Roller mechanism and stretch cutter for stretching and drawing low-elongation fibers

Abstract

The present invention discloses a roller mechanism and a cutting machine for cutting and stretching low-elongation fibers. The roller mechanism includes a smooth roller and a toothed roller arranged on a pair of rollers. The smooth roller has an elastic surface. The toothed roller is evenly provided with a plurality of oblique teeth in the circumferential direction. All oblique teeth on the toothed roller are inclined toward the same side compared to their respective radial directions. The oblique teeth include an oblique surface on one side and a tooth top directly connected to the oblique surface of the adjacent oblique teeth. The tooth top is an outer convex arc tooth top tangent to the oblique surface of the corresponding oblique teeth. One end of the tooth top is tangent to the oblique surface of the corresponding oblique teeth, and the other end extends to the tooth root of the adjacent oblique teeth. The distance of the closed interval formed by the oblique teeth on the toothed roller in the process of rolling is changed, so as to reduce the fiber breakage caused by the fiber cutting and stretching between two adjacent teeth at the same time. The present invention is suitable for cutting and stretching low-elongation fibers, so that the fiber dryness during cutting is guaranteed, the amount of broken fibers is reduced, and the fibers can be used in the next process in a better posture.

Description

Technical Field

[0001] The invention relates to a low-elongation fiber stretch cutting and drafting strip making technology, and in particular to a roller mechanism and a stretch cutting machine used for the low-elongation fiber stretch cutting and drafting. Background Art

[0002] Low-elongation fiber refers to the fiber whose elongation during the stretching and drawing process is lower than that of ordinary textile fibers, including but not limited to stainless steel metal fibers, glass fibers and carbon fibers. In the low-elongation fiber and derivative product processing industry, the stretching and drawing equipment all adopts the conventional stretching and cutting machines used in the textile field to stretch and cut strips and make yarns, and there are no stretching and cutting machines produced specifically for the characteristics of low-elongation fibers.

[0003] The rollers used for stretching and drawing of textile fibers are all standard S series synchronous belt toothed rollers or toothed rollers used in spinning machines. Several pairs of drafting rollers are provided on the strip making and drawing equipment. The fed fiber bundles are subjected to multiple continuous drafting actions of these pairs of drafting rollers. When the degree of stretching of the fiber bundle by the drafting roller exceeds the limit of fiber breaking elongation, each single filament will break at any weak point. Since its stretching breaking point is randomly distributed and the breaking point is not on a cross section of the stretched filament bundle, although the single filaments in the fiber filament bundle have been broken into a short fiber state, the entire fiber strip will not break. In this way, the fiber bundle processed by the stretching and cutting direct strip making machine is directly processed into short fiber strips, which is convenient for winding through the coiling disc to form a regular coil shape.

[0004] However, compared with organic / inorganic chemical fibers in the textile industry, low-extension fibers such as metal fibers have the inherent characteristics of high elastic modulus, high bending resistance, tensile strength, etc. of certain specific materials, as well as higher low elasticity, high bending resistance, tensile strength, etc., and there is no need to consider the problems caused by high static electricity in chemical fiber strips. However, other problems have also been added, such as difficulty in breaking the fibers. During the stretching and drawing process, since the rollers currently used are all standard synchronous belt teeth or rollers suitable for spinning machines, ordinary stretching machines will require greater pressure and stronger holding force to break the fibers than ordinary fibers. Under the action of huge pressure and holding force, the stretching strips are prone to excessive bending, poor cohesion, and a large amount of broken fibers during the stretching and drawing process, resulting in loss of raw materials and damage to the fiber strips. Summary of the invention

[0005] The technical problem solved by the present invention is: in view of the problem of many broken fibers when ordinary textile rollers are used for low-elongation fibers, a roller mechanism and a stretch-cutting machine for stretching and drawing low-elongation fibers are provided.

[0006] The present invention is implemented by the following technical solutions:

[0007] A roller mechanism for cutting and stretching low-elongation fibers comprises a smooth roller and a toothed roller arranged in pairs of rollers, wherein the smooth roller has an elastic surface, and the toothed roller is evenly provided with a plurality of oblique teeth along the circumferential direction, and all the oblique teeth on the toothed roller are inclined toward the same side compared to their respective radial directions, and the distance of the closed interval formed by the oblique teeth on the toothed roller during the rolling process changes, thereby reducing fiber breakage caused by the fibers being clamped simultaneously between two adjacent teeth.

