Embedded Composite Spinning Columns Embedded Composite Spinning Columns rr Editors According to the efficient short-flow embedded composite spinning technology is an innovative technology currently being completed by the R&D team headed by Professor Xu Weilin, the vice president of Wuhan University of Science and Technology. This technology achieves two major breakthroughs in traditional spinning technology and theory: First, it exceeds the record of the highest fineness of conventional wool ring spinning 556exi80 public branch), 2ex reaches (500 public branch) Second, it breaks through the original ring The spindle spinning technology has successfully realized the spinning of fine yarns with low-grade fiber raw materials and scraps, with restrictions on fiber length and fineness. Efficient and short-flow embedded composite spinning technology provides a new approach for optimal combination and multiple spinning of different raw materials, which will play a huge role in promoting the upgrade and transformation of China's textile industry.
Professor Chen Jun of Wuhan University of Science and Technology Institute of Textiles and Materials, based on the principle of embedded composite spinning technology, pointed out several technical points of the technology, such as the positioning distance of feeding materials, filament tension and filament content. Different spinning methods were studied in depth. In order to help textile companies understand and apply this technology better and faster, we have created an "Embedded Composite Spinning Column" and invited Chen Jun and related experts to give a series introduction to this breakthrough technology in the spinning field.
Influence of Output Spacing on the Structure and Properties of Embedded Composite Spinning Yarns CHEN Jun, XU Qiao-Lin, YE Wen-Xiang, XU Wei-Lin (Key Laboratory of New Green Processing and Functionalization of Textile Materials, Ministry of Education, Wuhan Institute of Science and Technology, Wuhan 43TO73, China) Influenced by the shape and single yarn force, it is believed that various pitch changes will cause variations in the angle between the "V"-shaped twisted triangle and the length of the single yarn segment, and based on this, other process parameters will remain unchanged and each change long. Yarn and filament spacing, roving-to-filament spacing, and center-of-weaving of yarn spinning were used for spinning. Theoretical analysis and experimental comparisons were conducted to discuss the effect of various pitches on yarn structure. The results show that with various pitch changes, the hairiness, strength and elongation of the yarns and the stems exhibit a non-monotonic change. Considering the yarn structure and performance synthetically, when the other parameters are the same, the optimal yarn forming process is: the distance between filaments and filaments is 12mm, the distance between rovings and filaments is 4mmZ, and the offset distance of spinning center is 1mm: spinning; Spinning; Yarn; Performance; Impact; Pitch; Embedded Composite Spinning: "V"-shaped twisted triangle When the spacing is large, because the "V" zone is elongated, the Y angle will be reduced, and the hair strands The length of the single yarn segment is large because the "V" shaped region is elongated, so the short fiber transfer path in the yarn becomes longer and the transfer is sufficient. However, if the pitch is too large, the length of the single yarn segment of the hair strand is likely to be greater than that of the wool. The length of the fiber body, the single yarn is easy to produce slippage, which is unfavorable for yarn formation, so the maximum distance between the experiment is 20mm 22 The variation of the pitch affects the shape of the V-shaped area and the force of the single yarn. When the spacing is large, due to the “V†shape If the zone is elongated, the angle Y will decrease, and the KGI length of the single strand of the sliver will be large due to the elongation of the "V" zone, so that the transfer path of the short fiber in the formed yarn becomes longer and the transfer is sufficient. The best spacing between ademicournalElectronic yarns and rovings and spinning center offset makes the yarn forming performance optimal. However, due to the different nature of raw materials used in spinning, and the difference in sample processing system may lead to the best spacing is not the same, this article through the embedded spinning spinning experiment and yarn performance testing, discussed the filament and filament The effect of spacing, roving and filament spacing, and spinning center offset on the structure and performance of embedded composite spun yarns.
1 Experimental 11 Raw material and yarn forming process parameters 111 Raw material 296gm filaments are white polyester filaments with a linear density of 50de. 2 Process parameters Filament pretensioning 2CN drafting multiples 50 times, spindle speed 7257 turns 436 turns/m design The embedded composite spinning fineness is 58 pitch filaments and filament spacings are 20, 16 128 mm, and the roving and filament spacings are 24 68 mm. The spinning center point offset distances are respectively a 4 2 experimental analysis methods. Other process parameters are the same When the distance between the filaments and the filaments is 20, 16128, the roving and the filaments are tested at a distance of 4 mm. The morphology of the twisting triangles and the vertical and horizontal structures of the yarns are observed. The yarn properties are tested and compared and the results are compared. Optimum yarning distances between filaments of compound-spun yarns.
