JP4524749B2 - Method and apparatus for applying sizing agent - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and an apparatus for uniformly applying a sizing agent to a glass filament taken out from a spinning furnace and drawn. <P>SOLUTION: A sizing agent retaining material 24 is provided adjacent to a sizing agent applying surface part of a coater type sizing agent applying apparatus to form a liquid pool in a gap between the sizing agent applying surface part and a sizing agent retaining material and the glass filament is passed through the liquid pool. The liquid pool is formed between the sizing agent applying surface part and the sizing agent retaining material by providing the sizing agent retaining material adjacent to the sizing agent applying surface part of the coater type sizing agent applying apparatus. <P>COPYRIGHT: (C)2006,JPO&amp;NCIPI

Description

  The present invention relates to a method and an apparatus for uniformly applying a sizing agent to the surface of a glass filament constituting a glass fiber for resin reinforcement.

  In the production of resin-reinforced glass fibers, molten glass is supplied to a bushing provided at the bottom of the spinning furnace, and the molten glass that has flowed out from a large number of orifices at the bottom of the bushing is stretched by the tension of a winding collet to form a large number of glass filaments. A sizing agent (focusing liquid) is applied to a large number of glass filaments by a sizing agent coating device, and then focused by one or a plurality of focusing rollers to form a bundle of glass filaments (hereinafter referred to as glass strands). To do so. The glass strand is usually wound on a winding collet and dried to evaporate the moisture of the sizing agent. The glass fiber for reinforcing resin thus produced is in the form of glass roving, glass roving cloth, glass chopped strand, glass chopped strand mat, glass milled fiber, glass yarn, glass yarn cloth, etc., depending on the purpose of use. To be processed.

  There are various types of sizing agents, such as starch-based sizing agents and synthetic resin emulsion-based sizing agents, and the glass filaments are bonded together by solidifying.

  As a method for applying the sizing agent, a method using a coater sizing agent application device and a method using a spray sizing agent application device are known. The coater-type sizing agent application device immerses the bottom of the rotating sizing agent application surface, such as the surface of a rotating roller, in a sizing agent liquid tank, attaches the sizing agent to the surface, and applies the glass filament drawn from the nozzle to the sizing agent It is an apparatus for applying a sizing agent to a glass filament by bringing it into contact with a surface portion. The roller type sizing agent application device and the belt type sizing agent application device are known as the coater type sizing agent application device, and the roller type sizing agent application device uses the surface of the rotating roller as the sizing agent application surface portion. The belt-type sizing agent application device uses a surface of a rotary belt driven by two rolls of a rotating roller and an oil supply roller as a sizing agent application surface portion. On the other hand, the spray-type sizing agent application device sprays the sizing agent with a spray gun and attaches the sizing agent to the glass filament. Patent Document 1 shows an example of a spray sizing agent coating apparatus. In this apparatus, the sprayed sizing agent is received by a funnel, and the sizing agent is reused.

  As a sizing agent application method combining a coater sizing agent application device and a spray sizing agent application device, the sizing agent application method described in Patent Document 2 or Patent Document 3 is focused by a spray sizing agent application device. There is a method in which a sizing agent is applied to a glass filament before being applied, and a sizing agent application surface portion such as a rotating roller or a rotary belt is brought into contact with the glass strand after the glass filament is focused. Further, as in Patent Document 4, there is a method in which a sizing agent applied to a glass filament before bundling is collected by a roller sizing agent application device, and then applied to a strand by a roller sizing agent application device. is there.

Japanese Patent Publication No.31-8921 Japanese Utility Model Publication No. 49-18489 Japanese Patent Publication No.42-1774 Japanese Patent Laid-Open No. 1-219035

  The sizing agent is applied for the purpose of protecting glass fibers for resin reinforcement and improving lubricity, in addition to focusing glass filaments. Furthermore, the sizing agent also has an effect of improving the adhesiveness between the glass fiber and the resin when manufacturing the fiber reinforced plastic product.

  If the sizing agent is not evenly applied to the surface of the glass filament, it may cause glass strands that are insufficiently focused. Moreover, when winding on a winding collet, the glass strand may be cut by friction between the glass strands. Furthermore, if resin-reinforced glass fibers not uniformly coated with a sizing agent are applied to fiber-reinforced plastics, adhesion between the resin and the resin-reinforced glass fibers is not sufficient when the resin is cured. In addition, a whitening phenomenon may occur in which bubbles remain between glass filaments and white stripes are generated. In either case, there arises a problem that the strength of the fiber reinforced plastic is lowered.

