(Shandong Morigin Textile Factory Co., Ltd.)

 

Because breaking ends of compact fabric was serious when adopting PVA, sizing practice of using less PVA was carried out. Through adjusting sizing instruction, modified starch PR-Su and CP-L, JCS-7 composite size mixture were selected as main size mixture. Processing of HS-40 sizing machine was optimized. Finally fine count high density compact fabric accepted beam rate could be improved from 50% to 68%, sizing cost of one hundred meter fabric could be reduced 26%, loom efficiency could be increased from 70% to 90%, sizing quality could be improved and usage of PVA could be reduced as well.

 

In recent years, compact spinning technology had developed rapidly. In technology application of compact spinning, qualities of cotton yarn had improved significantly on its internal structure and appearances. And also contrast on traditional ring-spun yarn, its hairiness had reduced 70% (over 3 mm hairiness were basically eliminated), along with increase of 10%-20% strength and improvement on cotton yarn evenness, thick places and thin places. Compact spinning with less hairiness could reduce flies, improve work environment, decrease fabric hairiness, shorten singeing time, even could cancel singeing process. Moreover, after finishing on the compact yarn, it could show excellent characteristics than traditional ring-spun yarn with same specifications such as fine feeling, strong mercerized feeling, no pilling, suitable no-iron finish and so on. Moreover, it had high-grade fabric style so that compact yarn had become the first one to apply in high-grade fabrics and household textile products.

 

Our company owns two Benninger warpers, one domestic high-speed warper, two Tsudkoma HS-40 sizing machines, two hundred and four ZAX-N-190 air-jet looms and 24 thousand spindles compact spinning machines. In order to improve product additional value, we explored the series of compact yarns as follows: CJ 14.6/18.2 650/484. 5 160, CJ 14.6/(CJ 14.6+ 44.4 dtex) 433/307 183 drill weave, CJ 14.6/29 689/354.5 160 crown twill, CJ 11.7/11.7 567/315 plain and so on. In their production, it was found that some serious problems for compact fabric such as low woven efficiency, incompetent fabric qualities etc.. The reasons were mainly shown as follows due to uneasily controlled sizing qualities. 

 

(1) Difficult sizing on the compact yarn and decrease of size permeability on yarn.

(2) More tangled yarns in size box so as to increase break ends while they returned.

(3) More breakages in dry split region, and more splinter, more adhesive fibers and crossed ends on a beam.

(4) Large usage of PVA-1799 had made operation more difficultly.

 

Analysis:

(1) As compact spinning technology twisted fibers while they were parallel and tight, each fiber was even stressed in high parallelism trim arrangement and tight structure. And also gaps inside the yarn were smaller than that of ring-spun yarn so that its size absorption property was poor.

(2) As hairiness in compact spinning had reduced largely, yarn would cause snarls as soon as force was loose. Moreover less hairiness relation in leases led the yarn places in leases to change frequently, even to tangle with its neighbor yarn. Therefore it caused more breakages at the dents in splits.

(3) Fibers were gathered tightly in compact spinning. And gaps inside the yarn were smaller than that of ring-spun, along with smaller yarn elasticity. While warp stop was happened for a slightly long time in productivity of plain or twill fabrics, it was easy to appear different stretch elongation so as to cause warp bulking. 

 

To solve the above problems, we adopted the processes as moderate density and small viscosity, high pressure and permeability, low sizing percentage, properly enhancement on moisture regain, control of small tensile, decrease of elongation and less or no PVA. 

 

In the early stage, we used PVA-1799, acrylic acid sizing agent and modified starch as main sizes, along with high size density and viscosity between 15 s to 17 s. Because PVA-1799 was used excessively, account of 45% in total size agents. Its higher degree of polymerization harmfully influenced on warps sizing and their followed processes. If PVA in the size liquid was surplus, dry splits would be difficult in sizing and increase break ends, as well as more leases and splits. Even to cause dents knocking so as to increase difficulties of sizing operation. And beams qualities and woven efficiency were all influenced. In order to solve these issues, we tried to replace less or no PVA with the other agents such as PR-Su, CP-L and so on so. After testing in laboratory or pilot-plant scale until large scale usage, it achieved its purpose basically through quality tracking in a half month.

 

Main properties of PR-Su and CP-L were as follows:

(1) Improve and enhance the properties of its mixed sizes, and then practically or totally replace on PVA.

 

(2) Adhesion was enhanced further. And also it was suitable for both hydrophilic fibers and hydrophobic ones.  

 

(3) Strengthen abrasion resistant and reduce sizing percentage effectively.

