JPH0577327A - Forming method for fiber reinforced synthetic resin composite body - Google Patents

Abstract

PURPOSE:To provide a forming method enabling synthetic bodies to be manufactured with an excellent productivity and excellent adhesion between a core material layer and a fiber reinforced synthetic resin layer in a forming method of a fiber reinforced synthetic resin composite body wherein the forming method of a core material and a composite body consisting of forming a fiber reinforced synthetic resin layer therearound is carried out in use of a extraction forming method. CONSTITUTION:Heating mandrels 2,2 are consecutively inserted into a core material 1 and, by taking advantage of the chemical reaction heat of reaction substances sealed into the heating mandrels, the surface temperature of the core material 1 is raised and, in the case of complete heat-hardening conducted in a forming mold 11, the temperature dispersion in the thickness direction that exerts the forming material in the heat-curing area is allowed to be uniform to thus improve the adhesion property of a core layer 16 and a fiber reinforced synthetic resin layer 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for molding a fiber-reinforced synthetic resin composite comprising a core material layer and a fiber-reinforced synthetic resin layer covering the core material layer.

[0002]

2. Description of the Related Art Conventionally, various methods have been known as a method for molding a fiber-reinforced synthetic resin molding, but the internal pultrusion molding method is capable of continuous molding, and has a long cross-sectional shape. It is attracting attention because it can produce the body efficiently.

In particular, when a molded body is molded by a pultrusion method, the strength difference between the drawing direction and the direction perpendicular thereto is large, and the use of the molded body is limited. As a composite formed by forming a fiber-reinforced synthetic resin layer, a molding method is generally used in which an isotropic body is used for the core material at this time so as to eliminate this drawback. Not only the directionality is improved, but also the characteristics of the pultrusion molding method in which the cross-sectional shape can be arbitrarily set by variously combining the core material and the type of resin or fiber material for the outer layer, the thickness of each layer, and the like. In combination, it is possible to obtain a desired product with various physical properties such as strength, weight and the like, and it is an excellent technique in that it is possible to easily obtain a product having rational properties according to the application.

However, the amount of heat for curing the molding material in the molding passage in the mold relies exclusively on heat transfer from the mold. Therefore, looking at the temperature distribution of the molding material in the heat-curing zone, the part that comes in contact with the mold has the highest temperature, the temperature gradually decreases inward (thickness direction), and the part that comes into contact with the core material has the lowest height difference. There is a certain temperature distribution.

Therefore, the curing phenomenon of the resin progresses from the portion in contact with the mold, and the curing in the portion in contact with the core material is delayed most, and since the curing rate of the resin in this outer layer portion is non-uniform, the core material is not cured. Poor resin impregnation due to curing shrinkage at the interface between the fiber-reinforced synthetic resin layer and the fiber-reinforced synthetic resin layer, resulting in voids and cavities, resulting in poor adhesion between the core layer and the fiber-reinforced synthetic resin layer, resulting in reduced strength. The problem of calling
If you try to keep the molding speed as low as possible in order to fully cure the part in contact with the core material, the thicker the fiber-reinforced synthetic resin layer, the lower the molding speed and the expected production speed. There was also the problem of not being able to do it.

To solve this problem, various studies have heretofore been made, one of which is Japanese Patent Laid-Open No. 63-3.
Japanese Patent No. 5332 describes a pultrusion molding method of a composite having a structure in which a metal material is used as a core material and a fiber reinforced synthetic resin layer is formed around the core material. According to this method, two molds are arranged in the molding direction, and the core material made of the metal material sent together with the reinforcing fiber impregnated with the thermosetting resin is,
Reinforcement fibers impregnated with a thermosetting resin are heated inductively by a high frequency in a mold that passes first, and then the reinforcing fibers are heat-cured by heat transfer from the mold by a mold that passes later. However, there can be almost no temperature difference between the surface in contact with the metal core material and the surface in contact with the inner wall surface of the mold. Therefore, the curing rate of the thermosetting resin that is the outer layer can be made uniform. This is a technology that is attracting attention because it can prevent the deterioration of quality and the decrease of production rate due to non-uniformity.

[0007]

However, since the above-mentioned prior art is a heating method utilizing electromagnetic induction, there is a restriction that the core material is limited to a metal, and a problem that it cannot be adopted with a material other than a metal. was there.

The present invention solves the above-mentioned drawbacks of the prior art, and of course, it is possible to heat the core material in advance even if the metal is other than the metal, and to cure the portion of the reinforcing fiber in contact with the core material. It is an object of the present invention to provide a molding method which prevents the delay of the molding, has good adhesion between the core material and the fiber-reinforced synthetic resin layer, and does not sacrifice the productivity.