[0008] In the above scheme, a roller mechanism for cutting and stretching low-elongation fibers is provided. Further, the bevel tooth includes a bevel on one side and a tooth top directly connected to the bevel of the adjacent bevel tooth. The tooth top is an outward convex arc tooth top tangent to the bevel of the corresponding bevel tooth. One end of the tooth top is tangent to the bevel of the corresponding bevel tooth, and the other end extends to the tooth root of the adjacent bevel tooth.

[0009] In the above scheme, a roller mechanism for cutting and stretching low-elongation fibers is further characterized in that the inclination angle between the inclined surface and the radial direction where the corresponding inclined teeth are located is 50°-70°.

[0010] In the above scheme, a roller mechanism for cutting and stretching low-elongation fibers, further, the arc radius of the tooth top is R1.2-R2.2.

[0011] In the above scheme, a roller mechanism for cutting and stretching low-elongation fibers is further characterized in that the number of teeth on the toothed roller is 1 / 2 of the circumferential diameter of the roller.

[0012] In a roller mechanism for cutting and stretching low-elongation fibers of the present invention, the inclination direction of the helical teeth faces the roller direction of the toothed roller to ensure that the change in the distance of the closed interval formed by adjacent helical teeth during the roller process can meet the requirements for the cutting effect on the fibers.

[0013] In the above scheme, a roller mechanism for cutting and stretching low-elongation fibers is further characterized in that all the oblique teeth on the toothed roller have the same inclination angle.

[0014] The present invention also discloses a stretching and cutting machine, comprising a stretching and cutting system formed by several groups of the above-mentioned roller mechanisms, wherein a pre-stretching zone, a main-stretching zone and a leakage-proofing zone are formed in sequence between two adjacent groups of roller mechanisms, and a first relaxation zone and a second relaxation zone are respectively arranged between the pre-stretching zone and the main-stretching zone and between the main-stretching zone and the leakage-proofing zone through two adjacent groups of roller mechanisms.

[0015] The stretch-cutting machine in the above scheme further includes a coiler connected to the stretch-cutting system to coil the fibers after stretch-cutting.

[0016] When stretching and cutting low-elongation fibers such as stainless steel metal fibers, unlike ordinary textile fibers, it is necessary to increase the roller pressure to ensure the holding force during the stretching and cutting process. If the holding force is too large, the fiber strips will be excessively bent and broken due to the tooth shape of the roller. If the pressure is not increased and the holding force is insufficient during stretching and cutting, there will be too many extra-long fibers in the fiber strips, resulting in uneven fiber strips and hard ends and breakage during the spinning process. The present invention aims at the existing stretching and cutting process for low-elongation fibers, which generally adopts standard S series rollers and rollers for textile machinery. The present invention adopts helical tooth rollers, which are specially designed for stretching and cutting of low-elongation fibers. The selection of tooth shape ensures that the stretching and cutting strips have a low amount of broken fibers. The selection of the number of helical teeth ensures that the fibers have sufficient holding force during the stretching and cutting process. By changing the tooth shape of the tooth roller, the holding force of the smooth roller and the roller on the stretching and cutting strip will become larger under the same pressure. The pressure adjustment range can be increased under different pressures without generating a large amount of broken fibers and excessive bending of the fiber strips caused by ordinary roller stretching and cutting. It ensures that the fibers can be fully broken and the dryness of the strips after stretching and cutting is guaranteed, and solves the stretching and cutting loss caused by low-elongation fibers during the stretching and cutting process, and the influence of uneven stretching and cutting strips on subsequent processes.

[0017] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1-3 This is a schematic diagram of the tooth-shaped holding point state of existing stainless steel metal fibers when they are cut by standard S series rollers.

[0019] Figure 4 This is an overall schematic diagram of the roller mechanism used in Example 1.

[0020] Figure 5 It is a partial schematic diagram of the helical teeth on the toothed roller in the first embodiment.

[0021] Figure 6 , 7 This is a schematic diagram of the tooth-shaped holding point state of the roller mechanism in Example 1 for cutting stainless steel metal fibers.

[0022] Figure 8 This is a schematic diagram of the stretch-cutting machine used in the second embodiment.

