The principle of the production process of colored spinning yarns is similar to that of the natural spinning technology. However, due to the high-temperature dyeing and drying of the fibers, the natural curl of cotton wax and cotton fibers on the surface of the cotton fibers are subject to various degrees of damage. The frictional cohesion between the two sides weakened, and during the process of dyeing, it was easy to agglomerate, and at the same time, there was an increase in short nap, a decrease in strength, an increase in the micronaire value, and a coarsening of fineness, which reduced the spinnability in various degrees. At the same time, in order to reduce color knots, Shuangqing double-comb technology is implemented, and fiber damage needs to be strengthened. Therefore, new requirements have been put forward for the carding process.

1 The difference between color and white spinning and its combing problems

1.1 Different combing objects

The differences between color spinning and white spinning combing are shown in Table 1.

Analysis in the table: After high temperature, acid-alkali treatment of dyed cotton or combed carded fiber strips, nets, secondary carding and re-spun yarn is the biggest difference. Using the original card clothing configuration and technology, it is difficult to meet the carding needs.

1.2 Differences between processing processes

1.2.1 White spinning process combing process

The carding process: raw cotton→cleaning→carding→one-sided→two-way→roofing→spinning→sponge

Combing process flow: Raw cotton→Cleaning→Carding→Pre-punch→Bar (or bar and roll)→Combing→Mixing→Banding→Rolling→Spinning→From

1.2.2 color spinning process

Carded yarn: (dyed cotton + carded cotton mesh + natural cotton → proportioned mixing → cleaning → carding → mixing together → mixing two → roving → spinning → from the network

Semi-combed yarn: (combed and dyed cotton mesh + natural cotton) → proportioned mixing → cleaning → combing → mixing together → mixing two and → roving → spinning → from the network

All combed yarn:

(1) (dyed cotton + combed dyed cotton mesh or combed cotton dyed cotton mesh + intrinsic cotton) → proportioned weighing → blending → cotton cleaning → carding → pre-tapping → bar (or bar and roll) → combing → Mix together → mix two → roving → spun → auto

(2) (Combing dyed cotton mesh + combed natural cotton mesh) → Weighing and mixing in proportion → Cleaning → Combing → Mixing together → Mixing two → Roving → Spinning → Self-allocating

Comparative analysis of process flow: The process of fiber in color spinning is longer, and the combing of dyed cotton is the most critical. The combing before dyeing has already caused damage to the fibers. The growth of fiber knots, the growth of neps, and the fiber carding damage after dyeing have been affected to a certain extent.

1.3 Different Color Spinning Quality Control

If the dyed fiber content or the natural fiber content is less than 15%, the dyed bundle fibers of the natural color fiber are tangled on the yarn. Since the color is comparatively manifested, all of them are obvious color knots. Clear color knots on the colored yarn are easily exposed on the surface of the yarn, and the cloth surface is particularly conspicuous and difficult to remove and cover after finishing. Therefore, it is important to control the neps and grain of the yarn. The visible color knots of the blended 30% ratio are controlled to be less than 8 yarns per 100 meters, and the requirements are very high. See Table 2 for differences in quality control of color spinning.

1.4 color combing technology problems

The comparison of synthetic yarns with white yarns contrasts with that of raw yarns. After cooking and bleaching, especially after opening and loosening, the number of cable ties is increased and the number of neps is increased. Nylon-quality nep is difficult to control. The secondary cleaning of the raw materials and the carding process of the dyed yarns and the combing process are particularities of the carding object; color spinning yarns have very high requirements for color knots and strength; it is difficult to eliminate neps and protect fiber damage during carding. Therefore, in the middle of the carding process, it is necessary to control the damage of the fiber, and to ensure that the carding effect is the key point of color-spun carding. Difficulties in quality control: fine combing of fiber bundles, eliminating color knots; reducing fiber damage and increasing strength; fully combing open fibers to eliminate fine impurities.