[0009]

The present invention provides a fiber reinforced synthetic resin for continuously molding a composite comprising a core material layer and a fiber reinforced synthetic resin layer encapsulating the core material layer by a pultrusion method. In the method of molding a composite, a core material having a hollow annular cross section is used, and a high heat is generated by mixing in a hollow container separated into two or more chambers by a partition wall that can be opened by an external force inside the hollow core material. A heating mandrel in which two or more types of reactants to be reacted are individually enclosed is sequentially fed in the molding direction while generating heat, and the core material is pultruded with a reinforcing fiber impregnated with a thermosetting resin to perform pultrusion molding. The gist of the present invention is a method for molding a fiber-reinforced synthetic resin composite, which comprises taking out a heating mandrel after cutting the obtained composite.

Materials for forming the core material of the present invention include metal, wood, ceramics, various synthetic resins, various fiber reinforced synthetic resins, foams of these synthetic resins, etc., but the material is not particularly limited, but is inserted therein. A heating mandrel that has heat resistance against heat generated by the heating mandrel and is excellent in heat transfer to the core material of the amount of heat is selected and used, and its shape must be hollow.

The shape of the heating mandrel used in the present invention is not particularly limited as long as it is suitable for being successively fed into the hollow inside of the core material that is continuously transported. Further, the material is naturally determined by the compound enclosed therein, but a metal material is generally preferable in terms of heat resistance and heat transfer. The length thereof is preferably 0.6 to 0.9 times the cutting length (length of the final product).

The partition wall that can be opened by an external force is, for example, a partition wall provided in the middle of the longitudinal direction of a cylindrical container made of a thin metal plate such as aluminum or iron, and the partition wall is opposite to this partition wall in advance. It has a structure in which a cutting groove that does not communicate with the side is engraved, and when using it, it is tapped from the outside of the container to break this cutting groove. At that time, the one that is used by pulling out the plug, or the same cylindrical container,
A structure in which the two are connected in series and are rotatable in the circumferential direction at the center of the connecting portion, and by the rotation, mutual communication is possible depending on the position of the watertight side plates of the connecting portion. (See FIGS. 2 to 4) and the like.

Further, as the two or more kinds of reaction products which are highly exothermic reaction upon mixing, quick lime and water, iron powder and oxygen and the like are suitable. The required amount of heat cannot be generally stated depending on the material of the core material, the thickness, the temperature required for heating the reinforcing layer, and the like, but normally, the hollow core material should be in the temperature range of 70 to 130 ° C. Well, for that purpose, for example, when quick lime and water are used, the compounding ratio thereof should be 5: 1 to 1: 1.

Examples of the reinforcing fibers used in the fiber-reinforced synthetic resin layer of the present invention include rovings such as glass fibers, carbon fibers, and organic fibers, chopped strand mats, cross mats, lami mats, and the like. Each can be used alone or in combination.

In the present invention, in order to impregnate the reinforcing fiber with the thermosetting resin, a method of impregnating the resin through a resin liquid tank in a step before feeding into the molding die, and opening in the molding passage of the molding die Other known methods such as a method of feeding a resin liquid through the resin liquid insertion port to impregnate the resin liquid can be adopted.

The mold used in the present invention may be a mold conventionally used in the pultrusion molding method, and the heat source may be a heating medium such as electric heat or oil, as well as heating utilizing infrared rays or high frequencies. Examples thereof include a method and the like, and these heat sources are usually used by adjusting the temperature so that the mold temperature is in the range of 100 to 200 ° C.

In the present invention, the other conventionally known pultrusion molding method can be adopted, and after heat curing in a molding die, it is cut as a composite with a drawer cutter to a fixed length. And it is sufficient. Molding speed is usually 0.1-2
It is preferably m / min.

