JP2022049755A - Roving, production method thereof, and roving package - Google Patents

Abstract

To provide a roving that can reduce defects in unwinding from the roving package, and can be easily withdrawn from a roving package.SOLUTION: A roving 1 is a multiple-wound yarn including a plurality of strand bundles 2 composed of 2 to 12 strands 3. The strand bundle 2 includes a first strand bundle 2a having a split ratio of 90% or more, and a second strand bundle 2b having a split ratio of less than 90%.SELECTED DRAWING: Figure 1

Description

The present invention relates to a roving in which a plurality of strands unwound from a cake in which a plurality of strands are wound are bundled and combined to form a roving, a method for producing the roving, and a roving package using the roving.

Conventionally, roving such as glass fiber roving has been used as a reinforcing fiber base material for SMC (Sheet Molding Compound) molding, spray-up molding, and the like. Such roving is formed by combining strands wound around a cake. In particular, in recent years, a strand is wound into one cake as a plurality of divided strands, and roving is manufactured using this cake. According to this method, workability in the spinning process and the yarn combining process can be improved. However, when such a cake is used, a loop may occur in the roving, and as a result, there is a problem that the roving is difficult to be pulled out from the roving package. Therefore, attempts have been made to reduce the unwinding failure of roving due to this loop.

For example, in Patent Document 1 below, in a roving strand bundle in which a plurality of split strands drawn from a glass fiber dried cake are combined, the split strands in the central portion are sequentially entwined by unwinding and twisting the strands in the peripheral portion, and the whole is entwined. The structure that is kept in a tight state is disclosed. Patent Document 1 describes that this structure can suppress the loop inherent in the dried cake.

Further, Patent Document 2 below discloses a method in which the division ratio of roving is 99% or more, and the number of bonding points between the divided strands is one or less per 100 m of roving length.

Japanese Patent No. 3743098 Japanese Patent No. 5266637

However, even by the methods of Patent Document 1 and Patent Document 2, it is not possible to sufficiently reduce the unwinding defect of roving.

An object of the present invention is to provide roving, a method for manufacturing the roving, and a roving package using the roving, which can reduce unwinding defects from the roving package and can be easily pulled out from the roving package.

The roving according to the present invention is a roving in which a plurality of strand bundles composed of 2 to 12 strands are bundled and spun together, and the strand bundle is a first strand having a division ratio of 90% or more. It is characterized by including a bundle and a second strand bundle having a division ratio of less than 90%.

In the present invention, when the roving cut to a length of 10 m is untwisted and pulled horizontally by holding both ends, the sag width to the strand that hangs down most with respect to the strand extending in the horizontal direction is It is preferably 10 cm or less.

In the present invention, the number of the first strand bundles is preferably larger than the number of the second strand bundles.

In the present invention, it is preferable that the strand bundle is composed of two strands.

In the present invention, the division ratio of the second strand bundle is preferably 30% or more.

In the present invention, it is preferable that the number of adhesion points between the strands in the first strand bundle is 100 or less per 100 m of the first strand bundle.

In the present invention, the division ratio of the first strand bundle is preferably 95% or more.

The roving package according to the present invention is formed by winding the roving configured according to the present invention.

The method for producing roving according to the present invention is composed of a first strand winding body having 2 to 12 strands and a division ratio of 90% or more, and 2 to 12 strands having a division ratio of 90. By twisting the strands drawn from the first winding body and the step of preparing the second winding body having a value of less than%, a first strand bundle is obtained and the second winding body is drawn out from the second winding body. It has a step of obtaining a second strand bundle by twisting the strands, and a step of obtaining roving by bundling the first strand bundle and the second strand bundle and combining them. It is characterized by.

According to the present invention, it is possible to provide roving, a method for manufacturing the roving, and a roving package using the roving, which can reduce unwinding defects from the roving package and can be easily pulled out from the roving package.