In the condition of 20mm long pitch of the embedded composite spun yarns, the distance between the filaments and the rovings was 2468 to be tested and spun. Yarn performance was tested and comparative analysis was conducted to obtain the optimal yarn formation distance between the embedded composite spinning filament and the roving.
In the embedded composite spinning filament spacing of 20mm filaments and roving spacing of 4mm, the spin center deviation were taken a 4-1202, 4mm were tested spinning. Yarn performance was tested and comparative analysis was performed to obtain the best center of the embedded composite spinning yarn.
13 Spinning equipment and yarn structure performance test? 4 multi-function spinning prototype.
Structure Characterization. The vertical and horizontal yarn structure was observed and analyzed using the Christie 3D video camera system.
Performance Testing. SFY13 type monofilament tension meter, YG(B)021DX type desktop electronic single yarn strength machine, YG172 eight type yarn hairiness tester, YG135E strip evenness tester and other test instruments were used to test the embedded composite yarns Dry evenness, hairiness, yarn breaking strength, and elongation.
Embedded composite spinning column n However, if the spacing is too large, due to the limitation of the width of the roller, it is unfavorable for yarn formation. Therefore, the maximum distance is 20mm. 3 Results and analysis 31. Analysis of yarn cross-section and longitudinal structure When filaments and lengths When the yarn spacing is 20 16128 wool roving and the filament spacing is 4, the lateral structure of the yarn does not change much. The filament and the wool fiber appear as two independent components in the cross section because the filament has a small triangle area Under certain tension conditions, due to the transfer of detour, the two components of the hair strands and the polyester filaments have a certain degree of twist before they are combined and twisted. Therefore, when twisting at the points of convergence, they can only be in the form of spirals. Wrap each other. When they are re-twisted at the rendezvous point, it is difficult for them to enter each other's structure again. ~5 is the longitudinal appearance of the yarns with a spacing of 20 16128mm between filaments and filaments.
As can be seen from the above figure, the longitudinal appearance of the yarn is a spiral appearance, but the spacing is different, the spiral appearance difference is obvious, and the yarn lateral compactness is also different.
It can be seen from ~5 that when the filament spacing is 2016, the tight sugar of the yarn is greater than the twist of the 12 long lung yarns, that is, the former yarn diameter and the linear density are smaller than the latter. As the spacing increases, Y will decrease and Ymi will be smaller. When Yma is reached, the single yarn twist in the formed yarn reaches a maximum value.
In addition, it can be seen from the above figure that when comparing the yarn surfaces with 20, 16 and 128 filaments and filaments, it is found that the yarn surface is smoother than the latter. This is due to the fact that The increase of the distance between the filaments and the filaments reduces the yarn hairiness. The increase of the distance between the filaments and the filaments causes the yarn body to become tighter and the latter is easily thrown out of the yarn body or exposed on the surface of the yarn. It is even more fluffy and worsens its finish.
32 yarn strength and elongation analysis ~ 11 for the comparison of yarn strength and elongation at different spacing.
Fig. Spindle center offset/mm 1 Effect of spinning center offset on yarn elongation at break 7 It can be seen that when the distance between filament and filament is changed from 20mm to 1612 and 8mm, the yarn strength decreases and then decreases. Smaller and then increased, the elongation first increases, then decreases, then increases, and the yarn strength is the maximum when the distance between the filaments and the filaments is 20 nm, and the elongation is the smallest when the spacing is 12 mm.
