JPH0326521A - Method for manufacturing fiber-reinforced composite molded product - Google Patents

Abstract

PURPOSE:To prevent a reinforcement fiber from coming up to the surface, by a method wherein at the time of or after bringing molten resin extruded through a die into contact with an external circumference of a matter in an uncured state under a state of pulling down, the title body is formed by cooling thermoplasitic resin while causing a form correcting device to abut against the external circumference of the thermoplastic resin. CONSTITUTION:An angular pipe 2 in a rectangular form is manufactured continuously of ABS resin by an extruding machine 1, a glass fiber roving 3 of an external circumference of the angular pipe 2 is impregnated with thermosetting resin through saturated polyester resin bath 4, a rectangular matter 6 in an uncured state is obtained with a squeezing nozzle 5 and the same is passed through an extruding machine 7 for coating. On the one hand, ABS resin is melt-extruded through a circular-ring-like die 23, a flow part 24 of conical resin comes into contact with the external circumference of the matter in the uncured state, directly after becoming almost angular form, a form correcting device 8 abuts against the same, the same is led to a cooling water tank 9 while performing external form control of angular four sides and the whole circumference of a coating layer is cooled for solidification. Then the same is cured in a hot water tank 10 and a fiber-reinforced composite molded body in a state of an angular pipe is obtained. With this construction, it becomes a state where the matter 6 in the uncured state is filled into a preshaped thermoplastic resin frame and surface smoothness of the whole of a product is secured.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Application Field) The present invention relates to a method for manufacturing a fiber-reinforced composite rod body, and in particular to a method for manufacturing a fiber-reinforced composite rod to prevent poor appearance due to streak-like protrusion of reinforcing fibers in an internal fiber-reinforced resin. Regarding the method.

<<Background of the Invention>> Fiber-reinforced thermosetting resin pultrusion molded products, which are made by impregnating a long reinforcing material with thermosetting resin and shaping and curing it into a predetermined shape, are lightweight. High strength and high resilience. High rigidity, corrosion resistance,
It is used for various purposes due to its excellent properties such as non-conductivity.

Conventionally, this type of pultrusion molded product is generally manufactured by impregnating reinforcing fibers such as glass fiber roving with an uncured thermosetting resin, and then curing it in a heated mold while taking it off. However, due to problems such as resistance to drawing from the mold, the drawing speed was extremely slow and there was a problem in productivity.

The present applicant has proposed a method that can solve this problem by coating a mixture of reinforcing fibers impregnated with an uncured thermosetting resin with a thermoplastic resin, and then coating the interior with an uncured thermosetting resin. Japanese Patent Publication No. 56-20188 has already provided a method in which productivity can be significantly improved by allowing the thermoplastic resin coating to function as the above-mentioned mold by curing.

According to this method, fiber-reinforced thermosetting resin products can be manufactured with high production efficiency, and the resulting products also have a thermoplastic resin coating layer on the outer periphery, which effectively protects the fiber-reinforced thermosetting resin. And weather resistance. Corrosion resistance, water resistance, bending resistance, etc. can also be improved.

However, when the outer diameter dimension is regulated and a predetermined high rigidity is required, it is necessary to increase the ratio of the fiber-reinforced thermosetting resin (hereinafter referred to as FRP) portion that contributes to strength such as bending rigidity.

However, if the ratio of the FRP part is increased and the thickness of the thermoplastic resin coating layer on the surface is reduced, a convex shape reflecting the protrusion of reinforcing fibers will occur on the surface of the thermoplastic resin coating layer after the FRP part is cured. There was a problem with the appearance.

Therefore, even if the thermoplastic resin coating layer is relatively thin, the present inventors have developed a fiber-reinforced resin coating layer that has a smooth surface with few irregularities on the thermoplastic resin coating layer that reflects the embossment of the reinforcing fibers after curing. The present invention was completed after intensive study on a method for manufacturing a composite molded body.

(Means for Solving the Problems) In order to achieve the above object, the method for manufacturing a fiber-reinforced composite molded article of the present invention includes an uncured fiber-reinforced composite molded article in which reinforcing fibers are impregnated with a thermosetting resin and shaped into a predetermined shape. After seamlessly covering the outer periphery of the object with a molten thermoplastic resin coating layer and cooling and solidifying the coating layer, the uncured thermosetting resin inside is cured to form a thermoplastic resin-coated fiber-reinforced composite molding. In the method for manufacturing a body, the formation of the thermoplastic resin coating layer is carried out when or after the molten resin extruded from the die is brought into contact with the outer periphery of the uncured material. The feature is that the shape correction tool is cooled while being brought into contact with the tool.