FIG. 1 is a schematic perspective view showing a roving and a roving package according to an embodiment of the present invention. FIG. 2 is an enlarged view of roving 1 of FIG. FIG. 3 is a diagram for explaining the bonded portion. FIG. 4 is a schematic view after cutting the strand bundle 2. FIG. 5 is a diagram for explaining a method for testing the sag width. FIG. 6 is a diagram for explaining a loop. FIG. 7 is a schematic diagram for explaining an example of a manufacturing apparatus for producing a cake in the roving manufacturing method according to the present invention. FIG. 8 is a schematic diagram for explaining another example of a manufacturing apparatus for producing a cake in the method for producing roving according to the present invention. FIG. 9 is a schematic diagram for explaining another example of a manufacturing apparatus for making a cake in the roving manufacturing method according to the present invention. FIG. 10 is a schematic cross-sectional view for explaining the method for manufacturing roving according to the present invention. FIG. 11 is a schematic cross-sectional view for explaining the method for manufacturing roving according to the present invention. FIG. 12 is a schematic cross-sectional view for explaining the method for manufacturing roving according to the present invention.

Hereinafter, preferred embodiments will be described. However, the following embodiments are merely examples, and the present invention is not limited to the following embodiments. Further, in each drawing, members having substantially the same function may be referred to by the same reference numeral.

[Robbing and roving package]
FIG. 1 is a schematic perspective view showing a roving and a roving package according to an embodiment of the present invention. In the roving package 10 shown in FIG. 1, the roving 1 is wound around a rotation axis O. More specifically, the roving package 10 is one in which the roving 1 is alternately wound and twilled so as to be layered in the radial direction.

The roving package 10 has a substantially cylindrical structure. Therefore, the inner peripheral side of the roving package 10 is hollow. A core such as a bobbin may be arranged in the center of the roving package 10.

The roving 1 is obtained by bundling a plurality of strand bundles 2 composed of 2 to 12 strands 3 and combining them. The strand 3 is composed of, for example, 200 or more and 10,000 or less glass filaments, and an organic solid component that bundles the glass filaments. The number of glass filaments constituting the strand 3 is preferably 8000 or less, and more preferably 6000 or less. In FIG. 2, the strand bundle 2 is composed of two strands 3.

The fiber diameter of the glass filament is, for example, 6 μm or more and 24 μm or less. The fiber diameter of the glass filament is more preferably 20 μm or less, and further preferably 17 μm or less. When the number of glass filaments and the fiber diameter are within the above ranges, the mechanical strength of the composite material when composited with the resin can be further increased. The fiber diameter of the glass filament can be adjusted, for example, by changing the viscosity of the molten glass when manufacturing the glass filament, which will be described later, the winding speed at the time of winding, and the like.

The composition of the glass filament is not particularly limited, and examples thereof include E glass, S glass, D glass, and AR glass. Among these, E-glass is inexpensive and can further increase the mechanical strength of the composite material when it is composited with a resin. Further, the S glass can further increase the mechanical strength of the composite material.

The strand bundle 2 can be obtained by pulling out and bundling 2 to 12 strands 3 from one cake (roller) wound up. As shown in FIG. 2, the strand bundle 2 is twisted. Since the number of strands 3 constituting the strand bundle 2 is 12 or less, a plurality of strand bundles 2 can be easily bundled to manufacture the roving 1. The strand bundle 2 is preferable because it can be bundled more easily by being composed of 2 to 6 strands 3. The number of strands 3 constituting all the strand bundles 2 does not have to be 2 to 12, and for example, the strand bundle may be composed of 13 or more strands 3. Further, the roving 1 may be a combination of a strand bundle 2 composed of 2 to 12 strands 3 and one strand 3.

The above strand bundle 2 is classified into two types. The first is a strand bundle having a division ratio of 90% or more (hereinafter, referred to as a first strand bundle 2a). The second is a strand bundle having a division ratio of less than 90% (hereinafter referred to as a second strand bundle 2b).

