A method for drawing super-large fiber strands

Abstract

The present invention belongs to the technical field of spinning, and relates to a method for super-drafting fiber whiskers, specifically: using a super-drafting device, the super-drafting device includes a rear drafting zone and a front drafting zone, after the fiber whiskers leave the rear drafting zone and before entering the front drafting zone, the fiber whiskers are gathered and twisted, so that the twist of the fiber whiskers when entering the front drafting zone is 2 to 4 twists / 10cm; the drafting multiple of the front drafting zone is 80 to 150 times, the drafting multiple of the middle drafting zone is 1, the drafting multiple of the rear drafting zone is 2 to 3 times, and the total drafting multiple is 240 to 300. The method for super-drafting fiber whiskers of the present invention solves the problem of insufficient internal friction field of the fiber whiskers after being drafted in the rear drafting zone during roller drafting, and the spun yarn has good yarn uniformity, less hairiness on the yarn surface, less coarse sections and fine sections, and the overall quality is significantly improved.

Description

Technical Field

[0001] The invention belongs to the technical field of spinning and relates to a method for super-large drafting of fiber strands. Background Art

[0002] Among the existing spinning technologies, ring spinning is the most mature, widely used, with the strongest raw material applicability and the best yarn performance, especially strength and elongation. However, compared with other spinning methods, ring spinning has the longest process flow and requires the most equipment sets, which makes the production efficiency of ring spinning low and the labor and capital costs high. Therefore, in the development of ring spinning, the research on the efficient spinning process of "heavy weight and large draft" and the ultra-large draft (i.e., the total draft multiple is greater than 200 times) device has become the focus of ring spinning research.

[0003] At present, the structure of the super-large drafting device of ring spinning can be divided into three forms according to the number of rollers: three rollers, four rollers and five rollers. Taking the patents with authorization announcement number CN109610052B and authorization announcement number CN109610053B as examples, they provide a super-large drafting method with reverse extension of the leather ring and a device for implementing the method. In actual use, the total drafting multiple of the method and the device can reach 147-503 times, and significant progress has been made in the drafting multiple. In addition, there are also a variety of gathering false twisting devices in the prior art, such as mechanical and airflow types. Taking the patent with authorization announcement number CN110117851B as an example, these devices are usually installed at the output jaws of the front rollers of the spinning machine, and are used to reduce the width of the triangular area of ​​the fiber when twisting before the fiber sliver is twisted into yarn, so that the fiber is more gathered, so as to increase the strength of the spun yarn, reduce the surface hairiness of the yarn, reduce the spinning breakage rate and improve the spinning stability.

[0004] However, these existing technologies have many shortcomings. The super-large drafting devices involved in the patents with authorization announcement numbers CN109610052B and CN109610053B have poor yarn unevenness in actual applications, and the CV% value can only reach about 15%, which is difficult to meet production scenarios with high requirements for yarn quality. The main reason is that the super-large drafting device of ring spinning has deficiencies in the twist processing of fiber slivers, resulting in a lack of internal friction field formed by twist distribution and inter-fiber cohesion in the front drafting zone, which in turn affects the control of the fiber and reduces the drafting quality. Existing gathering false twist devices, such as mechanical and air flow types, take the patent with authorization announcement number CN110117851B as an example. The gathering false twist device is installed at the output jaws of the front rollers of the spinning frame. It is only suitable for processing a small amount of fiber slivers after drafting and before twisting into yarn. The false twist effect produced cannot be directly applied to a large amount of untwisted fiber slivers drafted in the ultra-large drafting rear zone, and cannot effectively maintain the internal friction field required for subsequent drafting, and cannot meet the needs of the new ultra-large drafting process.

[0005] Therefore, it is necessary to improve the existing technology to meet the needs of ultra-large drafting process. Summary of the invention

[0006] The purpose of the present invention is to solve the problems in the prior art and provide a method for super-large drafting fiber strands.

[0007] In order to achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] A method for super-drafting fiber strands, using a super-drafting device, the super-drafting device comprising a rear drafting zone and a front drafting zone, after the fiber strands leave the rear drafting zone (at this time, the twist of the fiber strands is 0) and before entering the front drafting zone, the fiber strands are gathered and twisted, so that the twist of the fiber strands entering the front drafting zone is 2-4 twists / 10 cm; the drafting multiple of the front drafting zone is 80-150 times, the drafting multiple of the middle drafting zone is 1, the drafting multiple of the rear drafting zone is 2-3 times, and the total drafting multiple is 240-300.

[0009] As the preferred technical solution:

[0010] In the method for ultra-large drawing of fiber strands as described above, a gathering and twisting device is used to gather and twist the fiber strands. The gathering and twisting device is a mechanical gathering and twisting device or an airflow gathering and twisting device.

[0011] A method for drawing a super-large fiber strand as described above, wherein the mechanical gathering and twisting device comprises a twister, a friction wheel, a housing I, and a gear set;

[0012] The twister is a trumpet-shaped structure, the central axis is parallel to the front-to-back direction and the trumpet mouth is at the rear; the central axis of the friction wheel is parallel to the front-to-back direction and the friction surface is at the front; the front end of the twister and the rear end of the friction wheel are both inserted into the housing I, and both are connected to the gear set located in the housing I;

[0013] The friction surface of the friction wheel contacts the circumference of a roller in the super-large drafting device, and the roller drives the friction wheel to rotate around its own central axis. When the friction wheel rotates around its own central axis, it drives the twister to rotate around its own central axis through a gear set.