2 Color Spun Carding Technology Difficulties Solutions

2.1 Increased densification improves combing ability

Cloth density is the basic requirement for color spinning. The trend of the development of cylinder clothing is to increase the longitudinal tooth pitch and reduce the lateral tooth pitch, so as to achieve both carding and short-lasting effects. FA201 model configuration: with cotton grade 2.3; average fiber length 28 mm; clothing configuration: Xilin AC2030 × 01550, doffer AD4030 × 01890, cover TP45; color spinning varieties: C14.8 tex ~ 29.5 tex; raw cotton short Cashmere rate is 19%. The main tight spacing process: Xilin 360 r/min, the spur roller 800 r/min, cylinder-cover gauge 0.13 mm, 0.10 mm, 0.10 mm, 0.09 mm, 0.10 mm; Xilin ~ Road 0.10 mm; Fix the cover plate to cylinder 0.13 mm.

Analysis of the problem: 18/12 sticks/g sliver color, and 24.5% short fiber. The clothing life cycle is 8 months. Due to the strict control of color spinning on neps, the existing tooth density can not meet the needs of carding, and the quality of carding has been improved by choosing tooth-encrypted clothing. The clothing AC2030×01540 is replaced with the AC2040×01740 clothing. The cover plate is encrypted to MCH55, and the cylinder-cover spacing is 0.15 mm, 0.13 mm, 0.13 mm, 0.13 mm, and 0.15 mm to meet the carding requirements. Clothing life of 1 to 3 years.

2.2 The Effect of Finishing Area on the Quality

Closely spaced strong inserts have a very pronounced effect on the fine free carding zone, but the short lint damaged large neps caused by the tightly spaced increases. Model configuration: modal fiber 29.5 tex siro spinning; Xilin: AC2030 × 01550; doffer: AD4030 × 01890; cover TPT45. Closely spaced: 0.13 mm front fixed cover. Obviously, fixing the cover plate too tightly will cause fiber damage and increase the short fiber. The specific quality comparison is shown in Table 3.

Analysis of the problem: The 0.13 mm tightness of the front fixed cover plate caused fiber damage and increased short fiber. The auxiliary carding distance of the front fixed cover plate is too tight, causing serious damage to the fiber. Control measures: Before the adjustment measures, the fixed cover plate was adjusted to 0.18 mm, the short fiber rate was 5.2%, and the nep was 11 grains/g. The effect was very obvious. The tightly-spaced distance focuses on the carding zone and the transfer zone, ie, 0.13 mm to 0.15 mm for cylinder-cover plates, 0.10 mm for cylinders and doffers, and 0.15 mm to 0.18 mm for cylinders and licker-in rollers, enabling carding to be fully transferred and strengthened.

2.3 Reasonable clothing selection protects fibers from damage

The trend of the development of cylinder clothing is that the longitudinal tooth pitch is enlarged and the transverse tooth pitch is reduced, so that both carding and short-cutting can be achieved. FA221B model configuration; color spun glue 29.5 tex; Xilin clothing selection longitudinal tooth pitch 1.7 mm specifications model clothing: AC2030 × 01740; doffer pin AD4030 × 01890; cover card clothing: TPT42. See Table 4 for details.

From Table 4, it can be seen that by increasing the longitudinal tooth pitch of the optional cylinder clothing, the damage to the fibers is reduced and the carding effect is also improved.

2.4 Optimize the speed of the licker-in control of the nep to reduce the lint

A186G carding machine, color-spun cotton spur roller 1 040 r/min, Xilin 360 r/min, quantitative 19.5 g/5 m, neat high, short velvet high. The first is that the small speed ratio is not conducive to transfer, the licker-in rolls return at high speed, and the nep increases. The second is that the speed of the licker-in is too high and the short-staple increases Xilin's licker-in speed ratio is more than 2.1 to facilitate the transfer, moderate licker-in speed can reduce the impact on the fiber, play a role in protecting the fiber. The specific quality optimization comparison is shown in Table 5.