The division ratio of each strand bundle 2 is calculated by the following formula.
Split ratio of strand bundle = {(total number of strands 3 obtained by cutting strand bundle 2) + (number of thick strands 3a obtained by cutting strand bundle 2)} / {(uncut strand bundle) Number of strands 3 included in 2) × 100} × 100
Specifically, the roving 1 is cut to a length of 10 m, the twist is untwisted while pressing both ends of the cut roving 1, and the roving 1 is separated into a plurality of strand bundles 2. At that time, the roving 1 is separated into the strand bundle 2 so that the adhesive portion between the strands 3 is not peeled off. As shown in FIG. 3A, the strands 3 are in a twisted state except for the bonding points between the strands 3, but as shown in FIG. 3B, the bonding points between the strands 3 are bonded to each other. In, the strands 3 are stretched along the same direction while the strands 3 are adhered to each other. The bonded portion between the strands 3 is bonded by the organic solid component contained in the sizing agent. Next, an arbitrary 100 points are cut out for each strand bundle 2. The length of the cut out strand bundle 2 is 2.5 cm. By cutting the strand bundle 2 to 2.5 cm, the strand bundle 2 becomes a strand 3. However, as shown in FIG. 4, if there is an adhesive portion between the strands 3, even if the strand 3 is cut, a thick strand 3a that is thicker than the strand 3 is present. Therefore, the division ratio can be used as an index of the number of adhesion points between the strands 3 constituting the strand bundle 2, and it is shown that the smaller the division ratio, the larger the number of adhesion points between the strands 3.

The first strand bundle 2a has a division ratio of 90% or more, preferably 95% or more, and more preferably 99% or more. The upper limit of the division rate is not particularly limited, but may be, for example, 100%.

The second strand bundle 2b has a division ratio of less than 90%, preferably 85% or less, and more preferably 75% or less. The lower limit of the division rate is not particularly limited, but may be, for example, 30% from the viewpoint of quality.

Further, the number of strand bundles 2 constituting the roving 1 can be, for example, 5 or more and 100 or less. The number of the first strand bundle 2a can be 4 or more and 80 or less, and the number of the second strand bundle 2b can be 1 or more and 20 or less. Further, the number of the first strand bundle 2a is preferably larger than the number of the second strand bundle 2b. If the number of the second strand bundle 2b is larger, the mechanical strength of the composite material when composited with the resin tends to vary. The ratio of the number of the first strand bundle 2a to the second strand bundle 2b (first strand bundle / second strand bundle) is preferably 1 to 50, and more preferably 10 to 25.

The count of roving 1 can be, for example, 1000 tex or more and 8000 tex or less. The number of strands 3 included in the roving 1 can be, for example, 10 or more and 200 or less. The count of the strand 3 can be, for example, 10 tex or more and 150 tex or less.

In the present embodiment, the roving 1 has a division ratio of less than 99%. The division ratio of the roving 1 is different from the division ratio of the strand bundle 2 shown above, and the arbitrary 100 points of the roving 1 are 2.5 cm without untwisting while pressing both ends of the roving 1. It is obtained from the number of strands 3 and the number of thick strands 3a obtained when cut out to the length of.

In roving 1, the division ratio is preferably 98.5% or less, more preferably 96% or less. The lower limit of the division rate is not particularly limited, but can be, for example, 60% from the viewpoint of manufacturing. Further, if there are too many bonding points between the strands 3, quality problems other than loops may occur. From this point as well, the division ratio is preferably 90% or more, preferably 90% or more. Is more preferable, and 94% or more is further preferable.

Further, in the present embodiment, when the test shown in FIG. 5 is performed, the hanging width L up to the strand 3c that hangs down most downward with respect to the strand extending in the horizontal direction is 10 cm or less. The test shown in FIG. 5 can be performed as follows.

First, the roving 1 is cut to a length of 10 m, and the twist is untwisted while pressing both ends of the cut roving 1 to separate the roving 1 into strands 3. At that time, the strand 3 is separated so that the adhesive portion between the strands 3 is not peeled off. Next, both ends of each strand 3 are aligned and pulled in the horizontal direction x. At this time, both ends of each strand 3 are fixed to the support members 3A and 3B using an adhesive or the like. Next, the hanging width L from the strand 3b extending in the horizontal direction x to the most downwardly hanging strand 3c is measured. The hanging width L is the distance between the strand 3v extending in the horizontal direction x and the lowermost portion of the strand 3c hanging downward in the vertical direction z orthogonal to the horizontal direction x.

As described above, the hanging width L indicates the distance between the strand 3b extending in the horizontal direction X and the strand 3c hanging downward in the vertical direction Y, and can be used as an index of the yarn length difference between the strands 3. It is shown that the smaller the sag width L is, the smaller the difference in yarn length between the strands 3.

In roving 1, the sagging width L is preferably 7 cm or less, more preferably 5 cm or less. The lower limit of the sag width L is not particularly limited, but may be, for example, 0.1 cm.

