JPH10291832A - Glass roving - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide glass roving which substantially prevent the occurrence of an impregnation defect in FW molding or draw molding as strand bundles are liable to spread when loosened and which has a reinforcing effect in the direction perpendicular to glass fibers as well. SOLUTION: This glass roving is formed by doubling one to plural pieces of the first strands and plural pieces of the second strands of the fount smaller than the count of the first strands and winding these strands to a cylindrical shape. In such a case, the loosening direction from the inner layers of the winding body at the time of using this glass roving and the loosening direction from the inner layers of the cake of more than half the first strands and/or more than half the second strands at the time of producing the glass roving are reverse direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a glass roving used for filament winding molding (hereinafter referred to as "FW molding"), drawing or the like, which is a method for molding fiber reinforced plastic (FRP).

[0002]

2. Description of the Related Art FRP is manufactured by impregnating reinforcing fibers such as glass fibers with a liquid thermosetting resin and then curing the resin. Conventionally, FRP has been widely used as pipes and rods. Have been.

[0003] As a method of forming such an FRP, FW
A molding method, a drawing molding method, and the like are known. The FW molding method is suitable for producing a pipe-shaped or cylindrical molded body, and a mold (mandrel) is sagged while a tension is applied to a reinforcing material such as a glass roving impregnated with a liquid thermosetting resin. This is a method in which the resin is cured after being wound in a state where there is no void.

[0004] The pultrusion molding method includes pipe-like, plate-like,
It is suitable for producing an empty rod-shaped molded body, and pulls out a reinforcing material such as glass roving impregnated with a liquid thermosetting resin while passing through a mold having a predetermined cross-sectional shape, and heats the resin during this time. Is a method of hardening.

In general, in order to manufacture this kind of glass roving, a sizing agent is first applied to a glass filament having a diameter of 6 to 15 μm, and then 50 to 1600 strands are bundled to form a strand having a strand count of 20 to 735. The cake is formed by winding into an abacus ball shape while applying a twill, and then dried. Next, a method of preparing a plurality of the dried cakes, unwinding the strands from the inner layer of each cake, drawing a predetermined number of them, and laying them together is adopted.

The glass roving thus manufactured is wound into a cylindrical shape, and is packaged and shipped with a heat-shrinkable film having an opening at one end for taking out the roving when unwinding.

[0007]

In making the above-mentioned cake, generally, glass filaments having the same diameter are converged and wound into one strand and then wound, or a glass filament having the same diameter is formed. A method of dividing into approximately the same number, converging them into a plurality of strands, and winding them up is adopted.

[0008] Usually, glass roving is produced by twisting a plurality of strands having substantially the same count and then wound into a cylindrical shape. However, in order to obtain a certain cylindrical shape, glass roving is required. It is necessary to control the tension of the entire strand bundle constituting the roving. In the case of a strand unwound from the same kind of cake as described above, the unwinding tension and the total tension of the tension applied by the bar tensioner, which is the simplest tension applying device, are substantially uniform in each strand.
Each of the strands is wound into a cylindrical shape with almost no slack.

Therefore, even if the glass roving is unwound from the inner layer of the glass roving and impregnated with the resin by FW molding or drawing molding, the strand bundle is difficult to spread, and impregnation failure is likely to occur. .

In particular, in the case of the pultrusion molding, since the glass fiber is almost oriented in one direction, there is almost no reinforcing effect in the direction perpendicular to the glass fiber, and the molded product is broken when subjected to a slight impact such as dropping. Sometimes.

In order to prevent the breakage of such a molded product,
After the glass strands are spirally deposited, the strands are bonded, the continuous strand mat or the glass strand in the form of a sheet is cut into 10 to 100 mm, and the strands are deposited in a non-oriented manner, and then the strands are bonded to form a chopped sheet. Although the strand mat is used in combination with the roving to be molded, there are problems such as the fact that the continuous strand mat and the chopped strand mat are expensive and that they are easily torn during molding.

The present invention has been made in view of the above circumstances, and since the strand bundle is likely to spread when unwound, the F
It is an object of the present invention to provide a glass roving in which impregnation failure hardly occurs in W forming or drawing forming and which has a reinforcing effect also in a direction perpendicular to glass fibers.

[0013]

As a result of repeating various experiments to achieve the above object, the present inventors have found that two types of strands having different numbers are used in order to make it easier to spread the strand bundle constituting the glass roving. It was found that the direction of unwinding from the inner layer of the cake of some or all of the strands and the direction of unwinding from the inner layer of the wound when using glass roving should be reversed while using a plurality of .

