JPH02182421A - Manufacture of fiber reinforced thermoplastic synthetic resin molded article - Google Patents

Abstract

PURPOSE:To lessen the loss of a material and improve the molding efficiency by supplying a raw material containing thermoplastic synthetic resin and fibrous matter in a specific quantity in the form of a web or plate, and pre-heating it at the melting point or higher of thermoplastic synthetic resin so as to conduct kneading, furthermore, supplying it to a molding mold in order to obtain a molded article. CONSTITUTION:A raw material 1 comprises thermoplastic synthetic resin of 60 - 90vol.% and fibrous matter of 10 - 40vol.%, and the fibrous matter is non-woven fabric for consideration of handling them, and it may preferably be of a type which is carried by fusing slightly powder or fine particle-shaped thermoplastic synthetic resin thereon, or using an adhesive component. The raw material 1 supplied therein is forwarded to a pre-heating unit 2. The preheating is heated up to the temperature of melting point or higher of the thermoplastic synthetic resin of the raw material. Next, it is delivered to a screw-typed kneader 6 provided with a heater 7, and melted and kneaded thereby. And, the melted and kneaded matter reserved in an accumulator 8 is supplied to an upper mold 12 passing through a conduit 10, after that, it is molded therein.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for producing a fiber-reinforced thermoplastic synthetic resin molded article. Specifically, the present invention relates to a method for producing fiber-reinforced thermoplastic synthetic resin molded articles that are superior in moldability, material loss, molding efficiency, and the like.

[Conventional technology and its problems]

/ Methods for manufacturing fiber-reinforced thermoplastic synthetic resin molded products include so-called compound materials in which short fibers are kneaded into resin, and materials in which long fiber cloaks are impregnated with resin.

The method of obtaining molded products using these materials is to cut the original Kahozu sheet according to the weight and shape of the molded product, and then heat the sheet with an infrared heater, hot air heater, etc. to completely remove the resin. A molded product is obtained by bringing it into a molten state, conveying it onto a mold of a hot press machine, and press-molding it.

However, this method has the following problems.

a) Depending on the individual molded product, it is necessary to perform raw fabric sheathing, cutting, and sizing, which makes the process complicated and inefficient, and there is a lot of material loss because of the production of cut ends.

b) The material must be transported in a heated and molten state,
Handling is complicated and automation is difficult.

C) Since the heated and molten sheet remains open for a relatively long time, smoke, odor, etc. deteriorate the working environment.

[Means to solve the problem]

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a thermoplastic synthetic resin web or plate-like material containing a specific amount of fibrous material can be melt-kneaded and molded using a specific method. The inventors have discovered that the object can be achieved by doing the following, and have completed the present invention.

That is, the gist of the present invention is that thermoplastic synthetic resin 60-9
A raw material containing θ volume ratio, fibrous material 1o-eo answer St is supplied in the form of a web or plate, and this is preheated to a temperature equal to or higher than the melting point of the thermoplastic synthetic resin, and is then passed through a screw kneader in the preheated state. The present invention relates to a method for producing a fiber-reinforced thermoplastic synthetic resin molded article, characterized in that the melt-kneaded product is introduced into a press mold or an injection mold to obtain a molded article.

Thermoplastic synthetic resins that can be used in the method of the present invention, olefinic resins such as silica, polypropylene, polyethylene, ethylene-propylene copolymer, ethylene-acetic acid e-vinyl copolymer, nylon 6, nylon 6-6, nylon 6- I
O, amide resins such as nylon 12, ester resins such as polyethylene terephthalate and polybutylene terephthalate, styrene resins such as polystyrene, acrylonitrile-styrene copolymer, polyvinyl chloride, plastic IJ
Examples include thermoplastic synthetic resins commonly used in extrusion molding and injection molding, such as vinyl chloride resins such as vinylidene chloride.

Among them, olefin resins are preferably used from the viewpoint of moldability, strength, etc.

As the fibrous material that can be used in the method of the present invention, in addition to inorganic fibers such as glass fibers, carbon fibers, metal fibers, whiskers, and boron fibers, synthetic or natural organic fibers can also be used. Usually glass fiber or preferably 3~! A substance of about rOmg is preferably used.

The ratio of the thermoplastic synthetic resin to the fibrous material must be such that the amount of the fibrous material is 10-1. If it is less than 108% by volume, it will not serve as a reinforcement, and if it exceeds θ volume % (H), uniform melting and kneading will not be possible.

Hereinafter, an example of the method of the present invention will be explained in more detail using the drawings.

FIG. 1 is an explanatory diagram showing, partially in cross section, an example of an apparatus suitable for use in the method of the present invention.