[0014] In a method for ultra-large drawing of fiber strands as described above, the twister consists of a variable diameter section located on the rear side and a constant diameter section located on the front side; the variable diameter section has a length of 3-5 mm and an inner diameter of 5-6 mm at the rear end; the constant diameter section has a length of 5-10 mm and an inner diameter of 2-4 mm; and convex points or convex strips are distributed on the inner surface of the constant diameter section.

[0015] In the method for ultra-large drawing of fiber strands as described above, the friction surface of the friction wheel is distributed with protrusions or grooves.

[0016] A method for super-large drawing of fiber strands as described above, the super-large drawing device is a four-roller reverse extension rubber ring super-large drawing device or a four-roller forward extension rubber ring super-large drawing device, including a rear roller, a first middle roller, a second middle roller, and a front roller, and a mechanical gathering and twisting device is located between the first middle roller and the second middle roller; the friction surface of the friction wheel contacts the circumferential surface of the second middle roller, the distance between the rear end of the twister and the jaws of the first middle roller is 20~25mm, and the distance between the front end of the twister and the jaws of the second middle roller is 10~15mm.

[0017] A method for ultra-large drawing of fiber strands as described above, an airflow-type gathering and twisting device includes a shell II and an air supply device; a yarn channel and an injection hole are arranged inside the shell II; the yarn channel is composed of a tapered section, a constant section, and an increasing section which are sequentially connected from back to front, the diameter of the tapered section gradually decreases from back to front, the diameter of the constant section remains unchanged from back to front, and the diameter of the increasing section gradually increases from back to front; the injection hole is connected to the increasing section, the air supply device is used to continuously supply air to the injection hole, and the direction of the airflow injected from the injection hole forms an acute angle with the running direction of the fiber strands.

[0018] In the method for ultra-large drawing of fiber strands as described above, an air inlet and an air chamber are also provided inside the shell II, and the air supply device, the air inlet, the air chamber, and the injection hole are connected in sequence.

[0019] In the method for drawing a super-large fiber strand as described above, the length of the tapered section is 5-6 mm, and the diameter of the rear end is 3-5 mm; the length of the constant section is 10-15 mm, and the diameter is 2-4 mm; the length of the increasing section is 30-40 mm, and the diameter of the front end is 3-6 mm; the angle of the acute angle is 30-45 ° The vertical distance between the outlet center of the injection hole and the central axis of the increasing section is 1.5~3mm.

[0020] In the method for ultra-large drawn fiber strands as described above, the air supply device supplies an air flow of 200-300 Pa.

[0021] A method for super-large stretching of fiber strands as described above, the super-large stretching device is a four-roller reverse extension rubber ring super-large stretching device or a four-roller forward extension rubber ring super-large stretching device, including a rear roller, a first middle roller, a second middle roller, and a front roller, and an airflow-type gathering and twisting device is located between the first middle roller and the second middle roller; the distance between the rear end of the yarn channel and the jaws of the first middle roller is 5~8mm, and the distance between the front end of the yarn channel and the jaws of the second middle roller is 3~5mm.

[0022] In the method for super-large drawing of fiber slivers as described above, the yarn unevenness rate of the yarn leaving the front drawing zone is 5-8%, the number of thin sections is 3-5 pieces / km, the number of thick sections is 3-5 pieces / km, and the number of hairiness above 3 mm is 1-2 pieces / m.

[0023] Principle of the invention:

[0024] The present invention gathers and twists the untwisted fiber strands on the path before they enter the front stretching zone, so that a continuous dynamic internal friction field is formed inside the fiber strands, thereby improving the control ability of the front stretching zone over the fibers inside the fiber strands, making the fiber speed change points in the front stretching zone more concentrated, and effectively improving the yarn dryness, as well as quality indicators such as coarse and fine details, hairiness, and strength of the spun yarn; specifically, the present invention causes the fiber strands entering the middle stretching zone to generate twist distributions in different directions between the twister and the first middle roller and between the twister and the second middle roller under the action of the gathering and twisting device, thereby increasing the bonding force between the fibers inside the fiber strands entering the front stretching zone, and improving the strength and strength distribution range of the internal friction field of the fiber strands entering the front stretching zone, thereby improving the control ability of the front stretching zone over the fibers and improving the yarn dryness quality level of the spun yarn.

[0025] Beneficial effects:

[0026] The method of the present invention for ultra-large drafting of fiber whiskers solves the problem of insufficient internal friction field of fiber whiskers after drafting in the rear drafting zone during roller drafting. It can not only effectively aggregate the fiber whiskers, but also ensure that they maintain a sufficient internal friction field when entering the front drafting zone, thereby increasing the drafting multiple of the front drafting zone. On this basis, the drafting multiple of the rear zone or the middle zone can be appropriately reduced under the premise of ensuring the total drafting multiple, thereby reducing the problem of uneven drafting caused by the superposition of drafting waves, and further improving the drafting quality of ultra-large drafting.