  In the application of the sizing agent by the coater sizing agent application device, there is a problem that the surface on the side where the glass filament contacts the sizing agent application surface portion of the rotating belt or the rotary belt is applied, but the opposite side surface is not applied. Even in application by a spray sizing agent application device, spraying of the sizing agent by the spray gun is not uniform, and since it is sprayed from one direction, it is difficult to apply to the surface opposite to the spray. In particular, in the method of spraying the sizing agent on the glass strands that are focused on the glass filament as described in Patent Document 1, not only on the surface opposite to the spray but also on the glass filaments inside the bundle of glass strands. No sizing agent is applied.

Even in the methods described in Patent Document 2 and Patent Document 4, since the coater-type sizing agent is applied to the glass strand, the sizing agent application surface portion does not contact the inside of the bundle of glass strands and the opposite side of the contact portion. Uniform application is not possible.
Even in the method described in Patent Document 3, since the coater-type sizing agent is applied to the glass strand, uniform application cannot be performed for the above-described reason. Moreover, the apparatus described in Patent Document 3 is provided in such a manner that the coater-type sizing agent application device and the spray-type sizing agent application device face each other with the glass filament interposed therebetween. However, since the space in which spinning is performed is very narrow and the distance between adjacent bushings is small, it is difficult to arrange the coater-type sizing agent application device and the spray-type sizing agent application device on both sides of the glass filament. Even if it is installed, it becomes difficult to perform repair work when the glass filament or the glass strand is cut.

  Thus, in the conventional sizing agent coating method, it was difficult to uniformly apply the sizing agent. However, even if the sizing agent is not uniformly applied, if the sizing agent has sufficient time to dry after being applied, the sizing agent penetrates into the surface of the glass filament that is not sufficiently applied due to the capillary phenomenon between the glass filaments. I can go around to some extent. For this reason, conventionally, a sufficient time is required from the winding to the drying collet.

Conventionally, chopped strands are manufactured by winding glass strands on a winding collet, drying them sufficiently, and then cutting them into a predetermined length.
Recently, however, so-called “direct chopped strands” have been manufactured in which glass strands are cut into a predetermined length without being wound around a winding collet. In such “direct chopped strands”, the converged glass strands are directly cut in the production line, so that it is not possible to take a sufficient time from application of the sizing agent to drying. For this reason, it is impossible to reach a place where the sizing agent is not sufficiently applied by capillary action. Therefore, in the production of “direct chopped strand”, it is indispensable to uniformly apply the sizing agent to the glass filament.
An object of the present invention is to solve the above problems and to provide a method and an apparatus for uniformly applying a sizing agent to the surface of a glass filament before being focused.

  The method of applying the sizing agent of the present invention is to advance the glass filament through a pool of sizing agent formed in a bridging manner between a pair of support members with respect to the glass filament drawn continuously from the spinning furnace. Features. When the gap between the pair of support members is set to an appropriate size, the sizing agent forms a liquid mass that floats in the air in a state where the support members are bridged by the surface tension. The sizing agent can be uniformly applied to the surface of the glass filament by advancing the glass filament through the liquid pool.

Preferably, the pair of support members are configured such that a sizing agent is applied by immersing a bottom portion of a circulating sizing agent application surface portion in a sizing agent and bringing the sizing agent application surface portion into contact with the glass filament. A sizing agent application surface portion of the agent application device, and a sizing agent pool material provided close to the sizing agent application surface portion. The liquid pool is formed between the sizing agent application surface part and the sizing agent pool material, and the sizing agent adhering to the immersed application surface part is always replenished to the liquid reservoir. The pool is retained.
The sizing agent application surface portion may be a roller surface of a rotating roller or a belt surface of a rotary belt. The sizing agent pool material is preferably a bar provided at a predetermined interval from the sizing agent application surface portion. The interval is set so that a stable liquid pool is formed in consideration of conditions such as the surface tension of the sizing agent and the wettability between the sizing agent and the support member.

  Further, according to another aspect, the present invention is such that the bottom of the sizing agent application surface portion that circulates is immersed in the sizing agent, and the sizing agent application surface portion and the glass filament come into contact with each other to apply the sizing agent. In a sizing agent coating device, a sizing agent pool material is provided close to the sizing agent coating surface portion, thereby forming a liquid pool of sizing agent between the sizing agent coating surface portion and the sizing agent pool material. This is a sizing agent application device.

