Four-roll profiled plate negative pressure holding and fiber spreading type sandwich wrap spinning device and method

Abstract

The application provides a four-roller special-shaped plate negative pressure holding and fiber spreading type core-spun yarn wrapping device and method. The device overcomes the technical problem that the short fiber wide sliver needs to be accumulated before the wrapping area after being drafted. A negative pressure air suction port with a width greater than or equal to the width of the short fiber wide sliver is arranged on the special-shaped plate. Meanwhile, the distance between the core yarn and the overlapping body of the short fiber wide sliver / wrapped yarn is 2-5 mm. The core-spun yarn formed through the wrapping area and the core yarn transported to the mesh ring are on a straight line, and the short fiber wide sliver transported to the mesh ring forms a "y" shape structure. The rotation of the core yarn is driven and uniformly wrapped on the core yarn, and a different twisting structure of the traditional ring spinning core-spun yarn is obtained. The obtained core-spun yarn not only reduces the yarn exposure phenomenon, but also has less hairiness, and the core yarn accounts for up to 70%. The problems of easy core exposure, small core yarn ratio, and easy sliding and scattering between the core yarn and the outer wrapping fiber on the ring spinning machine are solved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of textile processing, and particularly relates to a four-roller special-shaped plate negative pressure holding and fiber spreading sandwich wrapping spinning device and method. BACKGROUND

[0002] Core-spun yarn is generally made of synthetic fiber filament with good strength and elasticity as core yarn, and is twisted with cotton, wool, viscose fiber and other short fibers to form yarn, also known as composite yarn or covered yarn. It is a new type of yarn with excellent performance of long filament core yarn and outer short fiber, and is loved by people.

[0003] At present, ring spinning is a mainstream technology for preparing core-spun yarn. The core-spun yarn is prepared by adding a filament feeding device to the ordinary ring spinning frame, so that the long filament is fed from the middle of the fiber sliver, and the short fiber sliver is wrapped around the long filament to form the core-spun yarn through the rotation of the ring. The ordinary ring spinning produces hairiness on the surface of the core-spun yarn due to the existence of the twisting triangle, and is prone to filament exposure. In order to eliminate the hairiness, the compact spinning technology uses the gathered fiber sliver to twist the yarn; the core is to add a gathering device in front of the front roller nip output, so that the short fiber sliver is gathered before being output and twisted, and the adhesion force between the edge fiber and the main body of the twisted sliver is increased, so as to reduce the hairiness of the yarn. However, the current ring spinning core-spun yarn is still prone to filament exposure. In order to ensure the wrapping effect and yarn quality of the core-spun yarn, the factory usually adopts the method of increasing the proportion of outer wrapping fiber, which leads to the proportion of core yarn in the yarn body generally below 15%.

[0004] In order to overcome the problem of thread exposure, the patent with application number CN202111337262.3 discloses a new structure of core spinning device and macro-core full-wrapping core spinning method. The core spinning device is additionally provided with an auxiliary core wrapping device between the front roller nip and the guide hook of the ordinary ring spinning frame. The auxiliary core wrapping device includes a first yarn channel for transmitting the outer wrapping material, a second yarn channel for transmitting the core layer material, and a wrapping point for wrapping convergence. During the spinning process, the short fiber sliver and the filament form a "y" shape twist structure with the filament in a straight state. The filament remains in a straight state at the wrapping point, and the short fiber sliver is wrapped around the filament outer layer at the wrapping point by relying on the twist rotation of the filament and its own partial twist, thereby forming a core yarn with good wrapping effect, solving the problem of thread exposure of ring spinning core yarn. The device has serious shortcomings: 1) the first yarn channel for transmitting the short fiber sliver has limited capacity, and the short fiber sliver is easily blocked in the first yarn channel during high-speed transmission, causing spinning breakage; 2) the short fiber sliver often touches the yarn channel side wall when passing through the first yarn channel, which cannot be fully stretched, resulting in limited wrapping area and limited wrapping effect, and the core filament ratio encounters a bottleneck and is difficult to break through 50% or more; 3) the essence is a self-rotating wrapping method of the core filament around the short fiber sliver, and the yarn is formed with the core filament as the core and the spiral wrapped short fiber sliver as the sheath, which causes the core filament and the outer wrapping fiber to easily slide and separate, and the interface bonding force between the wrapping layer and the core filament is weak and poor in fastness.

[0005] Therefore, it is necessary to design an improved four-roller special-shaped plate negative pressure holding fiber stretching sandwich wrapping spinning device and method to solve the above problems. SUMMARY

[0006] The purpose of the present application is to provide a four-roller special-shaped plate negative pressure holding fiber stretching sandwich wrapping spinning device and method. The device overcomes the technical prejudice that the short fiber sliver needs to be accumulated before the wrapping area after being drafted. A negative pressure suction port with a width greater than or equal to the width of the fed short fiber sliver is provided on the special-shaped plate. Under the coordinated stretching of the width and length direction forces, a fiber layer with a certain width, high parallelism and uniform distribution of fibers is obtained on the mesh ring. At the same time, the distance between the core filament and the short fiber sliver on the front roller is 2-5 mm, so that the core yarn formed after the wrapping area is in a straight line with the core filament transported to the mesh ring and forms a "y" shape structure with the short fiber sliver transported to the mesh ring, so that the core filament is uniformly wrapped around the core filament driven by the self-rotation, and a different twist structure is obtained compared with the traditional ring spinning core yarn.

[0007] To achieve the above-mentioned purpose of the application, the present application provides a ring spinning four-roller special-shaped plate negative pressure core spinning device, which comprises a feeding unit, an auxiliary core wrapping unit, and a core yarn winding unit.