[0027] The yarn spun by the present invention has good yarn evenness, less hairiness on the yarn surface, fewer thick sections and thin sections, and the overall quality is significantly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 It is a schematic diagram of the positions of the super-large drafting device and the condensing twisting device (mechanical type and air flow type) of the present invention;

[0029] Figure 2 Schematic diagram of the method for drawing fiber strands of the present invention when a mechanical gathering and twisting device is used;

[0030] Figure 3 It is a schematic diagram of the mechanical gathering and twisting device of the present invention;

[0031] Figure 4 Schematic diagram of the friction wheel of the mechanical gathering and twisting device of the present invention;

[0032] Figure 5 , Figure 6 It is a structural schematic diagram of a twister of the mechanical gathering twisting device of the present invention;

[0033] Figure 7 Schematic diagram of the method for drawing fiber strands of the present invention when an airflow type gathering and twisting device is used;

[0034] Figure 8 It is a schematic diagram of the airflow type gathering and twisting device of the present invention;

[0035] Among them: 1. gathering and twisting device; 2. first middle roller; 3. second middle roller; 1-1. mechanical gathering and twisting device; 1-11. shell I; 1-12. friction wheel; 1-13. gear set; 1-15. twister; 1-16. convex point; 1-17. convex strip; 1-2. airflow gathering and twisting device; 1-21. shell II; 1-22. air inlet; 1-23. air chamber; 1-24. injection hole; 1-25. gradually contracting section; 1-26. constant section; 1-27. gradually increasing section. DETAILED DESCRIPTION

[0036] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0037] Detection method of relevant indicators in the embodiment:

[0038] Twist: The test was conducted using the Y331C yarn twist tester from Wenzhou Fangyuan Instrument Co., Ltd., with a clamping length of 254 mm;

[0039] Strip unevenness, number of thin places, number of thick places: tested in accordance with the test standard GB / T 3292.1-2008, the instrument used is the CT3000 Strip Evenness Test Analyzer of Shaanxi Changling Textile Electromechanical Technology Co., Ltd.

[0040] Hairiness: The test is carried out in accordance with the standard FZ / T 01086-2020. The instrument used is the YG172A yarn hairiness tester of Shaanxi Changling Textile Electromechanical Technology Co., Ltd.

[0041] Example 1

[0042] A fiber strand drafting device, such as Figure 1 , Figure 2~Figure 6 As shown, it includes an extra-large drafting device and a gathering and twisting device 1;

[0043] like Figure 2 As shown, the super-large drafting device is a four-roller reverse-extending rubber ring super-large drafting device (or it can also be a four-roller forward-extending rubber ring super-large drafting device), including a rear roller, a first middle roller 2, a second middle roller 3, and a front roller; wherein the area between the rear roller and the first middle roller 2 is a rear drafting area, and the area between the second middle roller 3 and the front roller is a front drafting area;

[0044] The gathering and twisting device 1 is a mechanical gathering and twisting device 1-1, such as Figure 3~Figure 6 As shown, it includes a twister 1-15, a friction wheel 1-12, a housing Ⅰ 1-11, and a gear set 1-13;

[0045] The twister 1-15 is a trumpet-shaped tube structure consisting of a variable diameter section located at the rear side and a constant diameter section located at the front side. The central axis of the trumpet-shaped tube structure is parallel to the front-to-back direction and the trumpet mouth is at the rear; wherein the length of the variable diameter section is 3mm and the inner diameter of the rear end is 5mm; the length of the constant diameter section is 5mm and the inner diameter is 2mm; Figure 5 and Figure 6 As shown, the inner surface of the equal diameter section is distributed with convex points 1-16 or convex strips 1-17;

[0046] like Figure 3 and Figure 4 As shown, the central axis of the friction wheel 1-12 is parallel to the front-to-back direction and the friction surface is in the front; the front end of the twister 1-15 and the rear end of the friction wheel 1-12 are both inserted into the housing Ⅰ 1-11, and both are connected to the gear set 1-13 located in the housing Ⅰ 1-11;

[0047] The friction surface of the friction wheel 1-12 is distributed with protrusions or grooves;

[0048] like Figure 2 As shown, the mechanical gathering and twisting device 1-1 is located between the first middle roller 2 and the second middle roller 3, the distance between the rear end of the twister 1-15 and the jaws of the first middle roller 2 is 25 mm, and the distance between the front end of the twister 1-15 and the jaws of the second middle roller 3 is 15 mm; the friction surface of the friction wheel 1-12 is in contact with the circumferential surface of the second middle roller 3, and the second middle roller 3 drives the friction wheel 1-12 to rotate around its own center axis. When the friction wheel 1-12 rotates around its own center axis, it drives the twister 1-15 to rotate around its own center axis through the gear set 1-13.

[0049] A method for super-large drafting of fiber strands, using the above-mentioned fiber strand drafting device, after the fiber strands leave the rear drafting zone and before entering the front drafting zone, a mechanical gathering and twisting device 1-1 is used to gather and twist the fiber strands; wherein the fiber strands are polyester fibers, the fiber length is 32 mm, the twist when entering the rear drafting zone is 2 twists / 10 cm, the basis weight is 18 g / 10 m, the twist when entering the front drafting zone is 2 twists / 10 cm, the drafting multiple of the front drafting zone is 80 times, the drafting multiple of the middle drafting zone is 1, and the drafting multiple of the rear drafting zone is 3 times;

[0050] The yarn unevenness rate of the yarn leaving the pre-drafting zone is 5%, the number of thin sections is 3 / km, the number of thick sections is 3 / km, and the number of hairiness above 3mm is 1 / m.

