JPS61211367A - Composite material composed of long fiber and thermoplastic resin and thermoplastic resin and production thereof - Google Patents

Abstract

PURPOSE:To obtain continuously and simply a composite material having a high strength, by applying a treating agent to the surfaces of a plurality of long fibers, feeding them to a plasticating heating cylinder with a built-in screw to cut them into short fibers and kneading them together with a thermoplastic resin to combine them. CONSTITUTION:A plurality of continuous fibers 2 such as filament, strand or roving made of carbon or glass are fed to a treating tank 3 to apply a treating agent 4 such as a resin component and a lubricating component thereto, and the coated fibers are dried in a drying chamber 5 to form a coating film. The fibers are continuously fed to the opening 8 of a plasticating heating cylinder 7 with a built-in screw 9. While the long fibers 2 are wound up by the rotation of the screw 9, the fibers 2 are cut in lengths of screw groove pitch 16 between the flight 10 of the screw 9 and the inner wall of the cylinder 7. The cut fibers and a molten thermoplastic resin 12 fed from a resin feed mechanism 11 are kneaded together to obtain the desired composite material 14.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a composite material comprising various long fibers such as carbon or glass and a thermoplastic resin, and a method for producing the same.

[Conventional technology] In recent years, by adding carbon or glass fiber to thermoplastic resin, it has improved its strength and rigidity compared to the original resin, and has come to be used in industrial applications as a structural material. .

Conventionally, in composite materials using thermosetting resins, long fibers could be used very easily because the composite with fibers was mainly performed by impregnating the fibers in a liquid resin or a resin solution.

However, there are two main methods for producing thermoplastic resins: one is the usual molding methods such as injection molding and extrusion molding using pellets, and the other is the production of resin plates using long fibers. This is a method of molding this by heating and pressurizing it.

In the former case, fiber lengths of 3 to 6 m are mainly used for mixing with resin.
m short fiber type is used, and even if long fibers with a length longer than this are used and mixed with resin, they will be cut during pelletization, and the length of the fibers contained in the pellet will vary depending on the length of the pellet. In addition, no significant improvement in mechanical strength can be expected when compared to thermosetting materials during molding. In addition, the latter uses continuous long fibers as a reinforcing material, which improves mechanical strength and other properties, but there are restrictions on molding methods, etc., and the use of the resin is limited to a specific range. The current situation is that

[Problems to be Solved by the Invention] In view of the above-mentioned circumstances, the present invention provides a high-strength composite material, which could not be obtained with conventional composite materials of thermoplastic resin and short fibers, by combining long fibers and thermoplastic resin. The goal is to obtain this extremely easily and continuously.

[Means for Solving the Problems] The present invention applies a treatment agent such as a resin component or a lubricant component to the surface of continuous long fibers such as filaments, strands, or ropings made of carbon or glass as appropriate and dries them to form a coating. After forming, the long fibers are continuously fed into the opening of a plasticizing heating cylinder containing a screw, and as the screw rotates, the long fibers are wound up between the threaded part of the screw and the inner wall of the plasticizing heating cylinder. The long fibers are cut off by the length of the screw groove pitch, and then fed continuously or intermittently from the resin supply tank, and kneaded and integrated with the thermoplastic resin melted by the plasticizing heating cylinder to obtain a composite material. This is what I did.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a diagram showing the process of manufacturing the composite material of the present invention, where ■ is a supply reel in which long fibers [2] made of filaments of carbon, glass, etc. are wound and housed, ■ is a lubricating component, A tank filled with a processing agent [4] such as a resin component, ■ is a drying chamber, ■ is a fiber feeding roller, ■ is a plasticizing heating cylinder, ■
is the opening, ■ is the screw, [phase] is the screw thread,
■ is the resin supply tank, @ is the thermoplastic resin, [phase] is the front discharge port of the plasticization heating cylinder, ■ is the mixed composite material, [phase] is the coating on the fiber surface, [phase] is the screw groove pitch .