[0008] The feeding unit comprises a core-in-sheath filament feeding unit, a short fiber wide sliver feeding unit and a front roller at the input end of the auxiliary core-in-sheath unit; the core-in-sheath filament feeding unit simultaneously feeds at least one core filament and at least one sheath filament arranged at intervals; the short fiber wide sliver feeding unit simultaneously feeds at least one short fiber wide sliver arranged at intervals; the sheath filament coincides with the short fiber wide sliver close to the core filament, and the interval between the core filament and the short fiber wide sliver close to the core filament on the front roller is 2-5 mm;

[0009] The auxiliary core-in-sheath unit comprises a negative pressure suction assembly, a transmission gear and a wrapping area for wrapping convergence; the negative pressure suction assembly comprises a profiled plate, a transmission roller and a mesh ring wrapped around the peripheral surface of the profiled plate and the transmission roller; the profiled plate is provided with a negative pressure suction port with a width greater than or equal to the width of the short fiber wide sliver, and the negative pressure suction port is provided with a negative pressure suction mechanism; the front roller, the transmission gear and the transmission roller are in gear connection;

[0010] The short fiber wide sliver and the sheath filament cross and converge with the core filament at the wrapping area, and are wrapped on the core filament to form a core-in-sheath yarn, and then the core-in-sheath yarn is transmitted to the core-in-sheath yarn winding unit for twisting and winding.

[0011] As a further improvement of the application, the core-in-sheath filament feeding unit simultaneously feeds at least one core filament and at least one sheath filament arranged at intervals; the short fiber wide sliver feeding unit feeds one short fiber wide sliver; the sheath filament is arranged within 1 / 2 of the width of the short fiber wide sliver close to the core filament; the short fiber wide sliver, the sheath filament and the core filament converge to form a core-in-sheath yarn with the sheath filament and the core filament clamping the part of the short fiber wide sliver close to the core filament as the core and the part of the short fiber wide sliver away from the core filament as the sheath.

[0012] As a further improvement of the application, the core-in-sheath filament feeding unit simultaneously feeds at least one core filament and at least one sheath filament arranged at intervals; the short fiber wide sliver feeding unit simultaneously feeds a short fiber wide sliver and a second short fiber wide sliver away from the core filament in sequence; the sheath filament coincides with the short fiber wide sliver; the short fiber wide sliver, the second short fiber wide sliver, the sheath filament and the core filament converge to form a core-in-sheath yarn with the sheath filament and the core filament clamping the short fiber wide sliver as the core and the second short fiber wide sliver as the sheath.

[0013] As a further improvement of the application, the negative pressure suction port is one of an equal-width structure from top to bottom or an upper-narrow-and-lower-wide structure, so that the short fiber wide sliver is uniformly laid on the mesh ring with a certain width and fiber parallelism.

[0014] As a further improvement of the application, the core-in-sheath yarn formed through the wrapping area is on a straight line with the core filament fed onto the mesh ring, and forms a "y" shape structure with the short fiber wide sliver fed onto the mesh ring.

[0015] The short fiber wide strand fed in front of the wrapping zone is in a straight line.

[0016] As a further improvement of the present application, the ring spinning four-roller special-shaped plate negative pressure type core spinning device further comprises an auxiliary conveying unit arranged above the negative pressure adsorption assembly; the auxiliary conveying unit comprises a front roller, a transmission roller, and a bridge component arranged between the front roller and the transmission roller; the shaft core of the front roller, the bridge component, and the shaft core of the transmission roller are connected; the front roller is arranged in correspondence with the front roller from top to bottom, and the transmission roller is arranged in correspondence with the transmission roller from top to bottom; the transmission roller is in contact with the mesh ring.

[0017] As a further improvement of the present application, the distance between the wrapping zone and the front roller nip is greater than the fiber length of the short fiber wide strand.

[0018] As a further improvement of the present application, the auxiliary core spinning unit further comprises a guide rod arranged between the wrapping zone and the core yarn winding unit; a first groove for positioning the core yarn is arranged in the middle of the guide rod.

[0019] As a further improvement of the present application, the short fiber wide strand feeding unit comprises a horn for feeding the short fiber wide strand, a back roller and a back roller, a middle roller and a middle roller;

[0020] The core / sheath filament feeding unit comprises a guide wheel for guiding the core filament and the sheath filament;

[0021] The core yarn winding unit comprises a guide hook, a traveler, a ring traveler, and a spinning tube, the core yarn enters the balloon twisting section through the guide hook, the fibers of the outer layer of the core yarn are further twisted and held tightly in this process, and finally the core yarn is wound on the spinning tube through the rotation of the traveler on the ring traveler.

[0022] To achieve the above-mentioned purposes, the present application provides a ring spinning four-roller special-shaped plate negative pressure type core spinning method, which adopts the ring spinning four-roller special-shaped plate negative pressure type core spinning device of any one of the above-mentioned embodiments for core spinning, and specifically comprises the following steps:

[0023] S1'. Feeding at least one short fiber wide strand sheath filament and core filament arranged at intervals from the feeding unit to the auxiliary core spinning unit, respectively;

[0024] S2'. The short fiber and the short fiber wide filament strip close to the core yarn are coincided, the short fiber wide filament strip close to the core yarn is fed into the front nip formed by the engagement of the front roller and the front roller cover at a distance of 2-5mm from the core yarn, and is output to the grid ring through the front nip; the short fiber wide filament strip is adsorbed and held by the negative pressure suction mechanism at the negative pressure suction port, and is uniformly laid on the grid ring with a certain width and fiber parallelism; the core yarn drives the short fiber wide filament strip and the wrapped yarn to be wrapped in sequence at the wrapping area to the outer layer of the core yarn to form the core spun yarn;

[0025] S3'. The core spun yarn is twisted and wound by the core spun yarn winding unit.