This is because when the distance between the filaments and the filaments is 20mm, the enthalpies are transmitted back to the triangular area, the resulting twists on the woolen rovings are increased, and the fibers are fully transferred in the inner and outer layers. When the yarn is stressed, the strong utilization factor is high. Strong contribution, not easy to slide between each other. Y becomes smaller and the structure of the yarn body is tighter, but the yarn helix angle becomes larger, so the elongation of the yarn is dominated by the elongation of the yarn diameter and the helix angle of the yarn becomes larger, so the strength is high and the yarn is stretched. The length is also larger. When the spacing is reduced to 16mm, the length of the triangular area becomes shorter, and the short fibers are not fully stretched under the effect of the low spinning tension. The proportion of the straight fibers in the sliver is reduced, which is advantageous for the elongation of the yarn, and the cohesion of the yarn is not tight. When the yarn is stretched, the strength decreases and the elongation increases. The elongation of the yarn is composed of three parts: the slip between fibers, the elongation of the fibers themselves, and the elongation of the yarn diameter. At a pitch of 12, due to Y being large, the cohesion between the fibers is loose, and the elongation caused by the slip between the fibers during stretching is a major part of the elongation of the yarn. As a result, the strength is reduced and the elongation at break is reduced. At 12 mm, the elongation is minimal. When the spacing is reduced to 8m, due to the certain transfer and cohesion between the fibers of the roving sliver, the strength has a certain increase, and the elongation at break increases accordingly.
From 9 and 9 it can be seen that when the distance between the filaments and the filaments is 20mm and the distance between the filaments and the filaments is changed from 2mm to 8mm, the yarn strength gradually decreases and the elongation gradually decreases. The distance between rovings and filaments is 00 (Amicloumailectromc yarns have the highest breaking strength. When the distance between rovings and filaments is 2, the elongation at break is the largest. This is because when the distance between rovings and filaments changes from 2 to 8, the small triangle gradually enlarges and the length in the small triangle increases. The cohesion between the filament and the hair roving gradually becomes loose, and the slip between the fibers during stretching is the main factor, so the strength and elongation gradually decrease.
11 It can be seen that when Z is read, when the distance between the filaments is 20mm and the distance between the rovings is 4 and the spinning center is changed from a 4mm to a 4mm, the yarn strength shows a fluctuating state, which decreases first and then rises. The spinning center is offset. When the shift to 4, the strongest, the largest elongation. When the spinning center point offset is 0mm, because Z is the concept, the spinning torque is from right to left, forming an imbalance in the X-axis of the twisting triangle, thus forming the asymmetry of the twisting triangle, spinning The degree of asymmetry is further increased when the center point shift is from 0 to 4, and the effect of enveloping around one side of the sliver is formed. Therefore, when the strength is increased, the elongation is also large. In addition, this asymmetry of the twisted triangle during spinning results in a drastic change in the twisted triangle when the spinning ring is lifted once. When the center point of the spinning center shifts from 0 to 4 mm, the asymmetry of the twisting triangle area is gradually corrected, and therefore the strength is reduced. When the center point of the spinning center is offset by 2mm, the twisted triangle area is relatively symmetrical, the structure of the yarn body is tight, and the fiber slip is reduced, so the elongation is low. As the center point of spinning continues to shift to the left and increase, the yarn body structure is tight and the strength increases, but due to the asymmetric increase of the right sliver, a similar wrapping structure is formed, so the elongation decreases.
33 Yarn hairiness Analysis The hairiness index of embedded composite yarns is different when the distance between filaments and filaments, the distance between filaments and rovings, and the spinning center are different. See 2 to 14 because short hairiness has no significant effect on the weaving performance of yarns. Therefore, only the hairinesses with a length of 3 mm or more are compared.
Spinning Center Offset/mm 4 Spinning Center Offset The effect on the hairiness of the yarn is determined by 2. When the other conditions are unchanged, the filament and filament spacing changes from 20 mm to 1612 and 8 mm, the hairiness is gradually increased, and finally, the hairiness is gradually increased. reduce. The hairiness is the minimum when the spacing is 20, and the hairiness is the most when the spacing is 12mm.
From 3, it can be seen that when the other conditions are constant, the filaments and rovings change from 2 mm to 46 and 8 mm, the hairiness decreases first, and then increases again. The hairiness was the least when the distance was 2 and it was the largest when the distance was 6mm.
From 4 we can see that the hairiness appears wavy when the spinning center shifts from ?4mm to ?2, 2 and 4mm when other conditions are not changed.
The hairiness is the lowest when offset by 2mm, and the hairiness is the highest when offset by 4mm.
When the distance between filaments and filaments is 20mm, the twisting triangle area is long, and the angle Y of the “V†zone of the yarn forming section is small. The chance of the filaments catching short fiber hairiness is large, which helps to reduce the hairiness; at the same time, the whisker segment is obtained. With large twists and turns, the twist of a single yarn in a yarn is also large, which can reduce hairiness.