[0051] Comparative Example 1

[0052] A method for ultra-large drawing of fiber strands is basically the same as that of Example 1, except that the fiber strand drawing device used does not contain a gathering and twisting device.

[0053] The twist of the fiber strands when entering the front drafting zone is 0 twist / 10cm;

[0054] The yarn unevenness rate of the yarn leaving the pre-drafting zone is 12%, the number of thin sections is 9.3 / km, the number of thick sections is 6.8 / km, and the number of hairiness above 3mm is 3 / m.

[0055] By comparing Example 1 with Comparative Example 1, it can be seen that the quality indicators of the yarn spun in Example 1 are better. This is because the fiber whiskers drawing device of Example 1 is provided with a gathering and twisting device, which can make the fiber whiskers gather and have a certain twist when entering the front stretching zone. The fiber whiskers have a large and continuous internal friction field when being stretched in the front stretching zone, which effectively improves the control ability of the stretching zone over the internal fibers of the fiber whiskers, and the fiber speed change points in the stretching zone are more concentrated, resulting in less accidental stretching.

[0056] Comparative Example 2

[0057] A method for ultra-large drawing of fiber strands is basically the same as that in Example 1, except that the gathering and twisting device in the fiber strand drawing device is replaced by a gathering and false twisting device of the patent with authorization announcement number CN110117851B.

[0058] The twist of the fiber strands when entering the front drafting zone is 0 twist / 10cm (the patented gathering false twist device of CN110117851B cannot twist the fiber strands, so the twist does not exist);

[0059] The yarn unevenness rate of the yarn leaving the pre-drafting zone is 11.5%, the number of thin sections is 8.7 pieces / km, the number of thick sections is 6.5 pieces / km, and the number of hairiness above 3mm is 2.5 pieces / m.

[0060] By comparing Example 1 with Comparative Example 2, it can be seen that the quality of the yarn spun in Example 1 is better. This is because the gathering false twist device in Comparative Example 2 can only act on a small amount of fiber whiskers, and has limited effect on the fiber whiskers entering the front stretching zone. The effect of enhancing the friction field inside the fiber whiskers is limited, and no optimization effect can be achieved.

[0061] Example 2

[0062] A fiber strand drafting device, such as Figure 1 , Figure 2~Figure 6 As shown, it includes an extra-large drafting device and a gathering and twisting device 1;

[0063] like Figure 2 As shown, the super-large drafting device is a four-roller reverse-extending rubber ring super-large drafting device (or it can also be a four-roller forward-extending rubber ring super-large drafting device), including a rear roller, a first middle roller 2, a second middle roller 3, and a front roller; wherein the area between the rear roller and the first middle roller 2 is a rear drafting area, and the area between the second middle roller 3 and the front roller is a front drafting area;

[0064] The gathering and twisting device 1 is a mechanical gathering and twisting device 1-1, such as Figure 3~Figure 6 As shown, it includes a twister 1-15, a friction wheel 1-12, a housing Ⅰ 1-11, and a gear set 1-13;

[0065] The twister 1-15 is a trumpet-shaped tube structure consisting of a variable diameter section located at the rear side and a constant diameter section located at the front side. The central axis of the trumpet-shaped tube structure is parallel to the front-to-back direction and the trumpet mouth is at the rear; wherein the length of the variable diameter section is 4mm and the inner diameter of the rear end is 5mm; the length of the constant diameter section is 8mm and the inner diameter is 3mm; Figure 5 and Figure 6 As shown, the inner surface of the equal diameter section is distributed with convex points 1-16 or convex strips 1-17;

[0066] like Figure 3 and Figure 4 As shown, the central axis of the friction wheel 1-12 is parallel to the front-to-back direction and the friction surface is in the front; the front end of the twister 1-15 and the rear end of the friction wheel 1-12 are both inserted into the housing Ⅰ 1-11, and both are connected to the gear set 1-13 located in the housing Ⅰ 1-11;

[0067] The friction surface of the friction wheel 1-12 is distributed with protrusions or grooves;

[0068] like Figure 2As shown, the mechanical gathering and twisting device 1-1 is located between the first middle roller 2 and the second middle roller 3, the distance between the rear end of the twister 1-15 and the jaws of the first middle roller 2 is 23 mm, and the distance between the front end of the twister 1-15 and the jaws of the second middle roller 3 is 12 mm; the friction surface of the friction wheel 1-12 is in contact with the circumferential surface of the second middle roller 3, and the second middle roller 3 drives the friction wheel 1-12 to rotate around its own center axis. When the friction wheel 1-12 rotates around its own center axis, it drives the twister 1-15 to rotate around its own center axis through the gear set 1-13.

[0069] A method for super-large drafting of fiber strands, using the above-mentioned fiber strand drafting device, after the fiber strands leave the rear drafting zone and before entering the front drafting zone, a mechanical gathering and twisting device 1-1 is used to gather and twist the fiber strands; wherein the fiber strands are cotton fibers, the fiber quality length is 30 mm, the twist when entering the rear drafting zone is 3 twists / 10 cm, the basis weight is 18.5 g / 10 m, the twist when entering the front drafting zone is 3 twists / 10 cm, the drafting multiple of the front drafting zone is 100 times, the drafting multiple of the middle drafting zone is 1, and the drafting multiple of the rear drafting zone is 2.5 times;

[0070] The yarn unevenness rate of the yarn leaving the pre-drafting zone is 6.7%, the number of thin sections is 4.3 / km, the number of thick sections is 3.6 / km, and the number of hairiness above 3mm is 1 / m.

