JPS6321592Y2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a reinforced glass fiber body for FRP.

FRP is manufactured by impregnating and hardening a reinforcing fiber body such as glass fiber with liquid thermosetting resin, and has great strength and corrosion resistance.
Widely used as a structural material for various items such as ships.
The factors that affect the strength of FRP are (1) the type of reinforcing fibers and resin that make up FRP, (2) the blending ratio of reinforcing fibers and resin, (3) the molding method, and (4) the amount of thermosetting resin used. Among these factors, the type of reinforcing fibers and the blending ratio of reinforcing fibers and resin have a large effect on the strength of FRP, and various proposals have been made to obtain FRP with high strength. .

For example, by using glass fiber rovings aligned in one direction, the strength in that direction can be increased, but the strength in the direction perpendicular to that direction is extremely weak.

Generally the weight% of glass fiber reinforcement in FRP
The larger the GC (GC), the stronger the FRP tends to be.Furthermore, when using the pressing method, it is easier to obtain FRP with a large GC, but when using the hand-laying method, the GC tends to be higher.
It is difficult to obtain large FRP. Therefore, large objects that are difficult to mold using a press method, such as
In the case of FRP boats, it is difficult to obtain a product with sufficient strength.

By using a cloth made by weaving glass fiber roving (roving cloth) as a reinforcing fiber body, FRP with a high GC and high strength can be obtained even by hand-laid method, but there are the following difficulties. (1) The strength of the roving cloth in the bias direction is weaker than the strength in the vertical and horizontal directions (roving direction). (2) When impregnating roving cloth with liquid thermosetting resin, air bubbles are often mixed in.
When air bubbles get stuck between individual glass fibers, it is difficult to completely remove them, resulting in a decrease in FRP strength.
This may cause poor appearance.

The present invention is a new proposal based on research to solve the above-mentioned difficulties and to obtain a reinforcing fiber body for FRP that has a large GC, no undesirable non-uniformity of strength due to direction, and has easy removal of air bubbles. be.
That is, the present invention consists of a first layer 1 in which long glass fiber bundles 3 having a flat cross section and a weight of 550 to 150 gr per 1000 m are piled up in a curved manner in no direction, and glass fiber bundles 3 cut into short pieces. Smaller cross-sectional area and 1000m
For FRP, characterized in that glass fiber bundles 4 each having a weight of 50 to 10 gr are brought into close contact with a second layer 2 deposited in a non-directional manner, and the second layer is formed thinner than the first layer. This invention relates to a reinforced glass fiber body.

As detailed below, by using the reinforcing glass fiber for FRP of the present invention (hereinafter referred to as the "reinforcing material"), the strength parallel to the lamination direction has no directionality.
FRP can be obtained, but it is also possible to make the strength particularly high in one direction if desired. In this case, if the relationship between strength and direction is plotted in polar coordinates, it will be approximately circular, and the strength in other directions (bias direction) will not be significantly reduced as in the case of using a roving cloth.

Next, the present reinforcing member will be described in more detail with reference to the accompanying drawings.

1 is a first layer made of long glass fiber bundles 3, and 2 is a second layer made of glass fiber bundles 4 cut into short pieces. The glass fiber bundle 3 has a flat cross section and is stacked in a non-directionally curved manner, and the glass fiber bundle 4 has a smaller cross-sectional area than the glass fiber bundle 3 and is stacked non-directionally. These glass fiber bundles are bonded together using a binder made of thermoplastic resin such as polyester, epoxy, or polystyrene.

The glass fiber bundle 3 is produced by applying a general-purpose sizing agent such as vinyl acetate, polyester, or epoxy to a large number of glass fibers pulled out from a bushing, converging them into a glass fiber bundle, and traversing the glass fiber bundle. It can be manufactured by winding it up on a mandrel that rotates at high speed. When the glass fiber bundle is wound around a mandrel, it is tightly wound and has a flat cross section. The thickness to width ratio is about 1:10 to 1:20. Note that it is also possible to make the cross section flat by passing the glass fiber bundle between rolls and squeezing it. Also, the weight of glass fiber is 550 to 150g per 1000m of glass fiber bundle.
(approximately 2000 to 500 pieces). If the weight per 1000m of glass fiber bundle exceeds 550gr, the fibers will bounce and the fit will be extremely poor, especially at corners where the radius is small. Also, during FRP molding,
In the vertical section, the thicker the glass fiber bundle, the worse the reinforcing fiber body will be able to hold the resin.For example, when using the hand-laid method where general polyester resin is used, the resin will not be held as well and the resin will sag before it hardens. , tends to create hollow parts inside.

On the other hand, if the weight per 1000 m of glass fiber bundle is less than 150 gr, the amount of resin absorbed into the reinforcing fiber body will increase, making it impossible to obtain an FRP with sufficient strength and a large GC.

A large number of wound glass fiber bundles (referred to as cakes) are held by a creel, and the glass fiber bundles 3 are drawn out in parallel from these cakes and deposited on a moving conveyor while being applied with a binder to form the first layer. can be caused to form. As the binder, thermoplastic resins such as epoxy, polyester, and polystyrene are suitable, and the amount used is preferably 2 to 5 wt% of the glass fiber bundle as a solid content.