[0018]

The present invention provides a method for molding a fiber-reinforced synthetic resin composite in which a composite comprising a core material layer and a fiber-reinforced synthetic resin layer encapsulating the core material layer is continuously molded by a pultrusion molding method. , A hollow core material having a hollow cross section is used, and two or more kinds of highly exothermic reactions are generated by mixing in a hollow container separated into two or more chambers by a partition wall which can be opened by an external force inside the hollow core material. The heating mandrel, in which the reactants are individually encapsulated, is sequentially fed in the molding direction while generating heat, and is pultruded while being encapsulated with the reinforcing fiber impregnated with the thermosetting resin, and the resulting composite is obtained. Since the heating mandrel was taken out after cutting, the core material was heated by the reaction heat of the heating mandrel, and the reinforcing fiber impregnated with the resin introduced to the outer periphery of the core material was used in the molding die together with the core material. Molding In the temperature distribution in the thickness direction that the molding material receives in the heat curing section, the temperature is received from the wall surface of the molding die and the core material is in contact with the core material. The temperature difference from the temperature received from the part is reduced.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic explanatory view showing an example of a molding step when carrying out the method for molding a fiber-reinforced synthetic resin composite of the present invention, and FIG. 2 is an enlarged cross-sectional view of a heating mandrel used in the same, The container shows a state in which the containers are communicated with each other. Fig. 3 (a) is a sectional view taken along the line ii in the above view and viewed in the direction of the arrow, and Fig. 3 (b) is a roro line of Fig. 4 described later. 4 is a cross-sectional view taken along the line of FIG. 4 as seen in the direction of the arrow, and FIG. 4 is a view showing the heating mandrel shown in FIG. 2 when both containers are set in an independent state. Example In FIG. 1, 1 is a core material, which is made of fiber reinforced thermosetting resin hollow tube formed by filament winding method using No. 2300 glass fiber impregnated with unsaturated polyester resin. , Inner diameter 30mm, thickness 2m
It has a size of m and a length of 2 m. The heating mandrels 2, 2 ... Are sequentially inserted into the mandrel as the core material 1 is transferred.

As shown in FIGS. 2 to 4, the structure is such that the bottoms of the cylindrical containers 3 and 3 whose outer walls are made of an aluminum alloy are overlapped with each other and are rotatable about a shaft 4. There is. The lids 5 and 5 of the containers 3 and 3 are tightly closed, and the stoppers 6 are respectively attached.
Is inserted and removed freely.

A rib is provided on the inside of the peripheral edge portion of the bottom opening of each of the containers 3 and 3, and discs 7 and 7 which are bottom plates are provided on the rib. Both discs 7 and this rib, and one disc 7 and the shaft 4 are fixed, but the other disc 7 is fixed to the shaft 4.
, Is rotatable about its axis.
In addition, about half of each of the circular plates 7 and 7 is a blind plate, and the other half are openings 8 and 8.

Therefore, if the containers 3 and 3 are rotated around the axis 4 and the openings 8 and 8 are opposed to each other as shown in FIGS. Completely communicate with each other, and the containers 3 and 3 are rotated by 180 degrees relative to each other.
In the case of (B), the containers 3 and 3 are completely independent, and the shaft is made watertight by packing not shown.

Then, each container 3 of the heating mandrel 2,
Two or more kinds of reaction products, which are highly exothermic by mixing, are individually enclosed in 3, and in the case of the present embodiment,
One container 3 is filled with 300 g of quicklime A, and the other container is filled with 300 g of water B.

Reference numerals 9 and 9 denote an upper liquid tank and a lower liquid tank, respectively, into which unsaturated polyester resin liquids 10 and 10 which are hardened at a relatively high temperature are injected. 11 is a molding die, 12, 12 ...
..: Reinforcing fiber made of glass roving (Asahi Fiber Co., No. 4500) and continuous mat (Asahi Fiber Co., No. 450) unwound from a large number of bobbins arranged almost vertically in the core 1. However, in this embodiment, the continuous mat is arranged only in the outermost layer. Then, these reinforcing fibers are arranged by a guide plate or the like (not shown) while the upper and lower liquid tanks 1 are arranged.
It passes through 0 and 10 and is guided to the outer periphery of the core material 1 before the molding die 11. 13 is a take-up device, and 14 is a cutter that moves up and down in the direction of the arrow.

With such an apparatus, first, the core material 1 was continuously transferred in the molding direction, and an appropriate number of heating mandrels 2 and 2 were sequentially inserted into the hollow interior thereof. When the heating mandrels 2 and 2 were inserted, the openings 8 and 8 were opposed to each other so that the left and right containers were in communication with each other and shaken gently to mix both components. As a result, quicklime A and water B
React with each other, and slaked lime C is produced as a reaction product as shown in FIG. In addition, the surface of the mandrel 2 was heated.

Further, a hard foam made of an easily cleavable material such as acrylic home is used as a spacer at the planned cutting location, and when the cutting is carried out after the removal, the spacers 15, 15, ... I planned to do it.
By doing this, the cutting work is easy.