[0071] Example 3

[0072] A fiber strand drafting device, such as Figure 1 , Figure 2~Figure 6 As shown, it includes an extra-large drafting device and a gathering and twisting device 1;

[0073] like Figure 2 As shown, the super-large drafting device is a four-roller reverse-extending rubber ring super-large drafting device (or it can also be a four-roller forward-extending rubber ring super-large drafting device), including a rear roller, a first middle roller 2, a second middle roller 3, and a front roller; wherein the area between the rear roller and the first middle roller 2 is a rear drafting area, and the area between the second middle roller 3 and the front roller is a front drafting area;

[0074] The gathering and twisting device 1 is a mechanical gathering and twisting device 1-1, such as Figure 3~Figure 6 As shown, it includes a twister 1-15, a friction wheel 1-12, a housing Ⅰ 1-11, and a gear set 1-13;

[0075] The twister 1-15 is a trumpet-shaped tube structure consisting of a variable diameter section located at the rear side and a constant diameter section located at the front side. The central axis of the trumpet-shaped tube structure is parallel to the front-to-back direction and the trumpet mouth is at the rear; wherein the length of the variable diameter section is 5mm and the inner diameter of the rear end is 6mm; the length of the constant diameter section is 10mm and the inner diameter is 4mm; Figure 5and Figure 6 As shown, the inner surface of the equal diameter section is distributed with convex points 1-16 or convex strips 1-17;

[0076] like Figure 3 and Figure 4 As shown, the central axis of the friction wheel 1-12 is parallel to the front-to-back direction and the friction surface is in the front; the front end of the twister 1-15 and the rear end of the friction wheel 1-12 are both inserted into the housing Ⅰ 1-11, and both are connected to the gear set 1-13 located in the housing Ⅰ 1-11;

[0077] The friction surface of the friction wheel 1-12 is distributed with protrusions or grooves;

[0078] like Figure 2 As shown, the mechanical gathering and twisting device 1-1 is located between the first middle roller 2 and the second middle roller 3, the distance between the rear end of the twister 1-15 and the jaws of the first middle roller 2 is 20 mm, and the distance between the front end of the twister 1-15 and the jaws of the second middle roller 3 is 10 mm; the friction surface of the friction wheel 1-12 is in contact with the circumferential surface of the second middle roller 3, and the second middle roller 3 drives the friction wheel 1-12 to rotate around its own center axis. When the friction wheel 1-12 rotates around its own center axis, it drives the twister 1-15 to rotate around its own center axis through the gear set 1-13.

[0079] A method for super-large drafting of fiber strands, using the above-mentioned fiber strand drafting device, after the fiber strands leave the rear drafting zone and before entering the front drafting zone, a mechanical gathering and twisting device 1-1 is used to gather and twist the fiber strands; wherein the fiber strands are cotton fibers, the fiber quality length is 30 mm, the twist when entering the rear drafting zone is 3 twists / 10 cm, the basis weight is 18.5 g / 10 m, the twist when entering the front drafting zone is 4 twists / 10 cm, the drafting multiple of the front drafting zone is 150 times, the drafting multiple of the middle drafting zone is 1, and the drafting multiple of the rear drafting zone is 2 times;

[0080] The yarn unevenness rate of the yarn leaving the pre-drafting zone is 7.8%, the number of thin sections is 5 / km, the number of thick sections is 5 / km, and the number of hairiness above 3mm is 2 / m.

[0081] Example 4

[0082] A fiber strand drafting device, such as Figure 1 , Figure 7 , Figure 8 As shown, it includes an extra-large drafting device and a gathering and twisting device 1;

[0083] like Figure 7As shown, the super-large drafting device is a four-roller reverse-extending rubber ring super-large drafting device (or it can also be a four-roller forward-extending rubber ring super-large drafting device), including a rear roller, a first middle roller 2, a second middle roller 3, and a front roller; wherein the area between the rear roller and the first middle roller 2 is a rear drafting area, and the area between the second middle roller 3 and the front roller is a front drafting area;

[0084] The gathering and twisting device 1 is an airflow gathering and twisting device 1-2, such as Figure 8 As shown, it includes a housing II 1-21 and an air supply device;

[0085] The shell II 1-21 is provided with a yarn channel, an injection hole 1-24, an air inlet 1-22 and an air chamber 1-23;

[0086] The yarn channel is composed of a tapered section 1-25, a constant section 1-26, and an increasing section 1-27 which are connected in sequence from back to front. The diameter of the tapered section 1-25 gradually decreases from back to front, the diameter of the constant section 1-26 remains unchanged from back to front, and the diameter of the increasing section 1-27 gradually increases from back to front. The length of the tapered section 1-25 is 5 mm, and the rear end diameter is 3 mm; the length of the constant section 1-26 is 10 mm, and the diameter is 2 mm; the length of the increasing section 1-27 is 30 mm, and the front end diameter is 3 mm.