In the roving 1, the number of bonding points between the strands 3 is preferably 100 or less, more preferably 10 or less, still more preferably 2 or less, with respect to the length of the roving 1 of 100 m. When the bonding points between the strands are within the above range, loops can be made more difficult to occur, and roving 1 can be more easily pulled out from the roving package 10.

The height of the roving package 10 can be, for example, in the range of 100 mm to 1000 mm. The inner diameter of the roving package 10 can be, for example, in the range of 30 mm to 350 mm. The outer diameter of the roving package 10 can be, for example, in the range of 150 mm to 800 mm. The weight of the roving package 10 can be, for example, 10 kg to 300 kg.

As described above, since the roving 1 of the present embodiment includes the first strand bundle 2a having a division ratio of 90% or more and the second strand bundle 2b having a division ratio of less than 90%, the roving package 10 is used. It is possible to reduce the unwinding defect of the roving 1, and it is easy to pull out the roving 1 from the roving package 10. This detail will be described below with reference to FIG.

Conventionally, when a plurality of strands are unwound from one cake (winding body) to manufacture a roving, there may be a difference in yarn length due to the adhesion between the plurality of strands 3. This difference in yarn length may cause loops, making it difficult to pull roving out of the roving package.
As shown in FIG. 6A, when only the first strand bundle 2a having a high division ratio is used, once the strands 3 are adhered to each other, the difference in thread length between the bonded portions becomes large and the loop becomes large. .. Even if the number of loops is small, as shown in the right figure of FIG. 6A, if the loops are large, it is difficult to pull out the roving from the roving package.
On the other hand, as shown in FIG. 6B, when only the second strand bundle 2b having a low division ratio is used, the loops are small, but the number of loops is large, so that when the strands 3 are bundled, a plurality of strands 3 are used. The loops get entangled and it becomes difficult to pull out the roving from the roving package.

On the other hand, in the roving 1 of the present embodiment, as shown in FIG. 6C, a first strand bundle 2a having a high division ratio and a second strand bundle 2b having a low division ratio are mixed. Larger loops are entangled with smaller loops, but less frequently than smaller loops. On the other hand, the large loop becomes smaller due to the entanglement of the small loop and the large loop. Therefore, it is presumed that the roving 1 can be easily pulled out from the roving package 10.

Hereinafter, an example of a roving and a method for manufacturing a roving package according to the present invention will be shown.

[Production method]
(Cake making)
7 to 9 are schematic views for explaining an example of a manufacturing apparatus 21 for manufacturing a cake (rolled body) in the roving manufacturing method according to the present invention.

First, a plurality of glass filaments 22 are formed. First, the glass raw material put into the glass melting furnace is melted into molten glass. After the molten glass is brought into a homogeneous state, the molten glass is pulled out from a heat-resistant nozzle attached to the bushing. After that, the drawn molten glass is cooled to form a plurality of glass filaments (monofilaments) 22. As the bushing, for example, a platinum bushing can be used.

The thickness of the glass filament 22 can be adjusted by adjusting the temperature of the molten glass, the thickness of the nozzle, and the like.

Next, the sizing agent is applied to the surfaces of the obtained plurality of glass filaments 22 by the sizing agent applying mechanism 23. With the sizing agent applied evenly, the plurality of glass filaments 22 are aligned and focused. The plurality of glass filaments 22 can be aligned and focused by, for example, the focusing shoe 24. As a result, the strand 25 in a state where the film of the organic solid component is not formed is formed.

The sizing agent is, for example, one or more thermoplastic resins selected from the group of polypropylene resin, nylon resin, polyvinyl acetate and polyphenylene sulfide resin, or a group of polyester (unsaturated polyester) resin, epoxy resin and polyurethane resin. It may contain one or more heat-curable resins selected from the above. It is also possible to add each component such as a lubricant, a nonionic surfactant, and an antistatic agent to the sizing agent, and the blending ratio of these components may be appropriately set as necessary.

Next, the strand 25 is reciprocated in the axial direction by the traverse device 26 to perform twilling, and the strand 25 is wound around, for example, a collet 27. Examples of the traverse device 26 include a wire traverse and the like. The collet 27 is rotating while the traverse device 26 is reciprocating. The thickness of the glass filament 22 can also be adjusted by the rotation speed of the collet 27.

