JP4756479B2 - Glass roving manufacturing method and glass roving - Google Patents

Description

  The present invention relates to a method for producing glass roving used for a reinforcing material of fiber reinforced plastic (hereinafter referred to as FRP) and the like, and a glass roving obtained by this production method.

  Usually, glass roving is produced by the following method.

First, a sizing agent is applied to the surface of hundreds to thousands of glass filaments drawn from a number of nozzles formed on a platinum plate called a bushing, and these glass filaments are then collected by a sizing machine called a gathering shoe. A strand is produced by converging into one or splitting into a plurality of yarns and then converging, and a winding cake is produced on a paper tube attached to a winder while traversing the strand by a traverse. Next, a plurality of cakes are unwound by a roving winder, and rolled up again while being aligned (rewinding) to produce a glass roving. About glass roving and its manufacturing method, patent documents 1-patent documents 3 are known as a prior art, for example.
JP-A-10-251040 JP-A-10-297932 JP-A-8-091863

  Normally, when a large number of glass filaments drawn out from a bushing nozzle are normally split using a gathering shoe, they are split so that the number of bundles is almost uniform (± 10%). A method of producing a plurality of strands having a thickness is employed. The thickness of the strand is determined by the diameter and number of glass filaments. In the case of general-purpose glass roving used in molding methods such as sheet molding compound (hereinafter referred to as SMC), spray-up, and preform, glass having a diameter of 10 to 14 μm is used. 50 to 400 filaments are bundled, and a strand having a thickness of 20 to 160 TEX (TEX is a weight g per 1000 m of the strand and is called a count) is used. Therefore, for example, when 800 glass filaments with a diameter of 13.3 μm are divided into four pieces, four strands with a thickness of about 72 TEX are produced by dividing the 800 glass filaments into about 200 pieces each. Then, a method of taking up a single cake while traversing by traverse is adopted.

  However, in practice, the four strands that have been split and gathered by gathering shoes may be partially joined together and wound into a cake. That is, for example, when a glass filament is split into four strands using a normal gathering shoe 10 having a constant tip width T and comb width C as shown in FIG. Are separated by the comb width C of the gathering shoe 10, but the strands often come into contact with each other when they are traversed by traverse. That is, the traverse is reciprocated in parallel with the winder axis, and is laid across the strands by rotating, but as shown in FIG. 4, the gathering shoe (not shown) is located near the turn in the reciprocating motion of the traverse 11. ), The strands 12 that have been split by the yarn approach closer due to the inclination of the end of the traverse 11 on the paper tube 13, and the strands 12 come into contact with each other and are easily wound up in a coupled state. Since the strands thus combined are two, three, or four strands that have been split, it is an integral multiple of twice, three times, four times the thickness of the regular split strands. It becomes the thickness of.

  In order to prevent such strands from being bonded to each other, it is considered effective to widen the comb width of the gathering shoe to widen the spacing between the strands. However, if the comb width is widened, the gathering shoe becomes longer and the traverse is reduced. When it is located near the left and right turn in the reciprocating motion, the strand is detached from the traverse and cannot be normally wound and wound.

  By the way, a glass roving used as a reinforcing material for FRP formed by a method such as SMC, spray-up, or preform is cut into a length of 10 to 50 mm and used as a plurality of cut strands (glass chopped strands). ) Is dispersed or sprayed on a mold or a sheet, but the strands that are thickened by bonding as described above have different scattering and dropping behaviors compared to the strands of normal thickness. Therefore, the thick strand and the normal strand are easily separated at the time of cutting or spraying. As a result, there are a portion where many thick strands are distributed and a portion where many thin strands are distributed. Variations in strength are likely to occur.

  Especially in the case of SMC molding, when SMC sheet is press-molded, the portion where only thick strands are distributed is excellent in fluidity, and the strand flows easily to the end of the mold, whereas the portion where only thin strands are distributed is strand. Are entangled and entangled with each other to form a spiral lump, which is likely to cause a so-called ink smear.

  The present invention has been made in view of the above circumstances, and even when used as a reinforcing material for an FRP molded body, there is little variation in strength depending on the part, and a method for producing a glass roving that does not impair the appearance quality and its It aims at providing the glass roving obtained by a manufacturing method.

  As a result of repeating various experiments to achieve the above object, the present inventor has obtained a strand having a thickness that is an integral multiple (including 1) of a strand obtained by dividing a spun glass filament into regular (equal) yarns. As a reinforcing material, glass roving obtained by a glass roving production method in which the number of glass rovings is regulated to a predetermined amount is found to produce an FRP molded body with less variation in strength depending on the part and excellent in appearance quality. I came to propose.

