JPH0327921A - Manufacture of fiber reinforced thin wall mold material - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a manufacturing method for manufacturing fiber-reinforced thin-walled sections that can be suitably used as materials for various types of fixtures, furniture, fittings, etc. .

(Prior Art and Problems to be Solved by the Invention) In recent years, synthetic wood shaped using foamable resin with a low expansion ratio has been used for various purposes. It has the disadvantage of low rigidity. In order to improve this drawback, a composite wood product made by embedding reinforcing wires such as glass fiber roving inside the foam has been proposed, but simply embedding the reinforcing wires in the foam will not work. There has been a problem that the reinforcing wire does not play a reinforcing role, such as the foam and the reinforcing wire separating while the laminated wood is subjected to bending action or the like.

Therefore, in an attempt to solve this problem, a reinforcing wire was embedded in a high-density foam with an extremely low expansion ratio, so that the reinforcing wire and the high-density foam would not separate even when subjected to bending, etc. A combination of wood and wood has been proposed.

However, in the case of wood constructed in this way, the specific gravity of the high-density foam is high, which not only increases the weight of the wood but also makes processing such as cutting, drilling, and machining difficult. In addition to poor insulation properties, there was also the problem of increased manufacturing costs due to the large amount of resin. As a result of research in view of such conventional problems, the inventor has discovered the following ■~
With the structure (2) as its main feature, we have achieved a fiber-reinforced, thin-walled profile material that is highly rigid, has excellent dimensional stability, and is also easy to handle during processing and transportation.

■ The entire structure is made of a thin foam made of expandable thermoplastic resin with a low expansion ratio, and ■ Glass fiber rovings are impregnated with a resin liquid containing thermosetting resin at the required length. A core wire 7 made by heating and hardening the resin is buried; ■ The surrounding area of the core wire 7 is a high-density foam layer whose foam density gradually increases from the outside to the inside; ■ The surface is a skin. The biggest technical challenge in manufacturing such thin-walled sections was how to form a high-density foam layer around the core wire. ．． As a result of repeated research on this point, the inventor of the present invention found that it would be better to actively suppress the foaming of the chemical foaming agent used to foam the resin foam around the core wire. I got an idea. The object of the present invention is to provide a method for manufacturing fiber-reinforced thin-walled sections (hereinafter referred to as a manufacturing method) that has been completed by further developing this idea. (Means for Solving the Problems) The manufacturing method of the present invention involves extruding a foamable thermoplastic resin into a thin layer from a mold of an extrusion molding machine, foaming the resin at a low expansion ratio, and In this step, a core wire 7 made by impregnating a glass fiber roving with a resin liquid containing a thermosetting resin and heating and curing the resin is sequentially supplied while the core wire 7 is cooled to room temperature or a lower temperature. When the core wire 7 comes into contact with the foamable thermoplastic resin in the mold, the endothermic action of the core wire 7 causes the resin at the contact area to rise to the thermal reaction temperature of the chemical blowing agent mixed into the foamable thermoplastic resin. The core wire 7 is cooled to the lower limit temperature or a lower temperature to make the resin around the core wire 7 difficult to foam even after it comes out of the mold.
The surrounding area is a high-density foam layer 13 whose foam density gradually increases from the outside toward the inside, and the surface is a skin layer.

Here, as the foamable thermoplastic resin, for example, foamed polystyrene, foamed polyvinyl chloride, foamed polypropylene, etc. can be used, and the expansion ratio is such that the foamed body 2 and the core wire 7 are integrated, The extent to which thermal expansion/contraction and post-shrinkage are prevented, that is, approximately 1.1 to 5 times, preferably 2 to
It is best to set the magnification to a low magnification of 3x. The resin that can be impregnated into the glass fiber roving includes epoxy resin, polyester resin, phenol resin, thermosetting resins that are modified products thereof, acrylic resin, and PVC.
, a thermosetting resin mixed with a thermoplastic resin such as polyamide may be used. Furthermore, the surface hardness of the thin profile material 1 is set to be similar to that of natural wood. Note that the thin-walled shaped material of the present invention can be used not only as a profiled material but also as a plate-like material.