Specifically, in the present embodiment, the two strands 25a and 25b are passed through separate traverse devices 26a and 26b, respectively, and the traverse devices 26a and 26b are reciprocated in the axial direction to move the strands 25a and 25b back and forth. Are wound around the collet 27 while being twilled by reciprocating each of them in the axial direction.

Next, the sizing agent is heated and dried to evaporate the water content. As a result, a film composed of organic solid components is formed on the surface of the glass filament 22, and the strands 25a and 25b wound around the collet 27 become a cake. It should be noted that while the strand 25 is reciprocated in the axial direction by the traverse device 26 to perform twilling, for example, when the strands 25a and 25b are wound around the collet 27, the portions where the strands 25a and 25b are in contact are adhered by evaporating water. It becomes a place.

As a method of heat drying, for example, hot air drying or dielectric drying may be used. The heat drying is performed, for example, in a temperature range of 100 ° C. to 150 ° C. for 1 hour to 24 hours. Thereby, the cake 28 in which the strand 3 is wound can be obtained.

In the present embodiment, a cake having a division ratio of strand 3 of 90% or more (first winding body) and a cake having a division ratio of strand 3 of less than 90% (second winding body) are prepared. The division ratio of the strand 3 can be adjusted by adjusting the degree of contact between the strands 25a and 25b.

For example, when winding on the collet 27, by adjusting the speed of twilling, the movement pattern of the traverse devices 26a, 26b, etc., at least a part of the strands 25a, 25b come into contact with each other, or the strands 25a, 25b come into contact with each other. The strands 25a, 25b can be wound around the collet 27 so that they do not touch at all.

In this way, the division ratio of the cake obtained by adjusting the contact between the strands 25a and 25b can be adjusted. For example, the reciprocating speeds of the traverse devices 26a and 26b may be slightly different, or the reciprocating speeds of one or both of the traverse devices 26a and 26b may be changed regularly or irregularly during the reciprocating movement of the traverse devices 26a and 26b. It can be adjusted as described above by making the traverse devices 26a and 26b different in shape and the like. By changing the reciprocating movement speed of the traverse devices 26a and 26b, an inertial force acts on the strands 25a and 25b in the reciprocating movement direction, and the strands 25a and 25b are likely to come into contact with each other. When the traverse device 26 is a wire traverse, the strands 25a and 25b slide and move in the reciprocating direction by changing the material and shape of the wire, and the strands 25a and 25b come into contact with each other.

For example, in FIG. 7, adhesion between the strands 25a and 25b can be suppressed by reciprocating so that the distances between the traverse devices 26a and 26b are sufficiently maintained and these distances are always constant.

In the production of roving, in addition to the above cake 28, a cake in which one strand is wound or a cake in which 13 or more strands are wound may be used in combination.

Further, as shown in FIG. 8, two strands 25a and 25b may be passed through the same traverse device. Thereby, the strands 25a and 25b may be wound around the collet 27 so that at least a part of the strands 25a and 25b are in contact with each other, and the division ratio of the roving may be adjusted. For example, by changing the shape and material of the traverse devices 26a and 26b, the inertial force applied in the reciprocating movement direction of the strands 25a and 25b can be adjusted, the strands 25a and 25b are in appropriate contact with each other, and the lengths of the strands 25a and 25b are long. It is possible to reduce the fluctuation of the inertia. For example, by using the traverse devices 26a and 26b having a smooth surface, the inertial force easily acts on the strands 25a and 25b, and the strands 25a and 25b easily come into contact with each other.

Further, as shown in FIG. 9, when four strands 25a to 25d are used, the two strands 25a and 25b are passed through one traverse device 26a, and the two strands 25c and 25d are passed through one traverse device. It may be passed through 26b. In this case, the traverse device 26a may reciprocate within the range of the left half of the collet 27, and the traverse device 26b may reciprocate within the range of the right half of the collet 27. Further, by adjusting the speed of the twilling and the shapes of the traverse devices 26a and 26b, the strands 25a to 25d are wound around the collet 27 so that at least a part of the strands 25a and 25b and the strands 25c and 25d come into contact with each other. May be good. In addition, when using three strands 25, the same method can be applied.

(Making roving and roving packages)
10 to 12 are schematic cross-sectional views for explaining a method for manufacturing a roving according to the present invention.