That is, the glass roving manufacturing method of the present invention is a glass roving manufacturing method in which a bundling agent is applied to a glass filament and a plurality of strands are aligned using a gathering shoe, and the strands are formed according to the shape of the gathering shoe. by thickness is divided yarn so that the random, the thickness of the strand in the case of a plurality of prepared strands of the same thickness and Bun'ito to be focused number GaHitoshi etc. 90-110% A glass roving is obtained in which the ratio of the number of strands having an integral multiple (including 1 ×) thickness is 50% or less of the total number of strands.

  A glass roving manufacturing method in which a sizing agent is applied to a glass filament and a plurality of strands are aligned using a gathering shoe, wherein the glass filament coated with the sizing agent has a thickness of the strand using the gathering shoe. The number of strands having a thickness that is an integral multiple (including 1) of 90 to 110% of the thickness of the strand when a plurality of strands having the same thickness are produced by dividing the yarn so as to be random Is 50% or less of the total number of strands.

  Furthermore, the glass roving manufacturing method of the present invention only requires that the gathering shoe has two or more types of tip widths (groove opening widths) and the same comb width (width between the deepest portions of adjacent grooves). .

The glass roving of the present invention is manufactured by the method of manufacturing a glass roving of the present invention, and the thickness of the strands constituting the glass roving varies as a whole and splits the yarns so that the number of bundles is even. When a plurality of strands having the same thickness are produced, the ratio of the number of strands having an integer multiple (including 1) of 90 to 110% of the strand thickness is 50% or less of the total number of strands It is characterized by being.

As described above, the glass roving manufacturing method of the present invention is a glass roving manufacturing method in which a bundling agent is applied to a glass filament and a plurality of strands are aligned using a gathering shoe, and the form of the gathering shoe 90% to 110% of the thickness of the strand when splitting the strands so that the thickness of the strands is random, thereby splitting the strands so that the number of bundles is even and producing a plurality of strands of the same thickness the ratio of the number of strands having a thickness of an integral multiple (including 1 times) is, because it is intended to obtain 50% or less of the glass roving of the total strand number, glass rovings of the present invention obtained by the manufacturing method FRP molded products using as a reinforcing material have little variation in strength depending on the part, and are used in bathtubs, small ships, septic tanks, amusement parks. Ri, etc. it is possible to stabilize the quality of the FRP molded article, remarkable effect can be obtained when producing FRP moldings in particular by SMC molding.

According to the glass roving manufacturing method of the present invention, a gathering shoe is used to divide the number of bundles so that the number of bundles is uniform, so that the number of bundles is almost uniform, that is, a plurality of strands having the same thickness. The ratio of the number of strands having an integral multiple (including 1) of 90 to 110% of the thickness of the strand when produced is 50% or less (preferably 40% or less) of the total number of strands. However, in order to produce a glass roving having such a strand configuration, the shape of the gathering shoe may be devised. That is, when the shape of the gathering shoe has two or more kinds of tip widths (groove opening widths) and the same comb width (width between the deepest portions of adjacent grooves), the strand thickness is properly divided. Strands scattered in a wide range can be easily produced without being unevenly distributed in a thickness that is an integral multiple of the strands in the case of yarns.

  Hereinafter, the manufacturing method of the glass roving of this invention and the glass roving obtained by this manufacturing method are demonstrated in detail based on an Example.

  First, after spinning 1200 glass filaments having a diameter of 13.3 μm, a sizing agent (16.0% by mass of a vinyl acetate emulsion having a solid content of 50% by mass, 0.4% by mass of a methacrylic silane coupling agent, 1 wt% of the system lubricant and 83.3 wt% of ion-exchanged water) so that the adhesion amount is 1.0 wt%, and the thickness of the strand is increased by using the gathering shoe 14 of FIG. The yarns were split so as to be random and then bundled into 6 strands. Each strand was wound on a cake and dried at 130 ° C. for 10 hours. The tip width of the gathering shoe 14 is T1 = 18 mm, T2 = 38 mm, T3 = 10 mm, T4 = 26 mm, T5 = 20 mm, T6 = 32 mm, and the comb width is C = 24 mm.

  Eleven cakes thus obtained were prepared, the strands were unwound and drawn from these cakes, and rewinded with a roving winder to obtain glass roving.

