JPH0796552A - Method of manufacturing pultruded products - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a method for producing a pultruded article having no surface scratches and excellent surface smoothness and gloss. [Structure] A resin-impregnated reinforcing fiber 17 for forming a molded article body,
It is introduced into the pultrusion molding die 18. While the thermosetting resin for forming the molded article body is uncured or semi-cured, the thermosetting resin 20 for forming the surface layer is injected from the groove 185 into the mold 18 on the surface thereof. Between the semi-curing and the curing of the thermosetting resin for forming the surface layer, the opening 2 is formed in the mold 18.
Air heated to 120 ° C. is pressed between the mold surface and the thermosetting resin 20 for forming the surface layer at a pressure of 6 kgf / cm ² . The thermosetting resin 20 for forming the surface layer and the thermosetting resin for forming the molded article body are integrally cured and pulled out.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a pultruded product having no surface damage and excellent surface smoothness and gloss.

[0002]

2. Description of the Related Art Conventionally, molded articles obtained by the pultrusion method are
Since the fiber pattern of the base material is exposed on the surface, not only the surface smoothness is not good as it is, but the fiber pattern itself becomes defective in appearance, so that the surface layer portion,
Using a reinforcing fiber material such as a non-woven fabric or a surface mat, and laminating a large amount of resin impregnated with the matrix resin to form a resin-rich surface layer, or after once forming a pultruded product, It has been generally practiced to apply a coating to the pultruded product by a method such as coating to make the surface smooth.

However, when a reinforcing fiber material such as a non-woven fabric or a surface mat is used, the material itself is also composed of fibers, and the irregularities due to the fibers stand out on the surface and the pull-out resistance force. However, there is a problem that not only a large driving force is required to increase the driving force but also a scratch is easily generated on the surface, and a surface smoothness cannot be obtained.

Further, when coating is applied, the internal mold release agent leaches out onto the surface of the molded product, so that the adhesion of the paint layer is poor, and in order to improve it, pultrusion molding is performed before applying the coating. Since the surface of the product needs to be treated, there are problems that the number of steps is increased, the molding speed is slowed down, and the manufacturing cost is increased.

Further, when a transparent coating material is applied to give gloss, the fiber grain of the reinforcing fiber material on the surface is unsightly and unsightly. Therefore, it is necessary to apply the coating material in advance in order to hide the fiber grain. However, there is a problem that the molding speed increases, the molding speed becomes slow, and the manufacturing cost increases.

Further, as a method for reducing the drawing resistance with respect to the mold surface and preventing the surface of the pultrusion molded article from being rough, for example,
As described in JP-A-48-93671, when a fiber base material impregnated with a thermosetting resin is passed through a mold for continuous molding, an internal mold release is performed on the surface that contacts the fiber base material and the mold. A method in which a non-woven fabric coated with an agent is used to pull out and cure, and the like have also been proposed.

[0007]

However, only by interposing a non-woven fabric coated with an internal release agent, the pull-out resistance is still large, the surface is easily scratched, and the surface smoothness is sufficiently satisfied. There is a problem that you cannot get things.

The present invention has been made for the purpose of solving the above-mentioned conventional problems, and providing a method for producing a pultrusion molded article having no surface damage and excellent surface smoothness and gloss. .

[0009]

According to the present invention, a resin-impregnated reinforcing fiber for forming a molded article main body, which is obtained by impregnating a reinforced fiber composed of continuous fibers with an uncured thermosetting resin, is placed in a drawing mold. Leading, a method of manufacturing a pultruded molded article to pull out while thermosetting the thermosetting resin for forming the molded article body, while the thermosetting resin for forming the molded article body is uncured or semi-cured, A thermosetting resin for surface layer formation is supplied to the surface from a resin injection pipe provided in the mold, and the thermosetting resin for surface layer formation is applied to the mold during the period from semi-curing to curing. A thermosetting resin for forming a surface layer and a thermosetting resin for forming a molded article body while pressurizing heated air between a mold surface and a thermosetting resin for forming a surface layer through an air injection pipe provided. It is a method for producing a pultruded product that integrally cures.

In the present invention, as the reinforcing fiber in the molded article body, for example, roving of glass fiber, carbon fiber, organic fiber, etc., continuous strand mat, chopped strand mat, cross mat, lami mat, etc. are used. Usually, roving is mainly used, but various mats may be used together. The volume content of the reinforcing fibers in the resin-impregnated reinforcing fibers for molding the molded article body is preferably 30 to 50%.

