Skin-core structure staple fiber yarn and production process thereof

Abstract

The invention relates to the technical field of spinning, in particular to a skin-core structure staple fiber yarn and a production process thereof. According to the production technology of the skin-core structure staple fiber yarn, roving spun by water-soluble yarn and pure cotton slivers are made into core-spun roving in a core-spun mode after passing through a roving frame, then spun yarn is spun through a spinning procedure, a ring spinning mode is adopted in the spinning procedure, and the skin-core structure staple fiber yarn is made after spooling. According to the production technology of the skin-core structure staple fiber yarn, the rough yarn is spun in the mode that the slivers wrap the rough yarn in the roving process, the skin-core structure staple fiber yarn is spun after the spinning process, the yarn forming quality is good, and the structure is stable. According to the production technology, normal spinning equipment and technological processes are used, equipment does not need to be installed independently, and cost is not increased; and the produced skin-core structure yarn is soft in hand feeling after being treated by a subsequent process. According to the invention, spandex filaments and other filaments do not need to be purchased independently as yarn cores, and the soft skin-friendly effect of the fabric does not need an independent after-treatment mode.

Description

Technical Field

[0001] This invention relates to the field of textile technology, specifically to core-sheath structure staple fiber yarn and its production process. Background Technology

[0002] Traditional core-spun yarns are typically elastic core-spun yarns, with the core usually composed of spandex or other synthetic filaments to increase the fabric's elasticity or strength. The feel and wearability of the fabric require finishing processes, but these processes have limitations in altering the fabric's characteristics. Furthermore, using pure cotton to make soft-feel yarns currently generally employs methods like nylon spinning, which requires costly equipment modifications and doesn't offer significant improvements.

[0003] Patent CN108642628A discloses a soft covered yarn and its preparation method. This soft covered yarn includes a core yarn and an outer covering yarn. The core yarn is nylon filament, and the outer covering yarn is a soft yarn composed of coffee carbon fiber, ramie fiber, and banana fiber. The soft yarn winds around and covers the nylon filament. The core yarn of this invention is nylon filament, and the outer covering yarn is a soft yarn composed of coffee carbon fiber, ramie fiber, and banana fiber. It has a soft texture and comfortable feel, and can be made into soft, comfortable, and lightweight fabrics. While it can produce yarns with a soft hand feel, compared to pure cotton yarn, the raw material cost is higher, and the nylon core makes it less comfortable to wear than pure cotton fabrics.

[0004] Patent CN115467170A discloses a porous core-sheath structure yarn and its preparation method. The preparation includes the following steps: preparing a foaming solution and a polymer solution; then, ultrasonically impregnating the yarn in the foaming solution; after foaming, obtaining a yarn with a primary porous structure on the surface; then, rotating it in the polymer solution for further impregnation; finally, performing a non-solvent vapor gradient treatment and drying process to separate the polymer solution within the primary pores of the yarn surface into uniform secondary pores, thus obtaining a core-sheath structure yarn with a multi-level porous surface. Compared with the prior art, this invention constructs a uniform and stable multi-level porous structure on the yarn surface through foaming and phase separation methods. The primary pore diameter is 10–200 μm, and the secondary pore diameter is 40–600 nm. This multi-level porous structure can store a large amount of still air, giving the yarn excellent warmth retention properties. Furthermore, the fabric prepared from this yarn has high strength, high breathability, and washability. It utilizes air structure to create a warming effect and has good wearability, but the production process requires foaming solution and ultrasonic equipment, resulting in high production costs.

[0005] Patent CN114214761A discloses a spinning device for producing short-fiber core-sheath structure yarns. By designing an integral front roller with both large and small diameters, front upper rollers with two coaxial independent degrees of rotation, a front zone condenser, and guide rollers for the yarn guide section, and in conjunction with theoretically calculated spinning processes, this device enables one-step spinning of short-fiber core-sheath structure yarns on a ring spinning machine, achieving a full-spindle design. Furthermore, it does not require changes to the drafting drive system of the existing ring spinning machine; only the front roller and front upper roller need to be replaced, and a front zone condenser and guide rollers for the spinning section need to be added. It also overcomes the roller seizure problem caused by fibers entering the bearing of the nested ring through the gap between the nested ring and the fixed ring, which is common with coaxial nested front rollers. This invention features a simple structure, is easy to retrofit onto existing ring spinning machines, operates stably, is easy to maintain, and is readily applicable, providing an effective method for efficiently spinning short-fiber core-sheath structure yarns. Modifications to the spinning and front rollers are required, which presents certain operational challenges and increases production costs. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the purpose of this invention is to provide a core-sheath structure short fiber yarn, which helps reduce costs. The spun core-sheath structure yarn has a distinctive style, giving the cotton yarn a hollow structure, resulting in a softer hand feel and better wearability of the fabric.