[0087] The air supply device, the air inlet 1-22, the air chamber 1-23, and the injection hole 1-24 are connected in sequence, the injection hole 1-24 is connected to the increasing section 1-27, and the vertical distance between the outlet center of the injection hole 1-24 and the central axis of the increasing section 1-27 is 1.5 mm; the air supply device is used to continuously supply air to the injection hole 1-24, the air flow size supplied is 200 Pa, and the air flow direction of the injection hole 1-24 is 30° to the running direction of the fiber whiskers. ° Angle;

[0088] like Figure 7 As shown, the airflow gathering and twisting device 1-2 is located between the first middle roller 2 and the second middle roller 3; the distance between the rear end of the yarn channel and the jaws of the first middle roller 2 is 8 mm, and the distance between the front end of the yarn channel and the jaws of the second middle roller 3 is 5 mm.

[0089] A method for super-large drafting of fiber strands, using the above-mentioned fiber strand drafting device, after the fiber strands leave the rear drafting zone and before entering the front drafting zone, using an airflow type gathering and twisting device 1-2 to gather and twist the fiber strands; wherein the fiber strands are viscose fibers, the fiber quality is 33 mm, the twist when entering the rear drafting zone is 1.5 twists / 10 cm, the basis weight is 20 g / 10 m, the twist when entering the front drafting zone is 2 twists / 10 cm, the drafting multiple of the front drafting zone is 80 times, the drafting multiple of the middle drafting zone is 1, and the drafting multiple of the rear drafting zone is 3 times;

[0090] The yarn unevenness rate of the yarn leaving the pre-drafting zone is 5.3%, the number of thin sections is 4.1 / km, the number of thick sections is 3.5 / km, and the number of hairiness above 3mm is 1.3 / m.

[0091] Comparative Example 3

[0092] A method for ultra-large drawing of fiber strands is basically the same as that of Example 4, except that the fiber strand drawing device used does not contain a gathering and twisting device.

[0093] The twist of the fiber strands when entering the front drafting zone is 0 twist / 10cm;

[0094] The yarn unevenness rate of the yarn leaving the pre-drafting zone is 10.5%, the number of thin sections is 5.7 pieces / km, the number of thick sections is 6.4 pieces / km, and the number of hairiness above 3mm is 3.1 pieces / m.

[0095] By comparing Example 4 with Comparative Example 3, it can be seen that the quality indicators of the yarn spun in Example 4 are better. This is because the fiber whiskers drawing device of Example 4 is provided with a gathering and twisting device, which can make the fiber whiskers gather and have a certain twist when entering the front stretching zone. The fiber whiskers have a large and continuous internal friction field when being stretched in the front stretching zone, which effectively improves the control ability of the stretching zone over the internal fibers of the fiber whiskers, and the fiber speed change points in the stretching zone are more concentrated, resulting in less accidental stretching.

[0096] Comparative Example 4

[0097] A method for ultra-large drawing of fiber strands is basically the same as that of Example 4, except that the gathering and twisting device in the fiber strand drawing device is replaced by a gathering and false twisting device of the patent with authorization announcement number CN110117851B.

[0098] The twist of the fiber strands when entering the front drafting zone is 0 twist / 10cm (the patented gathering false twist device of CN110117851B cannot twist the fiber strands, so the twist does not exist);

[0099] The yarn unevenness rate of the yarn leaving the pre-drafting zone is 10.2%, the number of thin sections is 5.8 pieces / km, the number of thick sections is 6.3 pieces / km, and the number of hairiness above 3mm is 2.8 pieces / m.

[0100] By comparing Example 4 with Comparative Example 4, it can be seen that the quality of the yarn spun in Example 4 is better. This is because the gathering false twist device in Comparative Example 4 can only act on a small amount of fiber whiskers, and has limited effect on the fiber whiskers entering the front stretching zone. The effect of enhancing the friction field inside the fiber whiskers is limited, and no optimization effect can be achieved.

[0101] Example 5

[0102] A fiber strand drafting device, such as Figure 1 , Figure 7 , Figure 8 As shown, it includes an extra-large drafting device and a gathering and twisting device 1;

[0103] like Figure 7 As shown, the super-large drafting device is a four-roller reverse-extending rubber ring super-large drafting device (or it can also be a four-roller forward-extending rubber ring super-large drafting device), including a rear roller, a first middle roller 2, a second middle roller 3, and a front roller; wherein the area between the rear roller and the first middle roller 2 is a rear drafting area, and the area between the second middle roller 3 and the front roller is a front drafting area;

[0104] The gathering and twisting device 1 is an airflow gathering and twisting device 1-2, such as Figure 8 As shown, it includes a housing II 1-21 and an air supply device;

[0105] The shell II 1-21 is provided with a yarn channel, an injection hole 1-24, an air inlet 1-22 and an air chamber 1-23;

[0106] The yarn channel is composed of a tapered section 1-25, a constant section 1-26, and an increasing section 1-27 which are connected in sequence from back to front. The diameter of the tapered section 1-25 gradually decreases from back to front, the diameter of the constant section 1-26 remains unchanged from back to front, and the diameter of the increasing section 1-27 gradually increases from back to front. The length of the tapered section 1-25 is 6 mm, and the rear end diameter is 4 mm; the length of the constant section 1-26 is 12 mm, and the diameter is 3 mm; the length of the increasing section 1-27 is 35 mm, and the front end diameter is 4 mm.