In the present invention, the thermosetting resin for forming the molded article body and the thermosetting resin for forming the surface layer include thermosetting unsaturated polyester resin, epoxy resin, vinyl ester resin, phenol resin and the like. Resin is used. The thermosetting resin for forming the molded article body and the thermosetting resin for forming the surface layer may be thermosetting resins of the same system, or different types of thermosetting resins. Good. However, it is preferable to select and use those in which the thermosetting resins cross-link each other at the curing stage to form a chemical bond structure.

A filler may be added to the thermosetting resin for forming the surface layer in order to improve the adhesive strength due to the anchor effect to the thermosetting resin for forming the molded article body. As the filler, for example, calcium carbonate, aluminum hydroxide, glass powder, glass beads, glass balloons, whiskers, etc. that can be used in a solid state without being dissolved in a thermosetting resin can be used. It may be organic or organic.

As the filler, spherical particles, fibrous powders, flaky powders and the like can be used, but glass powders, glass beads, glass balloons and the like which maintain the light transmittance are used. preferable. The amount of the filler added is preferably 200 parts by weight or less based on 100 parts by weight of the thermosetting resin and having an average particle size of 5 to 50 μm.

In the present invention, the thickness of the surface layer is preferably 80 to 250 μm in order to obtain a stable product.

In the present invention, the pultrusion molding die is divided into two zones, with the inlet side serving as the first curing section and the outlet side serving as the second curing section in the molding direction. The temperature control of the mold is such that it can be operated independently, and the cross-sectional area of the mold surface is such that the thickness of the surface layer formed on the surface of the molded article is larger in the second hardening section than in the first hardening section. What is enlarged by a corresponding amount is preferably used.

In the present invention, when the thermosetting resin for forming the molded article body is uncured or semi-cured, for example, the thermosetting resin is used as a raw material in the first curing section of the pultrusion molding die. It refers to a stage in which a gelled state is maintained after being heated from an uncured state at the time of supply to proceed a curing reaction to some extent.

In the present invention, while the thermosetting resin for forming the molded article body is uncured or semi-cured, its surface is
As a means for supplying the thermosetting resin for forming the surface layer to the mold from the resin injection pipe provided in the mold, for example, a groove along the width direction is formed on the upper surface of the mold surface in the pultrusion molding mold. Is provided
Thermosetting resin for surface layer formation can be supplied to the groove from an external resin tank via a resin injection pipe, etc., and the fiber-reinforced resin heat for forming the molded product body that passes through the pultrusion mold. At the time when the curable resin passes through the portion provided with the recessed groove, a method of setting the thermosetting resin therein to be in an uncured or semi-cured state is adopted. The injection pressure of the resin liquid from the resin injection pipe into the groove is approximately 1.0 to 5 kgf /
A range of cm ² is preferred.

The position where the heated air is pressed between the mold surface in the mold and the thermosetting resin for forming the surface layer through the air-pressing pipe provided in the mold is the thermosetting for forming the surface layer. It is necessary to set the position between the semi-curing and the curing of the resin. When the thermosetting resin for forming the surface layer is from semi-cured to cured, for example, the thermosetting resin is heated at a low temperature in the second curing section of the pultrusion mold, and the curing reaction proceeds to some extent. It means a stage from a semi-cured state in which a gelled state has been reached to a certain extent to a completely gelled and cured state. The cured state is measured by, for example, separately measuring the curing time of the thermosetting resin for forming the surface layer with a curast meter (press molding is performed to track the torque behavior of the molding material). ) The method of guessing is adopted.

As a method for pressurizing the heated air, for example, an opening is provided on the upper surface of the mold surface on the outlet side in the drawing direction with respect to the resin injection pipe of the pultrusion molding die, and the opening is provided with the air injection pipe. Heated air is supplied from the outside of the mold so that the air is only in the direction perpendicular to the drawing direction and only the thermosetting resin for forming the surface layer hits the space between the mold surface and the surface layer. It is preferable to press-fit. When the pultruded product to be obtained has a wide width, it is preferable to properly arrange a plurality of the pultruded products along the width direction.

The pressure of the press-fitted air is 2 to 7 kgf / c.
m²Is preferred and 3 to 6 kgf / cm²Is more preferred
Yes. Pressure is 2kgf / cm²If less than, surface layer formation
It is possible to reduce the frictional force between the thermosetting resin for molding and the mold surface.
Not possible, conversely, 7 kgf / cm ²Above, the air is gold
It flows backward in the direction of the mold inlet and, on the contrary, has a smooth surface.
It is impossible to obtain a punched product. Temperature of press-fit air
Is preferably 100 to 150 ° C. As a means of heating air
For this, a method of passing an electric heater or the like is appropriately adopted.

In the present invention, the forming speed by the take-off device in the pultrusion process is usually preferably 20 cm / min to 2 m / min, and a cutter is installed immediately after passing through the take-off device to cut a product of a fixed length. And it is sufficient.

