Polymers used in the conventional melt spinning process to prepare fibers can generally be used to produce spunbonded nonwovens(China Spun-bond Non Woven Factory), including polyolefins (polypropylene, polyethylene, etc.) polyesters, polyamides and polyurethanes. polymer. Polypropylene spunbonded nonwoven fabrics using polypropylene as the raw material accounted for the first place, followed by polyester (polyester) and polyamide (nylon) spunbonded nonwoven fabrics.

Conventional production of raw materials

(1) Polypropylene (PP)

This is currently the most widely used raw material in spunlaid nonwovens. Polypropylene(Polypropylene Spun-bond Non Woven Supplier) is a thermoplastic synthetic resin with excellent properties, such as low density, non-toxicity, easy processing, impact strength, flex resistance and electrical insulation. However, the disadvantages of the dyeing diagram are difficult to overcome by the method of dyeing the original liquid, and the paint printing can also be performed after the cloth is formed. Among the raw materials for spunbonding nonwovens, polypropylene accounts for 79%, polyesters for 16%, and other polymers for 5%.

Polypropylene is a linear polymer composed of macromolecules with a main chain of carbon atoms. Polypropylene can be classified into isotactic polypropylene(PP Non Woven Fabric Manufacturer), syndiotactic polypropylene and atactic polypropylene depending on the position of the methyl group. In the polypropylene spunbonding process, isotactic polymerization is generally used.

The olefin, its isotacticity is generally above 95%.

(2) Poly (PET)

The scientific name of polyester is polyethylene terephthalate, and the trade name is polyester. It has excellent physical and mechanical properties and processing properties and has become one of the important raw materials for spunbonded nonwoven fabrics. Due to the greater rigidity of the PET molecular chain, the pure PFET point is higher, approximately 267 °C. The PET molecular chain is a linear structure with a high degree of stereoregularity. All the aromatic rings are almost in the same plane, so they have a tendency to crystallize: at the same time, because there is no large branch, the molecules are easily oriented along the fiber stretching direction. Arranged in parallel. The PT molecular chain is connected by a base, and its chemical properties are mostly related to the base, so the moisture content must be strictly controlled during the molding process of the PET filament.

(3) Polyamine (PA)

Polyamides are identical in structure to all fiber-forming polymers. Their molecules are linear long-chain molecules that are joined by a number of repeating structural units (ie, links) through the amine bond 1, and are fully extended planar serrations in the crystal. shape. The chain structure of polyhexamethyleneamine is an NH(CH2)3CO-, and the number of chains (degree of polymerization) contained in the macromolecular chain of polyhexamethylenediamine determines the length and molecular weight of the macromolecular chain.