JP2007112636A - Glass roving - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a glass roving formed by cross-winding one glass strand in a cylindrical form, having less occurrence of fluff as well as bundle lifting or collapsing and having less difference between strand lengths. <P>SOLUTION: The glass roving is formed by cross-winding one glass strand in a cylindrical form, and is characterized by having a glass strand pitch within the range of 50-80 mm and the number of winding in the range of 5 to 9. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to glass roving in which a single glass strand is wound in a cylindrical shape.

  Glass roving in which a single glass strand is wound in a cylindrical shape is generally manufactured by a method as described below and is called DWR (Direct Wound Roving).

  First, the molten glass is pulled out from a platinum bushing to form a glass filament with a diameter of several to several tens of μm. After a sizing agent is applied to the surface, hundreds to thousands of glass filaments drawn from the bushing are gathered at the same time. A glass strand is formed by converging it with a shoe.

  Next, a winding cake is produced while applying a twill to the collet rotating the glass strand. In addition, as a method of applying a twill, a method of reciprocating a yarn guide with a constant width while winding a glass strand using a cam traverse (hereinafter referred to as a traverse) disposed in the vicinity of a collet is generally used. Yes.

  Finally, the cake removed from the collet is dried to produce a DWR. The cake contains about 10% of moisture when the sizing agent is applied, and a film made of the sizing agent component is formed on the surface of the glass filament by drying. As a method for drying the cake, there are a method of blowing hot air of 120 ° C. to 140 ° C., a method of irradiating infrared rays, and a method of dielectric heating using electromagnetic waves such as microwaves and high frequencies.

  DWR is used as a reinforcing material for thermosetting resins and thermoplastic resins, and is formed into various shapes.

  In the case of a thermosetting resin, a filament winding method (hereinafter referred to as FW method) or a drawing method is used, and the glass strand drawn from the DWR is guided to a yarn guide, a tension bar, etc. In a step of defibrating to a glass filament and then immersing in a resin tank and passing through a die of a predetermined shape, or after winding into a tubular shape, it is heated and molded into a predetermined shape.

  In the case of a thermoplastic resin, tension is applied to the glass strand drawn from the DWR, and the glass strand is defibrated. Then, the glass strand is immersed in a thermoplastic resin bath softened by heat and pulled out from a nozzle. It becomes an intermediate for high-strength composite materials. LFTP is used as a material for injection molding by pellets cut to a length of about 10 mm, or as a composite material called ACM (Advanced Composite Material) after weaving or knitting (see, for example, Patent Document 1).

  In general, the produced DWR has a mass of about 17 to 20 kg, has a thick cylindrical shape as shown in FIG. 1, has a winding height H of about 250 mm, and an outer diameter D of about 250 to 300 mm. It has a hollow part with an inner diameter d of about 150 mm (see, for example, Patent Document 2). In addition, the winding height H is equal to the moving distance of the traverse when winding the glass strand.

  The number of times the glass strand is wound up in one way by the reciprocating traverse is called the wind number W, and is usually about 2 to 5. Moreover, as shown in FIG. 2, the distance that the traverse 3 moves while the glass strand is wound around the collet is called a strand pitch P, and the strand pitch is usually about 50 to 125 mm.

  Incidentally, the winding height H is also a product of the winding number W and the strand pitch P.

As shown in FIG. 3, the width of the glass strand 2 wound up as DWR1 is called a strand width S, and is usually about 1 to 10 mm, although it varies depending on the diameter and number of glass filaments. Further, the thickness of the glass strand 2 is indicated by the mass (g) per 1000 m of the glass strand 2, and the unit whose number is (tex) is used. In addition, an angle formed by the circumference of the DWR and the glass strand 2 is referred to as a twill angle θ and is expressed using °. The twill angle θ is usually about 3 to 15 °. Further, the glass strand has a V-shaped portion having a symmetrical bend of the twill angle θ at both ends of the reciprocating motion, and is called a turn portion. Since the width of the glass strand becomes wide at the turn portion, a difference in length occurs between the glass filaments, and the maximum length difference between the glass filaments is called a yarn length difference.
JP-A-6-278187 JP 2003-40640 A

  Since DWR is used by continuously unwinding glass strands, the following three characteristics are particularly required for continuous operation.

  ・ There is little generation of fluff.

  -There are few occurrences of lifting and collapsing.

  ・ The yarn length difference is small.

  In the DWR, the glass strands are usually unwound from the inner layer, but due to the strong bonding between the glass strands, several rounds to several tens of weeks of the glass strands are unraveled during unwinding. When the glass strands are unbonded at a slow speed, the glass strands of several to several dozen laps of the inner layer are peeled off and entangled into a lump. Refers to that.