When the distance between the filaments and the filaments is 8 mm, the hairiness is smaller than the filaments when the spacing between the filaments is 12 and 16 mm due to the small distance between the fibers. When the distance between the filaments and the rovings is kept at a certain distance, the angle between the filaments in the triangular region and the twisting triangles of the wool fibers can also be appropriately adjusted, and at the same time, the mutual influence between the two roving strands can be avoided and the hairiness can be reduced. . The spacing of 4 is better for yarn hairiness. When twisting clockwise, the right center of the spinning center is offset to the left, which helps to balance the direction of the torsion bar's torque, stabilize the twisting triangle, and reduce hairiness. At the same time, due to the twisting of the twisting strips of the two filaments and rovings, the yarn hairiness can be effectively reduced. Therefore, the embedded hairiness yarns have a large distance between the filaments and the filaments, and the distance between the filaments and the rovings is kept at a certain distance. When the center point of the spinning center is shifted to the left by a certain distance, it shows a decreasing trend, and the leftward deviation The effect is better when the shift is 2mm.
34 Yarn Evenness Analysis ~17 is the comparison of the dry uniformity of yarns at different pitches. Various spacings are important factors affecting the sliver dryness, and their effects are non-monotonic.
From 5, it can be seen that when the distance between the filaments and the filaments gradually decreases from 20 to 8 in the course, the resulting slivers are high first, and then gradually reduced, and the yarn is formed into a sliver dry when the pitch is 8 is the best.
When the distance between the filaments is 8mm, due to the small spacing, the fibers between the roving slivers have a certain mutual transfer and cohesion, the slip produced by the single strand yarns on the filaments is small, and the roving and the filaments are formed into tight yarns when compounded. So the article is good. When the pitch is increased from 8 to 16 mm, the slippage produced by the single-yarn yarn on the filament is large, the structure of the yarn body is not stable enough, and the stripe is gradually deteriorated. However, when the pitch is from 16 to 20, the stem becomes better. The reason may be that when the filament spacing is large, the composite in the large triangle area of ​​the yarn body structure is relatively stable, and the yarn formation causes the unevenness of the stem to become smaller.
From 6 we can see that when the distance between the filaments and the filaments is 20mm, the distance between the rovings and the filaments is increased from 2mm to 8mm, the resulting slivers show a fluctuating state, and when the distance between the rovings and the filaments is 4, the resulting slivers are the best.
When the distance between filaments and filaments is 20mm, and the distance between rovings and filaments is increased from 2mm to 8mm, the angle between the filaments in the triangular region and the twisted triangle of the wool fibers should be both properly and the two rovings must be embedded. The 7th type composite spinning column shows that when the distance between the filaments is 20mm and the distance between the rovings is 4mm, the spinning center increases from a 4 to 40% of the sliver and the state of the yarn fluctuates, and the center of the spinning center is 4mm. The sliver is best.
At Zæ», when the filament pitch is 20mm and the distance between the filaments and the roving is 4mm, the spinning center increases from a 4mm to 4mm into a wavy state. When the shift to the right is small, the two triangles are inconsistent, leading to instability in the large triangular area and poor drying of the slivers. When the left and right offsets are relatively large, they are somewhat like the core-in-core structure.
4 Conclusions (1) The variation of the spacing of the Locusts causes the change of the angle between the “V†shaped area and the length of the single-strip yarn section, and the redistribution of single strand yarn twist, which is the root cause of the change in yarn structure and properties.
(2) The variation of the spacing of Loxon has little effect on the cross-section structure of the yarn, but has an influence on the tightness and diameter coefficient of the yarn. The yarn diameter coefficient when the pitch of the filaments is 2016 mm is smaller than that when the pitches are 12 and 8. The wire diameter coefficient, ie, the appearance of the latter yarn is more bulky than the former, while the former yarn has a better finish than the latter.
(3) The effects of spacing of filaments and filaments, spacing of rovings and filaments, and distance of center point of yarn spinning on the strength and elongation properties of hairs, hairiness index, and evenness of strands were all non-monotonic.
Considering the yarn structure and properties synthetically, when the other process parameters are the same, the best yarn spacing is 12mm between filaments and filaments. The distance between rovings and filaments is 4mm. The spinning center offset distance is 2mm.
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