[0007] This invention also provides its production process, which is simple, easy to implement, and suitable for large-scale production.

[0008] The production process of the core-sheath structure short fiber yarn described in this invention involves core-spun roving made from water-soluble yarn and pure cotton sliver on a roving frame. The core weight of the core-spun roving accounts for 10.5%-12.5%. The roving is then spun into fine yarn through a ring spinning process. After winding, the core-sheath structure short fiber yarn is produced.

[0009] The roving spun from the water-soluble yarn is a 100% water-soluble polyvinyl alcohol fiber roving with a small basis weight of 0.8g / 10m-0.9g / 10m and a twist coefficient of 120-130.

[0010] The pure cotton sliver is a final-stage pure fine cotton sliver with a weight of 20.5g / 5m-21.5g / 5m after opening, carding, pre-drawing, and drawing. Preferably, the pure cotton sliver is a 100% American fine cotton carded and drawn two-stage sliver.

[0011] The pure cotton sliver is fed into the roving frame through the entire drafting zone of the roving. The roving spun from water-soluble yarn is fed into the roving frame from behind the second roller, passes through the spooler and is positioned in the center area of ​​the pure cotton sliver. The roving spun from water-soluble yarn is suspended on the rear rack of the roving frame and drafted together with the sliver.

[0012] The core-spun roving has a basis weight of 6.7g / 10m ± 0.1g / 10m and a twist coefficient of 70-80.

[0013] In the spinning process, the upper pin of the middle roller is moved back by 5-7 mm. The center distance between the front roller and the middle roller in the spinning process is 44 mm, and the center distance between the middle roller and the rear roller is 50 mm. The upper pin nip spacing in the spinning process is controlled to be larger than normal, with an upper pin nip spacing of 5 mm and a machine speed of 11000 r / min.

[0014] The back draft ratio of the spinning process is 1.25-1.32 times.

[0015] Preferably, the process specifically includes the following steps:

[0016] Production of S1 low-weight water-soluble yarn roving: Water-soluble polyvinyl alcohol fiber is spun into roving with a weight of 0.8g / 10m and a twist coefficient of 120 after going through opening, carding, pre-drawing, drawing and roving.

[0017] S2 pure cotton sliver production: American fine cotton is spun into slivers with a basis weight of 21.0g / 5m after undergoing opening, carding, pure spinning, and finishing.

[0018] S3 core-spun roving production: Pure cotton sliver is fed into the roving frame through the trumpet and passes through the entire roving drafting zone. A roving spun from a small amount of water-soluble yarn is fed into the roving frame from behind the second roller and passes through the condenser, ensuring that it is located in the middle area of ​​the pure cotton sliver. The core-spun roving is produced with a twist coefficient of 80 and a basis weight of 6.7g / 10m ± 0.1g / 10m.

[0019] S4 spinning: The spinning process is ordinary ring spinning, with the top pin moved back by 6mm, the spacer block being slightly larger and controlled at 5mm, the back draft ratio being 1.32 times, the center distance between the front roller and the middle roller being 44mm, the center distance between the middle roller and the back roller being 50mm, and the machine speed being 11000r / min.

[0020] S5 winding: produces packaged yarn, which is then processed into core-sheath structure staple fiber yarn. A schematic diagram of the core-sheath structure staple fiber yarn described in this invention is shown below. Figure 4 As shown.

[0021] Preferably, the carding machine has a carding quantity of 21.0g / 5m±2g / 5m, a cylinder-moving cover spacing of 8-9 silk threads, and a machine speed of 11kg / h.

[0022] Preferably, the pre-drawing weight is 22g / 5m±1.0g / 5m, the post-drawing ratio is 1.7, and the pre-drawing speed is 350m / min; the drawing weight is 21.0g / 5m±0.5g / 5m, the post-drawing ratio is 1.3, and the drawing speed is 300m / min.

[0023] The hollow structure and soft feel of this invention are achieved by controlling the weight ratio of the yarn core.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] The beneficial effects of this invention are as follows:

[0026] (1) The production process of core-sheath structure staple fiber yarn of the present invention involves spinning roving by wrapping roving in a sliver, and then spinning it into core-sheath structure staple fiber yarn after the spinning process. The yarn has good quality and stable structure, meeting the mass production indicators. Moreover, the production process of the present invention uses normal spinning equipment and process flow, without the need for separate equipment installation, and does not increase costs. After post-processing, the produced core-sheath structure yarn has a soft hand feel and good wearability, and is very popular.