The reinforcing fibers that can be used in the method of the present invention include inorganic fibers such as glass fibers, carbon fibers, ceramic fibers, and alumina fibers, or elongated fibers such as aromatic polyamide fibers, nylon fibers, polyester fibers, and vinylon fibers. Preferably, the material has adhesive properties with the thermosetting resin as the matrix resin and can exhibit a reinforcing effect.

In addition, thermosetting resins include unsaturated polyester resin and vinyl ester resin. Epoxy resin, phenol resin, etc. can be used.

On the other hand, the thermoplastic resin forming the outer layer can be any type of resin as long as it can be melt-extruded, but the thermoplastic resin after curing can be
When adhesion with the RP layer is desired, a material having affinity with the above thermosetting resin, such as ABS, which is a thermoplastic resin having styrene as a derivative when styrene is used as a crosslinking monomer of the thermosetting resin, is used. Resin, AAS resin, PS resin (polystyrene resin), or PC! resin (polycarbonate resin), etc.

In the manufacturing method of the present invention, covering in a drawn state means:
A coating die having an opening larger than the final coating cross-sectional area of the thermoplastic resin extrudes the molten resin at a speed slower than the take-up speed after coating, so that the die opening contacts the outer periphery of the uncured material. In other words, it means coating in a state where a truncated cone-shaped or truncated pyramid-shaped resin flow is formed between the coating end point and the coating end point.

When coating in the above-mentioned drawn state, in the process of coating the outer periphery of the uncured material while decreasing the temperature from a molten state to a softened state, the inner circumference corresponding to the final product shape is The external shape of the composite rod-shaped body is controlled by cooling the composite rod-shaped body while it is brought into contact with the shape correction tool, and then the entire body is cooled.

The position, length or surface temperature at which the shape correction tool is brought into contact, and the inner diameter dimension in the case where the entire circumference is brought into contact at the same time, are adjusted as appropriate in consideration of the coating conditions, speed, etc.

(Function) In the method of the present invention, when coating the outer periphery of an uncured material obtained by impregnating reinforcing fibers with an uncured thermosetting resin, the thermoplastic resin changes from a molten state to a solid state. While the layer is still in a softened state, it is cooled while being brought into contact with a shape correction tool whose inner shape corresponds to the shape of the final product, so that the surface of the coating layer is smoothed and the uncured material inside is also removed from the coating layer. The thermoplastic resin coating layer on the outer periphery is cooled and solidified while being shaped into the shape of the shape correcting tool through the . In this state, the surface smoothness of the entire product is ensured. In addition, since the thermoplastic resin coating layer on the surface is in close contact with the outer periphery of the uncured material, the two can be bonded or adhered in the subsequent curing process, and the effects of the surface coating, such as weather resistance, water resistance, and corrosion resistance. , handling, impact resistance, etc.
It is possible to produce a fiber-reinforced composite hollow body that has properties such as light weight, high strength, and high rigidity.

"Example} The present invention will be explained below using preferred embodiments.

Example 1. ABS resin is extruded from an extruder 1 to continuously produce rectangular square vipes 2 with an inner dimension of 4 C)+m and an outer dimension of 43 cm, and on the outer periphery of this rectangular pipe 2, a single yarn diameter of 23.5-m and a fabric weight of 4.4 are formed. g/
A required number of glass fiber rovings 3 of m are introduced into an unsaturated polyester resin bath 4 and impregnated with a thermosetting resin, and drawn with a drawing nozzle 5 to form a rectangular uncured material 6 with an outer dimension of 49 mm.
This was passed through a coating extruder 7 and coated with molten ABS resin.