[0026] The beneficial effects of the present application are:

[0027] (1) The four-roller special-shaped plate negative pressure holding fiber spreading sandwich wrapping spinning device provided by the present application overcomes the technical problems that the short fiber wide filament strip entering the wrapping area cannot be completely spread, is difficult to hold, and causes loose yarn and easy to scatter due to loose wrapping, a negative pressure suction port with a width greater than or equal to the width of the fed short fiber wide filament strip is arranged on the special-shaped plate, the negative pressure suction mechanism at the negative pressure suction port diffuses and spreads the short fiber wide filament strip in the width and length directions, the short fiber wide filament strip is uniformly laid on the grid ring, and at the same time, the short fiber wide filament strip is also subjected to the stretching force in the conveying direction, so that the single fiber is straightened, and under the synergistic stretching of the two forces in the width and length directions, the negative pressure holding short fiber with a certain width, high fiber parallelism and uniform distribution is obtained on the grid ring.

[0028] Meanwhile, the distance between the core yarn and the short fiber wide sliver / pack yarn coincident body on the front roller is ensured to be 2-5 mm, so that the core-spun yarn formed in the wrapping area is in a straight line with the core yarn delivered to the mesh ring, and forms a "y" structure with the short fiber wide sliver / pack yarn coincident body delivered to the mesh ring. The core yarn self-rotation drives the part of the short fiber wide sliver / pack yarn close to the core yarn, the short fiber wide sliver / pack yarn and the second short fiber wide sliver to be wrapped in the wrapping area in turn by negative pressure suction holding type tight wrapping to the outer layer of the core yarn, to form the core-spun yarn S3 with the pack yarn and the core holding the part of the short fiber wide sliver close to the core yarn as the core and the part of the short fiber wide sliver far away from the core yarn as the sheath, or to form the core-spun yarn with the pack yarn and the core holding the short fiber wide sliver as the core and the second short fiber wide sliver as the sheath, effectively improving the holding and cohesion between the core layer filament and the short fiber, increasing the interface bonding force and fastness between the wrapping layer and the core yarn, and completely solving the problem of easy sliding and scattering between the core yarn and the outer wrapping fiber. At the same time, the short fiber wide sliver is completely spread wrapped on the core layer, with good covering effect, realizing the non-core leakage wrapping of the core yarn with a content ratio of 60-70%, and solving the problems of core leakage and low core content of the core-spun yarn. In particular, the short fiber wide sliver is tightly wrapped on the core layer by negative pressure holding, with large wrapping force and high tightness, improved yarn strength and reduced hairiness.

[0029] (2) The four-roller special-shaped plate negative pressure holding fiber spreading type sandwich wrapping spinning device provided by the application comprises a negative pressure adsorption assembly, a transmission roller, a transmission gear, a mesh ring, a short fiber wide sliver / pack yarn coincident body, a core yarn, a wrapping area, a delivery roller, a delivery gear, a delivery mesh ring, a delivery short fiber wide sliver / pack yarn coincident body and a delivery core yarn. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1 It is a structure schematic view of embodiment 1 of the four-roller special-shaped plate negative pressure holding fiber spreading type sandwich wrapping spinning device of the application.

[0031] Figure 2 It is a connection relationship diagram of the negative pressure adsorption assembly and the auxiliary delivery unit.

[0032] Figure 3 It is a path diagram of the short fiber wide sliver / pack yarn and the core yarn forming the core-spun yarn of embodiment 1.

[0033] Figure 4 It is Figure 3 It is a composition diagram of the short fiber wide sliver.

[0034] Figure 5 It is a structure schematic view of embodiment 2 of the four-roller special-shaped plate negative pressure holding fiber spreading type sandwich wrapping spinning device of the application.

[0035] Figure 6Path diagram of the short fiber sliver, the wrapping sliver and the core sliver forming the core-spun yarn of Example 2.

[0036] Figure 7 Image of the core-spun yarn prepared for Example 1 under 3D microscope at 35 times magnification, with a scale of 200 μm.

[0037] Figure 8 Image of the core-spun yarn prepared for Comparative Example 2 under 3D microscope at 35 times magnification, with a scale of 200 μm.

[0038] Figure 9 Image of the core-spun yarn prepared for Comparative Example 3 under 3D microscope at 35 times magnification, with a scale of 200 μm.

[0039] Reference signs

[0040] S1 - short fiber sliver; S2 - second short fiber sliver; F1 - wrapping sliver; F2 - core sliver; S3 - core-spun yarn; S11 - part of the short fiber sliver close to the core sliver F2; S12 - part of the short fiber sliver away from the core sliver F2;

[0041] 10 - feeding unit; 11 - trumpet; 12 - back roller; 13 - back flat; 14 - middle roller; 15 - middle flat; 16 - guide roller; 17 - front roller;

[0042] 20 - auxiliary core-spun unit; 21 - negative pressure adsorption assembly; 22 - transmission gear; 23 - auxiliary conveying unit; 24 - guide rod; 25 - wrapping area; 211 - special-shaped plate; 212 - transmission roller; 213 - mesh ring; 214 - negative pressure suction port; 231 - front flat; 232 - transmission flat; 233 - bridge component; 234 - second groove;

[0043] 30 - core-spun yarn winding unit; 31 - guide hook; 32 - steel ring; 33 - ring traveler; 34 - spinning tube. DETAILED DESCRIPTION

[0044] In order to make the objects, technical solutions and advantages of the present application clearer, the present application will be described in detail below with reference to the drawings and specific examples.

[0045] Here, it also needs to be noted that, in order to avoid the present application being obscured by unnecessary details, only the structures and / or processing steps closely related to the solutions of the present application are shown in the drawings, and other details not closely related to the present application are omitted.

[0046] It is also important to note that the terms "comprises" and / or "comprising", or "includes" and / or "including" when used in this specification, specify the presence of stated features, integers, steps, operations, elements, or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or groups thereof.