[0022]

The method for producing a pultruded molded article according to the present invention is characterized in that while the thermosetting resin for forming the molded article body is uncured or semi-cured,
A thermosetting resin for surface layer formation is supplied to the surface from a resin injection pipe provided in the mold, and the thermosetting resin for surface layer formation is applied to the mold during the period from semi-curing to curing. A thermosetting resin for forming a surface layer and a thermosetting resin for forming a molded article body while pressurizing heated air between a mold surface and a thermosetting resin for forming a surface layer through an air injection pipe provided. By integrally curing the, by the pressurized heated air,
Since there is a gap between the surface of the thermosetting resin for forming the surface layer and the mold surface between the semi-cured state and the cured state, the mold surface of the thermosetting resin for forming the surface layer is formed. The frictional resistance to and is significantly reduced.

As a result, it is possible to continuously produce a pultrusion molded article having a surface layer excellent in surface smoothness and gloss without causing scratches on the surface. Further, since the heated air is press-fitted, the thermosetting resin for forming the molded article body is not rapidly cooled, and the integral curing with the thermoset resin for forming the molded article body is not hindered. The surface layer of the obtained pultruded article is fixed to the body of the article with excellent adhesive strength at the interface.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a front view for explaining the steps of one embodiment of the method for producing a pultrusion molding product of the present invention, and FIG. 2 is a cross-sectional view for explaining the peripheral portion of the pultrusion molding die which is the main part thereof. It is a figure. The reinforcing fiber 12 for forming the molded article body is passed through the impregnation tank 14 filled with the thermosetting resin 13 to obtain the reinforcing fiber 1
2 is impregnated with the thermosetting resin 13, and a cloth or sheet-like material 16 is superposed on the entire outer peripheral surface thereof,
A fiber-reinforced resin thermosetting resin 17 for forming a molded article body is formed, and this is guided to a drawing molding die 18.

The pultrusion molding die 18 is divided into two zones, and the first curing section 1 is located on the inlet side in the molding direction.
81, the outlet side is the second curing section 182, the first heating means 183 is provided on the outer periphery of the first curing section 181.
A second heating means 184 is provided on the outer periphery of the second curing section so that the temperature control in each curing section can be operated independently. The cross-sectional area of the mold surface is
The second hardening section 182 is larger than the first hardening section 181 by an amount corresponding to the thickness of the surface layer formed on the surface of the molded article body.

In the pultrusion mold 18, a groove 185 is formed in the widthwise direction on the upper surface of the mold surface at a substantially central portion, that is, a substantially intermediate portion between the first hardening section 181 and the second hardening section 182. Is provided in the groove 185.
1, the thermosetting resin 20 for forming the surface layer can be supplied through the resin injection pipe 19.

A cooling water passage 186 is provided around the recessed groove 185 of the pultrusion die 18 so that the cooling water can be circulated therein, whereby the recessed groove 185 is formed. Curing of the resin liquid injected inside is suppressed.

The thermosetting resin in the fiber-reinforced resin thermosetting resin 17 for forming the main body of the molded article that passes through the pultrusion molding die 18 is uncured or semi-cured when it passes through the concave groove 181. The temperature of the first curing section is controlled so that the cured state is achieved.

An opening 211 is provided on the upper surface of the mold surface of the second curing section 182, and the opening 211 connects the mold surface and the surface of the thermosetting resin 20 for forming the surface layer through the air press fit pipe 21. The heated air can be pressed in between. The thermosetting resin 20 for forming the surface layer passing through the pultrusion molding die 18 is temperature-controlled in the second curing section so as to be in a semi-cured state at the time of passing through the portion of the opening 211. It

Then, the fiber-reinforced resin thermosetting resin 17 for forming the main body of the molded article is introduced into the pultrusion molding die, and in the pultrusion molding die, the surface thereof is subjected to thermosetting for forming a surface layer. The resin 20 is supplied, and at a position where the thermosetting resin 20 for forming the surface layer is semi-cured, the thermosetting resin for forming the surface layer is formed between the mold surface and the opening 211 provided in the mold. While pressurizing the heated air, it passes through the drawing mold 18 and is heated and shaped and hardened by the heating means 184, which is continuously drawn out by the drawing device 22 and appropriately cut by a cutting device (not shown). By cutting into lengths, as shown in FIG. 3, a pultrusion molded product 11 is obtained by integrally curing a surface layer 112 on the outer peripheral surface of a molded product body 111.

