JPS63315218A - Injection molding method of plastic containing fiber - Google Patents

Abstract

PURPOSE:To improve sharply the strength of a plastic molded product containing a fiber and to unify the same, by constituting the title method so that the fibers in every layers of the plastic molded product containing the fibers to be formed in a plurality of layers are stretched in the direction crossing each other. CONSTITUTION:Adjustment is performed so as to widen an injection space formed by molds 1, 2 as shown by an arrow before a filled out plastic material 14 containing a fiber solidifies sufficiently. With this construction, the plastic material containing the fiber whose inside is not solidified yet is moved by leaving the same as it is stuck to the insides of the molds 1, 2, and a plastic shell 15 having a space 16 within the same is formed. Supply of the plastic material 14 containing the fiber based on a pressing-in supply machine 12 is performed again by opening a gate 9 continuously. With this construction, the material 14 is supplied and filled out within the space through an opening 7, whose direction is different from the foregoing supply direction by 90 deg., through a branch flow path 5 this time and a double-layer plastic molded product containing the fiber is molded. With this construction, a drastic improvement in strength of the molded product and lowering of directional properties in the strength can be attained.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for injection molding fiber-filled plastics.

[Prior Art] In recent years, attempts have been made to mix fibers into plastic to strengthen plastic molded products.

Figure 3 shows an example of a plastic injection molding machine.
A supply port d provided in the mold so as to communicate the plastic material from the push feeder C to the injection space formed by the male mold a and the female mold, for example, to the center of the injection space. The plastic is molded by supplying and filling the plastic through the plastic and solidifying it.

When molding a fiber-containing plastic material mixed with fibers using a plastic injection molding machine as described above,
As shown in FIG. 4, the direction of the fibers e in the plastic material is perpendicular to the flow direction F of the plastic material flowing in from the supply port d, that is, the direction of the circumference centered on the supply port d. It aligns in the same direction. For this reason, conventional fiber-containing plastic molded products have had the problem of not being able to secure sufficient strength because the directionality of the strength has been changed.

On the other hand, plastic molded products are being molded into multiple layers. That is, after injection molding is performed in the same manner as described above with the injection space between molds a and b made thinner than the target thickness of the molded product, the injection space between molds a and b is made as shown by arrow A before the plastic material has sufficiently hardened. Adjust so that the injection space between molds a and b is expanded. Then, the unsolidified plastic material inside moves while adhering to the inner surfaces of the molds a and b, and a plastic acid q having a space f inside is formed. Subsequently, when the plastic material is supplied by the push-in feeder C through the supply port d, the plastic material is supplied and filled into the space f.
It is possible to obtain plastic molded parts in layers.

Therefore, at this time, by supplying a different plastic material from the previous one to the space f using another push-feeding machine, it is possible to mold a plastic molded product using different materials for the inner and outer layers. . Further, by repeating the above operations, it is possible to mold a plastic molded product having three or more layers.

[Problems to be solved by the invention] However, even in the molding of the above-mentioned multi-layer plastic molded product, when molding is performed using fiber-containing plastic material,
As shown in Figure 4, since the fibers are aligned in the circumferential direction around the supply port d, there is a problem that the strength is directional, so there is little point in having multiple layers. .

The present invention was made by focusing on the above-mentioned conventional problems.
By applying conventional multi-layer plastic molding technology, the aim is to orient the fibers of a fiber-containing plastic molded product in cross directions to achieve uniform strength.

[Means for solving the problems] The present invention attempts to solve the above technical problems, and
A space created by supplying and filling a fiber-containing plastic material into the injection space while maintaining the injection space formed by the mold at a spacing thinner than the target thickness of the molded product, and then expanding the injection space. A layered fiber-filled plastic molded product is formed by supplying and filling the fiber-filled plastic material from a direction crossing the flow direction of the fiber-filled plastic material filled into the injection space. This invention relates to a method for injection molding fiber-filled plastic.

[Function] Therefore, in the present invention, the fibers in each layer are oriented so as to intersect with each other, thereby improving and making uniform the strength of the fiber-containing plastic molded product.