[0023] Numbers in the figure: 1-smooth roller, 2-toothed roller, 21-straight teeth, 22-oblique teeth, 221-inclined surface, 222-tooth top, 301-semi-enclosed section, 302-first enclosed section, 303-second enclosed section, 41-raw material rack, 42-strip coiler, 401-pre-drawing area, 402-first relaxation area, 403-main drawing area, 404-second relaxation area, 405-leakage-proof drawing area, 5-stainless steel metal fiber. DETAILED DESCRIPTION

[0024] See first Figure 1-3 , the state of the stainless steel fiber bundle in the low-elongation fiber when passing through the gripping point of the top roller roller is analyzed. The standard conventional S5M tooth shape is used as an example in the figure: when the top roller and the roller are in contact, the contact area will only change from n teeth to n+1 teeth, and n>0 is an integer (that is, the top roller and the roller will only change between odd teeth and even teeth).

[0025] Take the case where the diameter of the top roller is 100mm, the tooth type is standard S5M, and the pressure applied to the top roller is 60KG. The camera is used to shoot the top roller and roller contacting 2-3 teeth, and the operation process is divided into two states: Figure 1 As shown, the apex of the straight teeth 21 of the toothed roller 2 is aligned with the center of the smooth roller 1, as shown in FIG. Figure 2 As shown, the tooth groove center of the straight teeth 21 of the toothed roller 2 is aligned with the center of the top roller.

[0026] analyze Figure 1 In the semi-closed interval 301 that two adjacent straight teeth 21 are about to form with the smooth roller 1, within the interval, the point where the toothed roller 2 and the smooth roller 1 hold the fiber is only the straight tooth 21 that is first pressed against the smooth roller 1. At this time, the center distance between the smooth roller 1 and the toothed roller 2 is the farthest. In this area, a single holding point will not cause damage to the stainless steel fiber, but will only cause the fiber to break normally. When the toothed roller 2 rotates to make the smooth roller 1 tangent to the next adjacent straight tooth 21, a first closed interval 302 is formed in which the tooth contacts the smooth roller 1 in the rotation direction. The length of the stainless steel fiber in the first closed interval 302 is limited to a fixed value L1. After measuring two of the straight teeth, L1=2.523mm. When the smooth roller 1 is converted to be evenly pressed on the tooth groove between adjacent straight teeth 21, the fiber in the closed interval has two gripping points. At this time, a second closed interval 303 is formed in which two straight teeth 21 are symmetrically in contact with the smooth roller 1. At this time, the smooth roller is deformed and expanded in the closed interval due to pressure and the reduction of the distance between the center of the smooth roller and the center of the roller. At this time, the fiber length L2 in the closed interval is measured to be L2=2.936mm, L2>L1. This process causes the two adjacent straight teeth and the smooth roller to squeeze the fiber to change the length. When the deformation of the smooth roller seriously exceeds the elastic deformation of the stainless steel metal fiber, the fiber is broken. During this process, each time the stainless steel metal fiber passes through a closed space between adjacent straight teeth 21, a portion of the stainless steel metal fiber will be broken, resulting in a large amount of broken fibers and the destruction of the fiber strands.

[0027] Embodiment 1

[0028] See below Figure 4 and Figure 5The roller mechanism shown in this embodiment is a specific implementation scheme of the present invention, which is used for cutting and stretching stainless steel metal fibers, and includes a smooth roller 1 and a toothed roller 2 arranged in a pair of rollers. The smooth roller 1 is a leather roller with an elastic circumferential surface, which can avoid directly pinching off the metal fiber during the rolling process with the toothed roller 2. A plurality of oblique teeth 22 are evenly arranged on the toothed roller 2 along the circumferential direction, and a single oblique tooth 22 extends along the axial direction of the toothed roller. In the cross section of the toothed roller 2, all the oblique teeth 22 on the toothed roller 2 are inclined toward the same side compared to their respective radial directions.

[0029] Specific as Figure 5 As shown, the beveled tooth 22 includes a side bevel 221 and a tooth top 222 directly connected to the bevel 221 of the adjacent beveled tooth. The beveled tooth 22 in this embodiment has only one side bevel 221, and the tooth top 222 is an outward convex arc tooth top tangent to the bevel 221 of the corresponding beveled tooth. In this way, one end of the tooth top 222 is tangent to the bevel of the corresponding beveled tooth, and the other end extends to the root of the bevel 221 of the adjacent beveled tooth. The arc structure of the tooth top 222 simultaneously extends to form the tooth edge of the other side of the beveled tooth. The toothed roller 2 adopts a rigid structure. In the process of rolling with the smooth roller 1, the tooth top 222 of the beveled tooth can be partially pressed into the elastic surface of the smooth roller 1.