[0047] Referring to the drawings Figures 1 to 6 As shown in the drawings, the present application provides a four-roller special-shaped plate negative pressure holding fiber spreading type sandwich wrapping spinning device, which comprises a feeding unit 10, an auxiliary core-spun unit 20 and a core-spun yarn winding unit 30.

[0048] The feeding unit 10 comprises a core / sheath filament feeding unit, a staple fiber wide sliver feeding unit and a front roller 17 located at the input end of the auxiliary core-spun unit 20. The core / sheath filament feeding unit simultaneously feeds at least one core filament F2 and at least one sheath filament F1 which are arranged at intervals. The staple fiber wide sliver feeding unit simultaneously feeds at least one staple fiber wide sliver which are arranged at intervals. The sheath filament F1 coincides with the staple fiber wide sliver close to the core filament F2, and the interval between the core filament F2 and the staple fiber wide sliver close to the core filament F2 on the front roller 17 is 2-5 mm. In this way, the core filament F2 and the staple fiber wide sliver form a certain interval when passing through the front roller 17 without direct winding, which provides conditions for the smooth delivery of the staple fiber wide sliver to the subsequent auxiliary core-spun unit 20, and at the same time provides favorable conditions for the subsequent "y" shaped structure.

[0049] The auxiliary core-spun unit 20 comprises a negative pressure suction assembly 21, a transmission gear 22 and a wrapping area 25 for converging wrapping. The negative pressure suction assembly 21 comprises a profiled plate 211, a transmission roller 212 and a mesh ring 213 wrapped on the surfaces of the profiled plate 211 and the transmission roller 212; the profiled plate 211 is provided with a negative pressure suction port 214 with a width greater than or equal to the width of the staple width sliver, and the negative pressure suction port 214 is provided with a negative pressure suction mechanism; the mesh ring 213 only allows airflow to pass through, and plays a supporting and transporting role for the staple width sliver. The front roller 17, the transmission gear 22 and the transmission roller 212 are in gear connection. In this way, firstly, the front roller 17 rotates to drive the transmission gear 22 to rotate, thereby driving the transmission roller 212 to rotate, and further driving the mesh ring 213 on the surface of the transmission roller 212 to rotate; secondly, the staple width sliver input through the front roller 17 is transported onto the mesh ring 213 and passes through the negative pressure suction port 214; since the width of the negative pressure suction port 214 is greater than or equal to the width of the staple width sliver, the staple width sliver is uniformly laid on the mesh ring 213 with a certain width and fiber parallelism without accumulation during the process; thirdly, under the continuous transportation of the mesh ring 213, the staple width sliver finally converges with the core yarn F2 and the wrapper yarn F1 at the wrapping area 25, and the twist back formed by the rotation of the air ring makes the core yarn F2 rotate, thereby driving the staple width sliver and the wrapper yarn F1 to wrap and wind to the outer layer of the core yarn F2 to form the core-spun yarn S3. Then the core-spun yarn S3 is transmitted to the core-spun yarn winding unit 30 for twisting and winding.

[0050] As Figures 1-4As shown, the core / wrapper feeding unit simultaneously feeds at least one core filament F2 (multiple core filaments F2 overlapping) and at least one wrapping filament F1 (multiple wrapping filaments F1 overlapping) that are spaced apart from each other; the short fiber wide sliver feeding unit feeds one short fiber wide sliver S1, with the wrapping filament F1 positioned within 1 / 2 the width of the short fiber wide sliver S1 on the side closest to the core filament F2; the distance between the core filament F2 and the short fiber wide sliver S1 on the front roller 17 near the end of the core filament F2 is 2-5mm. Short fiber sliver S1 and wrapping filament F1 cross and converge with core filament F2 at the wrapping area 25. Short fiber sliver S11 near core filament F2, wrapping filament F1, and short fiber sliver S12 away from core filament F2 sequentially wrap and wind around the outer layer of core filament F2 at the wrapping area 25, forming a core-spun yarn S3 with the wrapping filament F1 and core filament F2 holding the short fiber sliver S11 near core filament F2 as the core, and the short fiber sliver S12 away from core filament F2 as the sheath. Specifically, the rotation of core filament F2 causes core filament F2, wrapping filament F1, and the short fiber sliver S11 near core filament F2 to twist together, forming a core layer structure where the wrapping filament F1 and core filament F2 hold the short fiber sliver S11 near core filament F2; then, the short fiber sliver S12 away from core filament F2 wraps and winds around the core layer under the rotation of core filament F2. During this process, the uniformly laid short-fiber wide sliver S1 is adsorbed onto the grid ring 213 without rotating. Subsequently, the short-fiber wide sliver S1 is wrapped by the core yarn F2 and the wrapping yarn F1 to form a core-spun yarn S3 with a special structure.

[0051] like Figures 5-6 As shown, the core / shroud feeding unit simultaneously feeds at least one core filament F2 and at least one wrapping filament F1, which are spaced apart from each other; the short fiber wide sliver feeding unit simultaneously feeds short fiber wide sliver S1 and a second short fiber wide sliver S2, which are sequentially moved away from the core filament F2; the wrapping filament F1 overlaps with the short fiber wide sliver S1; the distance between the core filament F2 and the end of the short fiber wide sliver S1 closest to the core filament F2 on the front roller 17 is 2-5 mm. The short fiber wide sliver S1, the second short fiber wide sliver S2, and the wrapping filament F1 cross and converge with the core filament F2 at the wrapping area 25. The short fiber wide sliver S1, the wrapping filament F1, and the second short fiber wide sliver S2 sequentially wrap and wind around the outer layer of the core filament F2 at the wrapping area 25, forming a core-spun yarn S3 with the wrapping filament F1 and the core filament F2 holding the short fiber wide sliver S1 as the core and the second short fiber wide sliver S2 as the sheath. Specifically, the core filament F2 rotates, causing the core filament F2, the wrapping filament F1, and the short wide fiber sliver S1 to twist together, forming a core layer structure in which the wrapping filament F1 and the core filament F2 hold the short wide fiber sliver S1; then, the second short wide fiber sliver S2 is wrapped around the core layer under the rotation of the core filament F2.

