JPH06190930A - Pultrusion method of fiber-reinforced phenolic resin formed article - Google Patents

Abstract

PURPOSE:To obtain a fiber-reinforced phenolic resin formed article not having voids nearly at all by pultusion, by controlling both first and second dies to be at temperatures of the boiling point of water or below any by compounding a curing agent in an optimum range in phenolic resin to be used for impregnation in the first die. CONSTITUTION:Two dies 8 and 9 are used and the first die 8 is kept in a range of temperature not exceeding 50 deg.C, while the second die 9 is heated in a range of temperature of 50 to 80 deg.C. A reinforcing fiber material is introduced into the first die 8, while phenolic resin containing a curing agent in the range of 5 to 15 pts.wt. is supplied, and the reinforcing fiber material is impregnated with the resin. The reinforcing fiber material impregnated with the phenolic resin is drawn out of the first die 8 and introduced into the second die 9 and the phenolic resin is cured in the second die 9. The reinforcing fiber material used for forming is of carbon fibers and composed of ten plies of cloth of 100mm wide. The sheets of this cloth are piled and charged into the first die 8.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a beam, a panel, a pipe made of a fiber-reinforced phenolic resin by pultrusion,
The present invention relates to a method of forming and manufacturing a rod or the like.

[0002]

2. Description of the Related Art As a pultrusion molding and manufacturing method for obtaining a fiber-reinforced phenolic resin molded product, for example, JP-A-2-23
The one described in Japanese Patent No. 5726 is known. In this pultrusion molding and manufacturing method, a phenol resin is heated to an appropriate temperature, the viscosity is lowered to 800 to 3000 cps to impregnate reinforcing fibers, and molding is carried out using a three-stage die at a temperature of 100 to 200 ° C. is there. As seen in this example, the phenol resin generally has a long curing time, and it was necessary to heat the die to a temperature of 100 ° C. or higher in order to obtain a curing rate suitable for pultrusion. As a result, the condensed water generated during the curing of the phenol resin is exposed to a temperature higher than the boiling point and vaporized, and remains as large voids in the molded product.

[0003]

In the above-mentioned pultrusion molding and manufacturing method, since the die is made into a three-stage type and the material is opened to the atmosphere between the dies, there is an effect of allowing condensed water to escape. Since the temperature is higher than the boiling point of water, the problem that voids may remain in the molded product still remains.

Further, in the above-mentioned pultrusion molding and manufacturing method, the phenol resin is heated to reduce the viscosity so that it can be easily impregnated into the reinforcing fiber material. However, the phenol resin may be reversed depending on the amount of the curing agent mixed and the heating temperature. In some cases, gelation proceeds rapidly and the viscosity increases, which may result in poor resin impregnation of the molded product. The heating of the phenol resin is difficult to control the temperature, and is not suitable for mass production of molded products.

An object of the present invention is to solve the above-mentioned problems and to obtain a fiber-reinforced phenolic resin molded product having almost no voids in pultrusion.

[0006]

A pultrusion molding method for a fiber-reinforced phenolic resin molded article according to the present invention, which is directed to this object, is a fiber-reinforced phenolic resin molding by drawing through a heated die while impregnating a reinforcing fiber material with a phenol resin. In the method of continuously obtaining the product, two dies are used, the first die is kept within a range not exceeding 50 ° C, and the second die is used.
The die is heated to a range of 50 to 80 ° C., the reinforcing fiber material is introduced into the first die, and a phenol resin containing a curing agent in a range of 5 to 15 parts by weight is supplied to impregnate the reinforcing fiber material. And the first phenolic resin impregnated reinforced fiber material
From the first die, introduced into the second die, and curing the phenol resin in the second die.

Further, the method for producing a fiber-reinforced phenolic resin molded product according to the present invention is a method for continuously obtaining a fiber-reinforced phenolic resin molded product by pulling it through a heated die while impregnating the reinforcing fiber material with the phenol resin. Two dies are used, the first die is maintained in a range not exceeding 50 ° C, the second die is heated in a range of 50-80 ° C, and the reinforcing fiber material is introduced into the first die. And, a phenol resin containing a curing agent in the range of 5 to 15 parts by weight is supplied to impregnate the reinforcing fiber material and the phenol resin-impregnated reinforcing fiber material is pulled out from the first die and introduced into the second die, The method comprises curing the phenolic resin in the second die.

Phenolic resin generates condensed water with the curing reaction. Therefore, when the curing temperature is set to 100 ° C. or higher, which is the boiling point of water, the generated condensed water becomes steam and, as a result, voids are generated in the molded product. Therefore publicly known literature Phenolic composites make a strong bid i
n high-heat, fire-safe applications (Modern Plasti
cs International, Sep.1989, pp.53-57), curing at temperatures well below the boiling point of water, below 80 ° C, can significantly reduce the cavities remaining in the molded article. it can.