[0027] (2) The core-sheath structure short fiber yarn of the present invention does not require the separate purchase of spandex or other filaments as yarn core, and its inherent soft and skin-friendly effect does not require separate finishing process, saving costs for enterprises; it increases the variety structure, enriches the yarn types of enterprises, and enhances the competitiveness of enterprises. Attached Figure Description

[0028] The accompanying drawings, which are provided to further illustrate the invention and form part of the invention, are included here. In the drawings:

[0029] Figure 1 This is a diagram showing the placement of roving and pure cotton sliver spun from water-soluble yarn after the roving frame of this invention.

[0030] Figure 2 This is a schematic diagram of the roving drafting zone sliver of the present invention;

[0031] Figure 3 This is a schematic diagram showing the positions of the upper and lower pins of the roller in the spinning machine of the present invention;

[0032] Figure 4 This is a schematic diagram of the core-sheath structure of short fiber yarn according to the present invention;

[0033] In the diagram: 1. Roving roller; 2. Pure cotton sliver; 3. Roving spun from water-soluble yarn; 4. Roving frame back rack; 5. Ring spinning frame spindle; 6. Sliver can; 7. Water-soluble roving tube; 8. Trumpet; 9. Fourth gear roller; 10. Fourth roller; 11. Sliver and water-soluble roving tube controller; 12. Third upper pin; 13. Third roller; 14. Third lower pin; 15. Second roller; 16. Second gear roller; 17. First roller; 18. Bundler; 19. First gear roller; 20. Core-spun roving; 21. Middle roller upper pin; 22. Middle roller; 23. Middle roller lower pin. Detailed Implementation

[0034] The present invention will be further described below with reference to the embodiments.

[0035] Unless otherwise specified, all raw materials used in the examples were commercially available.

[0036] The water-soluble fiber used is polyvinyl alcohol fiber.

[0037] Example 1

[0038] The production process of the core-sheath structure short fiber yarn, such as Figure 1-3 As shown, it includes the following steps:

[0039] Production of S1 small-weight water-soluble yarn roving 3: Water-soluble polyvinyl alcohol fiber is spun into roving with a basis weight of 0.8g / 10m and a twist coefficient of 120 by going through opening, carding, pure doubling, and final doubling.

[0040] Production of S2 pure cotton sliver 2: Fine cotton is spun into a 21.0g / 5m weight pure cotton sliver 2 by opening, carding, pure spinning, and finishing, and stored in sliver can 6; this is in preparation for subsequent drafting by roving roller 1, which includes roller 17, roller 15, roller 13, and roller 10.

[0041] S3 Core-spun roving production: Pure cotton sliver 2 is drawn out from sliver can 6 and fed at a speed of 3.2m / min by sliver and water-soluble roving tube controller 11. It is conveyed to the drafting zone of the roving frame along the set path and combed into a regular sliver when passing through trumpet mouth 8, in preparation for passing through the drafting zone.

[0042] The roving 3 spun from water-soluble yarn is drawn out from the water-soluble roving tube 7, suspended and positioned by the high frame 4 at the back of the roving frame, and kept stable by the spindle 5 of the spinning frame. It is fed in from behind the second roller 15 and precisely guided by the bundler 18 to the central area of ​​the pure cotton sliver 2 (ensuring the core layer is centered). The two meet at the entrance of the drafting zone.

[0043] The combined "outer layer (pure cotton sliver) + core layer (water-soluble roving tube)" enters the drafting zone of the roving frame, where it is drafted and twisted by multiple rollers and slip rollers to form a core-spun roving 20:

[0044] Drafting process: Initial drafting is achieved by roller 10 with the fourth-stage roller 9, followed by enhanced drafting control in the middle and rear zones via roller 13, the third upper pin 12, and the third lower pin 14. Final drafting is then completed by the speed difference between roller 15 with the second-stage roller 16 and roller 17 with the first-stage roller 19. The resulting core-spun roving has a strength of 6.7g / 10m ± 0.1g / 10m and a twist coefficient of 80; the core content of core-spun roving 20 is 11.76%.

[0045] S4 fine yarn: Core-spun roving 20 is used as raw material for the fine yarn process, and ordinary ring spinning is adopted.

[0046] The middle roller 22, the upper pin 21 of the middle roller, and the lower pin 23 of the middle roller form the nip of the main drafting zone. The upper pin 21 of the middle roller is moved back 6mm as required (to optimize the gripping force on the core-sheath structure sliver). The rear roller works in conjunction with the front roller to achieve graded drafting. The rear draft ratio is 1.32. The center distance between the front roller and the middle roller 22 is 44mm, the center distance between the middle roller 22 and the rear roller is 50mm, and the nip spacing of the spinning upper pin is 5.0mm. The spinning spindle speed is 11000r / min.