A detailed explanation of this ABS resin coating is as follows.
As shown in FIG. 2, in the head section 20 of the coating die, the uncured material 6 is first introduced into the central passage of the nipple 21, which has a jacket shape, and the cooling water 22 is circulated through the nipple 21. This prevents troubles such as partial hardening of the thermosetting resin attached to the tip of the nipple 21, etc. On the other hand, ABS resin (MFR-0.8) is melt-extruded at 220°C from an annular die 23 with an outer diameter of 86+a+*, and the ratio of the cross-sectional area of the coating after completion of coating to the cross-sectional area of the opening of the annular die, i.e. The drawing ratio was set to 2.5, and the conical resin flow part 24 was installed at the inlet of the cooling water tank immediately after it came into contact with the outer periphery of the uncured material and became approximately rectangular, and the inner side was set at 5 0 + am. corner, length 80
A shape correction tool 8 configured to be able to be divided into upper and lower parts by mm was brought into contact with the polygon, and the outer shape of the four sides of the rectangle was controlled while the coating layer was introduced into a cooling water tank 9 to cool the entire circumference of the coating layer. During the formation of the coating, the pipe 27 of the die head was connected to a vacuum line to reduce the pressure inside the coating layer, thereby discharging the generated gas and making the coating points uniform. In this example, the coating thickness was 0.5 mm.

After the coating layer is cooled and solidified, it is introduced into a hot water bath 1o and cured to produce a rectangular pipe in which the glass fiber volume content of the FRP layer is 54%, and the internal rectangular pipe, FRP layer, and external ABS coating are integrated. A fiber-reinforced composite molded article was obtained.

The coated surface of this composite molded product had significantly fewer streak-like irregularities compared to the composite molded product of Comparative Example 1, which will be described later, and had a surface roughness of 150-1 when measured with a micrometer.

Comparative example 1. A rectangular pipe-shaped fiber-reinforced composite molded article was obtained in the same manner as in Example 1, except that the shape correction tool was not brought into contact with the outer periphery during coating with the thermoplastic resin.

The obtained composite molded body has a height of about 0.3 to 0.4 on the coated surface.
+*m, 7 in 1 side 50 stripes with a width of about 3 to 5 squares
~8 lines stood out.

Example 2. When obtaining the same rectangular pipe 2 and uncured material 6 as in Example 1 and covering them with ABS resin, the nipple used in Example 1 was replaced, and only the essential parts are enlarged in FIG. As shown in FIG.
The inner periphery 25 of the cooling former is brought into contact with the uncured material 6 while being cooled by the cooling former, and at the same time as this contact, Example 1
In the same manner as above, the shape correcting tool 8 was brought into contact with both the inner and outer circumferences to cool and correct them, and the coating layer was cooled and solidified in a cooling tank.

Thereafter, the uncured thermosetting resin inside was cured in the same manner as in Example 1, and a rectangular vibrator having the same dimensions and the same glass fiber content as in Example 1 and having an integrated ABS layer and FRP layer was obtained. A fiber-reinforced composite molded article was obtained.

The coated surface of this composite molded article had a surface roughness of 80-1 as measured by a micrometer.

<Effects> According to the method of the present invention, the fiber-reinforced composite has a beautiful surface because there is less occurrence of streak-like irregularities on the surface of the thermoplastic resin coating layer due to reinforcing fibers popping out or disordering. This will improve the product value. In addition, conventionally, in order to reduce surface irregularities, it is necessary to increase the thickness of the coating, and in this case, the dimensions must be increased, or if the upper limit of the dimensions is regulated, the FRPWI must be made thinner. According to the present invention, it is possible to provide a method for manufacturing a fiber-reinforced composite molded article that takes advantage of the composite with a relatively thin thermoplastic resin while maintaining high productivity.

[Brief explanation of drawings]

Fig. 1 is an overall explanatory diagram of the manufacturing process of the fiber-reinforced composite molded article of the present invention, Fig. 2 is a sectional view of the die part of an extruder for coating thermoplastic resin, Fig. 3 is an enlarged view of the main part of Fig. 2, FIG. 4 is an enlarged view of the main parts of the second embodiment. 3...Glass fiber roving (reinforcing fiber) 6.
... Uncured material 8 ... Shape correction tool 9 ... Cooling water tank Fig. 3 Fig. 4

Claims (1)

[Claims] After impregnating reinforcing fibers with a thermosetting resin and shaping the uncured material into a predetermined shape, the outer periphery of the uncured material is seamlessly covered with a molten thermoplastic resin coating layer, and the coating layer is cooled and solidified. In the method for producing a thermoplastic resin-coated fiber-reinforced composite molded article by curing the uncured thermosetting resin, the formation of the thermoplastic resin coating layer is carried out when the molten resin extruded from the die is not yet drawn down. A method for manufacturing a fiber-reinforced composite molded article, which comprises cooling the thermoplastic resin while bringing a shape correction tool into contact with the outer periphery of the thermoplastic resin during or after contacting the outer periphery of the cured article.