In other words, the glass roving is made of two different numbers.
When composed of different types of strands, the strands having a lower count are inferior in rigidity to the strands having a higher count, so that the strands are twisted in a slightly loosened state, and the strand bundle is easily spread when unwound from the glass roving.

[0015] Usually, the strands are unwound from the inner layer of the cake when they are combined, so that all the unwound strands are twisted in the direction opposite to the unwinding direction. For example, when the strand is unwound clockwise when the strand is unwound from the inner layer of the cake, the strand is twisted counterclockwise (Z
On the contrary, when the strand is unwound counterclockwise when the strand is unwound from the inner layer of the cake, the strand is twisted clockwise (S twist).

For this purpose, for example, a strand unwound clockwise from a plurality of cake inner layers is twisted and wound to produce a rolled glass roving body, and glass roving is again performed clockwise from the rolled inner layer of the glass roving. When unwinding is performed, the strands constituting the glass roving are twisted counterclockwise untwisted twice during untwisting and unwinding, and the strand bundle is difficult to spread. Then, the twist of the strand was loosened when unwinding the glass roving.

That is, in the glass roving of the present invention, one or a plurality of the first strands and a plurality of the second strands having a smaller number than the first strands are combined and wound into a cylindrical shape. The direction of unwinding from the wound inner layer when using the glass roving, the half or more of the first strand and / or the second strand when manufacturing the glass roving. The unwinding direction from the cake inner layer of at least half of the above is reverse.

In the glass roving of the present invention, preferably, the difference in count between the first strand and the second strand is as follows:
Characterized in that it has a count of 400 or more, and the glass filament constituting the first strand has a single fiber diameter of 1
6 μm or more, and the diameter of the single filament of the glass filament constituting the second strand is 15 μm or less.

[0019]

According to the present invention, the first strand has a larger strand count than the second strand.
Is stiffer than the second strand. Therefore, when the first strand is combined with the second strand, the tension at the time of joining the first strand is greater than that of the second strand due to its rigidity. The yarn is twisted around the one strand in a slightly slack state. This makes it easier for the strand bundles constituting the glass rovings obtained by combining them to spread.

Further, in the present invention, the unwinding direction from the inner layer of the wound body when using the glass roving, the half or more of the first strand and / or the second strand when manufacturing the glass roving, Since the unwinding direction from more than half of the cake inner layer is reversed, when using glass roving, the twist of some or all of the strands is loosened and easily spread.

Further, in the present invention, when the unwinding direction of the first strand from the inner layer of the cake and the unwinding direction of the second strand from the inner layer of the cake in manufacturing the glass roving are reversed, This is more preferable because the strand (strand A) whose twist is unwound when unwound and the strand (strand B) that is further twisted coexist.

That is, when the strand unwound clockwise and the strand unwound counterclockwise are combined,
They will be unwound in opposite directions.
When using the glass roving thus produced, one strand (strand A) is untwisted when unwinding from the wound body layer, and the other strand (strand B) is further twisted. become.

As a result, the strands A and B, which were almost equal in length when they were combined, are unwound from the roving wound body, so that the apparent yarn length of the strand A becomes longer and the strand B Apparent yarn length becomes shorter. As a result, the strand A is in a state of being slackened around the strand B, and the strand bundle is easily spread.

The glass roving thus produced is
When used for W forming or drawing forming, it has a reinforcing effect even in the direction perpendicular to the glass fiber, and impregnation failure in the molded product is reduced, and the yield rate is improved.

The above effect depends on the impregnating device, mandrel, and mold of the molding equipment for performing FW molding and pultrusion molding. However, usually, the direction of unwinding the glass roving from the wound inner layer and the glass roving When the unwinding direction from the inner layer of the cake of at least half of the first strand or at least half of the second strand at the time of production is obtained in the opposite direction, particularly the unwinding direction from the inner layer of the glass roving winding The effect is great if the unwinding direction from the inner layer of the cake of at least half of the second strand is reversed. Further, the unwinding direction of the glass roving from the wound inner layer and the unwinding direction of the first strand from all the inner layers of the cake, or the unwinding direction of the second strand from all the inner layers of the cake were set to be opposite directions. The effect is more pronounced. By the way, the half or more mentioned here is based on the count.

In the present invention, if the difference between the counts of the first strand and the second strand is 400 or more, the slack of the second strand becomes larger, and the single filament of the glass filament constituting the first strand When the diameter of the glass filament constituting the second strand is 16 μm or more and the single fiber diameter of the glass filament constituting the second strand is 15 μm or less,
The glass filament itself constituting the strand of
Is more rigid than the glass filaments constituting the first strand, and the first strand is more rigid than the second strand. As a result, the yarn length difference between the two becomes large, the slack of the strand becomes larger, and the strand bundle is more easily spread, which is preferable.