[0047] S5 winding: produces packaged yarn, which is then made into core-sheath structured short fiber yarn.

[0048] Example 2

[0049] The difference from Example 1 is that in step S1, the roving twist coefficient of the small-quantity roving is 130.

[0050] Example 3

[0051] The difference from Example 1 is that in step S3, the small amount of roving is located slightly to the left of the middle of the sliver during the drafting process of the roving process.

[0052] Example 4

[0053] The difference from Example 1 is that in step S4, the spinning method is compact spinning.

[0054] Example 5

[0055] The difference from Example 1 is that in step S4, the position of the upper pin is not moved backward.

[0056] Example 6

[0057] The difference from Example 1 is that in step S4, the yarn spacer block is normally used at 3mm.

[0058] The evenness of the textiles in Examples 1-6 was tested using the Uster UT4 fully automatic yarn evenness tester at a speed of 400 m / min. The core-spun success rate of 100 randomly selected yarn bobbins was visually inspected under a D65 light source. The performance test results are shown in the table below.

[0059] Table 1. Performance test results of textiles in Examples 1-6

[0060]

[0061]

[0062] Regarding the yarn quality results of Examples 1-6, Example 1 has a clear advantage, provided that the core-spun effect is guaranteed.

[0063] The yarn obtained in Example 1 was woven into a fabric. A portion of the fabric from Example 1 was immersed in hot water at 95°C for 30 minutes, and then washed clean with lukewarm water. The hand feel comparison data between the fabric from Example 1 and a cotton fabric of the same specification is shown in Table 2 below.

[0064] Table 2 Comparison of hand feel between the fabric from Example 1 and cotton fabric of the same specification.

[0065]

[0066] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the system embodiments are basically similar to the method embodiments, so the description is relatively simple; relevant parts can be referred to the descriptions in the method embodiments.

[0067] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A production process for core-sheath structure staple fiber yarn, characterized in that, The roving (3) spun from water-soluble yarn and the pure cotton sliver (2) are core-spun after the roving frame to obtain the core-spun roving (20). The core weight of the core-spun roving (20) accounts for 10.5%-12.5%. Then, it is spun into fine yarn through the fine spinning process. The fine spinning process adopts the form of ring spinning. After winding, it is made into short fiber yarn with a core-sheath structure.

2. The production process of core-sheath structure staple fiber yarn according to claim 1, characterized in that, The roving (3) spun from the water-soluble yarn is a 100% water-soluble polyvinyl alcohol fiber roving with a basis weight of 0.8g / 10m-0.9g / 10m and a twist coefficient of 120-130.

3. The production process of core-sheath structure staple fiber yarn according to claim 1, characterized in that, The pure cotton sliver (2) is a pure fine cotton sliver with a weight of 20.5g / 5m-21.5g / 5m after opening, carding, pre-drawing and drawing.

4. The production process of core-sheath structure staple fiber yarn according to claim 1, characterized in that, The pure cotton sliver (2) is fed in from the trumpet mouth (8) of the roving frame and passes through the entire drafting area of ​​the roving. The roving (3) spun from water-soluble yarn is fed in from behind the second roller (15) of the roving frame, passes through the bundler (18) and is ensured to be located in the central area of ​​the pure cotton sliver (2). The roving (3) spun from water-soluble yarn is suspended on the rear high frame (4) of the roving frame and is drafted together with the pure cotton sliver (2).

5. The production process of core-sheath structure staple fiber yarn according to claim 1, characterized in that, The core-spun roving (20) has a basis weight of 6.7g / 10m ± 0.1g / 10m and a twist coefficient of 70-80.

6. The production process of core-sheath structure staple fiber yarn according to claim 1, characterized in that, The upper pin (21) of the middle roller (22) in the spinning process is moved back 5-7mm.

7. The production process of core-sheath structure staple fiber yarn according to claim 6, characterized in that, The center distance between the front roller and the middle roller (22) in the spinning process is 44 mm, and the center distance between the middle roller (22) and the back roller is 50 mm.

8. The production process of core-sheath structure staple fiber yarn according to claim 7, characterized in that, The spacing between the pin clamps in the fine spinning process is 5.0 mm.

9. The production process of core-sheath structure staple fiber yarn according to claim 8, characterized in that, The back draft ratio of the spinning process is 1.25-1.32 times.

10. A core-sheath structure staple fiber yarn, characterized in that, It is prepared using the production process described in any one of claims 1 to 9.

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