[0052] The negative pressure air suction port 214 is one of the upper and lower equal width structure or the upper narrow and lower wide structure, so that the short fiber wide sliver S1 and the second short fiber wide sliver S2 are evenly laid on the grid ring 213 with a certain width and fiber parallel degree. Preferably, the negative pressure air suction port 214 is the upper narrow and lower wide structure, that is, the negative pressure air suction port 214 is narrower near one end of the feeding unit 10 (still not less than the width of the short fiber wide sliver S1 and the second short fiber wide sliver S2 conveyed by the front roller 17), and is wider away from the feeding unit 10. In this way, when the short fiber wide sliver S1 and the second short fiber wide sliver S2 pass through the negative pressure air suction port 214 with the upper narrow and lower wide structure, the negative pressure air suction mechanism at the negative pressure air suction port 214 stretches the short fiber wide sliver S1 and the second short fiber wide sliver S2 in the width and length directions, the short fiber wide sliver S1 and the second short fiber wide sliver S2 are stretched to both sides, and then are evenly laid, and at the same time, the single fiber is straightened due to the stretching force in the conveying direction, under the synergistic stretching of the two forces in the width and length directions, the short fiber wide sliver S1 and the second short fiber wide sliver S2 will not be excessively widened to appear gaps, nor will be broken, and finally a fiber layer with a certain width, high fiber parallel degree and uniform distribution is obtained on the grid ring 213, the covering effect of the core yarn F2 is obviously better, which provides favorable conditions for obtaining a core spun yarn S3 with uniform structure. In addition, the negative pressure air suction port 214 can also capture uncontrolled floating fibers in the short fiber wide sliver S1 and the second short fiber wide sliver S2.

[0053] In particular, as shown in FIGS. 1 and 2, the short fiber wide sliver S1 and the second short fiber wide sliver S2 are conveyed to the grid ring 213 through the negative pressure air suction port 214, and the core yarn F2 is conveyed to the grid ring 213 through the feeding unit 10, and the core yarn F2 and the short fiber wide sliver S1 and the second short fiber wide sliver S2 are arranged in the "y" shape structure on the grid ring 213. Figure 3 and Figure 6 As shown in FIGS. 1 and 2, the core spun yarn S3 formed in the wrapping area 25 is in a straight line with the core yarn F2 conveyed to the grid ring 213, and forms the "y" shape structure with the short fiber wide sliver S1, the core yarn F1 and the second short fiber wide sliver S2 conveyed to the grid ring 213. In this way, since the downward core spun yarn S3 and the core yarn F2 conveyed to the grid ring 213 are in a straight line, the twist formed by the rotation of the balloon is transmitted to the wrapping area 25 from bottom to top, and then most of the twist is transmitted to the core yarn F2, so that the twist and tension of the core yarn F2 are much greater than those of the short fiber wide sliver S1 and the second short fiber wide sliver S2, which makes the core yarn F2 in a dominant position in the twisting process, provides enough power for it to rotate, and at the same time makes it in a straightened state; only a small part of the twist is transmitted to the short fiber wide sliver S1 and the second short fiber wide sliver S2, and at the same time, the suction force of the negative pressure air suction port 214 on the short fiber wide sliver S1 and the second short fiber wide sliver S2 further reduces the twist of the short fiber wide sliver S1 and the second short fiber wide sliver S2, so that they are laid on the grid ring 213, and are driven by the rotation of the core yarn F2 to be evenly wrapped around the core yarn F2.

[0054] The short fiber width sliver S1 input before the wrapping area 25 is in a straight line, the second short fiber width sliver S2 is in a straight line, further hindering the twist transmission of the short fiber width sliver S1 and the second short fiber width sliver S2, and further reducing the twist and tension of the short fiber width sliver S1 and the second short fiber width sliver S2.

[0055] The extension line of the core yarn F2 input onto the grid ring 213 before the wrapping area 25 is not in line with the fed core yarn F2, so that the core yarn F2 is input to the grid ring 213 in a zigzag form, further increasing the tension of the core yarn F2, providing auxiliary conditions for ensuring that the core yarn F2 is in a straight state at the wrapping area 25, and improving the wrapping effect.

[0056] In some embodiments, the distance between the wrapping area 25 and the nip of the front roller 17 is greater than the fiber length of the short fiber width sliver S1 and the second short fiber width sliver S2. In this way, first, the individual fibers in the short fiber width sliver S1 and the second short fiber width sliver S2 can be stretched enough to be straightened; second, the greater length further increases the twist and tension of the core yarn F2, which is beneficial for the core yarn F2 to drive the short fiber width sliver S1 and the second short fiber width sliver S2 to wrap; third, the high-speed rotation of the core yarn F2 can also produce a certain draft effect on the short fiber width sliver S1 and the second short fiber width sliver S2, further improving the quality of the yarn.

[0057] The four-roller special-shaped plate negative pressure holding fiber spreading sandwich wrapping spinning device further includes an auxiliary conveying unit 23 arranged above the negative pressure adsorption assembly 21. The auxiliary conveying unit 23 includes a front leather roller 231, a transmission leather roller 232, and a bridge component 233 arranged between the front leather roller 231 and the transmission leather roller 232. The shaft core of the front leather roller 231, the bridge component 233, and the shaft core of the transmission leather roller 232 are connected, and the bridge component 233 can play a role in structural fixation and leather roller positioning. As shown in Figure 2 The front leather roller 231 is arranged in correspondence with the front roller 17, and the transmission leather roller 232 is arranged in correspondence with the transmission roller 212. The transmission leather roller 232 is in contact with the grid ring 213, and the transmission leather roller 232 and the transmission gear 22 jointly drive the grid ring 213 to rotate. This arrangement makes the transmission of the grid ring 213 more stable, providing stable conditions for the wrapping process.