  When the amount of fluff generated is large, the working environment is deteriorated, and the glass strand is rubbed by rubbing with the glass strand supplied with the guide or tension bar to which the fluff has adhered, continuously producing glass fiber reinforced resin, etc. Had the problem of not being able to.

  Further, when the lifting or collapsing entanglement occurs, the glass strands entangled with each other are caught by a guide or the like, and there is a problem that the glass fiber reinforced resin or the like cannot be manufactured continuously as in the case of fluff.

  When the yarn length difference is large, glass filaments that are longer than the surroundings in the glass strand meander locally in a pleated or ring shape to form bulges or loops. If bulges and loops are used as they are as resin reinforcements, they tend to be defective in strength and appearance.

  Also, bulges and loops are not preferable because they cause fluff when passing through a guide or a tension bar.

  An object of the present invention is to provide a glass roving in which a single glass strand is spirally wound in a cylindrical shape, and generation of fluff, occurrence of lifting and collapsing is small, and a yarn length difference is small.

  In the glass roving, the inventors can increase the length (distance between the turn portions) from the turn portion of the glass strand to the next turn portion by appropriately adjusting the number of winds and the strand pitch. It is ascertained that the yarn length difference generated in the turn portion due to the tension of time can be canceled and unraveled without problems, and is proposed as the present invention.

  The glass roving of the present invention is a glass roving formed by winding a single glass strand into a cylindrical shape, the strand pitch of the glass strand is in the range of 50 to 80 mm, and the number of winds is 5 to 9 It is characterized by being in the range of

  Since the glass roving of the present invention has a wind number of 5 to 9 and a strand pitch of 50 to 80 mm, the occurrence of fluff and the occurrence of lifting and collapsing are reduced, and the yarn length difference can be reduced.

  That is, in the present invention, since the distance between the turn portions of the glass strand can be appropriately increased, even if a yarn length difference occurs in the turn portion, it can be canceled out by the elongation of the filament caused by the tension applied during unwinding. At the same time, collapse and lifting can be suppressed.

  Since the yarn length difference is small, bulges and loops are not easily generated in the glass strand, and the amount of fluff generated by rubbing against the bulges, loops and guides can be suppressed.

  In the glass roving of the present invention, if the strand pitch P is narrower than 50 mm, the adjacent glass strands tend to be entangled, so that it is difficult to suppress the occurrence of lifting.

  On the other hand, when the strand pitch P is wider than 80 mm, the twill angle θ tends to increase, the yarn length difference at the turn portion tends to increase, and the wire tends to collapse when wound as a cake.

  In the glass roving of the present invention, when the wind number W is less than 5, the traverse angle θ tends to increase, and the yarn length difference at the turn portion tends to increase.

  On the other hand, if the wind number W is larger than 9, the distance between the turn portions is long, so that one layer of glass strand tends to collapse and become entangled.

  If the winding height is constant, the wind number W and the strand pitch P are in an inversely proportional relationship. Therefore, the glass roving winding height H, the winding number W, and the strand pitch P cannot be determined independently.

  The winding number W and the strand pitch P are determined by the rotation speed of the collet and the reciprocating frequency of the traverse. Since the collet and the traverse are interlocked by a plurality of gears, the values of the winding number W and the strand pitch P are set. It is not easy to fine tune.

  The glass roving of the present invention preferably has a winding height H of 270 to 700 mm. More preferably, it is 280-670 mm, More preferably, it is 300-600 mm. If it is lower than 270 mm, the distance between the turn parts tends to be short, the yarn length difference tends to increase, and a large amount of fluff tends to occur. On the other hand, when the height is higher than 700 mm, the center of gravity becomes high, and the load collapses easily during transportation.

  Moreover, it is preferable that the shape of the glass roving is a double square end package because the amount of winding per roll is large and the roll is not easily collapsed and the load is not easily collapsed during transportation. Further, since the distance between the turn portions can be increased, the yarn length difference is likely to be small, which is preferable.

  When tension is applied to the glass strand, each glass filament stretches somewhat, so that the yarn length difference can be canceled out. Therefore, if the yarn length difference is 0.2% or less of the glass strand length, bulges and loops are generated. Can be used without problems. More preferably, it is 0.15% or less.

  The yarn length difference is measured as follows as shown in FIG.

  First, a glass strand 5 (sample) having a length of 2 m is collected from the glass roving, and both ends of the sample are fixed with an adhesive so that the glass filament is not displaced.

  Next, both ends of the sample are fixed with jigs 6 and 6, and all the glass filaments 7 are unwound until they fall apart.

