Technical Articles

Elastic bamboo woven fabric is a new type of product developed on the jet loom based on the market demand and the characteristics of elastic fabric and bamboo woven fabric. The warp thread of this kind is usually made of regular yarn or slush yarn. Variety has a dual characteristic of bamboo fabric and elastic fabric, have good resilience, wet gas absorption and obvious concave and convex stereo feeling, feel is good, wearing comfortable, deeply the general consumer's affection, has broad market prospects.

Fabric specifications

Fabric specification C29.2 / C29.2 (78dtex) 275.5/220.5 180 elastic bamboo sheeting. The ground is formed by the horizontal lines, while the side is organized to double the second and lower latitudes. The total number of roots is 4,980, of which 60 square roots of the square root are X2. The warp yarn is C29.2 Tex yarn, and the bamboo section is used in a variety of changes, with average length of 6.0 cm, and the average pitch length is 46.7 cm, and the section is 2.5 times of normal yarn. The weft yarn is a C29.2 (78dtex) slug slub, with a length of 5.3 cm, and the average pitch is 29.8 cm, which is 2.5 times the normal yarn.

The technical difficulties of producing slub yarn by air jet loom

With the unique style of the slub, the fracture strength decreased significantly compared with the normal yarn. In the process of production and processing, it is easy to break because of repeated machine drawing and friction, making it difficult to produce.
Because of slub roughness is about 2.5 times that of the normal part, ribbed torque is much bigger than other parts of the, the twist is much smaller than other parts, the holding force between the fiber decreased obviously. Warp in by warping machine, sizing machine, therefore, the expansion of reed, the drop needle loom, heddle, reed when parts are more prone to hairiness and pilling phenomenon, cause the weaving warp shedding is not clear. However, the speed of jet loom is high, and it is very strict to the opening and articulation of warp yarn. It is precisely the most easy to block the flight of the weft in the weaving mouth, which causes the filling to stop, which affects the efficiency of the loom and the quality of the cloth.

Since the jet loom adopts the fluid insertion method, the filling yarn is not controllable, and the initial tension and tension of the weft yarn are greatly increased, which is far higher than the normal tension of weft, especially the brake tension. For weft, on the one hand, because of using jet weft insertion of air-jet loom, in the process of weft weft untwisting, thus reduce strength, caused the weft feeder or woven mouths weft caused by bamboo parts of the weak twist off; On the other hand, due to the retraction of the elastic yarn, the twist of the slub yarn is large, and the fabric surface is easy to produce weft defect. In addition, it is easy to make the elastic yarn to be spun out of the fiber and the wick because of the effect of airflow, thus making the fabric surface similar to the "hundred feet" defect.

Main technical measures before weaving

In order to solve the above contradictions, and improve the weaving efficiency and product quality, we are in process design and product development process, the original yarn twist, warp tension, sizing agent, opening process conducted a series of aspects such as exploration, bold technical reform, has obtained the obvious effect.

3.1 Selection of bamboo shape

In the case of bamboo, the length of bamboo, the size of the spacing of bamboo, and the roughness of bamboo section directly affect the style of the cloth. In general, the more thick bamboo is a kind of imitation linen style, little and thick bamboo is used to reflect a more straightforward style, intensive and slender bamboo, give a person with elegant feeling. Therefore, we should choose according to the specific use and use of the fabric. At the same time, in order to ensure the spread uniformity and nature of the bamboo festival on the cloth, we should determine the circular rule of bamboo festival according to the width of the fabric.

3.2 Selection of warp twist

In general, C29.2 Tex yarn twist is commonly 68 twist / 10 cm, and bamboo species because of the weak link exists in the article yarn fragments, to improve the efficiency of warp yarn breaking strength and the loom, twist usually 5% ~ 10% higher than that of the normal variety. Therefore, we designed the twist design of C29.2 Tex yarns as 72 twist / 10cm to enhance the strength of the warp yarn and ensure the normal production of the latter process. At the same time, it is necessary to reduce the weight of the steel wire to reduce the breakage and ensure the smooth operation of the production and improve the yarn quality.

