JPS6210113Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a new glass strand mat used in press molding and resin injection molding, which are known as molding methods for glass fiber reinforced plastics (FRP) products.

Conventionally, various FRP products have been manufactured by press molding such as cold press molding and hot press molding, and resin injection molding.

Currently, glass contained strand mats (hereinafter referred to as "contained asmats") are widely used as reinforcing materials in press molding and resin injection molding of FRP products.
This container smut is an extremely bulky pine made by intertwining continuous glass strands in a curled shape and bonding them into a pine shape with a binder, so there are wide gaps between the glass strands, and the wood permeates through these gaps. It has good flow properties, so-called wet-through properties, and there are no drawbacks due to poor wet-through of the resin during press molding and resin injection molding.
It has the advantage of being less likely to occur in FRP products. However, the container strand mat has a problem in that it has poor cutting workability in cutting into predetermined dimensions compared to the glass chopped strand mat. In addition, the Container Smart
FRP products have lower mechanical strength than FRP products reinforced with glass chopped strand mats.
It also has the problem of poor strength isotropy, the tendency to cause glass whitening (a phenomenon in which glass strands become white on the surface of FRP products), and the surface appearance of having many uneven surfaces. There is.

The glass strand pine of the present invention solves the problems of the above-mentioned container strand pine.It is an FRP with excellent pine cutting workability, high strength and isotropic surface finish. It has the characteristics of being able to provide products, and having wet-through characteristics comparable to a container mat during press molding and resin injection molding, and excellent molding workability.

The present invention will be explained below with reference to the drawings.

Figure 1 shows one of the glass strand mats of the present invention.
An example is shown in a cross-sectional schematic diagram.

The glass strand mat shown in Figure 1 is a glass chopped strand mat with a mass of 150 g/1 square meter on both surface layers, which is made by bonding glass chopped strands with a cut length of 100 mm into a mat shape with a bonding agent. Layer 1, the middle layer is formed from a continuous mat layer 2 with a mass of 300 grams per square meter / 1 square meter of continuous glass strands mated together with a binder, with a total mass of 600
It has a three-layer structure of grams/1 square meter.

Stack 3 of these glass strand mats for 60
Place it in a press mold for a flat plate at ℃ and apply resin (unsaturated polyester resin containing a hardening agent) to the mat.
Press molding was carried out under the conditions of a press pressure of 5 kg/cm ² and a mold clamping time of 20 minutes to obtain an FRP board with a thickness of 4 mm. This FRP
The surface appearance of the plate was extremely good, with little glass whitening and a smooth surface finish, and the bending strength was extremely high at 26 kg/mm ² .

Under exactly the same conditions, using a conventional container mat with a mass of 600 g/1 square meter, the surface appearance of a 4 mm thick FRP obtained by press molding showed strong glass whitening, and the finished surface was also poor. It has many unevenness and its bending strength is poor.
It was 17Kg/ ^mm2 .

A press-formed plate reinforced with the glass strand mat of the present invention has a better surface appearance and significantly higher bending strength than a press-formed plate reinforced with a conventional container mat.

In addition, each FRP panel obtained by resin injection molding under exactly the same molding conditions using the glass strand mat of the present invention shown in Fig. 1 and a conventional container mat with a mass of 600 g/1 square meter. As a result of comparing the characteristics, the bending strength of the glass strand mat reinforced with the present invention was 24.6Kg/ ^mm2 , and that of the container reinforced with the continuous mat was 14.5Kg/mm2.
mm ² , the glass strand mat of the present invention is much higher in width, and the surface finish of the glass strand mat of the present invention is also smoother with less whitening and strand lifting. The finish was warm.

The containment mat layer that forms the middle layer of the glass strand mat of the present invention is a layer that mainly functions to improve the wet through of the resin during press molding and resin injection molding. It is preferable to make the layer bulky so that the gaps between the strands are wider than the pud strand pine layer. Further, the glass chopped strand mat layer forming the surface layer is a layer that mainly functions to improve the strength and surface finish of the FRP product. In other words, the glass chopped strands are joined into a uniform two-dimensional structure with a high reinforcing effect, and the glass chopped strand mat layer has a high glass density and has narrower gaps between the strands than the continuous mat layer. By strengthening the outermost layer of the FRP product, the glass fiber content of the outermost layer of the FRP product increases, and the glass strands in that area are arranged in a highly reinforcing arrangement.
The strength of FRP products can be greatly improved.

In addition, the glass chopped strand mat layer has a uniform two-dimensional strand structure, and the strands on the mat surface have less unevenness than conventional continuous mats with a three-dimensional strand structure. The microscopic distribution is also good and smooth, so it can be used like a continuous smut.
This has the effect of smoothing and improving the surface finish of FRP products without causing the glass strands on the outermost layer of FRP to stand up during FRP product molding.

The glass strand mat of the present invention has a three-layer structure in which both surface layers are made of glass chopped strand mat and the middle layer is made of glass container mat, and is suitable for press molding and resin injection molding of FRP products. By using it as a reinforcing material, it has the advantage that cutting workability is greatly improved and molding workability is also improved compared to when conventional container smuts are used. In addition, the resulting FRP products have better surface appearance, significantly higher strength, and better isotropy than conventional FRP products using containment smut as a reinforcing material.

[Brief explanation of the drawing]

FIG. 1 is a schematic cross-sectional view showing one example of the glass strand mat of the present invention. Explanation of symbols: 1...Glass chopped strand mat layer, 2...Contained strand mat layer.

Claims (1)

[Scope of utility model registration request] A glass strand mat having a three-layer structure in which both surface layers are formed of glass chopped strand mat and the middle layer is formed of glass continuous strand mat.