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

Figure 1.2 shows an example of an apparatus for carrying out the method of the present invention, in which a plastic material supply channel 3 is formed inside one of the male mold 1 and female mold 2 that form an injection space. At the same time, the supply channel 3 is branched into two branch channels 4 and 5,
One of the branch channels 4 is connected to the circumferential direction of the thin plate-shaped injection space. Open the lower part to the side to
In addition, an opening/closing device 10.1 is provided in each of the openings 6.7 with an opening/closing game 1-8.9 capable of opening and closing the openings 6.7 separately.
1 will be provided. In the figure, reference numeral 12 indicates a push feeder equipped with a screw 13 and introduces the fiber-containing plastic material 14 into the supply flow path 3, I5 indicates plastic acid, 16 indicates space, and 17 indicates fibers.

Injection molding of fiber-filled plastic according to the present invention is carried out as follows.

First, keep the injection space between the molds 1 and 2 thinner than the target thickness of the molded product, and open one gate 8.
With the other gate 9 closed, the fiber-containing plastic material 14 is forced and fed by the forced feeder J2. Then,
The material 14 is filled into the injection space from the opening 6 via the supply channel 3 and the branch channel 4. Gate 8 when supply ends
to close the opening 6.

Next, before the filled fiber-containing plastic material 14 is sufficiently hardened, the injection space formed by the molds 1 and 2 is adjusted to be expanded as shown by arrow A. Then, the inside or unhardened fiber-containing plastic material or mold 1,
A plastic acid 15 with a space (6) inside is molded onto the inner surface of (-1).

Subsequently, the gate 1-9 is opened and the fiber-containing plastic material 14 is again fed by the push-in feeder 12. Then, the material 14 is now fed through the branch flow path 5 in a direction 90° from the above-mentioned feeding direction. The material is supplied and filled into the space 16 from a different open lower part, thereby forming a two-layer fiber-filled plastic molded product.

At this time, since the feeding direction of the first layer material and the feeding direction of the second layer material are different by 90 degrees, the direction of the mixed fibers 17 is different between the first layer and the second layer. It's 90
The direction is changed so that they are oriented in intersecting directions as shown in FIG. Therefore, due to the orientation shown in "-", it is possible to significantly increase the strength of the fiber-containing plastic molded product and to reduce the directionality of the strength.

In the above embodiments, the case of molding a two-layer molded product was explained, but the above operation can be repeated to mold three or more layers, and in that case, the fiber-containing plastic material is supplied in three directions, By changing the directions such as four directions, the directions of the fibers can be intersected in a complicated manner, thereby improving the strength of the molded product and making the strength uniform.

Note that the present invention is not limited to the above-mentioned embodiments, and the material can be supplied as long as the direction of the large flow of the fiber-containing plastic material to be supplied and filled into the injection space is perpendicular or intersects at a required angle. The position of the opening can be selected arbitrarily, the material can be prepared using a plurality of feeders as shown in Fig. 3, and various methods can be adopted for the opening/closing device of the opening. Of course, various other changes may be made without departing from the gist of the invention.

[Effects of the Invention] As described above, according to the injection molding method for fiber-filled plastic of the present invention, the fibers in each layer of the fiber-filled plastic molded product formed in multiple layers are oriented in directions that intersect with each other. , the strength of the fiber-containing plastic molded product can be significantly increased and made uniform, which is an excellent effect.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing an example of a plastic injection molding machine that implements the method of the present invention, Fig. 2 is an explanatory diagram of the orientation of fibers when Fig. 1 is viewed from the FIG. 4 is an explanatory diagram of the orientation of fibers when FIG. 3 is viewed from the IV-IV force direction. 1 is a male mold, 2 is a female mold, 3 is a supply channel, 4°5 is a branch channel, 6.7 is an opening, 8.9 is an opening/closing gate, 10.11
12 is an opening/closing device, 12 is a push feeder, 14 is a fiber-containing plastic material, 16 is a space, and 17 is a fiber. Figure 4 8'106

Claims (1)

[Claims] 1) In a state where the injection space formed by the mold is maintained at a spacing thinner than the target thickness of the molded product, fiber-containing plastic material is supplied and filled into the injection space, and then the injection space is expanded. A layered fiber-filled plastic molded product is formed by supplying and filling the fiber-filled plastic material into the injection space from a direction crossing the flow direction of the fiber-filled plastic material filled in the injection space. An injection molding method for fiber-filled plastic.