However, if the curing temperature is simply lowered,
Since the curing time becomes long and the drawing speed must be considerably slowed down, practical molding cannot be performed. In order to cure at a temperature sufficiently lower than the boiling point of water and shorten the curing time, it is sufficient to increase the addition amount of the curing agent, but then the pot life of the phenol resin will be shortened, and it will be common for pultrusion molding. Resin bath, which is a resin impregnation method, cannot be used.

Therefore, in the present invention, the mixing ratio of the resin and the curing agent is 100: 5 to 15 by weight (that is, the curing agent is 5 to 15 parts by weight), which is sufficient for curing at a low temperature in the pultrusion die.
In addition, the necessary and sufficient amount of resin is fed to the first die while preferably being automatically and continuously mixed. If the amount of hardener is less than this range, the material will not cure sufficiently while passing through the die. On the other hand, if the amount of the curing agent is larger than the above range, the curing rate will be high even though it is a low temperature curing, and a heat generating effect will be accompanied, resulting in an increase in the die temperature and an increase in voids in the molded product.

The first die is responsible for the resin impregnation step. In order to impregnate the reinforcing fiber material with a sufficient amount of resin without heating the resin in the first die, it is preferable that the resin impregnated portion has a resin pool having a depth of 10 mm or less and a width of 20 mm or less. The inlet is provided on the top, bottom, left or right of the die so that it can be impregnated from both sides in the thickness direction of the molded product different from the inlet of the reinforcing fiber material, and the resin mixed with the curing agent is introduced into the die from this inlet. inject. If the depth and width of the groove of the resin-impregnated portion are out of the above range, the amount of resin accumulated in this groove increases and accompanies heat generation, so that the resin is hardened in the groove and the resin injection port is closed. The temperature of this first die is
Keep it in the range not exceeding 50 ° C.

It is desirable that the clearance through which the reinforcing fiber material of the first die passes is larger than that of the second die in order to easily contain the resin. By setting the clearance as described above, the surplus resin is squeezed at the entrance of the second die.

The temperature of the second die is set to 50 to 80 ° C., and before the material comes out of the second die, the resin is cured to at least a solid state even if it is not completely cured. When the resin has not been completely cured, it is preferable to install an oven between the die and the puller of the pultrusion molding machine so that the molded article can pass continuously, and perform on-line after-curing simultaneously with the pultrusion. If after-curing is performed at a temperature lower than 100 ° C., vaporization of condensed water generated by the reaction of the uncured phenol resin with the reaction is prevented, and a molded product with less voids can be obtained. In addition, if the resin is not completely cured even after this after-cure, the second
After-cure treatment may be applied. Furthermore, if the temperature of the inlet of the second die is set to be lower than 50 ° C., it is possible to prevent the excess resin that has been squeezed and adhered to the inlet from hardening at the inlet, which enables more stable introduction of the material. Become.

When it is necessary to trim the end portion of the molded product, another part is provided upstream of the puller part of the pultrusion molding machine or between the cutter for cutting the molded product on the downstream side of the puller part. Install a cutter or grinder and trim the end of the molded product online at the same time as the pultrusion process. If the trimming amount is relatively small, it can be cut off with a grinder, but if the trimming amount is large, it is preferable to cut off the unnecessary end portion with a cutter.

[0015]

As described above, in the pultrusion molding and manufacturing method of the present invention, both the first and second dies are controlled to a temperature below the boiling point of water, so that condensed water is basically prevented from becoming steam. To be done. The phenol resin impregnated in the first die contains a curing agent in the optimum range, and the second die cures at 50 to 80 ° C. (that is, below the boiling point of water). As a result, the molded product pultruded from the second die is kept in a state where voids are extremely small.

Further, the resin injection port provided in the first die supplies resin from both sides in the thickness direction of the molded product,
The reinforcing fiber material is sufficiently impregnated with the resin, and it is not particularly necessary to heat the resin.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be specifically described below with reference to FIGS. The reinforcing fiber material used for molding is carbon fiber, and is a cloth 10 ply having a width of 100 mm. 10 pieces of this cloth 1 are piled up and put into the first die 8. The first die 8 is at room temperature and the cross section for passing the reinforcing fiber material is 2.5 × 100 mm. The length of the first die 8 was 200 mm, and the drawing speed was 100 mm / min. Separately from the reinforced fiber material inlet of the first die 8, a φ8 resin injection port 2 having a groove 13 having a depth of 6 mm and a width of 13 mm is provided in the resin impregnated portion, and the inside of the first die 8 is provided. The resin was impregnated with. The phenol resin is stored in the resin tank 3, and the curing agent is stored in the curing agent tank 4, and the mixer 7 is used while measuring each piston 5 and 6 at 10: 1.
And then continuously sent to the resin injection port 2. The resin flow rate after mixing was 20 cc / min.

