JPH04259517A - Manufacture and its device for double layer injection molded product - Google Patents

Abstract

PURPOSE:To manufacture a double layer molded product constituted of different kinds of resin materials which are not compatible with each other. CONSTITUTION:The first bottom force 1a and second bottom force 1b are fixed by adjoining to each other and a pair of top forces 2, 2 which are formed in the same form as each other by facing on those bottom forces 1a, 1b are supported axially and freely turnably by a support frame 3. The support frame 3 is constituted freely turnably, consequently, the top force 2 is rotated to the support frame 3 and the top force 2 can be revolved to a position facing on the second bottom force 1b from a position facing on the first bottom force 1a by a rotation of the support frame 3. Then an adhesive agent coating device 4 applying an adhesive agent C to the primary molded product M1 molded by the first bottom force 1a and top force 2 while rotating under a state where the primary molded product M1 is held on the top force 2 is provided in the vicinity of the first bottom force 1b.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a multilayer molded article and an apparatus therefor.

0002

[Prior Art] In general, multi-layered plastic resins are laminated into multiple layers by simultaneous molding using the same or different plastic materials for the purpose of improving functionality such as reinforcement or improving design such as design. Molding is known.

0003

However, in such multilayer molding, when different plastic materials are used, adhesion (natural adhesion) between the two is required. However, since incompatible resins do not stick together in injection molding, it has been impossible to commercialize multilayer molded products by injection molding.

The present invention has been made in view of these problems, and provides a method for producing a multilayer molded product by injection molding even with incompatible resins, and a method for producing a multilayer molded product by injection molding. The present invention provides manufacturing equipment for the same.

[0005]

[Means for Solving the Problems] The method for manufacturing a multilayer molded product of the present invention includes pressurizing and filling a first molten resin into a cavity formed by closing a first lower mold and an upper mold. After the mold is opened and adhesive is applied to a predetermined position of the primary molded product held in the upper mold under the rotation of the upper mold,
The upper mold holding the primary molded product is rotated to a position facing the second lower mold, and the mold is closed with the second lower mold, and then the second mold is placed in the cavity formed by the upper mold and the second lower mold. The method is characterized in that after the molten resin is filled under pressure to perform secondary molding, the mold is opened and the molded product is taken out.

[0006] Furthermore, the multilayer molded product manufacturing apparatus of the present invention includes:
A first lower mold and a second lower mold installed adjacent to each other are alternately opposed to the first lower mold and the second lower mold, and are formed in the same shape and rotated on the support frame respectively. It consists of a pair of upper molds that are pivotably supported, and an adhesive applicator located near the first lower mold. When the primary molded product is rotated to a position facing the second lower mold, adhesive is applied to a predetermined position of the primary molded product held by the upper mold under the rotation of the upper mold. be.

[0007]

[Operation] The first lower mold, the second lower mold, and each upper mold installed adjacent to each other are closed, and the first molten resin is poured into the cavity formed by the first lower mold and the upper mold. After pressure filling and primary molding, the primary molded product is held in an upper mold and the mold is opened. Then, when the adhesive is supplied from the adhesive application device to a predetermined position of the primary molded product while the upper mold is rotating, the adhesive is applied to the entire circumference of the predetermined position.

[0008] Next, the upper mold is revolved to move the primary molded product held by the upper mold to a position opposite to the second lower mold, and the mold is closed with the second lower mold. Then, a cavity formed by the upper mold, the primary molded product held by the upper mold, and the second lower mold is filled with the second molten resin under pressure to perform secondary molding. The cavity during the secondary molding corresponds to the area where the adhesive is applied, and the second molten resin is bonded to the primary molded product via the adhesive. When the secondary molding is completed, the upper mold and the second lower mold are opened, and the secondary molded product is removed from the upper mold to obtain a multilayer molded product.

[0009] In this way, even incompatible resins can be used to produce multilayer molded products by injection molding.

0010

Embodiments Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 shows a schematic configuration of the entire device.
In the figure, 1 is a lower mold fixed on a fixed frame (not shown), and this lower mold 1 is composed of a first lower mold 1a and a second lower mold 1b which are arranged adjacent to each other. . Moreover, these first lower mold 1a and second lower mold 1b
Above, a pair of upper molds 2, 2 each formed in the same shape are supported by a support frame 3 and face each other, and these upper molds 2, 2 are connected to the support frame 3 by a hydraulic motor (not shown) or the like. The rotational axes Ja and Jb are connected to each other via a drive device.
It is rotatably supported around the shaft. On the other hand, the support frame 3 is configured to be movable up and down with respect to a fixed frame (not shown) by a lifting device such as a hydraulic cylinder, and is rotatably supported around a rotation axis J by a hydraulic motor (not shown).

By the way, a first molten resin Ra is pressurized from an injection molding machine (not shown) through a nozzle Na into a cavity Ca formed by closing the first lower mold 1a and the upper mold 2. On the other hand, the cavity Cb formed by closing the second lower mold 1b and the upper mold 2 is filled with a second mold from an injection molding machine (not shown) through a nozzle Nb. It is configured to be filled with molten resin Rb under pressure. In this case, the first molten resin Ra
As polypropylene, polycarbonate or A
BS resin or the like is used, and as the second molten resin Rb, polypropylene, elastomer, or the like is used.