Example 1 By the steps shown in FIGS. 1 and 2, pultrusion molding was performed at a speed of 20 cm / min to obtain a pultrusion molded article 11 having a surface layer 112 having a thickness of 0.1 mm as shown in FIG. It was

As the reinforcing fiber 12 for forming the molded body,
Glass roving (Asahi Fiber Co., No. 4450)
Continuation mat (Asahi Fiber Co., Ltd., 45
No. 0) was used. As the thermosetting resin 13 in the resin-impregnated reinforcing fiber 17 for forming the molded article body, 100 parts by weight of an isophthalic acid-based unsaturated polyester resin, 1.0 part by weight of t-butylperoxybenzoate, and 10 parts of calcium carbonate.
A mixture of 1 part by weight and 0.7 part by weight of an orthophosphoric acid internal release agent was used.

As the thermosetting resin 20 for forming the surface layer,
100 parts by weight of isophthalic acid-based unsaturated polyester resin, 1.5 parts by weight of t-butylperoxybenzoate, and glass powder (manufactured by Nippon Fellow, trade name "M-50
0S ", average particle diameter 35 μm) 150 parts by weight, and an orthophosphoric acid internal release agent 0.7 parts by weight were used.

The mold temperature was 100 ° C. for the first curing section, 150 ° C. for the second curing section, and 60 ° C. near the groove 181.
The mold size is 1000 mm in total length (first curing section 500
mm, second hardening zone 500 mm), and the portion of the concave groove 181 was set to 500 mm from the die inlet. The injection pressure of the thermosetting resin 20 for forming the surface layer was set to 5 kgf / cm ² . Set the position of the heated air inlet 211 from the mold inlet to 7
It was set to 50 mm. The pressure at which heated air is pressed in through the opening 211 is set to 6 kgf / cm ² , and the temperature is set to 120
℃ was made.

With respect to the obtained pultruded product, the appearance was observed and the glossiness was measured. The glossiness is
According to JIS K 7105, 60 ° specular gloss (%) was measured with a gloss meter. As a result, the pultruded product obtained has no scratches on the surface and has excellent surface smoothness,
Moreover, the 60 ° specular gloss was 95%, which was excellent in gloss.

Example 2 A pultruded product was obtained in the same manner as in Example 1 except that the pressure of the heated air to be injected was 3 kgf / cm ^2, and the appearance was observed in the same manner as in Example 1. The glossiness was measured. As a result, the obtained pultruded product had no surface scratches, excellent surface smoothness, and 60 °
The specular gloss was 95%, which was excellent in gloss.

Comparative Example 1 Example 1 except that the pressurization of heated air was not performed.
In the same manner as in Example 1, a pultruded product was obtained, and the appearance was observed and the glossiness was measured in the same manner as in Example 1. As a result, the pultrusion molding obtained had a scratch on the surface, was inferior in surface smoothness, and had a 60 ° specular gloss of 65%, which was inferior in gloss.

[0039]

EFFECTS OF THE INVENTION Since the pultrusion molded article manufacturing method of the present invention is constructed as described above, it is possible to continuously produce a pultrusion molded article having no surface scratches and excellent surface smoothness and gloss. You can

[0040]

[Brief description of drawings]

FIG. 1 is a front view illustrating one step of a method for manufacturing a pultrusion molded product of the present invention.

FIG. 2 is a cross-sectional view illustrating a peripheral portion of a mold which is a main part of FIG.

FIG. 3 is a perspective view showing an example of a pultrusion molded product obtained by the present invention.

[Explanation of symbols]

 11 Molded Product 12 Reinforcing Fiber 13, 20 Thermosetting Resin 14 Impregnation Tank 17 Resin Impregnated Reinforcing Fiber 18 Pultrusion Mold 19 Resin Injection Pipe 20 Thermosetting Resin 21 Air Pressurizing Pipe 22 Pulling Device 111 Molded Product Main Body 112 Surface Layer 185 Groove 211 opening

Claims (1)

[Claims] 1. A resin-impregnated reinforcing fiber for forming a molded article main body, which is obtained by impregnating reinforced fibers made of continuous fibers with an uncured thermosetting resin, is introduced into a pultrusion molding die to form a molded article main body. A method for producing a pultruded molded article, in which the thermosetting resin is heat-cured while being pulled out, and the thermosetting resin for forming the molded article body is provided on the surface of the mold while it is uncured or semi-cured. The thermosetting resin for forming the surface layer is supplied from the resin injection pipe, and the surface of the thermosetting resin for forming the surface layer is pressed from the semi-cured to the cured surface by the air injection pipe provided in the mold. The thermosetting resin for forming the surface layer and the thermosetting resin for forming the molded article body are integrally cured while pressurizing heated air between the thermosetting resin for forming the surface layer and the thermosetting resin for forming the surface layer. A method for producing a pultruded product.