[0058] In some embodiments, the transmission leather roller 232 has a second groove 234 in the middle for the core-spun yarn S3 to pass through; the width of the second groove 234 is less than the width of the grid ring 213 and greater than one-third of the width of the transmission leather roller 232. In this way, the convex structure at both ends of the transmission leather roller 232 is more convenient for pressing the grid ring 213 and driving it to rotate and convey; at the same time, the second groove 234 is more convenient for the core-spun yarn S3 to pass through between the transmission leather roller 232 and the grid ring 213.

[0059] The auxiliary core-spun unit 20 further comprises a guide rod 24 arranged between the wrapping zone 25 and the core-spun yarn winding unit 30. The middle part of the guide rod 24 is provided with a first groove for positioning the core-spun yarn S3, and the core-spun yarn S3 passes through the first groove in the middle part of the guide rod 24 to position the yarn path. Specifically, the left and right movement of the guide rod 24 can adjust the offset of the core yarn F2 path, thereby adjusting the "y" shape structure; the up and down movement of the guide rod 24 perpendicular to the yarn path can not only adjust the tension of the core-spun yarn S3 on the grid ring 213, but also eliminate the yarn traverse caused by the air ring, make the structure of the core-spun twisting more stable, and adjust the tension and twist of the core yarn F2.

[0060] The short fiber wide staple strip feeding unit comprises a trumpet 11, a back roller 12 and a back roller 13, a middle roller 14 and a middle roller 15 for feeding the short fiber wide staple strip S1 and the second short fiber wide staple strip S2; the core yarn feeding unit comprises a guide wheel 16 for guiding the core yarn F2 and the wrapping yarn F1.

[0061] The core-spun yarn winding unit 30 comprises a guide hook 31, a steel ring 32, a steel ring 33 and a fine yarn tube 34, the core-spun yarn S3 enters the air ring twisting section through the guide hook 31, the fibers on the outer layer of the core-spun yarn S3 are further twisted and held tightly in this process, and finally the core-spun yarn S3 is wound on the fine yarn tube 34 through the rotation of the steel ring 32 on the steel ring 33.

[0062] The working principle of the four-roller special-shaped plate negative pressure holding fiber stretching sandwich wrapping spinning device is as follows: firstly, the roving is unwound and enters the short fiber wide sliver feeding unit through the trumpet 11, the short fiber wide sliver S1 after drafting through the rear roller 12, the rear flat roller 13, the middle roller 14 and the middle flat roller 15 is further drafted through the front roller 17 and then output, secondly, the short fiber wide sliver S1 and the second short fiber wide sliver S2 are adsorbed on the grid ring 213 by the negative pressure suction mechanism in the special-shaped plate 211, in the process, the front roller 17 rotates to drive the transmission gear 22 to rotate, and then drives the transmission roller 212 to rotate, at the same time, the auxiliary conveying unit 23 is pressed down, the transmission flat roller 232 is pressed on the transmission roller 212, and the grid ring 213 is further rotated to convey the short fiber wide sliver S1 and the second short fiber wide sliver S2 forward; the core yarn F2 and the wrapping yarn F1 are unwound and fed into the nip formed by the front roller 17 and the front flat roller 231 under the guidance of the guide roller 16, and then output, so as to ensure that the wrapping yarn F1 is located within 1 / 2 width of the short fiber wide sliver S1 close to the core yarn F2 or the wrapping yarn F1 overlaps the short fiber wide sliver S1, and the interval between the core yarn F2 and the short fiber wide sliver S1 close to the core yarn F2 on the front roller 17 is 2-5 mm; the short fiber wide sliver S1 is conveyed forward under the support of the grid ring 213, and the short fiber wide sliver S1, the wrapping yarn F1 and the second short fiber wide sliver S2 are sequentially wrapped and wound on the outer layer of the core yarn F2 at the wrapping area 25 under the rotation of the core yarn F2, to form the core spun yarn S3; and then the core spun yarn S3 is twisted and wound through the guide rod 24 and the guide hook 31, and then wound on the spinning tube 34 by the steel ring 32 rotating at high speed on the spindle 33.

[0063] The application also provides a four-roller special-shaped plate negative pressure holding fiber stretching sandwich wrapping spinning method, which adopts the four-roller special-shaped plate negative pressure holding fiber stretching sandwich wrapping spinning device to perform core spinning, and specifically includes the following steps.

[0064] S1'. At least one short fiber wide sliver S1, a wrapping yarn F1 and a core yarn F2 arranged at intervals are fed from the feeding unit 10 to the auxiliary core spinning unit 20;

[0065] S2'. The wrapping yarn F1 overlaps the short fiber wide sliver close to the core yarn F2, and the short fiber wide sliver close to the core yarn F2 is fed into the front nip formed by the engagement of the front roller 17 and the front flat roller 231, and then output to the grid ring 213; the short fiber wide sliver S1 is adsorbed and held by the negative pressure suction mechanism at the negative pressure suction port 214, and uniformly laid on the grid ring 213 with a certain width and fiber parallelism; the core yarn F2 rotates to drive the short fiber wide sliver, the wrapping yarn F1 to be sequentially wrapped and wound on the outer layer of the core yarn F2 at the wrapping area 25, to form the core spun yarn S3;

[0066] S3'. The core spun yarn S3 is twisted and wound through the core spun yarn winding unit 30.

[0067] The application will be described in detail below through multiple embodiments.