When producing a composite material, first the long fibers [2] are fed out from the supply reel ■ and passed through the tank ■, where a treatment agent such as a lubricating component or a resin component is applied to the surface of the long fibers ■.
4] and then passed through a drying chamber to form long fibers.
The unnecessary solvent that adheres to the surface is scattered and removed, and a film (phase) of the lubricating component or resin component is formed. After that, the long fibers [2] are continuously fed to the opening (■) of the plasticizing heating cylinder [7] containing a screw (■), and while the long fibers [2] are wound up by the rotation of the screw (■), The long fibers [2] are scraped off by the length of the screw groove pitch between the threaded part [phase] of the screw ■ and the inner wall of the plasticizing heating cylinder, and then fed continuously or intermittently from the resin supply tank ■.
While being kneaded and integrated with the thermoplastic resin @ melted by the plasticizing heating cylinder [7], it is sent out to the front discharge port [phase] of the plasticizing heating cylinder [7].

The kneaded molten resin (2) discharged from the discharge port may be used as a raw material, or it may be cut into appropriate sizes and used as a material for pressure molding using a mold or the like.

At this time, since a coating is formed on the surface of the fed fibers, damage to the fibers due to friction between the fibers and resistance from the molten resin is suppressed, and the formation of short fibers is prevented.

In this way, a composite material consisting of long fibers and thermoplastic resin can be easily obtained.

[Effects of the Invention] As mentioned above, the composite material according to the present invention is made of long fibers having a fiber length of about 20 to 30 mm cut at the screw groove pitch and a highly productive thermoplastic resin,
Conventional thermoplastic resin molded products made by combining single fibers could only achieve a tensile strength of about 480 kg/c7, whereas the tensile strength of the composite material made of glass fiber and polypropylene according to the present invention was only about 480 Kg/c7. The mechanical strength is approximately 890 kg/c112, which is twice as high as that of conventional products, making it possible to provide extremely superior molded products.

In addition, in the composite material of the present invention, the types of fibers and resin to be mixed can be freely combined by appropriately selecting a treatment agent for the fiber surface, and furthermore, by adjusting the amount of fiber supplied, the fibers and resin in the composite material can be mixed. It goes without saying that the filling amount can be freely set, and this invention is extremely useful in today's world where there is a demand for highly functional resins. −

[Brief explanation of the drawing]

FIG. 1 shows an example of a method for producing a composite material made of long fibers and a thermoplastic resin according to the present invention, and FIG. 2 shows a cross-sectional view of a case where a film of a lubricating component or a resin component is formed on the surface of the long fibers. FIG. 3 is an enlarged view showing an example of how the long fibers are fed to the plasticizing heating tube and the fibers are cut by the screw. ■: Long fibers, ■: Processing agents such as lubricating components and resin components, ■: Screws, ■: Plasticizing heating tubes, ■: Thermoplastic resins, ■: Composite materials. Patent applicant: Taiheiyo Kogyo Co., Ltd. Figure 1

Claims (2)

[Claims] (1) A film is formed on the surface of long fibers such as carbon or glass having a fiber length of 20 to 30 mm with a treatment agent 4 such as a resin component or a lubricant component, and this is kneaded and integrated with a thermoplastic resin. Composite material. (2) After applying a treatment agent [4] such as a resin component or a lubricating component to the surface of a plurality of continuous long fibers such as filaments, strands, or roping [2] and drying it to form a coating [15], Plasticizing heating cylinder [with built-in screw [9]
Continuously feed the opening [8] of the screw [9]
While winding up the long fibers [2] by rotation, the long fibers [2] are scraped by the length of the screw groove pitch between the threaded part [10] of the screw and the inner wall of the plasticizing heating cylinder [7]. The long fibers and heat are then continuously or intermittently supplied from the resin supply tank [11] and kneaded and integrated with the thermoplastic resin [12] melted by the plasticizing heating cylinder [7]. A method for manufacturing a composite material comprising a plastic resin.