 

(4) Size film was soft, smooth and splitting easily, along with decrease of second regeneration hairiness. 

 

(5)  Quick resolution, energy conservation and stream saving, stable viscosity, excellent solubility and liquidity, strong permeability, no skin and starch lump.

 

Now the drill weave kraftpaper fabric, which was compact yarn of CJ 9.7/C 14.6 787.5/539.5 160, was testing as a sample. Its warp tightness was 90.74%. And weft tightness was 76.25%. Cover factor of double size box was 36.4%. Its primitive instruction was 42 kg PVA-1799 account of 33.6% in total weight, 15 kg PVA-205MB  (12%), 50 kg acetate starch ( 40%) , 15 kg LMA2001 solidified acrylate sizing agents (12%), 3 kg SLMO-96 (2.4%). New instruction was: 18 kg PVA-1799 (14.17%), 25 kg PR-Su ( 19 . 69 %) , 25 kg CP-L (19.69%),  25 kg  JSC-7 (19.69%), 12.5 kg phosphate starch (9.84%), 12.5 kg enantiotropic starch (4.7%), 6 kg SD acrylate sizing agents (4.7%), 3 kg SLMO-96 (2.4%).

 

Its process flows were as follows. First, PR-Su and CP-L were poured slowly into quantitative water with stirring. After three minute stirring, they were added to the other sizes and agents in accordance with instructions. Then it was boiled and rised temperature to 115¡æ in a high-pressure bucket, then to keep for 15 min. In order to reach the indicators of solids content and volume that meet process requirements, the brewed size liquid was pressed into a supply bucket at a certain density and volume. And then it was adjusted indicators in a wait state. Indicators of the size liquid in the supply bucket were 95¡æ,800 L, viscosity of 11 s, solid contents of 12.6%.

 

2.3 Sizing process and quality

Sizing was done in Tsudkoma HS-40 sizing machines with double-dip-three-press sizing process and 55 m/min speed.

 

Contrast on the primitive instruction and the new instruction was as follows.

The fabric was woven in ZAX-N-190 air-jet loom with 701 r/min speed, 1,800 N loom tension, opening time of 290¡ã, loose warp of 290¡ãand 3 mm, back bearer height of 90 and place of 6, stop warp shelf height of 3 and place of 11.

As keyboard shown, the condition of loom efficiency, warp stop and weft stop were as follows.

As shown in above data, the looms employed the new instruction to reduce 34.78% warp stop and 32.61% weft stop in a loom and one work time, as well as enhancement 23.54% loom efficiency. When the primitive instruction was adopted, bonded beam number reached to 18. But there was no serious bonded beam in processing with application in new instruction. In addition, original qualified beam ratio was not overpass 50%, contrast with 68% now. It had improved apparently.

 

Cost of the primitive instruction was shown in Table 1.

Seen from Table 1, cost of the primitive instruction was RMB 1,746.9 Yuan/bucket. And cost of new instruction was shown in Table 2.

As shown in Table 2, sizing cost of new instruction was RMB 1,397.1 Yuan /Bucket. In practical data, unit price per hundred meters in the primitive instruction was RMB 34.38 Yuan, against with RMB¡¡25.40¡¡Yuan per meter in new instruction. If it was calculated as 1,000 km per month in a loom, sizing cost could be saved RMB 9,080 Yuan per loom.

 

Series products of PR-Su and CP-L could fully enhance and improve properties of their mixture sizes. So they were suitable for products of compact yarn with small counts and high density, along with suitable size film strength, easy dry-splits, large decrease of sizing defects of bonded beams and splits etc.. And size cost in per hundred meters decreased RMB 9.08 Yuan so it was benefit for saving cost. In addition, as a compact yarn has better abrasive resistance, PVA consumption was reduced from 45.6% to 19.69 in total consumption. So it had reached to the aim that used less PVA. 

 

[1] Li Fenglan, Geng Qinglan, Liu Anjun. Several Measures to Reduce Sizing Breakages of Compact Spinning Color Fabric [J]. Cotton Textile Technology, 2006, 34 (5): 54-55.

 

[2]Shi Bosheng, Chen Weidong. Key Points Analysis on Sizing Process of Compact Yarn [J]. Cotton Textile Technology, 2006, 34(2): 56-58.

 

[3] Wu Jianhua. High-density Satin Drill Development with CJ 5.8 tex Compact Yarn [J]. Cotton Textile Technology, 2006, 34(11): 29-31.

Cotton Textile Technology English Version - 2010 / 2

(2010-05-05)