[0068] Example 1

[0069] As shown in Figures 1 to 4 , the core-spun yarn is spun by using the four-roller special-shaped plate negative pressure holding and fiber spreading sandwich wrapping spinning device, the core-spun yarn feeding unit simultaneously feeds 1 core yarn F2 and 1 wrapping yarn F1, and the short fiber wide sliver feeding unit feeds 1 short fiber wide sliver S1; the process parameters of the core-spun spinning process are as follows: the core yarn F2 is a black polyamide filament with a fineness of 81D, the wrapping yarn F1 is a white polyamide filament with a fineness of 50D, and the short fiber wide sliver S1 is a pink colored cotton fiber roving with a fineness of 450tex; the speed of the front roller 17 outputting the short fiber wide sliver S1 is 9.48m / min; the rotation speed of the spinning tube 34 is 11000r / min; the twist of the yarn is 80T / 10cm; the total draft ratio (i.e. the draft ratio of the short fiber wide sliver S1 by the drafting unit) is 57.40; the linear density of the skin cotton fiber (i.e. the linear density of the roving after drafting) is 7.84tex; the back zone draft (i.e. the difference ratio of the rotation linear speed of the roller and the middle roller) is 1.25; the proportion of the double core yarn (the core yarn F2 and the wrapping yarn F1) in the whole yarn is 65%; the distance between the wrapping yarn F1 and the core yarn F2 on the front roller 17 is 6.5mm, and the distance between the core yarn F2 and the short fiber wide sliver S1 on the front roller 17 is 5mm; the wrapping yarn F1 is fed at the right center of the short fiber wide sliver S1 (as shown in Figure 3 ).

[0070] Figure 7 The core-spun yarn spun in Example 1 is shown in the image under the 3D microscope with 35 times magnification. As can be seen from Figure 7 , in the obtained core-spun yarn, the outer pink colored cotton fiber completely covers the core yarn and the wrapping yarn material, the overall yarn covering effect is good, and there is no long filament exposure phenomenon; at the same time, the parallelism of the outer covering fiber is high.

[0071] Example 2

[0072] As shown in Figure 5 and Figure 6As shown, the core-spun yarn is spun by using the four-roller special-shaped plate negative pressure holding and fiber spreading sandwich wrapping spinning device, the core / spinning fiber feeding unit feeds one core fiber F2 and at least one wrapping fiber F1 at the same time, the short fiber wide sliver feeding unit feeds one short fiber wide sliver S1 and one second short fiber wide sliver S2, and the short fiber wide sliver S1 is close to the core fiber F2, and the wrapping fiber F1 coincides with the short fiber wide sliver S1; the process parameters of the core-spun spinning process are as follows: the core fiber F2 is a black polyamide filament with a fineness of 81D, the wrapping fiber F1 is a white polyamide filament with a fineness of 50D, the short fiber wide sliver S1 is a pink colored cotton fiber roving with a fineness of 450tex, and the second short fiber wide sliver S2 is a pink colored cotton fiber roving with a fineness of 450tex; the speed of the front roller 17 outputting the short fiber wide sliver S1 and the second short fiber wide sliver S2 is 9.48 m / min; the rotation speed of the spinning tube 34 is 11000 r / min; the twist of the yarn is 80T / 10cm; the total draft ratio (i.e. the draft ratio of the short fiber wide sliver S1 by the drafting unit) is 57.40; the linear density of the skin cotton fiber (i.e. the linear density of the roving after drafting) is 7.84tex; the back zone draft (i.e. the difference between the rotation linear speeds of the roller and the middle roller) is 1.25; the proportion of the double core fiber (the core fiber F2 and the wrapping fiber F1) in the whole yarn is 70%; the distance between the wrapping fiber F1 and the core fiber F2 on the front roller 17 is 5mm, and the distance between the short fiber wide sliver S1 and the second short fiber wide sliver S2 on the front roller 17 (i.e. the distance between the left edge of the short fiber wide sliver S1 and the right edge of the second short fiber wide sliver S2) is 5mm; the distance between the side of the short fiber wide sliver S1 close to the core fiber F2 and the core fiber F2 on the front roller 17 is 3.5mm; and the wrapping fiber F1 is fed at the center of the short fiber wide sliver S1 (as shown). Figure 6 Figure 6

[0073] Comparative Example 1

[0074] Compared with Example 1, the difference is that the core / spinning fiber feeding unit only feeds one core fiber F2, and the other parameters are substantially the same as those of Example 1, which will not be repeated here.

[0075] Although the core-spun yarn obtained in Comparative Example 1 does not have a very serious yarn exposure phenomenon, compared with Example 1, the yarn exposure phenomenon occasionally occurs, and the core fiber F2 and the outer wrapping fiber short fiber wide sliver S1 are prone to slip and scatter.

[0076] Comparative Example 2

[0077] The core-spun yarn is spun by using the traditional ring spinning core-spun spinning device, and the auxiliary core unit 20 is not set, and the other parameters are substantially the same as those of Example 1, which will not be repeated here.

[0078] Figure 8 The image of the core-spun yarn spun in Comparative Example 2 under the 3D microscope with a magnification of 35 times. As shown, Figure 8 ​​It can be seen that the core-spun yarn spun by the comparative example 2 has obvious filament exposure, and the filament exposure can be obviously seen at many places.

[0079] Comparative example 3

[0080] By adjusting the guide rod 24, the core-spun yarn S3 formed by the wrapping area 25 is not in a straight line with the core yarn F2 conveyed to the grid ring 213, and the core-spun yarn S3 formed by the wrapping area 25 is also not in a straight line with the short fiber wide sliver S1 conveyed to the grid ring 213, thereby destroying the "y" shape structure. The remaining parameters are substantially the same as those of example 1, and will not be described here.

