Development of PLA fiber yarn

Development of PLA fiber yarn

Song Jingtao Men Wenjuan

PLA (polylactic acid) fiber, or polylactate fiber, is a new type of environmentally friendly fiber made from corn by Cargill Dow. The PLIA fiber produced by Cargill Dow is called Natureworks.
The raw material of PLA fiber is derived from corn starch, not petroleum minerals. Therefore, after the product is used up, it can be used as a compost or buried in the ground and decomposed by underground microbial action. Either way, the decomposition products can be converted to starch by photosynthesis of plants. In addition, when it is incinerated, the combustion gas does not contain harmful gases, and the heat of combustion is extremely low. Therefore, it is called "the environmental cycle material of non-oil in the 21st century.
Corn fiber has a high melting point, high crystallinity, and good transparency. It has the same high strength as traditional polyester fibers and is flame retardant, so it is very versatile. Corn fiber fabrics have a silky sheen, a very good hand and brightness, a good wicking effect and the like.
The corn fiber used by our company is IngeoTM produced by Far East of Taiwan authorized by Cargill Dow. Its product specification is 1.4D × 38mm. The main indicators are as follows:
The index of PLA (Ingeo) fiber used by our company It can be seen from the above indicators that the fiber has a large elongation at break, a smooth fiber and a low moisture regain. Therefore, the process adjustment should be carried out during the spinning process.
2 PLA series yarn trial production
2.1 Trial Spinning Species PLA40S, JC/PIA (50/50) 40S, B/PLA (50/50) 40S
2.2 Description of the spun yarn a. 100% PLA fiber yarn:
Such yarns have a good gloss but do not produce metallic glare. Its elegant silk look and feel comes from the lower refractive index of the fiber; although the yarn has a low moisture regain, it has good wicking properties, water absorption/hygroscopic properties and fast drying effect; Both elastic and elastic recovery properties are superior to polyester yarns, adding to the comfort stretch of the fabric.
b. JC/PLA blended yarn:
The high-quality combed cotton is blended with the PLA fiber to make the moisture regain of the yarn improved, the moisture absorption effect is improved, and the cotton texture of the yarn is added. However, due to the higher elongation at break of PlA single fiber, it is far superior to cotton fiber. At this time, attention should be paid to the determination of yarn blending ratio.
c. B/PLA blended yarn:
The combination of corn fiber and bamboo fiber can make up for their respective shortcomings and improve the taking effect of the yarn. The higher moisture regain of bamboo fiber makes up for the shortcomings of poor absorption of PLA fiber. The addition of bamboo fiber adds to the natural antibacterial properties of the yarn while at the same time improving the softness of the fabric. The shortcomings of the hard and brittle of the PLA fiber are improved. Corn fiber and bamboo fiber are a combination of environmentally friendly materials and become a continuation of the green and environmental performance of yarns and fabrics.
2.3 Spinning process The development of the above three yarns is mainly for the exploration of the spinnability of PlA fiber. The spinning process of 100% PLA40S yarn is taken as an example to illustrate the process flow: A002D cotton picker-A006B blending machine —A036C type opener-A092A double cotton box feeding machine-A076E type winding machine-186D type carding machine-FA305 draw frame (two-in-one)-FA411 type roving frame-FA503 spinning frame-1332MD type winder
2.2.1 Blooming process Because the dyeing performance of PLA fiber is different from other fibers, the passage of the fiber in the clearing process must be thoroughly cleaned to avoid mixing with other fibers and producing foreign fibers. The process is carried out by the principle of “multi-comb less hit, lower beater speed, proper quantification, lighter pressurization”. This trial spinning uses a porcupine. The beater is beaten in the form of a beater, and the speed of the beater is reduced to 450r/min. The comprehensive beater speed is reduced from 900r/min to 800r/min, and the lap length is 365g/m. Through testing, the unevenness of the lap was 1.05%.
2.2.2 Carding process According to the characteristics of high elongation and elongation of PLA fiber, the carding process adopts the principle of “low speed, tight gauge, light weight and small tension”. Fiber damage should be minimized, short fiber rate should be reduced, and neps should be reduced. Among them, the type of cover card clothing adopts JsT-18 double-row cover plate, the cylinder clothing is 2815*1565, the doffer needle is 4030*1880, and the thorn roller clothing is 5605*05011.
Among them, the raw strips are 18 g/5 m, the licking speed is 700, the cylinder speed is 310, the cylinder squeezing speed ratio is 2 or more, and the cylinder cover spacing is 0.25 ram, 0.23 mm, 0.2 mm. , 0.2mm, 0.23mm. The stretch draw ratio of the cotton web is 1.31.
After testing, the sliver rate is below 4.5% and the neps are 5/g.
2.2.3 The drawing process adopts the principle of “contracting, large gauge and low speed”, and the two slivers are combined to make the sliver evenly blended, the strip is evenly distributed, and the strip spacing is 12 /22mm, the head and draw ratio is 8.14, the rear zone is stretched 1.8 times, the second is always drafted 8.58, and the rear zone draw ratio is 1.25. The equipment should ensure that the channel is smooth, pressurized and stable, and there is no mechanical wave. At the end of the test, the dry CV value was less than 2.2%.
2.2.4 Roving process The FA411 roving machine is used. Because the PLA fiber has good uniformity and good cohesion, the roving twist coefficient is small. The roving process parameters are as follows: the draw ratio in the rear zone is 1.21 times, the roving gauge is 10/27/37, the roving twist factor is 60, and the roving strip is controlled within 4.5%.
2.2.5 Spinning process The spinning process is to reduce the generation of hairiness and the spindle speed is low. It is preferably a steel ring traveler. The imported Zs/hf 8/0 traveler is used, and the spindle speed is controlled at 14000r/min.
2.2.6 Winding process The winding process has a certain elasticity due to the PLA fiber, the winding tension should be controlled to a small extent, and the speed of the drum is low, so as to reduce the occurrence of the broken yarn phenomenon. With the 1332MD winder, the speed of the drum is controlled at 500m/min. To ensure the joint quality, the pressure of the knotter is controlled above 5.5bar.
3 The yarn forming index is the yarn quality index of the three varieties of the textiles. Reference quality target (provided by Taiwan Far East Company)
3.1 1.5dtex/38mm Ingeo fiber-ring spinning yarn quality target From the above indicators, it can be seen that the yarn index is relatively high in the thick section and the cotton section, and the yarn strength is low, which needs to be Improvements will be made in mass production in the future.
4 PLA yarn application A new textile product made from cotton, wool and other natural fibers blended with Ingeo fiber. It is fully biodegradable and naturally recyclable. It has a number of excellent characteristics derived from Ingeo fibers and has superior properties similar to fabrics composed of synthetic fibers and natural fibers.
Corn fiber is a lactic acid polymer synthesized from lactic acid contained in the human body, which is absolutely safe for the human body. It has been tested that round knit fabrics made from corn fiber yarns do not irritate the skin and are beneficial to human health and have a comfortable feel.
Corn fiber yarn has excellent performance, excellent drapability, slipperiness, moisture absorption and permeability, good heat resistance and UV resistance, and is lustrous and elastic. It can be used for clothing, sportswear, fashion, etc. due to corn fiber. The yarn is soft and bright, especially suitable for women's wear.