(Example) Next, an example of the present invention will be described based on the drawings. FIG. 1 shows a fiber-reinforced thin profile material manufactured by the manufacturing method of the present invention and used, for example, in handrail applications. Below, we will explain this thin-walled material, and then explain its manufacturing method. (11 Structure of the fiber-reinforced thin-walled shape material The thin-walled shape material 1 has a rectangular cylindrical shape as a whole formed by a thin-walled (for example, about 4 to 8III1) foam 2 made of a foamable thermoplastic resin with a low expansion ratio. , its upper part 3
A core wire 7 is embedded in the lower portion 5 and both side portions 6, 6, and the surface 9 is a skin layer.

In addition, in the longitudinal center of the lower part 5, there is a groove part 1 for fixing the handrail.
0 and a recess l1 are provided. Note that the reference numeral 12 is a metal fitting for fixing the handrail. As the foamable thermoplastic resin,
For example, boristyrene is used, and its expansion ratio is set to about 2.5 times, and the foam 2 and core wire 7 are brought into close contact and integrated by the foaming action of the foamable thermoplastic resin. The core wire 7 is constructed as a wire rod made by impregnating a glass fiber roving with a thermosetting resin liquid (e.g., epoxy-modified resin 'e.) and heating and curing the resin. It is small, has excellent rigidity, is lightweight, and is easy to cut. When the core wire 7 is embedded in the foam 2, a high-density foam layer 13 is formed around the core wire 7, as shown in an enlarged view in FIG. The high-density foam layer 13 is a part of the foam 2, and its density gradually increases from the outside toward the inside, and the portion in contact with the core wire 7 is almost unfoamed. The hardness of the skin layer is set to be close to that of natural wood, although there are some differences depending on the use of the thin-walled shape material.

(2) Production method In order to produce a thin profile material having the above configuration, a foamable thermoplastic resin is extruded from a mold of an extrusion molding machine, and the resin is foamed at a low expansion ratio. The core wires 7 having the above-mentioned structure and cooled to room temperature or lower temperature are sequentially supplied. When the core wire 7 comes into contact with the foamable thermoplastic resin in the mold, the heat absorbing action of the core wire 7 causes the resin at the contact area to be heated by the heat of the chemical foaming agent mixed into the foamable thermoplastic resin. It is cooled to the lower limit of the reaction temperature or a lower temperature.

The chemical foaming agent here generates gas by its thermal reaction and foams the resin with this gas, and the temperature of the thermal reaction is usually appropriately selected between 100°C and 150°C. Therefore, the cooling temperature of the core wire 7 is determined depending on the thermal reaction temperature of the chemical blowing agent used, etc., so that the resin at the contact area of the core wire 7 is at the lower limit temperature of the thermal reaction temperature of the chemical blowing agent.
It is set so that it can be cooled to a low temperature close to O''C or even lower.

This cooling makes the resin around the core wire 7 difficult to foam even after it comes out of the mold, and as a result, the foaming density gradually increases from the outside to the inside of the core wire 7. It becomes high-density foam 7113. Further, the surface of the thin profile material is formed into a skin layer by a conventional method.

(Effects of the Invention) In the present invention, when forming a high-density foam layer around the core wire, the core wire in a cooled state is sequentially supplied into a thin resin extruded from a mold. By suppressing the foaming of the chemical foaming agent based on the cooling effect, it is possible to easily form a high-density foam layer around the core wire in which the foaming density gradually increases from the outside to the inside. and the core wire can be tightly integrated.

For this reason, according to the present invention, it is possible to provide a thin-walled profiled material having the above-mentioned excellent properties.

[Brief explanation of drawings]

FIG. 1 is a perspective view showing an example of the thin-walled profile material manufactured by the manufacturing method of the present invention, together with its usage state, and FIG. 2 is a sectional view showing a high-density foam layer around the core wire. 1... Thin profile material, 2... Foam, 7... Core wire, 9
...Surface, 13...High-density foam layer.

Claims (1)

[Claims] A foamable thermoplastic resin is extruded into a thin layer from a mold of an extrusion molding machine, and the resin is foamed at a low expansion ratio, and a resin liquid containing a thermosetting resin is contained in a glass fiber roving in the extruded resin. The core wire 7 impregnated with the resin and heated and cured is sequentially supplied while being cooled to room temperature or a lower temperature, and when the core wire 7 comes into contact with the foamable thermoplastic resin in the mold. Due to the endothermic action of the core wire 7 at The resin in the portion is made in a state where it is difficult to foam even after it comes out of the mold, thereby forming the surrounding portion of the core wire 7 into a high-density foam layer 13 whose foaming density gradually increases from the outside to the inside, Also, a method for producing a fiber-reinforced thin-walled profile material, characterized in that the surface is a skin layer.