  Subsequently, both ends are pulled lightly until the shortest glass filament 7a disappears. At this time, the long glass filament 7b is loosened, but the most loose glass filament is found and pulled down until it is taut using a needle or the like at the center. Thus, the height E of the triangle surrounded by the glass filament is read. The above operation is repeated 10 times, and the average value (mm) is defined as the even value.

  Finally, the length of the longest glass filament 7b is calculated from the even value and the glass strand 5 of 2 m using the three-square theorem, and the difference in length from the glass strand 5 is defined as the yarn length difference.

  In the glass roving of the present invention, it is preferable that a large number of through holes are provided radially from the inner surface to the outer surface because moisture can be easily evaporated from the cake, so that the drying time of the cake can be shortened. The through hole may be linear or helical.

  When the glass roving of the present invention is produced by a direct winding method, the mass is preferably 20 to 50 kg. Preferably it is 25-45 kg, More preferably, it is 28-40 kg. When the mass is lighter than 20 kg, productivity tends to be low in a continuous production method such as the FW method or the drawing method. On the other hand, if it is heavier than 50 kg, there is a problem in workability such as carrying the rolled up glass roving.

  In the glass roving of the present invention, the glass may be A glass, C glass, D glass, or E glass, and an appropriate glass can be selected according to the application. Further, glass other than those described above may be used.

  The glass roving of the present invention includes not only DWR but also glass roving produced by unwinding one glass strand, but DWR costs less than glass roving produced by unwinding. Since it does not start, it is preferable.

  Hereinafter, the glass roving of the present invention will be described in detail using Examples and Comparative Examples.

  Table 1 shows Examples 1-4 and Comparative Examples 1-4.

  The sample of Example 1 was produced as follows.

  First, a polyolefin-based sizing agent was applied to the surface of 4000 E glass filaments having a diameter of 17 μm and converged into one using a gathering shoe to form a glass strand having a count of 2310 tex. The solid content of the sizing agent used here is 3.5%, and it is a relatively highly lubricating sizing agent containing aminosilane and a lubricant in addition to the polyolefin resin. The target was 0.40% ± 0.15%.

  Next, the glass strand is wound around a winding collet while traversing a winding having a winding number W of 5.79, and the inner diameter d of the cylinder as shown in FIG. 1 is 150 mm, the outer diameter D is 280 mm, and the winding height is H. A cake of a double square end package with a 440 mm was produced.

  Next, the cake was put in a hot air drying oven and dried at 130 ° C. for 20 hours to prepare a sample of Example 1. The mass of the sample obtained after drying was 30 kg and the adhesion rate was 0.36%.

  In Example 2, a sample was prepared according to the same procedure as in Example 1 except that the wind number W was 7.91.

  In Example 3, a sample was prepared according to the same procedure as in Example 1 except that the winding height H was 300 mm and the wind number W was 5.35.

  In Example 4, a sample was prepared according to the same procedure as in Example 1 except that the winding height H was 600 mm and the wind number W was 7.91.

  In Comparative Example 1, a sample was prepared according to the same procedure as in Example 1 except that the winding height H was 250 mm and the wind number W was 3.54. The shape of the sample and the number of winds W coincide with the values of general-purpose DWRs that are widely produced in Japan and overseas.

  In Comparative Example 2, a sample was prepared according to the same procedure as in Example 1 except that the winding height H was 250 mm and the wind number W was 7.91.

  In Comparative Example 3, a sample was prepared according to the same procedure as in Example 1 except that the winding height H was 600 mm and the wind number W was 5.35.

  In Comparative Example 4, a sample was prepared according to the same procedure as Example 1 except that the winding height H was 600 mm and the wind number W was 10.81.

  Lifting and collapsing entanglement were determined by the following method.

  Prepare 10 rolls of each sample, and install a guide plate with a diameter of 20 mm above each sample and a guide plate with 10 eyelets (diameter 2 mm) at a distance of about 5 m in the horizontal direction. . Each glass strand drawn from the sample was unwound at a speed of 10 m / min through the guide and eyelet.

  When a glass strand lump such as lifting or collapsing entanglement is generated on the glass strand released from each sample, the lump is caught on the yarn guide, and a tension exceeding a normal level is applied. A tension sensor is attached to the yarn guide, and the number of catches caused by glass strands is counted.

  The collapse entanglement was determined as “◯” when the DWR10 roll could be unwound 7000 m without cutting the glass strand, and “X” when cutting even one glass strand.

  Lifting was indicated as “X” when a catch that did not depend on the entanglement occurred, and “○” when it did not occur once.

  The amount of fluff was evaluated by the following procedure.