Further, an adhesive applicator 4 is installed on a fixed frame near the first lower mold 1a, and a primary molded product M, which will be described later, is injected from an injection nozzle 41 of the adhesive applicator 4.
An adhesive C such as a hot melt adhesive can be supplied to a predetermined position of 1. In this case, the application of the adhesive C may be carried out by an operator while supporting the injection nozzle 41, or the application may be performed automatically by moving the injection nozzle 41 to a predetermined position using an air cylinder or the like. It's okay.

Next, using these devices, a multilayer molded product M
(See Figure 8) To explain the manufacturing procedure, Figure 1
When the first lower mold 1a and the upper mold 2 are in the closed state shown in FIG. molten resin Ra is filled under pressure and primary molding is performed (Figure 2)
.

Next, when the support frame 3 is raised and the upper mold 2 is opened from the first lower mold 1a, the primary molded product M1 is held in the upper mold 2 by a vacuum suction device (not shown), and the upper mold 2 is opened from the first lower mold 1a. It separates from the lower mold 1a (Fig. 3).

From this state, after the injection nozzle 41 of the adhesive applicator 4 is opposed to a predetermined position of the primary molded product M1, the upper die 2 is rotated about the rotation axis Ja with respect to the support frame 3 (
When the adhesive C is discharged from the injection nozzle 41 while rotating (rotating), the adhesive C is applied to the entire circumference of the primary molded product M1 at a predetermined position (FIG. 4). The primary molded product M1, which is thus suction-held by the upper die 2 and coated with the adhesive C all around the predetermined position, is moved to the second molded product by rotating (revolving) the support frame 3 180 degrees around the rotation axis J. (FIG. 5).

After that, the support frame 3 is lowered and the upper mold 2, which holds the primary molded product M1 under suction, and the second lower mold 1b are closed (FIG. 6). Then, from an injection molding machine (not shown), a second molten resin Rb is injected into a cavity Cb formed by an upper mold 2, a primary molded product M1 held in this upper mold 2, and a second lower mold 1b through nozzles Nb, Nb. Pressurized filling via
Perform secondary forming (Figure 7). In this case, the cavity Cb corresponds to the part to which the adhesive C was applied in the previous step, and as a result, the second molten resin Rb is adhered to a predetermined position of the primary molded product M1 via the adhesive C. Thereafter, by raising the support frame 3 and opening the upper mold 2 from the second lower mold 1b, a multilayer molded product M (FIG. 8), which is a secondary molded product, can be obtained.

Note that during secondary molding, if the cavity Ca formed between the first lower mold 1a and the other upper mold 2 is filled with the first molten resin Ra under pressure, primary molding and Secondary molding can be performed, and molded products can be manufactured continuously by proceeding from primary molding to secondary molding (Figure 7
).

[0019]

Effects of the Invention As described above, according to the manufacturing method of the present invention, it is possible to manufacture a multi-layer molded product made of different types of incompatible resin materials by using injection molding, and the multi-layer molded product can significantly expand the range of production.

Furthermore, according to the manufacturing apparatus of the present invention, a multilayer molded product can be continuously manufactured using an injection device even when different types of resin materials are incompatible.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing a manufacturing apparatus for a multilayer molded product according to the present invention, with some parts omitted;

[Figure 2] Schematic cross-sectional view partially omitting the manufacturing process of a multilayer molded product

[Fig. 3] Schematic cross-sectional view partially omitting the manufacturing process of a multilayer molded product

[Fig. 4] Schematic cross-sectional view partially omitting the manufacturing process of a multilayer molded product

[Fig. 5] Schematic cross-sectional view partially omitting the manufacturing process of a multilayer molded product

[Fig. 6] Schematic cross-sectional view partially omitting the manufacturing process of a multilayer molded product

[Figure 7] Schematic cross-sectional view partially omitting the manufacturing process of a multilayer molded product

[Figure 8] Front view showing a part of the multilayer molded product in cross section

[Explanation of symbols]

1 Lower mold 1a First lower mold 1b Second lower mold 2 Upper mold 3 Support frame 4 Adhesive applicator Na, Nb nozzle J, Ja, Jb Rotating axis M Multi-layer molded product

Claims (2)

[Claims] Claim 1: A cavity formed by closing a first lower mold and an upper mold is filled with a first molten resin under pressure to perform primary molding, and then the mold is opened and held in the upper mold. After applying adhesive to a predetermined position of the primary molded product under the rotation of the upper mold, the upper mold holding the primary molded product is rotated to a position facing the second lower mold, and the second lower mold is After closing the mold and performing secondary molding by pressurizing and filling the cavity formed by the upper mold and the second lower mold with a second molten resin, the mold is opened and the molded product is taken out. A method for manufacturing a multilayer injection molded product characterized by: [Claim 2] A first lower mold and a second lower mold installed adjacent to each other, alternately facing the first lower mold and the second lower mold, and formed in the same shape. a pair of upper molds each rotatably supported on a support frame;
When the upper mold is rotated from a position facing the first lower mold to a position opposite to the second lower mold, 1. An apparatus for manufacturing a multilayer injection molded product, characterized in that the adhesive is applied to a predetermined position of a primary molded product held by an upper mold under rotation of the upper mold.