First, the first winding body and the second winding body produced by the above method are prepared. For example, 1 to 18 first windings and 1 to 10 second windings are prepared, and these windings are arranged in series to form a row of cakes. The order of arrangement of the first winding body and the second winding body may be appropriately determined.
In FIG. 10, as an example, a row of four cakes is shown. Here, the right side in FIG. 10 is the front stage, and the left side is the rear stage. From the latter stage to the first stage, cake 31A (first roll), cake 31B (first roll), cake 31C (first roll), and cake 31D (second roll) are arranged in this order. do. Further, as shown in FIG. 11, the rows of cakes are arranged in parallel, for example, 2 to 100 stages. In FIG. 11, as an example, an example in which four cake rows are arranged in three rows is shown. In the present invention, a plurality of cakes may be arranged in parallel one by one. Further, no bobbins are arranged on the inner peripheral side of the plurality of cakes.

Next, as shown in FIG. 10, the strands are unwound from the inner peripheral sides of the cakes 31A, 31B, 31C, and 31D.
Specifically, first, the two strands 32a and 32b in the cake 31A are bundled and unwound as a strand bundle 32. As shown in FIG. 12A, the strand 32b is unwound so as to orbit around the strand 32a. Thereby, the strand 32b can be twisted with respect to the strand 32a for each circumference of the cake 31A.

Next, the strand bundle 32 is passed through the inner peripheral side of the cake 31B in the previous stage. Then, the two strands 33a and 33b of the cake 31B are bundled and unwound as a strand bundle 33, and bundled together with the strand bundle 32 to form a bundle 34. As shown in FIG. 12B, the strands 33a and 33b are twisted with respect to the strand bundle 32 for each circumference of the cake 31B.

Similarly, the bundle 34 is passed through the inner peripheral side of the cake 31C in the previous stage and bundled so as to be twisted by the strand bundle 35 unwound from the cake 31C to form a bundle 36. Further, the bundle 36 is passed through the inner peripheral side of the cake 31D and bundled so as to be twisted by the strand bundle 37 unwound from the cake 31D to form a bundle 38.

Next, as shown in FIG. 11, each bundle 38 drawn from the cake 31D in the final stage of each row is bundled into one and combined to obtain one roving 1.
Finally, by winding the roving 1 around a bobbin, for example, the roving package 10 shown in FIG. 1 can be obtained. At this time, it is desirable to wind the roving 1 until it reaches 10 kg to 300 kg. Further, after winding, the bobbin may be removed from the roving package 10 before use.

Hereinafter, the present invention will be described in more detail based on specific examples. The present invention is not limited to the following examples, and can be appropriately modified and implemented without changing the gist thereof.

(Example 1)
First, a plurality of glass filaments drawn from the bushing were coated with a sizing agent and bundled to obtain two glass strands. The two glass strands thus produced are reciprocated in the axial direction using a wire traverse device to perform twilling, and the strands are wound around a collet so that the strands do not come into contact with each other, and the sizing agent is dried. A cake (first volume) was produced by allowing the cake (first volume). The wire traverse device used for manufacturing the first winding body has an axis that is substantially parallel to the axis of the collet, and has a rotation axis that rotates about the axis and a first wire that extends from the rotation axis. It extends from a position on the axis of rotation that is distant from the position where the first wire extends in the direction of the axis of rotation, and in a plan view seen from the axis side of the axis of rotation, it extends from a position different from that of the first wire and is shorter than the first wire. It has a second wire and a plurality of wires including a linear third wire connecting the ends of the first wire and the second wire. The division ratio of the strands wound around the first winding body is 100%.

Next, the two glass strands are reciprocated in the axial direction using a wire traverse device to perform a twill swing, and the strands are wound around a collet so that a part of the strands come into contact with each other, and the sizing agent is dried. As a result, a cake (second volume) was prepared. The wire traverse device used for manufacturing the second winding body is the same as that used for manufacturing the first winding body, except that the third wire is curved. Further, the division ratio of the strand wound around the second winding body is 52%.

Next, 30 pieces of the prepared cakes are arranged (29 pieces of the first winding body and one piece of the second winding body), and two strands are unwound and twisted from the inner peripheral side of each cake. A roving was made by bundling the bundles of strands.