From Table 5, it can be seen that the use of a reasonable speed and speed ratio of the licker-in can reduce the impact on the fiber and the color knot caused by the licker-in, and improve the quality.

2.5 Xilin cover plate process gradually combing

The change law of combing force in the carding area of ​​cylinder and movable cover plate: The combing force gradually decreases from the entrance to the exit is the theoretical basis of its size. Therefore, the gauge change should be gradually reduced from the entrance to the exit. This arrangement is in line with the idea of ​​gradually increasing the combing strength, and can also prevent the fibers from being seriously damaged due to improper combing. On the color-spun A186 carding machine, the quality of the cotton yarn of the cover plate 106 was compared. Improvements were made using a gradual process. See Table 6 for process optimization.

Analysis in the table: Progressive splitting of the gauge, reducing the original gauge The design of the small entrance, large resistance to the lateral transfer of fibers, there is a large resistance to the process of the carding, fiber aggregation caused by the difficulty of the transfer of cotton, cotton and uneven even more. After adopting progressive gauge, the transfer resistance of imported fibers is reduced, progressive splitting is achieved, the combing area enhances the combing effect, provides conditions for the fine combing area, and cooperates with the cover plate abscission control measures to improve the combing effect.

2.6 Increase the number of original combs to improve combing ability

The increase in the number of original combs in the front zone and the enhancement of the combing of fibers prior to the transfer to the gap points in Toff and Xilin can reduce the effect of missing combs. The front fixed cover plate mainly arranges the fiber after the cover plate and the Xilin carding, so that the parallelism of the fiber straightness is further improved. The installation of a fixed cover increases the carding area and the needles involved in carding. The fixed cover plate can enhance the degree of carding and supplement the combing of the leaking comb, which effectively improves the carding effect. See Table 7 for the effect on the quality after the color spinning cotton FA201B carding machine is installed.

According to the analysis in the table, after fixing the cover plate before adding the fiber, the fiber bundle of the leaking comb can be supplemented and combed before entering into the sillin doffer distance point, and the impurities are cleared and fluffed during multiple times of combing. Exclusion provides conditions that can effectively improve product quality.

2.7 Beveled Wire Cloth Reduces Neps Protection Fibers

Due to its unique design of angular arcs, the taper roller clothing reduces fiber damage and reduces color knots. Sharp edge, small tooth top area, good puncture and certain ability to hold fibers; needle gap capacity and good ability to absorb and release fibers; needle teeth should be sharp, smooth, wear-resistant, needle surface to be flat. The effect of the specific taper roller cloth on the quality is shown in Table 8.

The analysis in the table shows that the general clothing cloth is encrypted and the damage to the fiber is large. The taper pin cloth can be used to encrypt and improve the combing effect.

Xilin bevel pin clothing: tooth top area ø 0.035 mm; general clothing L×b: 0.08 mm× 0.07 mm; pitch error: bevel tooth clothing: ≤ 0.005 mm; ordinary clothing: 0.01 mm to 0.02 mm. The sharpness of the tooth tip, the enhanced puncture ability, and the improvement of the smoothness of the tooth body have a significant effect on the reduction of the nep. See Table 9 for details.

Analysis in the table: The tooth top area is the key to the sharpness of the clothing. After dyeing, the fibers in the dyed fabric are more compacted after being dyed. Increasing the sharpness of the clothing can improve the puncture ability, and the reduction of neps has a significant effect.

3 Conclusion

After the color spinning fabric is dyed, the spinnability is poor, and the color knot is not easy to be discharged. With the double-comb process, the fiber is easily damaged and the strength is reduced. In practice, the optimization of the process, the rational selection and configuration of the clothing, and the adjustment of the relevant discharging process can effectively protect the fibers during carding, fully combing, and finely combing, providing favorable benefits for spinning high-quality yarns. conditions of.