[0030] It has been verified through experiments that the inclination direction of the bevel teeth 22 of the toothed roller 2 should face the counter-roll direction of the toothed roller 2, and the inclination angle of the bevel surface 221 of the bevel tooth 22 to the radial direction where the bevel tooth is located is 50°-70°. In this way, the change in the distance of the closed interval formed by the bevel teeth 22 on the toothed roller 2 during the counter-roll process can reduce the fiber breakage caused by the metal fiber being clamped between two adjacent teeth at the same time, and the inclination angles of all the bevel teeth 22 on the toothed roller 2 are the same.

[0031] The following is an example of the process of cutting the stainless steel metal fiber 5 by the roller structure of this embodiment. Figure 6 and Figure 7 , the principle of the toothed roller 2 of this embodiment in reducing the clamping of the stainless steel metal fiber and causing fiber breakage when the stainless steel metal fiber passes through the gripping point of the leather roller is described in detail.

[0032] Figure 6 and Figure 7 In the roller structure, in the bevel teeth 22 of the toothed roller 2, the inclination angle of the bevel 221 is 65°, the arc radius of the tooth top 222 is R1.6, Figure 6 In the process of stretch cutting, when the smooth roller 1 contacts the next bevel tooth 22 and is about to form the first closed section 302, due to the inclined surface 221 of the bevel tooth 22, the length L1 of the stainless steel metal fiber in the first closed section 302 in this embodiment is 2.736 mm, which is relatively Figure 2 In the straight tooth roller, the length L1 is extended. Figure 7In the embodiment, when the center of the first closed section 302 turns to the center line of the smooth roller 1 and the toothed roller 2, the left side roller of the stainless steel metal fiber continues to be gradually pressed downward by the top of the helical tooth in contact, but due to the inclined surface of the tooth 22, the contact area between the helical tooth and the surface of the smooth roller 1 increases, and the amount of the top of the tooth 222 pressed into the surface of the smooth roller 1 will decrease. Figure 2 At the same time, the tooth top 222 of the helical tooth 22 of the leather roller pressed into the right side of the stainless steel metal fiber will gradually rise from the deepest position pressed into the surface of the smooth roller 1, so that the stainless steel metal fiber held by the helical tooth is released. In the second closed interval 303 where the two helical teeth 22 are pressed and contacted with the smooth roller 1 at the same time, the length L2 of the stainless steel metal fiber is 2.668 mm, which is relatively Figure 3 In the straight tooth roller, the length is reduced, and in the two closed intervals when the toothed roller 2 rotates back and forth, L1>L2, the stainless steel metal fiber will not break, and no broken fibers will be produced, thereby not destroying the uniformity of the yarn.

[0033] The selection of the inclination angle of the bevel teeth 22 of the toothed roller 2 is based on the pressing depth of the toothed roller on the smooth roller. When the inclination angle of the bevel teeth 22 is higher than 70°, the bevel teeth 22 are basically all pressed into the surface of the smooth roller 1, so that 90% of the two adjacent bevel teeth are in contact with the smooth roller 1, so that L1>L2 does not hold. At the same time, the large contact surface between the two will make the fiber strips have no holding force. When the inclination angle of the bevel teeth 22 is lower than 50°, the tooth top of the bevel teeth 22 is far below the pressing depth, and it has no effect on cutting the stainless steel metal fiber.

[0034] When the diameter of the toothed roller 2 is the same, the more teeth the bevel teeth 22 have, the more closed areas will be on the gripping points of each smooth roller and the roller. The increased contact area will lead to a worse bonding force of the fiber strip after it is formed into a disk. After many experimental studies, it was found that the most appropriate number of teeth of the bevel teeth 22 on the toothed roller 2 is selected to be half of the roller diameter, which ensures that the stainless steel metal fiber maintains a certain bonding force during the entire pulling and cutting process.