  Since the glass fiber for resin reinforcement obtained by the sizing agent coating method of the present invention is uniformly coated on the surface of the glass filament, a good glass fiber without filament damage can be obtained. In particular, in the “direct chopped strand”, when used in a fiber reinforced plastic product, a whitening phenomenon due to nonuniform application of the sizing agent does not occur, and a high strength can be obtained.

Hereinafter, preferred embodiments of a sizing agent coating method and apparatus according to the present invention will be described in detail with reference to the accompanying drawings. In addition, the same code | symbol shall be used for the same element and the overlapping description is abbreviate | omitted.
A method for producing resin-reinforced glass fibers using the sizing agent coating method of the present invention will be described with reference to FIG. When the molten glass is supplied to the bushing 10, the molten glass that has flowed out from 100 to 4000 orifices 11 provided at the bottom of the bushing 10 is continuously drawn out by the winding device, and is wound from the winding collet. It is stretched under tension, and the diameter is reduced to become a glass filament. A coater-type sizing agent application device 20 is provided below the bushing 10. A sizing agent pool member 24 is provided at a predetermined gap from a portion where the sizing agent application surface portion 23 and the glass filament are in contact with each other.

The viscosity of the sizing agent is preferably 10 to 1000 centipoise, more preferably 30 to 500 centipoise, and most preferably about 50 to 100 centipoise.
The glass filament 3 coated with the sizing agent by the coater-type sizing agent coating apparatus 20 is focused by the focusing roller 7 to become the glass strand 4 and wound around the winding collet 8.

  FIG. 3 shows a roller sizing agent coating apparatus. The rotating roller 21 has a diameter of 50 mm or more, and the surface material is hard rubber, ceramics, carbon or the like. A sizing agent is supplied to the sizing agent liquid tank 22 so that the liquid level is maintained at a certain height. The rotating roller 21 is immersed in the sizing agent in the liquid tank by 3 mm or more to attach the sizing agent to the surface, and supplies the sizing agent to the liquid reservoir. The rotation speed of the rotating roller is preferably 5 to 50 m / min, more preferably 15 to 45 m / min, and most preferably about 30 to 40 m / min.

The sizing agent pool material 24 is preferably a carbon round bar, preferably 0.1 to 3.0 mm, more preferably 0.3 to 1.5 mm, from the contact portion of the sizing agent application surface portion 23 with the glass filament 3. Optimally, it is installed with a gap of 0.6 to 0.8 mm. When this interval is set, the surface tension of the sizing agent adhering to the rotating roller, and the wettability between the sizing agent and the rotating roller and the pool material , the bridge of the sizing agent floating between the rotating roller and the pooled sizing agent A liquid pool is formed.

The reason for using a round bar made of carbon as the sizing agent pool material is that a liquid pool is easily formed because carbon has good wettability with the sizing agent. However, the material of the sizing agent pool material need not be limited to carbon, and can be hard rubber, ceramics, or the like. Further, the shape of the sizing agent pool material may be a rod shape or a plate shape. The bar is not necessarily limited to a round bar, and the cross-sectional shape thereof may be a semicircle, a triangle, or the like. In the case of using a plate material, one end surface of the plate material and the surface of the rotating roller are arranged with a predetermined gap as in the case of the bar material. The cross-sectional shape of the end face of the plate facing the rotating roller may be any shape such as a square, a semicircle, or a triangle.
As described above, the roller-type sizing agent application device has been described as the coater-type sizing agent application device. However, the belt-type sizing agent application device shown in FIG. 4 may be used. Furthermore, various modifications are possible.

  By the method of the present invention, “direct chopped strand” was produced as a glass fiber for resin reinforcement. The sizing agent was applied using a roller-type sizing agent application device. The diameter of the rotating roller was 50 mm, the width was 300 mm, and carbon was used for the sizing agent application surface portion. As the sizing agent, a urethane sizing agent was used, and its viscosity was about 50 centipoise. The rotating roll was immersed in a sizing agent solution tank by about 5 mm and rotated at a surface speed of 30 m / min. As the rotating sizing agent pool material, a carbon round bar having a diameter of 20 mm was used, and the gap between the pool material and the sizing agent application surface of the rotating roller was set to 0.8 mm over the entire width of the application surface. In this gap, it was confirmed that a liquid pool 25 was formed between the pool material and the sizing agent application surface portion. A bushing having 408 orifices was used to supply molten glass. The glass used was E glass. After applying a sizing agent to the glass filament, the glass filament was focused by a focusing roller. The glass strand was dried in a line without being wound on a winding collet, and cut to a length of 3 mm. The diameter of the cut glass fiber (direct chopped strand) was 0.5 mm, and the diameter of the glass filament was 13 μm.