[0107] The air supply device, the air inlet 1-22, the air chamber 1-23, and the injection hole 1-24 are connected in sequence, the injection hole 1-24 is connected to the increasing section 1-27, and the vertical distance between the outlet center of the injection hole 1-24 and the central axis of the increasing section 1-27 is 2 mm; the air supply device is used to continuously supply air to the injection hole 1-24, the air flow size supplied is 250 Pa, and the air flow direction of the injection hole 1-24 is 40° to the running direction of the fiber whiskers. ° Angle;

[0108] like Figure 7 As shown, the airflow gathering and twisting device 1-2 is located between the first middle roller 2 and the second middle roller 3; the distance between the rear end of the yarn channel and the jaws of the first middle roller 2 is 6 mm, and the distance between the front end of the yarn channel and the jaws of the second middle roller 3 is 4 mm.

[0109] A method for super-large drafting of fiber strands, using the above-mentioned fiber strand drafting device, after the fiber strands leave the rear drafting zone and before entering the front drafting zone, using an airflow type gathering and twisting device 1-2 to gather and twist the fiber strands; wherein the fiber strands are viscose fibers, the fiber length is 38 mm, the twist when entering the rear drafting zone is 1 twist / 10 cm, the basis weight is 20 g / 10 m, the twist when entering the front drafting zone is 3 twists / 10 cm, the drafting multiple of the front drafting zone is 100 times, the drafting multiple of the middle drafting zone is 1, and the drafting multiple of the rear drafting zone is 2.5 times;

[0110] The yarn unevenness rate of the yarn leaving the pre-drafting zone is 6.2%, the number of thin sections is 3.7 / km, the number of thick sections is 4.6 / km, and the number of hairiness above 3mm is 1.3 / m.

[0111] Example 6

[0112] A fiber strand drafting device, such as Figure 1 , Figure 7 , Figure 8 As shown, it includes an extra-large drafting device and a gathering and twisting device 1;

[0113] like Figure 7 As shown, the super-large drafting device is a four-roller reverse-extending rubber ring super-large drafting device (or it can also be a four-roller forward-extending rubber ring super-large drafting device), including a rear roller, a first middle roller 2, a second middle roller 3, and a front roller; wherein the area between the rear roller and the first middle roller 2 is a rear drafting area, and the area between the second middle roller 3 and the front roller is a front drafting area;

[0114] The gathering and twisting device 1 is an airflow gathering and twisting device 1-2, such as Figure 8 As shown, it includes a housing II 1-21 and an air supply device;

[0115] The shell II 1-21 is provided with a yarn channel, an injection hole 1-24, an air inlet 1-22 and an air chamber 1-23;

[0116] The yarn channel is composed of a tapered section 1-25, a constant section 1-26, and an increasing section 1-27 which are connected in sequence from back to front. The diameter of the tapered section 1-25 gradually decreases from back to front, the diameter of the constant section 1-26 remains unchanged from back to front, and the diameter of the increasing section 1-27 gradually increases from back to front. Among them, the length of the tapered section 1-25 is 6 mm, and the rear end diameter is 5 mm; the length of the constant section 1-26 is 15 mm, and the diameter is 4 mm; the length of the increasing section 1-27 is 40 mm, and the front end diameter is 6 mm.

[0117] The air supply device, the air inlet 1-22, the air chamber 1-23, and the injection hole 1-24 are connected in sequence. The injection hole 1-24 is connected to the increasing section 1-27. The vertical distance between the outlet center of the injection hole 1-24 and the central axis of the increasing section 1-27 is 3 mm. The air supply device is used to continuously supply air to the injection hole 1-24. The air flow size supplied is 300 Pa. The direction of the air flow injected by the injection hole 1-24 is 45° to the running direction of the fiber whiskers. ° Angle;

[0118] like Figure 7 As shown, the airflow gathering and twisting device 1-2 is located between the first middle roller 2 and the second middle roller 3; the distance between the rear end of the yarn channel and the jaws of the first middle roller 2 is 5 mm, and the distance between the front end of the yarn channel and the jaws of the second middle roller 3 is 3 mm.

[0119] A method for super-large drafting of fiber strands, using the above-mentioned fiber strand drafting device, after the fiber strands leave the rear drafting zone and before entering the front drafting zone, using an airflow type gathering and twisting device 1-2 to gather and twist the fiber strands; wherein the fiber strands are polyester fibers, the fiber length is 55 mm, the twist when entering the rear drafting zone is 1 twist / 10 cm, the basis weight is 22 g / 10 m, the twist when entering the front drafting zone is 1.5 twists / 10 cm, the drafting multiple in the front drafting zone is 150 times, the drafting multiple in the middle drafting zone is 1, and the drafting multiple in the rear drafting zone is 2 times;

[0120] The yarn unevenness rate of the yarn leaving the pre-drafting zone is 8%, the number of thin sections is 5 / km, the number of thick sections is 5 / km, and the number of hairiness above 3mm is 2 / m.

Claims

1. A method for super-drafting fiber strands, using a super-drafting device, the super-drafting device is a ring spinning super-drafting device, the super-drafting device includes a rear drafting area and a front drafting area, characterized in that: After the fiber strands leave the rear stretching zone and before entering the front stretching zone, the fiber strands are gathered and twisted so that the twist of the fiber strands entering the front stretching zone is 2 to 4 twists / 10 cm; the stretching multiples in the front stretching zone are 80 to 150 times, the stretching multiples in the middle stretching zone are 1, the stretching multiples in the rear stretching zone are 2 to 3 times, and the total stretching multiples are 240 to 300; the twisting direction remains unchanged during twisting.