  First, as shown in FIG. 5, the glass strand 12 drawn out from the glass roving 11 is passed through guides 13, 14, 19 and brass rods 15, 16, 17, 18, 20, and the end of the glass strand 12 is passed through a winder 21. The part was fixed. The diameters of the brass bars 15, 16, 17, 18 are 10 mm. The interval between the brass rods 15 and 16 is 250 mm in the vertical direction, and the interval between the brass rods 16, 17 and 18 is 10 mm in the horizontal direction.

  Next, the glass strand 12 was wound up by 1500 m at a speed of 300 m / min using the winder 21. Finally, the fluff adhering to the brass rods 15, 16, 17, and 18 and the fluff falling under the brass rods 15, 16, 17, and 18 were collected and their masses were measured.

  The case where the fluff generation amount was less than 4 mg was determined as “◯”, and the case where the fluff generation amount was 4 mg or more was determined as “x”. In addition, if it is less than 4 mg, it is considered that there is no problem in normal drawing work.

  The yarn length difference was evaluated by measuring filament slack by the following method.

  As shown in FIG. 6, a total of two glass strands 32 are drawn from a sample 31 of two rolls one by one at a speed of 6 m / min, and the glass strand 32 is passed through a guide 33 to three tension bars 34, 34, After applying tension by 34, the glass strand 32 was passed through the resin bath 35, and excess resin was squeezed through a nozzle 36 having a diameter of 1.5 mm. The tension of the glass strand 32 immediately after the nozzle 36 was adjusted to 20 N by the tension bars 34, 34, 34.

  The glass strand 32 is pulled out for 20 minutes (120 m), and the looseness of the glass filament immediately before the nozzle 36 is visually observed. When the filament slack did not occur or immediately disappeared even when it occurred, “◯” was indicated, and when filament slack occurred, “x” was indicated. Filament loosening means that some glass strands 32 are caught or looped near the nozzle 36.

  The adhesion rate was measured by the following method.

  First, a sample obtained by cutting the glass strand 12 unwound from the DWR with an appropriate length was placed on an evaporating dish (A) whose mass was measured, and the mass (B) was measured.

  Next, the evaporating dish on which the sample was placed was left in a constant temperature drying oven at 110 ° C. for 60 minutes, then transferred to a desiccator and allowed to stand at room temperature, and the mass (C) was measured.

  Subsequently, the evaporating dish on which the sample was placed was allowed to stand in a constant temperature combustion furnace at 625 ° C. for 40 minutes, then transferred to a desiccator and allowed to stand at room temperature, and the mass (D) was measured.

  Finally, the adhesion rate of the sizing agent was calculated from [(CD) / (BA)] × 100.

  As is clear from Table 1, Examples 1 to 4 had a small amount of fluff generation, and neither filament slack nor lifting nor collapse entanglement occurred.

  On the other hand, filament slack occurred in Comparative Example 1, and lift occurred in Comparative Example 2. In Comparative Example 3, filament slack and a lot of fluff occurred, and in Comparative Example 4, collapse entanglement occurred.

  The glass roving of the present invention can be suitably used not only as a reinforcing material for fiber reinforced resin using a FW molding method or a pultrusion molding method, but also as a reinforcing material for LFTP and a reinforcing material for GRC.

It is a perspective view which shows glass roving. It is explanatory drawing which shows the winding pitch which is the distance between glass strands. It is explanatory drawing which shows the yarn length difference in a turn part. It is explanatory drawing which shows the measuring method of a yarn length difference. It is explanatory drawing which shows a fuzz measuring device. It is explanatory drawing which shows the apparatus which measures a filament slack.

Explanation of symbols

1 DWR
2, 5, 12, 32 Glass strand 3 Traverse 6 Jig 7 Glass filament 7a Shortest glass filament 7b Longest glass filament 11, 31 Glass roving 13, 14, 19, 33 Guide 15, 16, 17, 18, 20 Brass Rod 21 Winding machine 34 Tension bar 35 Resin tank 36 Nozzle d Inner diameter D Outer diameter E Triangular height H Winding height P Strand pitch S Strand width W Wind number θ Twill angle

Claims (4)

  A glass roving in which a single glass strand is wound in a cylindrical shape, wherein the strand pitch of the glass strand is in the range of 50 to 80 mm, and the wind number is in the range of 5 to 9. Glass roving.   The glass roving according to claim 1, wherein a winding height of the glass roving is in a range of 270 to 700 mm.   The glass roving according to claim 1 or 2, wherein the glass roving is a double square end package.   The glass roving according to any one of claims 1 to 3, wherein the glass roving has a hole penetrating radially inside.