  Using the “direct chopped strand” obtained by the above method, a fiber reinforced plastic having a glass fiber content of 30% by weight for resin reinforcement was produced. As the resin, 66 nylon was used, and glass fibers for resin reinforcement were kneaded with the resin using a biaxial rudder to produce pellets. Molding was performed with an injection molding machine using the pellets. About this fiber reinforced plastic, the adhesion rate to the glass filament of a sizing agent, tensile strength, Izod impact strength (with notch), and Izod impact strength (without notch) were measured. As a comparative material, the same measurement was performed on a glass fiber produced without using a pool material under the same conditions as described above. The adhesion rate of the sizing agent is a ratio (% by weight) of the sizing agent adhering to the glass fiber to the glass fiber, and was measured by reducing the ignition strength of the glass strand. Tensile strength was measured by breaking the sample into a rod piece sample having a cross section of 3 mm × 12 mm and pulling the sample with an autograph tester. The Izod impact strength was measured by the method defined in JISK6911. The results are shown in Table 1. In the glass fiber for resin reinforcement according to the present invention using the pooled material, the adhesion rate of the sizing agent was 0.65%, which was larger than that of the comparative material not using the pooled material of 0.49%. Both the tensile strength and the Izod impact strength (with and without notch) of the fiber reinforced plastic have a high strength, and it can be seen that a fiber reinforced plastic excellent in tensile and impact strength can be obtained.

The front view of the glass fiber manufacturing apparatus for resin reinforcement | strengthening using this invention. The side view of the glass fiber manufacturing apparatus for resin reinforcement | strengthening using this invention. A roller type sizing agent coating apparatus according to the present invention. The belt type sizing agent coating apparatus according to the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Glass fiber manufacturing apparatus for resin reinforcement 3 Glass filament 4 Glass strand 7 Condensing roller 8 Winding collet 10 Bushing 11 Orifice 20 Sizing agent application device 21 Rotating roller 22 Sizing agent liquid tank 23 Sizing agent application surface part 24 Sizing agent accumulation material 25 Sizing agent Fluid reservoir 26 Rotating roller 27 Oiling roller 28 Rotary belt

Claims (8)

In a method of continuously drawing a large number of glass filaments from a spinning furnace and applying a sizing agent to the glass filaments ,
Immerse the bottom of the sizing agent application surface portion that circulates in a sizing agent having a viscosity of 10 to 1000 centipoise to attach the sizing agent to the sizing agent application surface portion
A liquid pool is formed in a bridging manner between the sizing agent application surface portion and a sizing agent pool material provided at a predetermined interval from the sizing agent application surface portion ,
A method of applying a sizing agent to the glass filaments, characterized in that to proceed the glass filaments through the sump of the sizing agent. The method for applying a sizing agent to a glass filament according to claim 1 , wherein the sizing agent application surface portion is a roller surface of a rotating roller. The method for applying a sizing agent to a glass filament according to claim 1 , wherein the sizing agent application surface portion is a belt surface of a rotary belt. The sizing agent pool material is a bar provided at a predetermined interval from the sizing agent application surface portion, and sizing the glass filament according to any one of claims 1 to 3. A method of applying the agent. The bottom of the sizing agent applying surface portion circling is immersed in the sizing agent, the sizing agent applying device and said sizing agent applying surface portion and the glass filaments are adapted to apply the sizing agent in contact, from the sizing agent applying surface A sizing agent pool material is provided at a predetermined interval , whereby a sizing agent pool having a viscosity of 10 to 1000 centipoise is formed in a bridging manner between the sizing agent application surface portion and the sizing agent pool material. A sizing agent applicator characterized by being adapted to be used. The sizing agent application apparatus according to claim 5 , wherein the sizing agent application surface portion is a roller surface of a rotating roller. The sizing agent application device according to claim 5 , wherein the sizing agent application surface portion is a belt surface of a rotary belt. The sizing agent application according to any one of claims 5 to 7, wherein the sizing agent pool material is a bar provided at a predetermined interval from the sizing agent application surface portion. apparatus.

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