A second die 9 was installed at a distance of 20 cm from the first die 8. The cross section of the second die 9 for passing the reinforcing fiber material was 2.0 × 100 mm, the set temperature was 75 ° C., and the inlet temperature was 40 ° C. Since the length of the second die 9 is 1000 mm and the drawing speed is 100 mm / minute, the curing time in the second die 9 is 10 minutes. The material coming out of the second die 9 is in a solid state, but the curing is still insufficient, so the length is 3000 m.
A hot air oven 10 having a temperature of 90 ° C. and a set temperature of 90 ° C. is installed so that materials can be passed through the oven 10 for post-curing online at the same time as the pultrusion process.
And the end of the molded product was trimmed with the cutter 12.

The cross-section of the thus-pultruded molded product was observed under a microscope (magnification: 100 times), and the void ratio [(void area / total area) × 100] was examined.
% Was extremely low. Moreover, the resin impregnation failure did not occur. Further, by installing the hot air oven 10 for after-cure between the second die 9 and the puller section 11, it is possible to efficiently perform after-cure even for a long molded product without requiring a large oven. I was able to.

[0020]

【The invention's effect】

(1) By the pultrusion molding and manufacturing method according to the present invention, a fiber-reinforced phenolic resin molded product having a small void ratio can be molded. (2) In addition to the reinforced fiber material inlet, the first die has a resin injection port having a groove as a resin reservoir above and below the die,
By providing the resin on the right and left sides or both of them, the reinforcing fiber material can be sufficiently impregnated with the resin without heating the resin, and labor saving in the molding operation can be achieved. (3) If the after-cure oven is installed in the pultrusion molding machine, the efficiency of the molding operation is improved, and even a long molded product can be after-cured without the need for a large oven. (4) Furthermore, if a trimming cutter or the like is installed in the pultrusion molding machine, the molding work can be made more efficient.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a pultrusion molding machine for carrying out a method according to an embodiment of the present invention.

FIG. 2 is a schematic vertical sectional view of the first die of the above embodiment.

[Explanation of symbols]

 1 cloth (reinforcing fiber material) 2 resin injection port 3 resin tank 4 curing agent tank 5 resin delivery piston 6 curing agent delivery piston 7 mixer 8 first die 9 second die 10 hot air system for after cure Oven 11 Puller 12 Cutter 13 Resin pool groove

Claims (7)

[Claims] 1. In a method for continuously obtaining a fiber-reinforced phenolic resin molded product by drawing through a heated die while impregnating a reinforcing fiber material with a phenolic resin, two dies are used, and the first die is 50 The second die is heated to a range of 50 to 80 ° C., the reinforcing fiber material is introduced into the first die, and the temperature of the second die is 5 to 80 ° C.
A phenolic resin containing a curing agent in the range of 15 parts by weight is supplied to impregnate the reinforcing fiber material, and the phenolic resin-impregnated reinforcing fiber material is pulled out from the first die and introduced into the second die. A method for pultruding a fiber-reinforced phenolic resin molded product, characterized in that the phenolic resin is cured in the resin. 2. The pultrusion molding method for a fiber-reinforced phenolic resin molded article according to claim 1, wherein the phenolic resin and the curing agent are continuously mixed and supplied to the first die. 3. The fiber-reinforced phenol according to claim 1, wherein resin injection ports are provided on the top, bottom, left and right, or both of the first die, and a phenol resin is supplied from the resin injection ports to impregnate the reinforcing fiber material. Pultrusion molding method for resin molded products. 4. The first die has a depth of 10 mm or less and a width of 20.
The pultrusion method for a fiber-reinforced phenolic resin molded article according to claim 1, 2 or 3, wherein a resin reservoir having a size of not more than mm is provided, and a phenol resin is supplied to the resin reservoir to impregnate the reinforcing fiber material. 5. The method of pultrusion molding a fiber-reinforced phenolic resin molded article according to claim 1, 2, 3 or 4, wherein the temperature of the inlet of the second die is kept lower than 50 ° C. 6. The molded product drawn from the second die has 10
The pultrusion molding method for a fiber-reinforced phenolic resin molded product according to claim 1, 2, 3, 4, or 5, wherein after-cure treatment is performed at a temperature lower than 0 ° C. 7. In a method for continuously obtaining a fiber-reinforced phenolic resin molded product by drawing through a heated die while impregnating a reinforcing fiber material with a phenolic resin, two dies are used and the first die is 50 The second die is heated to a range of 50 to 80 ° C., the reinforcing fiber material is introduced into the first die, and the temperature of the second die is 5 to 80 ° C.
A phenolic resin containing a curing agent in the range of 15 parts by weight is supplied to impregnate the reinforcing fiber material, and the phenolic resin-impregnated reinforcing fiber material is pulled out from the first die and introduced into the second die. A method for producing a fiber-reinforced phenolic resin molded article, characterized in that a phenolic resin is cured therein.