  In order to measure the strand thickness of the glass roving, several portions of the glass roving were cut into a length of 100 cm, and the respective strand weights (TEX) were measured. The result is shown in FIG. As apparent from FIG. 2, the thickness of the strands constituting the glass roving varies as a whole, and is a thickness that is an integral multiple of 90 to 110% of the strand thickness (72 TEX) in the case of normal splitting. The ratio of the number of strands having a ratio of 28% to the number of all strands was 28%.

  [Comparative Example] A cake was produced under the same conditions as in the Examples except that only the yarn splitting conditions with Gathering Shu were changed. As for the yarn splitting condition, according to a conventional method, using a gathering shoe 10 having a constant tip width (T = 24 mm) and comb width (C = 24 mm) shown in FIG. Produced.

  Eleven cakes thus obtained were prepared, the strands were unwound and drawn from these cakes, and rewinded with a roving winder to obtain glass roving.

  In order to measure the strand count of the glass roving, several portions of the glass roving were cut into a length of 100 cm, and the respective strand weights (TEX) were measured. The result is shown in FIG. As is apparent from FIG. 5, the strands constituting this glass roving are mostly unevenly distributed in four peaks centered on 72TEX, 144TEX, 216TEX, and 288TEX. The ratio of the number of strands having an integral multiple of 90 to 110% of the thickness was 88% with respect to the number of all strands.

  Next, the glass rovings of the example and the comparative example were cut into a length of 1 inch (about 25 mm) using a cutting machine, and these were dispersed on an SMC compound, and an SMC sheet having a glass content of 25% by mass was obtained. Produced. The composition of the SMC compound was 75 parts of unsaturated polyester resin, 25 parts of low shrinkage agent, 1 part of curing agent, 3 parts of polymerization inhibitor, 5 parts of toner, 5 parts of internal release agent, 120 parts of filler, thickening agent. 1 part of the agent.

  Thereafter, each SMC sheet was aged at 40 ° C. overnight and then press-molded with a bathtub mold for fluidity test under the conditions of 50% charge rate and mold temperature (upper mold temperature 150 ° C., lower mold temperature 140 ° C.). A bathtub was made. The press molding was performed by using a 500 t press molding machine manufactured by Kawasaki Oil Works Co., Ltd. for 3 minutes at a pressurization speed of 3 seconds.

    After visually observing the number of black stains on the surface of each bathtub, it was cut, and bent specimens were collected from one bottom part, three side parts, and two edge parts, and their bending strength was based on JIS K6911. Measured. These results are shown in Table 1.

As is clear from Table 1, the FRP molded body using the SMC sheet of the example has no black stains observed, and since the standard deviation σ _n-1 of the bending strength of the FRP molded body is small, the variation is small. Quality was stable. On the other hand, the FRP molded body using the SMC sheet of the comparative example had a lot of ink stains and had a large variation in bending strength, and the quality was not stable.

It is a perspective view which shows the gathering shoe used in the Example. It is a graph which shows the strand thickness of the glass roving of an Example. It is a perspective view which shows the conventional gathering shoe. It is explanatory drawing which shows the state by which a strand is wound up on a paper tube. It is a graph which shows the strand thickness of the glass roving of a comparative example.

Explanation of symbols

10, 14 Gathering Shu 11 Traverse 12 Strand 13 Paper Tube C Gathering Shu Comb Width T Gathering Shu Tip Width

Claims (3)

A glass roving manufacturing method in which a sizing agent is applied to a glass filament and a plurality of strands are aligned using a gathering shoe,
By the thickness of the strand depending on the form of the gathering oxalic is divided yarn so that the random strands in the case where the plurality of prepared strands of the same thickness and Bun'ito to be focused number GaHitoshi etc. A method for producing a glass roving characterized by obtaining a glass roving in which the ratio of the number of strands having an integer multiple (including 1 times) of 90 to 110% of the thickness is 50% or less of the total number of strands .   The glass roving according to claim 1, wherein the gathering shoe has the same comb width (width between the deepest portions of adjacent grooves) as two or more types of tip widths (groove opening widths). Manufacturing method. It is manufactured by the manufacturing method of the glass roving according to claim 1 or claim 2 ,
The thickness of the strands constituting the glass roving varies as a whole, and 90 to 110% of the thickness of the strands when splitting the strands so that the number of bundles is even and producing the same number of strands. A glass roving characterized in that the ratio of the number of strands having a thickness that is an integral multiple of (including 1 times) is 50% or less of the total number of strands .

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