[0081] Figure 9 The image of the yarn spun by the comparative example 3 under the 3D microscope with 35 times magnification. It can be seen that the yarn spun by the comparative example 3 has the structure of a plying yarn, and the core yarn F2 and the wrapped yarn F1 are twisted and wrapped with the short fiber wide sliver S1, and the filament is exposed. Figure 9

[0082] In summary, the present application provides a four-roller special-shaped plate negative pressure holding fiber spreading sandwich wrapping spinning device and method. The device overcomes the technical prejudice that the short fiber wide sliver needs to be accumulated before the wrapping area after being drafted, and through the negative pressure suction port with a width greater than or equal to the width of the fed short fiber wide sliver on the special-shaped plate, the fiber layer with a certain width, high parallelism and uniform distribution of fibers is obtained on the grid ring under the synergistic stretching of the two forces in the width and length directions. At the same time, the distance between the core yarn and the short fiber wide sliver on the front roller is 2-5 mm, so that the core-spun yarn formed by the wrapping area is in a straight line with the core yarn conveyed to the grid ring, and forms a "y" shape structure with the short fiber wide sliver conveyed to the grid ring, so that the rotation of the core yarn is driven and uniformly wrapped on the core yarn, and a different twisting structure is obtained compared with the traditional ring spinning core-spun yarn.

[0083] The above examples are only used to illustrate the technical solutions of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present application.​

Claims

1. A four-roller profiled plate negative pressure holding and fiber spreading type sandwich wrap spinning device, characterized in that, The device comprises a feeding unit, an auxiliary core-spun unit and a core-spun yarn winding unit. The feeding unit comprises a core-in-sheath filament feeding unit, a staple sliver feeding unit and a front roller at the input end of the auxiliary core-spun unit. The core-in-sheath filament feeding unit feeds at least one core filament and at least one sheath filament which are arranged at intervals. The auxiliary core-spun unit comprises a negative pressure suction assembly, a transmission gear and a wrapping area for wrapping convergence. The core-in-sheath filament feeding unit feeds at least one core filament and at least one sheath filament which are arranged at intervals. The sheath filament is arranged within 1 / 2 of the width of the staple sliver near the core filament.

2. The four-roller profiled plate negative pressure holding spread-fiber type sandwich wrap spinning device according to claim 1, characterized in that, The negative pressure suction port is one of an equal-width structure or an upper-narrow-and-lower-wide structure, so that the staple sliver is uniformly laid on the mesh ring with a certain width and fiber parallelism.

3. The four-roller profiled plate negative pressure holding spread-fiber type sandwich wrap spinning device according to claim 1, characterized in that, The device further comprises an auxiliary conveying unit arranged above the negative pressure suction assembly. The auxiliary conveying unit comprises a front roller, a transmission roller and a bridge component arranged between the front roller and the transmission roller. The shaft core of the front roller, the bridge component and the shaft core of the transmission roller are connected. The front roller is arranged in correspondence with the front roller, and the transmission roller is arranged in correspondence with the transmission roller. The transmission roller is in contact with the mesh ring.

4. The four-roller profiled plate negative pressure holding spread-fiber type sandwich wrap spinning device according to claim 1, characterized in that, The distance between the wrapping area and the front roller nip is greater than the fiber length of the staple sliver.

5. The four-roller profiled plate negative pressure holding spread-fiber type sandwich wrap spinning device according to claim 1, characterized in that, The auxiliary core-spun unit further comprises a guide bar provided between the wrapping area and the core yarn winding unit; a first groove for positioning the core yarn is arranged in the middle of the guide bar.

6. The four-roller profiled plate negative pressure holding spread-fiber type sandwich wrap spinning device according to claim 1, characterized in that, The staple sliver feeding unit comprises a trumpet, a back roller and a back flat, a middle roller and a middle flat; The core / sheath filament feeding unit comprises a godet for guiding the core filament and the sheath filament; The core-spun yarn winding unit comprises a guide hook, a traveler, a ring traveler and a bobbin, the core-spun yarn enters the balloon twisting section through the guide hook, the fibers of the outer layer of the core-spun yarn are further twisted and held in place in the process, and finally the core-spun yarn is wound onto the bobbin through the rotation of the traveler on the ring traveler.

7. A four-roller profiled plate negative pressure holding and fiber spreading type sandwich wrap spinning method, characterized by, The core-spun yarn is spun by using the four-roller special-shaped plate negative pressure holding spread-fiber sandwich wrapping spinning device according to any one of claims 1 to 6, and the specific steps include the following: S1'. At least one of the staple sliver, the sheath filament and the core filament arranged at intervals is fed from the feeding unit to the auxiliary core-spun unit; S2'. The sheath filament coincides with the staple sliver close to the core filament, the staple sliver close to the core filament is fed into the front nip formed by the engagement of the front roller and the front flat at a distance of 2-5 mm from the core filament, and is output to the grid ring through the front nip; the staple sliver is adsorbed and held by the negative pressure suction mechanism at the negative pressure suction port, and is uniformly laid on the grid ring with a certain width and fiber parallelism; the core filament drives the staple sliver and the sheath filament to be wrapped in turn to the outer layer of the core filament at the wrapping area to form a core-spun yarn; S3'. The core-spun yarn is twisted and wound again by the core-spun yarn winding unit. S1'. At least one of the staple sliver, the sheath filament and the core filament arranged at intervals is fed from the feeding unit to the auxiliary core-spun unit; S2'. The sheath filament coincides with the staple sliver close to the core filament, the staple sliver close to the core filament is fed into the front nip formed by the engagement of the front roller and the front flat at a distance of 2-5 mm from the core filament, and is output to the grid ring through the front nip; the staple sliver is adsorbed and held by the negative pressure suction mechanism at the negative pressure suction port, and is uniformly laid on the grid ring with a certain width and fiber parallelism; the core filament drives the staple sliver and the sheath filament to be wrapped in turn to the outer layer of the core filament at the wrapping area to form a core-spun yarn; S3'. The core-spun yarn is twisted and wound again by the core-spun yarn winding unit.

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