（1） Yarn setting:
In the production of denim, weft yarn, especially when using the rotor yarn with larger twist as warp yarn, should be wet and heated to stabilize its twist.
Objective: to improve the quality of fabric by reducing the weft, weft shrinkage and ring up during weaving.
Requirements: increase tension, wet supply, heating and other methods to stabilize yarn twist, and reasonable moisture return rate is 8% - 9%
（2） The significance of yarn winding cylinder for denim
(1) Change the form of roll up
(2) Removing yarn defects removing harmful defects on original yarn in winding cylinder
(3) Improve yarn tension
(4) Reduce the yarn
（3） , whole Sutra
1. the main purpose is to make the tension, arrangement and winding of yarn pieces or strands three uniform, and to make a certain number of bobbin yarn uniformly and closely wound on the warp or special ball shaft according to the specified length with uniform and consistent tension, so as to prepare for dyeing and sizing processing of the next channel.
2. mainly 1452A or gai2i batch warping machines, which are used for dyeing and pulp joint production line can meet the quality requirements.
Dyeing and finishing technology of denim
Denim is a kind of product which is dyed with indigo blue first and then woven.
1. dyeing and sizing
Indigo Dyeing of denim warp includes rope dyeing, sliver dyeing and hanging ring dyeing. The first two are connected with the sizing, and the latter is dyed and then sizing.
(1) , rope like staining
(ring yarn) cross winding cylinder - (rotor yarn) warping rope frame indigo continuous rope dyeing long chain axle warp sizing weaving fabric post treatment pre shrinking finishing
(2) Dyeing and sizing of yarn
(ring yarn) cross winding cylinder - (rotor yarn) finishing - Indigo Dyeing sizing - weaving - fabric inspection - wool - post treatment - pre shrinking finishing
(3) Ring hanging dyeing
This method adopts a dyeing groove, and the warp yarn is repeatedly dyed repeatedly in this groove, and it has reached the depth requirement. The dyeing and sizing process is as follows:
Warp yarn feeding - alkali boiling (or wetting) - washing indigo dyeing - air oxidation (indigo dyeing) - air permeability oxidation process cycle for six times - washing four times - drying - yarn storage sizing drying upper axle
Finishing of denim
The technological process of the post finishing of the conventional denim
Grey cloth → wool burning → sizing → whole weft (pulling) → pre drying → rubber blanket pre shrinkage → blanket drying → finished product inspection → packaging
1、 Firing hair
1. Technical requirements for firing
Remove the feather and small impurities on the surface of the fabric, so that the finished product surface is smooth and smooth.
2. Standard for rating of quality of burnt wool
Under certain tension conditions, the fabric must be observed and evaluated in a place with sufficient light. The firing of denim must reach above grade 4.
2、 Sizing
The water repellency of the fabric is improved, and the moisture return rate is maintained to make the pre shrinkage finishing go smoothly. The pre shrinkage effect of the fabric can be kept, and the upper pulp drying can play a fixed role to prevent the fabric from returning to elongation after the machine is down, so as to increase the shrinkage rate of the fabric stably; Improve the hand feel of the fabric and improve the sewing performance; Ensure that the fabric meets the specified weight requirements and stiffness.
3、 Whole latitude (cable)
The potential weft deflection stress in the fabric is eliminated due to the factors such as yarn twist, tension and fabric structure. Denim with different yarn number and variety structure has different potential weft stress, and different weft inclination requirements are required. The inclination of the general heavy (above 440g/m2) denim is 3 ° - 4 ° 30 'after the whole latitude, or the latitude slope is between 7% and 8.5%.
Process arrangement: after sizing and before drying.
4、 Preshrunk
The potential shrinkage stress of most of the fabrics is eliminated, and the shrinkage of finished products is reduced, and the requirements of garment processing can be met. The requirement of the final denim fabric is within 3% of the longitudinal and latitudinal shrinkage, and the super pre shrunk denim with special requirements is within 1%. The shrinkage of the same denim in, middle, right and head, middle and tail is uniform, and the shrinkage rate of the same batch of denim is basically the same.
5、 Washing water
There are many processes for finishing denim clothing, which is an important part of developing the denim clothing series. Among them are: enzyme, stone grinding, sand spraying, cat hair, silicone oil, bleaching color, color, color, snowflake washing.
Classification of washing technology for jeans
1. Hand rub
2. Water washing: general washing, stone washing, enzyme washing, rinsing, stir fried snowflake, chemical washing, blue grain washing
3. Cat beard: sand spraying, sand washing, monkey washing, stereo cat beard
4. Destruction washing