2. A method for ultra-large drafting fiber strands according to claim 1, characterized in that: A gathering and twisting device (1) is used to gather and twist the fiber strands. The gathering and twisting device (1) is a mechanical gathering and twisting device (1-1) or an airflow gathering and twisting device (1-2).

3. A method for ultra-large drafting fiber strands according to claim 2, characterized in that: The mechanical gathering and twisting device (1-1) comprises a twister (1-15), a friction wheel (1-12), a housing I (1-11), and a gear set (1-13); The twister (1-15) is a trumpet-shaped structure, the central axis of which is parallel to the front-to-back direction and the trumpet mouth is at the rear; the central axis of the friction wheel (1-12) is parallel to the front-to-back direction and the friction surface is at the front; the front end of the twister (1-15) and the rear end of the friction wheel (1-12) are both inserted into the housing I (1-11), and both are connected to the gear set (1-13) located in the housing I (1-11); The friction surface of the friction wheel (1-12) contacts the circumferential surface of a roller in the super-large drafting device, and the roller drives the friction wheel (1-12) to rotate around its own central axis. When the friction wheel (1-12) rotates around its own central axis, it drives the twister (1-15) to rotate around its own central axis through the gear set (1-13).

4. A method for ultra-large drafting of fiber strands according to claim 3, characterized in that: The twister (1-15) is composed of a diameter-reducing section located at the rear side and a constant diameter section located at the front side; the length of the diameter-reducing section is 3 to 5 mm, and the inner diameter of the rear end is 5 to 6 mm; The length of the equal diameter section is 5 to 10 mm, and the inner diameter is 2 to 4 mm; convex points or convex strips are distributed on the inner surface of the equal diameter section.

5. A method for ultra-large drafting of fiber strands according to claim 3, characterized in that: The super-large drafting device is a four-roller reverse-extending rubber ring super-large drafting device or a four-roller forward-extending rubber ring super-large drafting device, comprising a rear roller, a first middle roller (2), a second middle roller (3), and a front roller. The mechanical gathering and twisting device (1-1) is located between the first middle roller (2) and the second middle roller (3); the friction surface of the friction wheel (1-12) contacts the peripheral surface of the second middle roller (3); the distance between the rear end of the twister (1-15) and the jaws of the first middle roller (2) is 20 to 25 mm, and the distance between the front end of the twister (1-15) and the jaws of the second middle roller (3) is 10 to 15 mm.

6. A method for ultra-large drafting of fiber strands according to claim 2, characterized in that: The airflow type gathering and twisting device (1-2) comprises a shell II (1-21) and an air supply device; a yarn channel and an injection hole (1-24) are arranged inside the shell II (1-21); the yarn channel consists of a gradually contracting section (1-25), a constant section (1-26), and a gradually increasing section (1-27) which are connected in sequence from back to front; the diameter of the gradually contracting section (1-25) gradually decreases from back to front, the diameter of the constant section (1-26) remains constant from back to front, and the diameter of the gradually increasing section (1-27) gradually increases from back to front; the injection hole (1-24) is connected to the gradually increasing section (1-27); the air supply device is used for continuously supplying air to the injection hole (1-24); the direction of the airflow injected by the injection hole (1-24) forms an acute angle with the running direction of the fiber strands.

7. A method for ultra-large drafting of fiber strands according to claim 6, characterized in that: An air inlet (1-22) and an air chamber (1-23) are also provided inside the shell II (1-21), and the air supply device, the air inlet (1-22), the air chamber (1-23) and the injection hole (1-24) are connected in sequence.

8. A method for ultra-large drafting of fiber strands according to claim 6, characterized in that: The length of the tapering section (1-25) is 5 to 6 mm, and the rear end diameter is 3 to 5 mm; the length of the constant section (1-26) is 10 to 15 mm, and the diameter is 2 to 4 mm; the length of the increasing section (1-27) is 30 to 40 mm, and the front end diameter is 3 to 6 mm; the angle of the acute angle is 30 to 45°, and the vertical distance between the outlet center of the injection hole (1-24) and the central axis of the increasing section (1-27) is 1.5 to 3 mm; the air flow size supplied by the air supply device is 200 to 300 Pa.

9. A method for ultra-large drafting of fiber strands according to claim 6, characterized in that: The super-large drafting device is a four-roller reverse extension rubber ring super-large drafting device or a four-roller forward extension rubber ring super-large drafting device, comprising a rear roller, a first middle roller (2), a second middle roller (3), and a front roller, and an airflow type gathering and twisting device (1-2) is located between the first middle roller (2) and the second middle roller (3); the distance between the rear end of the yarn channel and the jaws of the first middle roller (2) is 5 to 8 mm, and the distance between the front end of the yarn channel and the jaws of the second middle roller (3) is 3 to 5 mm.

10. The method for ultra-large drafting of fiber strands according to claim 1, characterized in that: The yarn unevenness rate of the yarn leaving the front drafting zone is 5-8%, the number of thin sections is 3-5 / km, the number of thick sections is 3-5 / km, and the number of hairiness above 3mm is 1-2 / m.

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