3.3 Selection of weft twist

According to the experience of production of pure cotton elastic core yarn, in general, because of the special leather core structure of the elastic core yarn, the cohesion of the fiber is greatly reduced. In order to achieve good cladding effect, meet the demand of the winding and weaving process, and increase the breaking strength of single yarn, the twist of yarn is usually 10% ~ 15% higher than regular yarn. Slub yarn unique style also increase in yarn twist is ordinary, in order to ensure that the strength of soft twist place, however, the adoption of the free end air-jet loom weft insertion, if excessive twist, weft are prone to shrinkage defect, and affect the quality of the cloth. Therefore, choosing the appropriate filling twist is the key to ensure the efficiency of looms.
3.4 Technical measures to prepare the process
In order to overcome the warp bamboo parts of the strong weak link, reduce the regeneration of hairiness, we in winding, warping, use the "slow speed, small tension", in order to reduce the warp end-breakage preparation process, to ensure production run smoothly. In order to strictly control the uniform tension of the warp thread, the tension coil adopts the arc configuration and the tension ring quality is small. Sizing process accurately are adopted in the tension control of zuk sizing machine, enhancing the effect of insurance and good PVA and starch phosphate ester paste, with a small amount of smoothing agent, and USES the wet lease and after waxing process, make the sizing quality had improved obviously, warp yarn hairiness stick v, increased the loom open definition, improve the efficiency of the loom. The concrete formula is as follows: phosphatate starch 100kg, PVA 25kg, acrylic acid 12.5 kg, smooth agent 2kg, solid 10.3%, and the sizing rate 12.5%.

Main technical measures in weaving process

Adopting jet loom weaving. The machine is equipped with two nozzles, and the loom is set at 700r/min. The main reason is that the weft is the slub yarn, the yarn twist is too large and the jet pressure is difficult to master. When the pressure is at an hour, the weft of the weft is easy to generate and the h1-stop is caused. When the air pressure is too high, the weft will be blown off to cause H2 stop. When spraying the yarn with two nozzles, the weft of the intermittent nozzle is easy to blow off, especially the breakage of the bamboo section, which seriously affects the production efficiency and product quality. After repeated experiments, the following measures have been taken to achieve better results.

(1) To find the most suitable air pressure range by adjusting the jet pressure, once determined, it is not easy to change.
(2) Turn off the two nozzles, spray the yarn with single nozzles, reduce the time of the filling in the main nozzle, and reduce the chance of the weft being blown off in the main nozzle.
(3) Increase the tension of the machine properly, make the warp yarn have a good opening, increase the Angle of the main nozzle and the stop yarn, and reduce the pulling force required for weft insertion.

Main processing parameters are as follows: check yarn sells 76 ° ~ 190 °, the main nozzle 86 ° ~ 170 °, and auxiliary nozzle 80 ° ~ 160 °, 100 ° ~ 180 °, 120 ° ~ 180 °, 140 ° ~ 240 °, 240 ° ~ 260 °, 180 ° ~ 260 °, computer 3 kn tension, back rest height 6 scale, menopause frame height 2.5 scale.

Through our repeated analysis and the corresponding measures, the quality of the products has been greatly improved, and the production efficiency of the loom has reached about 83%, which has achieved better results.

Conclusion

(1) To produce elastic bamboo fabric, the key is to overcome the weak ring of the yarn, and minimize the loss of strength to the bamboo section.
(2) The determination of the twist of the yarn should be taken into account both the strength and the increase of the strength, so that the weaving can be carried out smoothly, and the fabric surface will not have the defects of weft and 100 feet.
(3) Reducing the yarn hair feather is an important part of the air jet loom, and it is helpful to reduce the regeneration of the wool feathers and to improve the efficiency of the loom.
(4) The control of air jet pressure should be made to reduce the weft stop and the quality of the cloth.