However, on the peripheral surface of the core material 1, a large number of glass rovings and continuous mats 12, 12, ... It was introduced into the molding die 11 while adjusting the arrangement by means such as the above. Mold 11
Used a molding material having a length of 900 mm with the molding temperature adjusted to 150 ° C. Here, the molding material such as the reinforcing fiber is heated by heat transfer from the wall surface of the molding passage, and the heating mandrels 2, 2 are already used. ..Heated by the heat transfer from the core material 1, which is heated by the heat transfer from
The unsaturated polyester resin liquid is cured. Thus, the heat-cured molding material was taken by the take-up device 13 and cut into a regular size by the cutter 14. The obtained product was a composite P having a two-layer structure in which the core layer 16 and the fiber-reinforced synthetic resin layer 17 formed on the outer periphery thereof were firmly integrated. The roving amount used in this example was 100 in total. Further, the mandrel 2 in the core material layer 16 was taken out together with the spacer 15, but the mandrel 2 was in a state in which it could be used repeatedly by replacing the reactant therein. Comparative Example A composite was produced in the same manner as in Example except that the heating mandrel was not used.

Thus, the adhesion strength at the interface between the core material layer 16 and the fiber reinforced synthetic resin layer 17 in the test pieces collected from the above-mentioned Examples and Comparative Examples was measured, and the result was 0.7 in the former case.
It was Kg / mm ² , whereas in the latter case 0.2
It was Kg / mm ² .

The adhesion strength was measured according to ASTM C273-61.

[0030]

[Effects] The present invention provides a method for molding a fiber-reinforced synthetic resin composite in which a composite comprising a core material layer and a fiber-reinforced synthetic resin layer encapsulating the core material layer is continuously molded using a pultrusion molding method. , A hollow core material having a hollow cross section is used, and two or more kinds of highly exothermic reactions are generated by mixing in a hollow container separated into two or more chambers by a partition wall which can be opened by an external force inside the hollow core material. The heating mandrel, in which the reactants are individually sealed, is sent in the molding direction while generating heat, and the resulting composite is subjected to pultrusion while encapsulating it with reinforced fibers impregnated with a thermosetting resin. Since the heating mandrel was taken out after cutting, the core material was heated by the reaction heat of the heating mandrel, and the reinforcing fiber impregnated with the resin introduced to the outer periphery of the core material was used in the molding die together with the core material. Molding In the temperature distribution in the thickness direction that the molding material receives in the heat curing section, the temperature is received from the wall surface of the molding die and the core material is in contact with the core material. The temperature difference from the temperature received from the part is reduced.

Accordingly, the curing phenomenon of the resin correspondingly progresses not only from the portion in contact with the mold but also from the portion in contact with the core material, and the curing time is shortened by that much, and at each depth in the thickness direction of the reinforced resin. The curing speed is uniformized, the impregnation of the resin due to curing shrinkage does not occur at the interface between the core material and the fiber reinforced synthetic resin layer, and the one with excellent quality is promptly
It can be obtained stably.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing an example of a molding step when carrying out the method for molding a fiber-reinforced synthetic resin composite of the present invention.

FIG. 2 is an enlarged cross-sectional view of the heating mandrel used in the above, showing a state in which both containers are in communication with each other.

FIG. 3A is a cross-sectional view taken along the line EE of FIG. 2 and viewed in the direction of the arrow, and FIG. 3B is similarly cut along the line ROLL of FIG. It is sectional drawing seen in the direction.

FIG. 4 is an enlarged sectional view of the heating mandrel shown in FIG. 1, showing a state in which both containers are in an independent state.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Core material 2 Heating mandrel 3 Cylindrical container 4 Shaft 7 Disc 8 Opening 9 Resin liquid tank into which thermosetting resin liquid which is hardened at a relatively high temperature is poured 11 Molding die 12 Reinforcing fiber 13 Pulling device 15 Spacer 16 Core Material layer 17 Fiber reinforced synthetic resin layer P Composite

Claims (1)

[Claims] 1. A method for molding a fiber-reinforced synthetic resin composite comprising continuously molding a composite comprising a core material layer and a fiber-reinforced synthetic resin layer encapsulating the core material using a pultrusion method. While using a core material whose surface is a hollow ring,
Inside the hollow, there is a partition wall that can be opened by external force.
A heating mandrel, which individually encloses two or more types of reactants that undergo highly exothermic reaction by mixing, is fed into the hollow container separated into more than one chamber sequentially in the molding direction while generating heat, and this is thermosettable. A method for molding a fiber-reinforced synthetic resin composite, which comprises pultrusion molding while encapsulating with a resin-impregnated reinforced fiber, cutting the obtained composite, and taking out a heating mandrel.