As for the division ratio of the cake, the strands drawn from the above-mentioned first and second winding bodies were cut at 100 points so as to have a length of 2.5 cm, and each was dispersed from the cut out rovings. The number of strands was actually measured, and the division ratio was calculated by the following formula.
Division rate = X / (2 x 100) x 100 (%)
X: Average value of the measured number of strands (the number including thick strands) The division ratio is 2.5 cm from the points 4100 m, 8200 m, 12300 m, 16400 m, 20500 m, 24600 m, 28700 m from the tip of the roving. As a result, 100 pieces were collected and measured (15 pieces for 4100m and 8200m, 14 pieces for 12300m, 16400m, 20500m, 24600m and 18700m), and the average value was obtained.

(Comparative Example 1)
The roving was produced by the same method as in Example 1 except that 30 of the above-mentioned second winding bodies were arranged and two strands were unwound and twisted from the inner peripheral side of each winding body.

(Comparative Example 2)
A cake with a strand split ratio of 93% was obtained using a traverse device with a curved third wire. The difference in the manufacturing method from the second winding body obtained in the above Examples and Comparative Examples is that the reciprocating pattern of the traverse is changed. Specifically, the division ratio changes due to the difference in the distance between the two strands at the start of winding to the collet. In the second winding body, the spacing between the strands is smaller than in the case of producing the cake of Comparative Example 2.
Then, 30 pieces of the above cakes were arranged, and roving was produced by the same method as in Example 1 except that two strands were unwound and twisted from the inner peripheral side of each winding body.

(Measurement of sagging width)
The 10 m long roving was untwisted and separated into strands. At this time, the strands were separated so as not to peel off the adhesive portion between the strands as shown in FIG. 3 (b). Next, both ends of each strand were aligned and pulled horizontally. Next, the sag width L from the horizontally extending strand to the most downward sagging strand was measured.
The sagging width was measured by collecting 10 m of roving from each of 4100 m, 8200 m, 12300 m, 16400 m, 20500 m, 24600 m, and 28700 m from the tip of the roving, and the average value was obtained.
The results are shown in Table 1 below.

As shown in Table 1, as a result of pulling out the roving from the roving package of Example 1, there was no catch. On the other hand, as a result of pulling out the roving from the roving packages of Comparative Example 1 and Comparative Example 2, catching occurred.

1 ... Robbing 2,2a, 2b ... Strand bundle 3 ... Strand 10 ... Robbing package 25,25a-25d ... Strand 26,26a-26b ... Traverse device 27 ... Collet 28,31A, 31B, 31C, 31D ... Cake 32,33 , 35, 37 ... Strand bundle 32a, 32b, 33a, 33b ... Strand 34, 36, 38 ... Bundle

Claims (9)

It is a roving made by bundling a plurality of strand bundles composed of 2 to 12 strands and combining them.
The strand bundle is
The first strand bundle having a division ratio of 90% or more,
A second strand lattice with a split ratio of less than 90%,
Including roving. When the roving cut to a length of 10 m is untwisted and pulled horizontally by holding both ends, the sag width to the strand that hangs down most with respect to the strand extending in the horizontal direction is 10 cm or less. , The roving according to claim 1. The roving according to claim 1 or 2, wherein the number of the first strand bundles is larger than the number of the second strand bundles. The roving according to any one of claims 1 to 3, wherein the strand bundle is composed of two strands. The roving according to any one of claims 1 to 4, wherein the division ratio of the second strand bundle is 30% or more. The roving according to any one of claims 1 to 5, wherein the number of adhesion points between the strands in the first strand bundle is 100 or less per 100 m of the first strand bundle. The roving according to any one of claims 1 to 6, wherein the division ratio of the first strand bundle is 95% or more. A roving package in which the roving according to any one of claims 1 to 7 is wound. Prepare a first winding body composed of 2 to 12 strands and having a division ratio of 90% or more, and a second winding body composed of 2 to 12 strands having a division ratio of less than 90%. And the process to do
The first strand bundle is obtained by twisting the strands drawn from the first winding body, and the second strand bundle is obtained by twisting the strands drawn out from the second winding body. And the process of getting
A step of obtaining roving by bundling the first strand bundle and the second strand bundle and combining the yarns.
A method for manufacturing roving.

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