[0035] Embodiment 2

[0036] See also Figure 8The stretch-cutting machine for stainless steel metal fibers disclosed in this embodiment is a specific implementation scheme of the stretch-cutting machine in the present invention, which includes a stretch-cutting system formed by several groups of roller mechanisms in the first embodiment and a coiler 42. The stretch-cutting system includes six groups of roller mechanisms arranged in the horizontal direction, and a pre-tightening zone 401, a first relaxing zone 402, a main tightening zone 403, a second relaxing zone 404 and a leakage-proof tightening zone 405 are formed in sequence between two adjacent groups of roller mechanisms. The structural parameters of the roller mechanisms in each zone are the same, and the drafting ratio between the front and rear roller mechanisms in different zones is determined according to the process requirements. The roller speeds of the roller mechanisms in the outlet direction of the pre-tightening zone 401, the main tightening zone 403 and the leakage-proof tightening zone 405 are higher than the roller speeds of the roller mechanisms in the inlet direction, and the roller speeds of the roller mechanisms in the outlet direction and the inlet direction of the first relaxing zone 402 and the second relaxing zone 404 are the same. After the stainless steel fiber 5 is drawn out from the raw material rack 41, it passes through the smooth rollers and toothed rollers of the six groups of roller mechanisms in sequence, and is pulled through the pre-pulling area 401, the first relaxation area 402, the main pulling area 403, the second relaxation area 404 and the leakage-proof pulling area 405 in sequence, and then is pulled into the coiler 42 for coiling and closing.

[0037] The roller mechanism and the stretch cutter of this embodiment are suitable for stretch cutting of stainless steel metal fibers. By selecting the toothed rollers, the amount of broken fibers is reduced during the stretch cutting of stainless steel metal fibers, and the strand dryness is guaranteed, so that the stainless steel metal fibers can be used in the next process in a better posture. The above embodiment can not only be used for the stretch cutting and drafting of stainless steel metal fibers, but also for the stretch cutting and drafting of other low-elongation fibers.

[0038] The above embodiments describe the basic principles and main features of the present invention and the advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions only illustrate the specific working principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which shall fall within the scope of the present invention to be protected. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. Roller mechanism for cutting and drawing low-elongation fibers, including smooth rollers and toothed rollers set in pairs, Features: The toothed roller adopts a rigid structure, the smooth roller adopts a leather roller, the smooth roller has an elastic surface, a plurality of helical teeth are evenly arranged on the toothed roller along the circumferential direction, and all the helical teeth on the toothed roller are inclined toward the same side compared to their respective radial directions; the helical teeth include an inclined surface on one side and a tooth top directly connected to the inclined surface of the adjacent helical teeth, the tooth top is an outward convex arc tooth top tangent to the inclined surface of the helical teeth to which it belongs, one end of the tooth top is tangent to the inclined surface of the helical teeth to which it belongs, and the other end extends to the tooth root of the adjacent helical teeth; in the process of rolling with the smooth roller, the tooth top of the helical teeth can be partially pressed into the elastic surface of the smooth roller, and the inclination angle of the inclined surface to the radial direction where the helical teeth to which it belongs is 50°-70°; the roller mechanism is used for cutting and stretching of stainless steel metal fibers.

2. According to the roller mechanism for cutting and stretching low-elongation fibers according to claim 1, the arc radius of the tooth top is R1.2-R2.

2.

3. The roller mechanism for cutting and stretching low-elongation fibers according to claim 2, wherein the number of teeth on the toothed roller is 1 / 2 of the circumferential diameter of the roller.

4. The roller mechanism for cutting and stretching low-elongation fibers according to any one of claims 1 to 3, wherein the inclined direction of the helical teeth faces the counter-roll direction of the toothed roller.

5. The roller mechanism for cutting and stretching low-elongation fibers according to claim 4, wherein all the oblique teeth on the toothed roller have the same inclination angle.

6. Stretch cutting machine, Features: A stretching and cutting system comprising several groups of roller mechanisms for stretching and cutting low-elongation fibers as described in any one of claims 1 to 5, wherein a pre-stretching zone, a main stretching zone and an anti-leakage stretching zone are formed in sequence between two adjacent groups of roller mechanisms, and a first relaxation zone and a second relaxation zone are respectively arranged between the pre-stretching zone and the main stretching zone and between the main stretching zone and the anti-leakage stretching zone through two adjacent groups of roller mechanisms.

7. The stretch-cutting machine according to claim 6, further comprising a strip coiler connected to the stretch-cutting system.

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