[0027]

EXAMPLES Hereinafter, the glass roving of the present invention will be described in detail based on examples and comparative examples.

Example 1 First, a single fiber diameter of 18.7 μm
After the sizing agent was applied to the glass filament of No. 1, 1600 of these were bundled and the 1150th strand (first
Then, a cake (first cake) having a loss on ignition of 0.4% by weight was prepared by winding the piece into an abacus ball shape while applying a twill, followed by drying.

After applying a sizing agent to a glass filament having a single fiber diameter of 13.3 μm, 800 of these are bundled and wound into an abacus ball shape while applying a twill as a 290th strand (second strand). The cake was taken and dried to prepare a cake (second cake) having a loss on ignition of 0.4% by weight.

As the sizing agent, 7.0% by weight of vinyl acetate emulsion (Yodosol LD-1010, manufactured by NSC) as a sizing agent, and γ-methacryloxypropyl trimethoxysilane (as a silane coupling agent) Nippon Unicar Co., Ltd .: A-174) 0.2
%, A surfactant consisting of 0.03% by weight of a cationic surfactant and the balance water.

Next, the first strand is unwound clockwise from the two inner layers of the first cake, and the second strand is unwound clockwise from the inner layer of the second second cake. Was wound into a cylindrical shape, thereby producing a 9260-numbered glass roving wound body.

Then, the rolled glass roving body is
Individually prepared, the roving was unwound counterclockwise from these inner layers, impregnated with an unsaturated polyester resin in a nip roll type impregnation tank, and subjected to pultrusion at a speed of 0.5 m / min. An empty rod-shaped drawing product was produced.
In addition, the strand bundle was loosened during the drawing.

When the cross section of the FRP molded product thus obtained was visually observed, the state of impregnation of the strand with the unsaturated polyester resin was good.

Example 2 The first cake of Example 1 was replaced with 2
Except that the individual strands were prepared and the first strand was unwound counterclockwise from the inner layer, a roll of glass roving was prepared under the same conditions as in Example 1 and three rolls of glass roving were prepared. Then, the glass roving was unwound counterclockwise from these inner layers, impregnated with an unsaturated polyester resin in a nip roll type impregnation tank, and subjected to pultruding at a speed of 0.5 m / min. When a rod-shaped pultruded product was prepared, loosening of the strand bundle was observed during pultruding.

When the cross section of the FRP molded product thus obtained was visually observed, the state of impregnation of the strand with the unsaturated polyester resin was good.

(Comparative Example) 13.3 μm as in Example 1.
After applying a sizing agent to the glass filament of above, these 800 pieces are bundled, wound into an abacus ball shape as a 290th strand, and then dried to obtain a cake having a loss on ignition of 0.4% by weight. Was prepared.

A strand was unwound counterclockwise from the 32 inner layers of these 32 cakes, twisted and wound into a cylindrical shape to produce a 9280-th glass rolled roll.

Next, three rolled glass rovings were prepared, and the glass rovings were unwound counterclockwise from the inner layers of these rolls, and a hollow rod-shaped drawn product having a diameter of 6 mm was produced in the same manner as in Example 1. As a result, no loosening of the strand bundle was observed during the pultrusion molding.

When the cross section of the FRP molded product thus obtained was visually observed, there was some defect in the impregnated state of the unsaturated polyester resin into the strand, and the unimpregnated strand was observed.

[0040]

As described above, when the glass roving of the present invention is used for FW molding or drawing molding, the strand bundle is easily spread at the time of molding, the resin is well impregnated into the strand, and impregnation failure in the molded product is reduced. And the non-defective rate is improved. Further, a pultruded product having a reinforcing effect also in the direction perpendicular to the glass fiber can be obtained.

Continued on the front page (72) Inventor Kazuma Fukuhara 2-7-1 Hararashi, Otsu City, Shiga Prefecture Nippon Electric Glass Co., Ltd.

Claims (3)

[Claims] 1. One or more first strands,
A glass roving in which a plurality of second strands having a smaller number than the first strand are combined and wound into a cylindrical shape. The unwinding direction and more than half of the first strand when producing this glass roving and / or
Or the glass roving characterized in that the unwinding direction from at least half of the cake inner layer of the second strand is the reverse direction. 2. The glass roving according to claim 1, wherein the difference in count between the first strand and the second strand is 400 or more. 3. The glass filament forming the first strand has a single fiber diameter of 16 μm or more, and the glass filament forming the second strand has a single fiber diameter of 15 μm or less. 2. The glass roving according to 2.