What Is Warp Sizing?
In ancient times, sizing was done by hand: the warp was spread out into sheets, smeared with a brush or reed, dried and wound into a weaving beam. In the Yuan Dynasty of China, Wang Zhen showed pictures of sizing warp with a brush in his famous book “NONG SHU”. The methods and tools of using starch, cowhide, and bone glue silk are recorded in ancient Chinese books.
At the end of the 18th century, the power loom appeared in British, which separated sizing and weaving into an independent process, and the prototype of the modern sizing machine appeared. After many improvements, the British had developed a machine similar to the modern sizing machine in 1853.
Why We Need Warp Sizing?
The process of applying sizing to warp yarns is in order to improve their weavability. Weavability refers to the ability of warp yarn to withstand repeated friction, stretching, bending, etc. on the loom without causing a lot of fluff or even breakage.
The unsized single yarn fibers are not tightly attached to each other, and the surface hairiness is more, so it is difficult to be used for weaving. After sizing, a part of the sizing liquid penetrates between the fibers, and the other part adheres to the surface of the warp yarn. Sized yarns are stronger and more suitable for weaving.
There are six main sizing methods for warp yarns.
1. Warp beam sizing
The warp yarns on several warp beams are drawn out at the same time, immersed in the slurry, pressed to remove the remaining liquid, dried, separated, and finally rolled into a woven beam according to the specified length. This is the most widely used sizing method.
2. Weaving beam sizing
The sectional warping machine firstly separates the yarn and winds it on the sizing beam, and then rolls it into a weaving beam after sizing. This method is mostly used for multi-variety and small batch production of silk weaving and yarn-dyed weaving.
3. Warping and sizing joint
The process of combining warping and sizing into one process. The process of winding the warp yarn into a beam during warping and unwinding again during sizing can be omitted.
4. Dyeing and sizing joint
Dyeing and drying equipment is installed in front of the sizing tank of the sizing machine, so that the sizing yarn is dyed and dried first, and then sizing. The dyeing and sizing are combined into one process, which is mostly used for sizing of warp yarns that need to be dyed.
5. Single yarn sizing
The single yarn is withdrawn from the bobbin, sized by the single yarn sizing machine, and then wound into a sizing bobbin. The single-yarn sizing machine is formed by adding a sizing tank and a drying mechanism to the low-speed winder. Although this method has low yield and high labor consumption, the quality of serosa is good, and it is sometimes used in silk and ramie weaving.
6. Sizing of the hank
There are two methods, manual and mechanical, in which the skein is soaked in the slurry, twisted, fluffed, and then dried. This method is suitable for small batch production such as yarn-dyed and webbing.
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Since the 1970s, solvent sizing, hot melt sizing, foam sizing and other methods have appeared one after another, which can save drying energy. With the development of electronic technology, the research on automation of sizing machine has also made progress, which can automatically control the moisture regain, elongation, sizing rate, warp tension, sizing liquid level, concentration, temperature and steam during sizing. pressure, etc.
The warp beam and the weaving beam are a necessary equipment for sizing, so their quality also affects the sizing, which means that it is also very important for the subsequent weaving process. If you want to find high quality shafts, please feel free to contact us.