Polyester’s Transformation – Cationic Polyester Yarn
The resilience of chemical fiber filament refers to the sample wire plus a certain load. After stretching to a certain length, it will be kept for a certain period of time and the load will be released. In a short time (3min), the ability of the deformation to recover immediately is used to measure the resilience of the chemical fiber. The rebound rate is expressed. There are currently two methods, one is the fixed load rebound rate and the other is the fixed elongation rebound rate.
Cationic polyester: full name cationic dyeable polyester
Chemical name: polybutylene terephthalate (elastic polyester);
English name: cationic dyed polyester;
Abbreviation: PBT, also known as CD in the factory. The cationic polyester is a denatured/modified polyester which can be dyed with a cationic dye at 110 °C.
Method for modifying cationic polyester
The cationic dye-dyeable polyester modification method is to copolymerize a polyester dyeing modifier, such as sodium methacrylate-5-sulfonate (commonly known as three monomers, English abbreviation SIPM), with polyester, and copolymerized polyester molecular chain. Sulfonic acid groups are introduced, which can be dyed with cationic dyes. The dyed fabrics are brightly colored, the dye exhaustion rate is high, and the discharge of printing and dyeing wastewater is greatly reduced. The copolyester chips can increase antistatic, anti-pilling and moisture absorption properties. It is one of the main methods to improve the dyeing performance of polyester in recent years.
Japanese Unijika Company uses 4 parts of cationic dyeable polyester with sulfonic acid group-containing isophthalate unit and 1 part of ethylene glycol/polyethylene glycol/sulfonic acid sodium isophthalate/p-benzene The block copolymer of dicarboxylic acid is blended and spun to form ultrafine fibers with high dyeing depth; before the spinning or during spinning, a cationic active agent and a small amount of a denaturant are copolymerized with BHET.
When it is made into a random linear polymer, its spinnability becomes good. This modified polyester can be dyed not only with cationic dyes, but also with pilling resistance and improved wrinkle recovery.
Properties Of Cationic Polyester
The cationic polyester obtained by copolymerization of SIPM has a lower melting point than ordinary polyester, and its crystallinity is lower than that of ordinary polyester, so that the dye molecules are easily penetrated, the fiber is easily dyed, the color absorption rate is improved, and the hygroscopicity is also improved.
The molecular weight, crystallinity and strength of cationic polyester are lower than those of ordinary polyester, and the anti-pilling characteristics of the fabric are better than ordinary polyester. The Young’s modulus of cationic polyester is 10% to 30% lower than that of ordinary polyester, so the fabric is softer than ordinary polyester fabric.
In addition, the cationic polyester has a much higher rate of alkaline hydrolysis than ordinary polyester. Therefore, when alkali treatment at the same temperature, the alkali reduction rate of the cationic polyester is much higher than that of the ordinary polyester fabric. The cationic polyester not only ensures the cations are easy to dye, but also increases the micropores of the fibers, improves the fiber dyeing rate, gas permeability and moisture absorption, thereby further adapting to the simulated silking of the polyester fibers; the silk fabric can be soft and breathable by simulating silking. Comfortable, antistatic, normal temperature and normal pressure dyeable; through cationic modification of multi-functional wool, the fabric can be soft, antistatic, anti-pilling, normal temperature and pressure and co-dye.
Properties Of Cationic
1. The color is bright and the dyeing is good;
2. High moisture absorption performance;
3. Good light fastness and color fastness;
4. When color matching is dyed, the dye compatibility is good;
5. Good stability in high temperature dye bath;
6. Low staining of other fibers including ordinary polyester fibers;
7. The diffusion rate to the inside of the fiber is fast, no ring dyeing phenomenon;
8. Dye stability is high when the pH value changes in the dyebath.
Cationic modified polyester filaments can not be distinguished from polyester filaments. If you want to distinguish them, you can only use the dyeing method! The cationic raw materials are generally dark!
The figure below shows the contrast between cationic and glossy polyester fibers, which is difficult to distinguish with the naked eye.
A cationic fabric is one in which a yarn is a specially treated cationic yarn, such as a cationic polyester yarn or a cationic nylon yarn.
One of the characteristics of cationic fabrics is the two-color effect. With this feature, some yarn-dyed two-color fabrics can be replaced, which reduces the cost of the fabric. This is the characteristic of cationic fabrics, but it also limits its characteristics. Colored yarn-dyed fabrics, cationic fabrics can only be replaced.
The cationic fabric is brightly colored and is very suitable for use as artificial fiber, but it is used for the washing and light fastness of natural cellulose and protein fabrics.
The wear resistance of cationic fabrics is also very good. After adding some artificial fibers such as polyester and spandex, the strength is higher, the elasticity is better, and the wear resistance is second only to nylon.
Cationic fabrics have some chemical properties, such as corrosion resistance, alkali resistance, bleach resistance, oxidants, hydrocarbons, ketones, petroleum products and inorganic acids, as well as some physical properties such as UV resistance.