic ram (5) in a manner known per se. (6) is the nozzle of the injection molding machine. The mold (11, +21 in FIG. 1 is for a container-type double-structure molded product such as a container, tank, etc.).

Close the molds (1) and (2), and move the hot runner of the movable platen (3) to the nozzle touch part (6) of the manifold (4).
Touch the molding nozzle (6) to the nozzle, and the molten molding material is passed through the hot runner manifold (4) and its nozzle o6), Qel, and into the molding cavities +71 and +8+ of the mold fi+ and (2). Inject and mold at the same time.

When the molding is completed, the molds tl) and +2+ are opened and the outer shell body (9) and the inner shell body (101C Figs. 2 and 3) are taken out.The outer shell body (9) and the inner shell body (+o) is 1. Molding cavity f7), (according to the appropriate design of 8J, mating shoulder part (+1),
(It is molded as having 121. This joint shoulder part (1), θ4 has concave and convex steps that interlock as necessary (
13) , (may be added with +41 (Figure 8).

Obtained outer shell body (9) and inner shell body (10)
The chest (11, Q21) are fitted together, and the shoulders (1) and (1) are joined by appropriate means such as adhesive.In this way, the desired container-shaped double-structure plastic molded product is obtained. The molded product produced by the mold fil +21 in FIG. 1 is that shown in FIG. 2, that is, a molded product as a container or tank.

As another example, a molded product having a hollow structure is shown in FIG. The molded article can be obtained in the same manner as described above, except that a mold with a corresponding molding cavity is used.

Movable fi (31 hot runner manifolds (41
is preferably equipped with a suitable suction and pressure reduction means, such as a hydraulically driven slide rod θ6). According to this, after the end of injection molding, the pot runner manifold (4) is
By placing the molding material under reduced pressure, it is possible to eliminate so-called dripping of the molten molding material from the nozzle (16i (16)) in the hot runner manifold (4).

If the intended molded product is a container, a lid 0η may be provided if desired. In this case, the lid 07) has a snap-engaging type stop piece with an engaging claw (I9) at the tip integrally formed on the outer shell body (9) of the container body θ8), and the stop piece The lid can be locked by snapping the engaging claw (19) of the lid Oη onto the engaging stepped portion of the lid Oη.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional front view showing an example of an injection molding mold device used for carrying out the method of the present invention, and Fig. 2 shows a joined assembly of an outer shell body and an inner shell body molded by the mold of Fig. FIG. 3 is a partially vertical front view of the intended molded product, and FIG. 3 is an inside view of the molded product similar to FIG. A longitudinal cross-sectional view showing an example of a modification of the connection of the outer shell body, Fig. 4 is a longitudinal cross-sectional front view of a helmet with a hollow structure as another example of a molded product, and Fig. 5 is a case in which the molded product as a container has a lid. FIG. 2 is a partially cutaway front view. (1) is a mold for molding the outer shell body, and (2) is a mold for molding the inner shell body. (3) is a hot runner manifold movable platen, (4) is a hot runner manifold, (5) is a hydraulic ram, and (6) is a hot runner manifold movable platen.
) is the nozzle of the molding machine, and (6) is the nozzle touch part 1.
(71+ +8+ is the molding cavity, f91 is the outer shell body, (Ill is the inner shell body, (121
is the joint shoulder, 031 +' (14! is the concave and convex step,
(15) is the slide rod, (161 is the nozzle in the bot runner manifold, θη is the lid, Ol is the claw, - is the stopper piece, (21) is the engaging step, (2'4 is the hinge part. (above)) -riゝFigure 1Figure 2Figure 3Figure 4

Claims (1)

[Claims] ■ The molten molding material is simultaneously injected into the mold for molding the outer shell body and the mold for molding the inner shell body of the desired molded product through a hot runner manifold to mold the outer shell body and the inner shell body. A method for manufacturing a container-type double-structure plastic molded product in which inner and outer shell bodies are joined to form a container-type double-structure product, the method comprising: forming a joining rJ portion where the outer shell body and the inner shell body fit together; A method for manufacturing a container-type double-structured plastic molded product, characterized in that: