JP2023122676A - Crimping device, crimped fiber manufacturing device, crimped fiber manufacturing method, and pair of lateral members - Google Patents

Abstract

To provide a crimping device capable of suppressing agglutination of fibers due to friction.SOLUTION: The present invention provides a crimping device, which includes a pair of rollers to nip fibers and a pair of lateral members disposed on both lateral surfaces of the pair of rollers so as to face each other. The pair of lateral members individually have a concavity having an opening on a surface facing the roller and are formed using resin material, and the concavity has a specific size. The present invention also provides a crimped fiber manufacturing device including the crimping device. The present invention also provides a crimped fiber manufacturing method using the crimping device or the crimped fiber manufacturing device.SELECTED DRAWING: Figure 1

Description

The present invention relates to a crimping device, a crimped fiber manufacturing device, a crimped fiber manufacturing method, and a pair of side members.

A crimped fiber can be generally produced by collecting a large number of undrawn yarns obtained by spinning to form a tow, subjecting the tow to drawing heat treatment, and optionally mechanically crimping the tow. In crimping equipment for applying mechanical crimps, fibers may stick or break due to friction.

Various means for reducing the friction of fibers have been proposed so far, and a so-called slide plate is known as one of the means. The slide plates are a pair of flat plate-like backing plates arranged at both ends of the pressing roller for the purpose of protecting the ends of the tow passing through the nip points of both ends of the pressing roller from friction. The slide plate is generally made of a metal material, such as a copper alloy or an aluminum alloy, or a plastic material having a hardness lower than that of the pressing roller.

Metal slide plates can wear out over time. Wear is caused by contact with the ends of the pusher rollers and friction with the tow passing through the nip points of the ends of the pusher rollers. Wear of the slide plate can lead to contamination of the product with metal powder and line contamination with metal ions. Therefore, metal slide plates are not suitable, especially in the production of textiles for industrial material applications such as battery separators.

Plastic slide plates can wear out in a relatively short time. The cause of wear is friction with the tow passing through the nip at the ends of the indenter roller. The ends of the tow may stick or break due to friction with the slide plate, significantly impairing the dispersibility of the fibers.

Further, as another means for reducing the friction of fibers, Patent Document 1 below discloses a technique of forming the inner wall of a compression box with a metal belt in a compression box type crimper.

JP-A-60-215827

A main object of the present invention is to provide a crimping device capable of suppressing agglutination of fibers due to friction.

That is, the present invention
a pair of rollers for nipping the fibers;
a pair of side members arranged to face both side surfaces of the pair of rollers,
each of the pair of side members is provided with a concave portion having an opening on a surface facing the roller, and is formed using a resin material;
Each of the recesses is located at a position corresponding to each nip point of the pair of rollers,
In the opening, a first virtual line passing through a point corresponding to the nip point and parallel to the moving direction of the fibers is drawn, and the intersection of the first virtual line and an upstream end of the opening in the moving direction. is a first intersection, and the intersection of the first imaginary line and the downstream end of the opening in the moving direction is a second intersection, the point corresponding to the nip point and the second intersection a second length between is greater than a first length between the nip point and a point corresponding to the first intersection point;
The crimping device is provided, wherein the second length is greater than or equal to 4.0% of the diameter of the roller.
The second length may be 8.0% or less of the diameter of the roller.
The first length may be between 0.5% and 2.5% of the diameter of the roller.
In the opening, a second virtual line passing through a point corresponding to the nip point and perpendicular to the moving direction of the fibers is drawn. A point corresponding to the nip point and the third intersection point are defined as a third intersection point and a fourth intersection point between the second imaginary line and the lower end portion of the opening. and/or the second width between the point corresponding to the nip point and the fourth intersection point may be 0.15% or more and 1.25% or less of the diameter of the roller .
The depth of the recess may be 0.1% or more and 0.4% or less of the diameter of the roller.
The resin material may have a Rockwell hardness of 112 or more as measured by the R scale.
The resin material may have a water absorption rate of 0.25% by mass or less.
The resin material may contain polyetheretherketone or polyacetal.
The present invention also provides a crimped fiber manufacturing apparatus including the crimping device.
The present invention also provides a crimped fiber manufacturing method using the crimping device or the crimped fiber manufacturing device.
The method for producing the crimped fibers may include supplying a papermaking oil to the nip points on the both side surfaces of the pair of rollers.
The speed of supplying the papermaking oil may be 70 mL/min or more and 130 mL/min or less.
The present invention
A pair of side members for a crimping device, comprising:
The crimping device includes a pair of rollers that nip the fibers,
The pair of side members are arranged to face both side surfaces of the pair of rollers,
each of the pair of side members is provided with a concave portion having an opening on a surface facing the roller, and is formed using a resin material;
Each of the recesses is arranged at a position corresponding to each nip point of the pair of rollers,
In the opening, a first imaginary line passing through a point corresponding to the nip point and parallel to the moving direction of the fibers is drawn, and the intersection of the first imaginary line and an upstream end of the opening in the moving direction. is a first intersection point, and the intersection point of the first imaginary line and the downstream end of the opening in the movement direction is a second intersection point, the point corresponding to the nip point and the second intersection point a second length between is greater than a first length between a point corresponding to the nip point and the first intersection;
A pair of side members are also provided, wherein the second length is greater than or equal to 4.0% of the diameter of the roller.

The present invention provides a crimping device capable of suppressing agglutination of fibers due to friction. Note that the effects of the present invention are not limited to the effects described here, and may be any of the effects described in this specification.

It is a figure which shows a crimping apparatus typically. FIG. 4 is a diagram schematically showing an example of the shape of a recess having an opening; FIG. 4 is a schematic diagram showing an opening; FIG. 4 is a diagram schematically showing the positional relationship between both ends of the toe and recesses having openings.

Preferred embodiments for carrying out the present invention will be described below. The embodiments described below show representative embodiments of the present invention, and the scope of the present invention is not limited only to these embodiments.

1. Crimp device

A crimping device 1 according to this embodiment will be described with reference to FIG. FIG. 1 is a diagram schematically showing a crimping device 1. As shown in FIG. In FIG. 1, (A) is a schematic side view, (B) is a schematic front view, and (C) is a schematic top perspective view.

A crimping device 1 is a device used to mechanically crimp fibers. The crimping device 1 includes a pair of rollers 10, 10 for nipping fibers, and a pair of side members 20, 20 arranged to face both side surfaces of the pair of rollers 10, 10. As shown in FIG.

1-1. a pair of rollers

The pair of rollers 10 , 10 consists of two rollers 10 . The two rollers 10 are identical in shape and have the same diameter. The roller diameter may be, for example, 200 mm, but is not so limited. The pair of rollers 10, 10 are arranged vertically. A pair of rollers 10, 10 rotates to nip the tow T (fiber) and send it out in a certain direction. An arrow MD shown in FIG. 1 indicates the direction of movement of the tow T. As shown in FIG. The tow T is pressed at a nip point (a portion where the pair of rollers 10, 10 nip the tow T). For example, when the tow T passes through the nip point and the pressure is released, the tow T may be finely crimped. The tow T that has passed through the nip point can be pushed into, for example, a stuffing box (not shown) and crimped.

1-2. A pair of side members

The pair of side members 20 , 20 consists of two side members 20 . The contours of the two side members 20 are preferably identical. The pair of side members 20, 20 are arranged to face both side surfaces of the pair of rollers 10, 10. As shown in FIG. Specifically, one side member 20 (hereinafter also referred to as “first side member 20 a ”) faces at least a portion of one side surface of each roller 10 . That is, the first side member 20a faces at least part of one side surface of the pair of rollers 10, 10 (hereinafter also referred to as "first side surface of the pair of rollers 10, 10"). The other side member 20 (hereinafter also referred to as “second side member 20 b ”) faces at least a portion of the other side surface of each roller 10 . That is, the second side member 20b faces at least a part of the other side surface of the pair of rollers 10, 10 (hereinafter also referred to as "second side surface of the pair of rollers 10, 10").

Each of the pair of side members 20 , 20 (the first side member 20 a and the second side member 20 b ) has a concave portion having an opening on the surface facing the roller 10 . The recess in the first side member 20a and the recess in the second side member 20b are preferably of the same shape. Each of these recesses is located at a position corresponding to the nip point of the pair of rollers 10,10. That is, the concave portion of the first side member 20a is located at a position corresponding to the nip point of the first side surfaces of the pair of rollers 10,10. The concave portion of the second side member 20b is located at a position corresponding to the nip point of the second side surfaces of the pair of rollers 10,10.

The shape of the opening includes, for example, circular, elliptical, semicircular, triangular, rounded triangular, square, rounded square, rectangular, rounded rectangular, pentagonal or more polygonal shapes, and Rounded polygonal shapes with pentagons or more can be mentioned. The shape of the opening is preferably elliptical or rectangular with rounded corners.

The recess has a bottom portion in addition to the opening. Examples of the shape of the bottom portion include a flat bottom shape, a round bottom shape, a U bottom shape, and a V bottom shape. The shape of the bottom portion is preferably round bottom shape or U bottom shape.

FIG. 2 is a diagram schematically showing an example of the shape of the recess 22 having the opening 21. As shown in FIG. The shape of the recess 22 is preferably a shape consisting of an elliptical opening 21 and a round-bottomed bottom, a shape consisting of an elliptical opening 21 and a U-bottomed bottom, or a rounded rectangular opening. 21 and a round-bottomed bottom portion, or a shape made up of a rectangular opening 21 with rounded corners and a U-bottomed bottom portion.

The size of the opening 21 will be described with reference to FIG. FIG. 3 is a schematic diagram showing the opening 21. As shown in FIG. The arrow MD shown in FIG. 3 indicates the direction of movement of the fibers (tows). In FIG. 3, the left side is the upstream side in the moving direction of fibers (tows), and the right side is the downstream side.

Units for length, width, and depth described below are not particularly limited, but may be, for example, "mm".

The opening 21 is located at a position corresponding to the nip point NP between the pair of rollers 10 , 10 . At the opening 21, a first virtual line VL1 is drawn through a point corresponding to the nip point NP and parallel to the moving direction of the fibers. The intersection point between the first virtual line VL1 and the upstream end portion of the opening 21 in the moving direction is defined as a first intersection point P1. The intersection of the first virtual line VL1 and the downstream end of the opening 21 in the moving direction is defined as a second intersection P2. At this time, the second length L2 between the point corresponding to the nip point NP and the second intersection point is longer than the first length L1 between the point corresponding to the nip point NP and the first intersection point P1. and the second length L2 is equal to or greater than 4.0% of the diameter of the roller 10; If the second length L2 is shorter than the first length L1, or if the second length L2 is less than 4.0% of the diameter of the roller 10, sticking of both ends of the tow may not be sufficiently suppressed.

The lower limit of the second length L2 is preferably 4.5% or more, more preferably 5.0% or more, and even more preferably 5.5% or more of the diameter of the roller 10 . The upper limit of the second length L2 is preferably 8.0% or less, more preferably 7.5% or less, even more preferably 7.0% or less, and particularly preferably 6.5% or less of the diameter of the roller 10. is. A preferred numerical range for the second length L2 may be a combination selected from the lower and upper limits described above. The second length L2 is preferably 4.0% or more and 8.0% or less, more preferably 4.5% or more and 7.5% or less, and even more preferably 5.0% or more and 7.5% or more of the diameter of the roller 10. 0% or less, particularly preferably 5.5% or more and 6.5% or less or 5.5% or more and 6.0% or less. In order to more effectively suppress sticking or breakage of both ends of the tow, the numerical range of the second length L2 as described above is preferable. Also, it is preferable that the second length L2 is not excessively long. This is so that the tow that has passed through the nip point NP can be sent smoothly to the next process.

The lower limit of the first length L1 is preferably 0.5% or more, more preferably 0.75% or more, even more preferably 1.0% or more, and particularly preferably 1.25% or more of the diameter of the roller 10. Or it is 1.5% or more. The upper limit of the first length L1 is preferably 2.5% or less, more preferably 2.25% or less, and even more preferably 2.0% or less of the diameter of the roller 10 . A preferred numerical range for the first length L1 may be a combination selected from the lower and upper limits described above. The first length L1 is preferably 0.5% or more and 2.5% or less, more preferably 0.75% or more and 2.5% or less, and even more preferably 1.0% or more2 of the diameter of the roller 10. 0.25% or less, particularly preferably 1.25% or more and 2.25% or less or 1.5% or more and 2.0% or less. In order to more effectively suppress sticking or breakage of both ends of the tow, the numerical range of the first length L1 as described above is preferable.

Next, the opening 21 will be described with reference to FIG. At the opening 21, a second virtual line VL2 is drawn through the point corresponding to the nip point NP and perpendicular to the moving direction of the fibers. Let the said moving direction be a left-right direction. The intersection of the second virtual line VL2 and the upper end of the opening 21 is defined as a third intersection P3. The intersection of the second virtual line VL2 and the lower end of the opening 21 is defined as a fourth intersection P4. At this time, the first width W1 between the point corresponding to the nip point NP and the third intersection point P3 and/or the second width W2 between the point corresponding to the nip point NP and the fourth intersection point P4 A predetermined length for ten diameters is preferred.

The lower limit of the first width W1 and/or the second width W2 is preferably 0.15% or more, more preferably 0.25% or more, and still more preferably 0.5% or more of the diameter of the roller 10. The upper limit of the first width W1 and/or the second width W2 is preferably 1.25% or less, more preferably 1.0% or less, and even more preferably 0.75% or less of the diameter of the roller 10. A preferred numerical range of the first width W1 and/or the second width W2 may be a combination selected from the lower and upper limits described above. The first width W1 and/or the second width W2 is preferably 0.15% or more and 1.25% or less, more preferably 0.25% or more and 1.0% or less, even more preferably 0.25% or more and 0.75% or less, particularly preferably 0.5% or more and 0.75% or less. In order to more effectively suppress agglutination or breakage of both ends of the toe, it is preferable that the first width W1 and/or the second width W2 are within the numerical ranges described above, and the first width W1 and the second width W2 are More preferably, the numerical range is as described above. The first width W1 and the second width W2 are preferably the same numerical value.

Depth D of recess 22 is preferably a predetermined length relative to the diameter of roller 10 . The depth D of the recess 22 is the distance from the opening surface surrounded by the opening 21 to the deepest part of the bottom surface. An example of the depth D is shown in FIG. The lower limit of the depth D is preferably 0.1% or more, more preferably 0.15% or more, and even more preferably 0.2% or more of the diameter of the roller 10 . The upper limit of the depth D is preferably 0.4% or less, more preferably 0.35% or less, still more preferably 0.3% or less of the diameter of the roller 10 . A preferred numerical range for the depth D may be a combination selected from the lower and upper limits described above. The depth D is preferably 0.1% or more and 0.4% or less, more preferably 0.1% or more and 0.35% or less, still more preferably 0.1% or more and 0.3% of the diameter of the roller 10. % or less, particularly preferably 0.15% or more and 0.3% or less or 0.2% or more and 0.3% or less. Such a numerical range for the depth D is preferable in order to more effectively suppress sticking or breakage at both ends of the tow.

It is believed that the reason that the sticking of the ends of the tow is suppressed by the recess 22 having the opening 21 of a particular size is that the recess 22 can effectively accommodate the tow. The reason for this will be specifically described with reference to FIG.

First, FIG. 4 will be described. FIG. 4 is a diagram schematically showing the positional relationship between both ends of the tow T and the recess 22 having the opening 21. As shown in FIG. 4A to 4C correspond to FIGS. 1A to 1C. FIG. 4A, specifically (A1) to (A3), is an enlarged schematic diagram of the vicinity of the nip point in FIG. 1A. In FIG. 4A, an arrow MD indicates the moving direction of the tow T, and an imaginary line (double-dot chain line) is a line passing through the nip point and perpendicular to the tow moving direction MD. (B) of FIG. 4, specifically (B1) to (B3), is a schematic diagram in which the vicinity of one side member in (B) of FIG. 1 is enlarged to visualize the concave portion 22. FIG. (C) of FIG. 4, specifically (C1) to (C3), is a schematic diagram in which the vicinity of one side member in (C) of FIG. 1 is enlarged to visualize the concave portion 22. FIG. In FIG. 4C, an arrow MD indicates the moving direction of the tow T. As shown in FIG. (A1), (B1), and (C1) of FIG. 4 are examples in which sticking and breakage at both ends of the tow are suppressed, and Example 1, which will be described later, is given as an example. (A2), (B2), and (C2) of FIG. 4 are examples in which sticking and breakage at both ends of the tow were not suppressed, and Comparative Example 11, which will be described later, is given as an example. (A3), (B3), and (C3) in FIG. 4 are other examples in which sticking and breakage at both ends of the tow were not suppressed, and Comparative Example 15, which will be described later, is given as an example.

Next, the reason why the agglutination and breakage of both ends of the tow is suppressed will be described. In Example 1, the second length L2 of the opening 21 is longer than the first length L1, and the second length L2 is 4.0% or more of the roller 10 diameter. Therefore, the opening 21 is wider on the downstream side than on the upstream side of the nip point. Thereby, as shown in (A1), (B1), and (C1) of FIG. considered to be effectively contained within the interior of the It is considered that the recessed portion 22 effectively releases the tow T1 that spreads out from the pair of rollers 10,10. In this way, it is believed that friction at the ends of the tow is reduced, which in turn reduces sticking and breaking of the tow ends.

In Comparative Example 11, the second length L2 of the opening 21 is shorter than the first length L1. That is, the opening 21 is wider on the upstream side than on the downstream side of the nip point. Therefore, as shown in (A2) and (C2) of FIG. 4, the tow T2 spreading out from the pair of rollers 10, 10 is considered to be pushed into the recess 22 on the downstream side. As a result, the spreading tow T2 is considered to be agglutinated and broken.

In Comparative Example 15, the opening 21 is not located at a position corresponding to the nip point. Therefore, as shown in (A3) and (C3) of FIG. 4, the tow T3 spreading out from the pair of rollers 10 is considered to be crushed before being accommodated in the recess 22. FIG. As a result, the spreading tow T3 is considered to stick and break.

In this embodiment, the pair of side members are formed using a resin material. The pair of side members are preferably formed only from a resin material. That is, the pair of side members are preferably made of a resin material.

The resin material preferably has a Rockwell hardness of 112 or higher, more preferably 115 or higher, still more preferably 120 or higher, and particularly preferably 125 or higher, as measured by the R scale. Such high hardness can effectively suppress wear of the pair of side members.

The Rockwell hardness of the resin material may be the nominal value of the manufacturer of the resin material. For example, when the nominal value does not exist (for example, when the resin material is not commercially available) or when the nominal value is unknown, the Rockwell hardness is measured according to ASTM D785 (scale: R). value.

The resin material preferably has a water absorption of 0.25% by mass or less, more preferably 0.20% or less, and even more preferably 0.15% or less. Due to such a low water absorption rate, the pair of side members are less likely to absorb moisture and, as a result, less likely to swell even when used for a long period of time. Therefore, a pair of side members formed using a resin material having such a water absorption rate is more suitable for long-term use.

The water absorption rate of the resin material may be the nominal value of the manufacturer of the resin material. For example, if the nominal value does not exist (eg, not for commercially available resin materials) or if the nominal value is unknown, the water absorption can be the value measured according to ASTM D570.

The resin material may be one or a combination of two or more of known resin materials. The resin material preferably contains polyetheretherketone (PEEK) or polyacetal (POM), more preferably PEEK.

As described in detail above, the pair of side members can suppress sticking of fibers in the crimping device. Accordingly, the present invention also provides a pair of side members for a crimping device. The pair of side members according to one embodiment of the present invention is as described in 1-2 above, and the description also applies to this embodiment.

An example of the pair of side members for the crimping device according to this embodiment is as follows. A crimping device includes a pair of rollers that nip the fibers. The pair of side members are used by being arranged to face both side surfaces of the pair of rollers. Each of the pair of side members has a concave portion having an opening on the surface facing the roller, and is formed using a resin material. Each of the recesses is arranged at a position corresponding to each nip point of the pair of rollers. A first imaginary line passing through a point corresponding to the nip point in the opening and parallel to the movement direction of the fiber is drawn, and the intersection of the first imaginary line and the upstream end of the opening in the movement direction is defined as the first intersection point. The intersection point between the first virtual line and the downstream end of the opening in the moving direction is defined as the second intersection point. At this time, the second length between the point corresponding to the nip point and the second intersection point is longer than the first length between the point corresponding to the nip point and the first intersection point, and the second length The height is at least 4.0% of the roller diameter.

1-3. other material

The crimping device according to this embodiment may include other members. The other member may be, for example, a known member used in a fiber crimping device. The crimping device according to this embodiment may include, for example, a stuffing box. The stuffing box is arranged downstream of the pair of rollers in the moving direction of the fibers (tows). A tow that has passed through the nip point of the pair of rollers is pushed into a stuffing box. The fibers are buckled in the stuffing box and crimped.

1-4. crimped fiber

The fibers are crimped by the crimping device according to the present embodiment to produce crimped fibers. The material used for the fiber may be, for example, a resin material, preferably at least one selected from polyolefin, polyester, polyamide, polyacetal, polycarbonate, and polyetherimide, more preferably polyolefin. The polyolefin is preferably at least one selected from high density polyethylene, polypropylene, and ethylene copolymerized random copolymers. In particular, fibers containing such polyolefins on their surfaces are preferred. The unit fineness of the crimped fibers is preferably 0.2 dtex or more and 20 dtex or less, more preferably 0.8 dtex or more and 6.6 dtex or less.

2. Crimped fiber manufacturing equipment

The present invention provides the above 1. Also provided is a crimped fiber manufacturing apparatus including the crimping apparatus described in . The crimping device included in the crimped fiber manufacturing device according to one embodiment of the present invention is the same as in 1. above. , and the description also applies to this embodiment.

The crimped fiber manufacturing apparatus according to this embodiment may include devices other than the crimping device. Apparatuses other than the crimping apparatus may be appropriately selected by those skilled in the art from among apparatuses known in the art, according to the type of crimped fibers, the application, and the like. For example, when producing crimped staple fibers using a resin material, the crimped fiber producing apparatus includes a device for melt-spinning the resin material, a device for drawing the spun fibers (tows), and an oil agent that adheres to the fibers (tows). It may include an apparatus, an apparatus for drying the crimped fibers obtained by the crimping apparatus, an apparatus for cutting the dried crimped fibers, and the like.

3. Method for producing crimped fiber

The present invention provides the above 1. or the crimping device described in 2. above. A crimped fiber manufacturing method using the crimped fiber manufacturing apparatus described in 1. is also provided. The crimping device or the crimped fiber manufacturing device used in the manufacturing method according to one embodiment of the present invention is the same as in 1. above. or 2. , and the description also applies to this embodiment.

The manufacturing method according to the present embodiment preferably includes supplying a papermaking oil to nip points on both side surfaces of the pair of rollers. Supplying the papermaking oil increases the lubricity at both ends of the tow, which contributes to prevention of breakage and sticking of both ends of the tow, and can also contribute to suppression of wear of the side members. In this case, the crimping device or the crimped fiber manufacturing device may include, for example, an oil supply unit that supplies a papermaking oil to each of the nip points. The papermaking oil is preferably supplied continuously while the fibers are being crimped.

The papermaking oil agent may be an oil agent used when producing a nonwoven fabric by a papermaking method using fibers as a raw material, and may be one or a combination of two or more of such oil agents. The papermaking oil agent used in the present embodiment is preferably at least one selected from ester oil agents, fatty acid soaps, phosphate metal salts of higher alcohols having 8 to 22 carbon atoms, silicone oil agents, and anionic surfactants. is.

Depending on the type, the papermaking oil may be diluted with water before use. In this case, the concentration of the papermaking oil after dilution is preferably 1% by mass or more and 10% by mass or less.

In the manufacturing method according to the present embodiment, for example, when the fiber is drawn and the finishing oil is used after drawing, the papermaking oil is preferably the same or similar oil as the finishing oil or a dilution thereof, and more It is preferably the same oil as the finishing oil or a dilution thereof. For example, the papermaking oil may be an aqueous solution obtained by diluting a finishing oil with water.

The speed at which the papermaking oil is supplied to each nip point on both side surfaces of the pair of rollers is preferably 70 mL/min or more and 130 mL/min or less at each nip point. At such a feed rate, the lubricity at both ends of the tow is increased, which is effective in preventing breakage and sticking of both ends of the tow, and is also effective in suppressing wear of the side members. From the viewpoint of obtaining sufficient lubricity, the above lower limit is preferable, and from the viewpoint of cost, the above upper limit is preferable.

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

(1) Production of crimped staple fibers

Using a crimped fiber manufacturing apparatus including a crimping device, crimped staple fibers were manufactured according to the following procedure. The crimping device is a device including at least a pair of rollers, a pair of side members arranged to face both side surfaces of the pair of rollers, and a stuffing box.

<Example 1>

A first resin material (polypropylene) forming the core and a second resin material (high-density polyethylene) forming the sheath are melt-spun into a sheath-core form to form an undrawn yarn. got After stretching in hot water of 85° C. or higher or in steam of 100° C. or higher, a papermaking oil (an anionic surfactant containing polyether) was adhered. After that, the fibers were crimped by a crimping device. In the crimping device, an aqueous solution of a papermaking oil (5% by mass aqueous solution of an anionic surfactant containing polyether) was supplied at a rate of 100 mL/min to each nip point on both side surfaces of a pair of rollers. In the crimper, the nip pressure was 0.11 MPa and the stuffing pressure was 0.09 MPa. After that, the crimped fibers were cut to 5 mm with a rotary cutter. As a result, crimped short fibers having a single filament fineness of 1.7 dtex, a number of crimps of 11 to 25/25 mm, and a fiber length of 5.2 mm were obtained.

The pair of rollers consisted of two rollers of the same shape arranged one above the other, as shown in FIG. 1, and each roller had a diameter of 200 mm. Each of the pair of side members had a concave portion having a rectangular opening with rounded corners and a bottom portion with a round bottom. The pair of side members were made of the following resin materials, and the recess had the following dimensions (length, width, and depth). The definitions of these lengths, widths and depths are as explained in 1-2 above.

[Resin material]
Polyetheretherketone (PEEK)
Rockwell hardness of R scale: 125 (manufacturer's nominal value)
Water absorption: 0.14% by mass (manufacturer's nominal value)

[Size of recess]
First length L1: 3.0mm
Second length L2: 12.0mm
First width W1: 1.5mm
Second width W2: 1.5mm
Depth D: 0.50mm

<Example 2>

A crimped staple fiber was obtained under the same conditions as in Example 1, except that the single filament fineness of the crimped staple fiber was changed to 3.3 dtex and the number of crimps was changed to 6 to 24/25 mm. The fiber length of the crimped short fibers was 5.2 mm, the same as in Example 1.

<Example 3>

Crimped short fibers were produced under the same conditions as in Example 1, except that the first length L1 was changed to 4.0 mm and the second length L2 was changed to 11.0 mm, and the oil for papermaking was not supplied to the crimping device. Obtained.

<Example 4>

Crimped staple fibers were obtained under the same conditions as in Example 1, except that the papermaking oil was not supplied to the crimping device.

<Example 5>

Crimped short fibers were obtained under the same conditions as in Example 1, except that the pair of side members were changed to those made of the following resin materials, and the oil for papermaking was not supplied to the crimping device.

[Resin material]
Polyacetal (POM)
Rockwell hardness of R scale: 112 (manufacturer's nominal value)
Water absorption: 0.22 to 0.25% by mass (manufacturer's nominal value)

<Example 6>

Crimped short fibers were obtained under the same conditions as in Example 5, except that the first width W1 was changed to 0.5 mm and the second width W2 was changed to 0.5 mm.

<Example 7>

The first length L1 was changed to 4.0 mm, and the second length L2 was changed to 16.0 mm. Crimped short fibers were obtained under the same conditions as in Example 5, except that a 5% by mass aqueous solution of an anionic surfactant containing the anionic surfactant was supplied at a rate of 100 mL/min.

<Example 8>

Crimped short fibers were obtained under the same conditions as in Example 7, except that the second length L2 was changed to 11.0 mm, the first width W1 to 2.0 mm, and the second width W2 to 2.0 mm.

<Example 9>

Crimped staple fibers were obtained under the same conditions as in Example 7, except that the second length L2 was changed to 11.0 mm, the first width W1 to 0.5 mm, and the second width W2 to 0.5 mm.

<Example 10>

Crimped short fibers were obtained under the same conditions as in Example 7, except that the second length L2 was changed to 11.0 mm and the depth D was changed to 0.30 mm.

<Comparative Example 1>

The second length L2 was changed to 7.0 mm, the first width W1 was changed to 1.0 mm, and the second width W2 was changed to 1.0 mm. Crimped short fibers were obtained under the same conditions.

<Comparative Example 2>

Crimped short fibers were obtained under the same conditions as in Comparative Example 1, except that the first width W1 was changed to 1.5 mm and the second width W2 was changed to 1.5 mm.

<Comparative Example 3>

A crimped short fiber was obtained under the same conditions as in Comparative Example 2, except that the depth D was changed to 1.00 mm.

<Comparative Example 4>

In the crimping device, an aqueous solution of a papermaking oil (a 5% by mass aqueous solution of an anionic surfactant containing polyether) was supplied to each nip point on both side surfaces of a pair of rollers at a rate of 100 mL/min. , under the same conditions as in Comparative Example 2, crimped short fibers were obtained.

<Comparative Example 5>

Crimped short fibers were obtained under the same conditions as in Example 1, except that the pair of side members were changed to those without recesses and the papermaking oil was not supplied to the crimping device.

<Comparative Example 6>

Crimped staple fibers were obtained under the same conditions as in Comparative Example 1, except that the pair of side members were made of POM described in Example 5 and had no recesses.

<Comparative Example 7>

Crimped short fibers were obtained under the same conditions as in Comparative Example 1, except that the pair of side members were made of the following resin material and did not have recesses.

[Resin material]
Polytetrafluoroethylene (PTFE)
Rockwell hardness of R scale: 20 (manufacturer's nominal value)
Water absorption: 0.01% by mass (manufacturer's nominal value)

<Comparative Example 8>

Crimped short fibers were obtained under the same conditions as in Comparative Example 1, except that the pair of side members were made of the following resin material and did not have recesses.

[Resin material]
Perfluoroalkoxyalkane (PFA)
Rockwell hardness of R scale: 50 (manufacturer's nominal value)
Water absorption: 0.01% by mass (manufacturer's nominal value)

<Comparative Example 9>

Crimped short fibers were obtained under the same conditions as in Comparative Example 1, except that the pair of side members were made of the following resin material and did not have recesses.

[Resin material]
Ultra high molecular weight polyethylene (UHPE)
Rockwell hardness of R scale: 52 (manufacturer's nominal value)
Water absorption: less than 0.01% by mass (manufacturer's nominal value)

<Comparative Example 10>

Crimped short fibers were obtained under the same conditions as in Comparative Example 1, except that the pair of side members were made of the following resin material and did not have recesses.

[Resin material]
Polyamide (PA)
Rockwell hardness of R scale: 120 (manufacturer's nominal value)
Water absorption: 0.8% by mass (manufacturer's nominal value)

<Comparative Example 11>

Crimped short fibers were obtained under the same conditions as in Comparative Example 1, except that the first length L1 was changed to 7.0 mm and the second length L2 was changed to 3.0 mm.

<Comparative Example 12>

Crimped short fibers were obtained under the same conditions as in Comparative Example 11, except that the first width W1 was changed to 1.5 mm and the second width W2 was changed to 1.5 mm.

<Comparative Example 13>

A crimped short fiber was obtained under the same conditions as in Comparative Example 12, except that the depth D was changed to 1.00 mm.

<Comparative Example 14>

The same as Example 1 except that the resin material of the pair of side members was changed to the POM described in Example 5, the first length L1 was changed to 9.0 mm, and the second length L2 was changed to 6.0 mm. Crimped short fibers were obtained under the conditions of

<Comparative Example 15>

Crimped short fibers were obtained under the same conditions as in Comparative Example 14, except that the first length L1 was changed to -1.0 mm and the second length L2 was changed to 16.0 mm. The fact that the first length L1 is “−1.0 mm” means that the first intersection P1 shown in FIG. 3 is located 1.0 mm downstream from the nip point NP.

In Examples 3 to 10 and Comparative Examples 1 to 15, the unit fineness, the number of crimps, and the fiber length of the obtained crimped staple fibers were all the same as in Example 1.

(2) Evaluation of crimped tow

In Examples 1 to 10 and Comparative Examples 1 to 15, 20 m of crimped tow was collected from the crimper. The ends of the crimped tow were stretched by about 50 mm with a finger, and the number of broken portions present at both ends of the crimped tow was counted while revealing the broken portions (several tens of broken lines) buried in the crimp. . The total number of broken portions present at both ends of the crimped tow was divided by 20 to calculate the breaking frequency (unit: pieces/m) at both ends of the tow. In Table 1 below, which describes the fracture frequency, the term "continuous agglutination" indicates that almost the entire length of the toe end was agglutinated, and the term "partial agglutination" indicates that the toe end was intermittent. It indicates that it was stuck to

(3) Evaluation of crimped staple fibers

The dispersibility in water of the crimped staple fibers of Examples 1 to 10 and Comparative Examples 1 to 15 was evaluated based on the results of primary opening and secondary opening. It can be said that the better the dispersibility in water, the less sticking of the fibers. In the primary opening, 20 g of crimped staple fibers were stirred in 150 L of test water at 1100 rpm for 50 seconds. In the second opening, the fiber bundle that was not dispersed in the first opening was extracted and strongly stirred at 7000 rpm in 300 mL of test water. Evaluation was performed according to the following evaluation criteria. Among the following evaluation criteria, A and B were judged to be acceptable, and C and D were judged to be unacceptable.

<Evaluation Criteria>
A (Very good dispersibility in water): There are no undispersed fiber bundles in the primary opening, and each single fiber spreads neatly in water.
B (Good dispersibility in water): Undispersed fiber bundles are extracted in the primary opening, and there are 1 or more and less than 2 undispersed fiber bundles in the secondary opening.
C (Poor dispersibility in water): There are two or more undispersed fiber bundles in secondary opening.
D (extremely poor dispersibility in water): Several or more undispersed fiber bundles are found in the primary opening, and many single fibers are entangled with each other.

(4) Evaluation of a pair of side members

In Examples 1 to 10 and Comparative Examples 1 to 15, the surfaces of the pair of side members used for a total of about 24 hours were observed with a microscope, and the degree of wear of the side members was evaluated according to the following evaluation criteria.

<Evaluation Criteria>
Small: Almost no dents are observed.
Middle: A dent is slightly confirmed.
Large: Abrasion marks are observed.

The evaluation results of Examples 1 to 10 and Comparative Examples 1 to 15 are shown in Table 1 below.

As shown in Table 1, in Comparative Examples 5 to 10, in which a pair of side members having no concave portion were used, the dispersibility of fibers in water was extremely poor. In Comparative Examples 11 to 14, in which the second length L2 was shorter than the first length L1 even though they had recesses, the dispersibility of the fibers in water was very poor, and the tow was broken. Even though the second length L2 is longer than the first length L1, Comparative Examples 1 to 4, in which the second length L2 is 3.5% (7.0 mm) of the diameter of the roller, have excellent dispersibility in water. was unsatisfactory, and a break was observed in the tow. In Comparative Example 15, in which the concave portion was not located at the position corresponding to the nip point, the dispersibility of the fibers in water was extremely poor, and breakage was observed in the tow.

On the other hand, in Examples 1 to 10 in which the second length L2 is longer than the first length L1 and the second length L2 is 4.0% or more of the diameter of the roller, the dispersibility of the fibers in water is good. Met. From these results, it is considered that the specific size of the opening of the recess in the present invention contributes to the suppression of fiber agglutination.

1 Crimping Device 10 Roller 20 Side Member 21 Opening 22 Recess NP Nip Point P1 First Intersection P2 Second Intersection P3 Third Intersection P4 Fourth Intersection T Toe VL1 First Virtual Line VL2 Second Virtual Line

Claims (13)

a pair of rollers for nipping the fibers;
a pair of side members arranged to face both side surfaces of the pair of rollers,
each of the pair of side members is provided with a concave portion having an opening on a surface facing the roller, and is formed using a resin material;
Each of the recesses is located at a position corresponding to each nip point of the pair of rollers,
In the opening, a first virtual line passing through a point corresponding to the nip point and parallel to the moving direction of the fibers is drawn, and the intersection of the first virtual line and an upstream end of the opening in the moving direction. is a first intersection, and the intersection of the first imaginary line and the downstream end of the opening in the moving direction is a second intersection, the point corresponding to the nip point and the second intersection a second length between is greater than a first length between a point corresponding to the nip point and the first intersection;
The second length is 4.0% or more of the diameter of the roller,
Crimp device. 2. The crimping device of claim 1, wherein the second length is 8.0% or less of the diameter of the roller. 3. The crimping device according to claim 1 or 2, wherein the first length is 0.5% or more and 2.5% or less of the diameter of the roller. In the opening, a second virtual line passing through a point corresponding to the nip point and perpendicular to the moving direction of the fibers is drawn. A point corresponding to the nip point and the third intersection point are defined as a third intersection point and a fourth intersection point between the second imaginary line and the lower end portion of the opening. and/or the second width between the point corresponding to the nip point and the fourth intersection is 0.15% or more and 1.25% or less of the diameter of the roller The crimping device according to any one of items 1 to 3. The crimping device according to any one of claims 1 to 4, wherein the depth of the recess is 0.1% or more and 0.4% or less of the diameter of the roller. The crimping device according to any one of claims 1 to 5, wherein the resin material has a Rockwell hardness of 112 or more as measured by the R scale. The crimping device according to any one of claims 1 to 6, wherein the resin material has a water absorption rate of 0.25% by mass or less. The crimping device according to any one of claims 1 to 7, wherein the resin material includes polyetheretherketone or polyacetal. A crimped fiber manufacturing apparatus comprising the crimping apparatus according to any one of claims 1 to 8. A method for producing a crimped fiber, using the crimping apparatus according to any one of claims 1 to 8 or the crimped fiber producing apparatus according to claim 9. 11. The method for producing crimped fibers according to claim 10, comprising supplying a papermaking oil to the nip points on each of the two side surfaces of the pair of rollers. The method for producing crimped fibers according to claim 11, wherein the papermaking oil is supplied at a rate of 70 mL/min or more and 130 mL/min or less. A pair of side members for a crimping device, comprising:
The crimping device includes a pair of rollers that nip the fibers,
The pair of side members are arranged to face both side surfaces of the pair of rollers,
each of the pair of side members is provided with a concave portion having an opening on a surface facing the roller, and is formed using a resin material;
Each of the recesses is arranged at a position corresponding to each nip point of the pair of rollers,
In the opening, a first virtual line passing through a point corresponding to the nip point and parallel to the moving direction of the fibers is drawn, and the intersection of the first virtual line and an upstream end of the opening in the moving direction. is a first intersection, and the intersection of the first imaginary line and the downstream end of the opening in the moving direction is a second intersection, the point corresponding to the nip point and the second intersection a second length between is greater than a first length between a point corresponding to the nip point and the first intersection;
The second length is 4.0% or more of the diameter of the roller,
A pair of side members.