Note that the glass fiber bundle 3 may be fed onto the conveyor uncut, or may be cut as appropriate and fed.
The supply amount of the glass fiber bundle is suitably 2000 to 300 gr, preferably 1000 to 400 gr per 1 m ² .

Note that when cutting the glass fiber bundle, it is desirable to make the cutting length as long as possible in order to improve the performance of FRP. It is appropriate that the cutting length is 100 cm or more, preferably 150 cm or more, and even when using glass fiber bundles cut in this way, the strength is sufficiently high.
You can get FRP.

By constructing the reinforcing glass fiber body for FRP of the present invention based on the first layer 1 constructed in this way,
FRP with large GC and sufficient strength can be obtained.

The curved shape of the glass fiber bundle is controlled by controlling the moving speed of the conveyor when depositing the glass fiber bundle on the conveyor, or the speed at which the glass fiber bundle is dropped and deposited on the conveyor. A desired directionality can be given to the strength of FRP using layers (tensile strength parallel to the laminated plane), or an isotropic FRP with equal tensile strength in each direction parallel to the laminated plane can be obtained.

For example, when the moving speed of the conveyor is increased, the glass fiber bundles tend to be arranged in the moving direction, and the tensile strength in the moving direction becomes large. Conversely, if the moving speed of the conveyor is made small, the tensile strength in the moving direction becomes small, and by using an intermediate conveyor speed, an isotropic FRP with equal tensile strength in each direction can be obtained.

A relatively small number of glass fibers drawn out from the bushing are treated with a sizing agent such as vinyl acetate, polyester, epoxy, etc. and bundled into a glass fiber bundle 4, which is once wound up and then pulled out and cut. The second layer can be formed by cutting the cut material without winding it up and depositing the cut material on a moving conveyor while applying a binder. As the binder, thermoplastic resins such as epoxy, polyester, and polystyrene are suitable, and the amount used is approximately 2 to 5 wt% of the glass fiber bundle as a solid content.

Glass fiber bundle 4 has a weight of 50 to 1000 glass fibers.
Use 100gr (about 120 to 80 pieces).

When using relatively thick fiber bundles with a weight of over 50gr per 1000m of glass fiber bundles, FRP
Unevenness occurs on the surface, making it impossible to obtain a smooth surface, and the weight per 1000m of glass fiber bundle
When using thin fiber bundles such as less than 10gr,
Defoaming of minute air bubbles in the fiber bundle becomes difficult. The cross-sectional area of the glass fiber bundle 4 is 3 to 3 of the cross-sectional area of the glass fiber bundle 3.
It is about 10%.

The cutting length of the glass fiber bundle is 25 to 100 mm, preferably 40 to 60 mm, and the supply amount of glass fiber bundle is 600 per ¹ m2.
~250 gr, preferably 550~450 gr, and the thickness of the second layer is approximately 10~60% of the thickness of the first layer (assuming the same bulk density).

The second layer is composed of cut glass fiber bundles having a small cross-sectional area, and the glass fiber bundles are non-directionally (macroscopically) uniformly distributed. For this reason, the second layer smoothes the surface of FRP and
It has the effect of preventing regions with low glass fiber content from being formed on the FRP, and also preventing long glass fiber bundles from being wrapped around the rolls when uncured FRP is rolled.

It is also possible to manufacture the first layer and the second layer separately, overlap them, apply a binder, and heat to harden or soften the binder to bond both layers.
It is practical to form one layer on a moving conveyor, form another layer on top of this, and then apply heat and pressure to bond the glass fiber bundles within each layer and the layers together in one step. be.

The reinforcing glass fiber for FRP of the present invention has the following excellent properties in conjunction with the above-mentioned structure.

(1) Since the first layer with a long and flat cross section has a large cross-sectional area, the GC of FRP can be extremely large, and the strength in the bias direction can be increased as in the case of using cloth. There is no deterioration, resin impregnation is good, bubbles can be easily removed, and FRP with high strength can be obtained.

(2) The second layer is stacked on the first layer, and the second layer is composed of short glass fiber bundles with a small cross-sectional area, so it has a smooth surface and can produce a homogeneous FRP. Moreover, the glass fiber bundle does not get wrapped up during rolling, and defoaming is easy.

(3) When a gel coat is applied to FRP using roving cloth, there is a drawback that the weave pattern of the roving cloth stands out on the gel coat surface, but when using the reinforcing glass fiber for FRP of this invention, it is completely smooth. It is possible to obtain a smooth surface.

It is also possible to mix some colored fiber bundles into the reinforcing fiber body for FRP of the present invention for use as a marker.

[Brief explanation of the drawing]

FIG. 1 is a plan view with a part of the second layer of the reinforcing fiber body for FRP of the present invention removed, and FIG. 2 is an enlarged sectional view of a long glass fiber bundle. In the figure, 1 is a first layer, 2 is a second layer, 3 is a long glass fiber bundle, and 4 is a short glass fiber bundle.

Claims (1)

[Scope of utility model registration request] It has a flat cross section and a weight per 1000m.
The first layer 1 is made by stacking long glass fiber bundles 3 of 550 to 150 gr in a curved manner in no direction, and the glass fiber bundles 3 are cut into short pieces.
It is characterized in that a glass fiber bundle 4 of 50 to 10 gr is adhered to a second layer 2 deposited in a non-directional manner, and the second layer is formed thinner than the first layer.
Reinforced glass fiber body for FRP.