In the figure, l is the raw material (web), C is the preheating device, 3 is the air pump, l is the heater; S is the porous drum, 6 is the kneading machine, 7 is the heater, g is the accumulator, D is the pulp,
IO is conduit 1. , are pulp, ia, i2' are lower and upper molds, respectively. Raw material l is a thermoplastic synthetic resin with a volume of 40-90 and a fibrous material lO~e (with a volume of 17). Preferably, the fibrous material is in the form of a non-woven fabric and a thermoplastic synthetic resin in the form of powder or fine particles is slightly welded or supported using an adhesive component (web form).Such a structure If so, it can be handled by winding it around a core, etc.Of course, this web-like material can be heated to release the resin component 'f.
If the material is melted and then cooled and solidified, a hard plate-like body can be obtained, but such a plate-like body can also be used as a raw material. If a plate-like material is used as the raw material, the subsequent preheating step will be performed in a different manner than when a web-like material is used.

The supplied raw material (if it is in the form of a web) is then sent to a preheating device to be scraped. The preheating device shown in the figure has a built-in perforated drum, and while the web 1 is wound around this perforated drum and transferred, air heated by a heater is passed from the outside of the perforated drum to the inside, and this heat is transferred. Yoshiuepu l
It is a method of heating. Therefore, for this device,
The raw material is applied in the form of a flexible web. If a hard plate-shaped raw material is used, it will be heated with a far-infrared heater, hot air heater, etc. while being transported in a flat state.

This preheating involves heating to a temperature higher than the melting point of the raw thermoplastic synthetic resin, preferably 20° C. or higher than the melting point, and more preferably 50° C. or higher than the melting point. Of course, the resin should not be heated to a temperature that would cause it to decompose.

The raw material consisting of preheated resin and fibrous material is then sent to a screw-type kneading chamber equipped with a heater and melt-kneaded in a bath.

If this melt-kneading is performed too vigorously, the fibrous material will break, so light kneading is preferred, and the purpose is to degas, pressurize, and uniformly disperse the raw materials.

The melted and kneaded material may be sent to its box or press mold, but as shown in the figure, it passes through the pulp 9 and is then sent to the accumulator g.
It is preferable to accumulate the amount once to ensure accurate measurement and to perform smooth delivery all at once.

The melted and kneaded material accumulated in the accumulator g is transferred to the conduit 10.
The material is fed through the lower mold onto the lower mold.

The conduit io is preferably flexible.

By this method, the melted and kneaded material can be supplied to any desired position of the lower mold, and it is possible to handle molded products with large thickness changes. Conversely, the same effect can be obtained even if the mold /λ, /, 2' is made movable. The timing of supply to the mold is done in pulp/l.

Although the figure shows a mold for press molding, it is also possible to place an injection mold here and perform injection molding.

In this case, the melted and kneaded material may be injected all at once from the accumulator g and filled into the cavity of the injection mold.

In the case of injection molding, short length fibrous materials,
That is, the length lO++I! It is preferable to use questions of I+ or less, preferably 5 or less questions, from the viewpoint of dispersibility.

The apparatus used in the method of the present invention is preferably a one-type accumulator, but during kneading, the screw retreats and accumulates the bath melt kneaded material at the tip of the unlinder, and the screw advances all at once to inject (extrude) the bath melt kneaded material. ) may also be used.

〔Effect of the invention〕

There is no need for processes such as sizing the original fabric for each molded product, so there is less occurrence of edge loss. In addition, it can easily handle molded products with changes in wall thickness, and the work is simple. Since the time when the heated sheet etc. is open is short, there are fewer problems such as smoke and odor. It is very effective in practical terms, as it is easy to automate the forming stem.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an example of a device suitable for use in the method of the present invention, partially in section. In the figure, l is the raw material (web), 2 is the preheating device, 3 is the air pump, q is the heater, 5 is the perforated drum, O is the kneading machine,
7 is heater g is accumulator ta is pulp, I
O is conduit, ll is pulp, /2. /l' indicates the bottom and clasp molds respectively.

Claims (1)

[Claims] (1) A raw material containing 60 to 90% by volume of a thermoplastic synthetic resin and 10 to 40% by volume of a fibrous material is supplied in the form of a web or plate, and this is preheated to a temperature equal to or higher than the melting point of the thermoplastic synthetic resin. , a fiber-reinforced thermoplastic composition characterized in that it is introduced into a screw kneader in a preheated state to perform melt-kneading, and the melt-kneaded product is supplied to a press molding mold or an injection molding mold to obtain a molded product. Method for manufacturing resin molded products.