Classification of Pulp

The characteristics of pulp are determined by the processing technology, and there are several types:

1. Mechanical pulp, groundwood

The traditional method is stone pulp, which uses mechanical grinding force to obtain wood fibers. Mechanical pulp mainly includes mechanical pulp, refined mechanical pulp, and hot ground mechanical pulp. Mechanical pulp has short fibers, high separation degree, and is easy to form a dense surface, but low breaking strength and poor stiffness. Due to the presence of a large amount of lignin, the whiteness is low. But the yield is high. Mainly used for producing short-term printed materials such as newsprint.

2. Chemical pulp

Chemical pulp is a process of separating fibers from lignin using chemical methods to obtain fibers. Chemical pulp is divided into soda pulp, sulfite pulp, and sulfate pulp. Chemical pulp has long fibers, good stiffness, high rupture strength, and durability. Bleached chemical pulp is mainly used for advanced printing paper, photocopy paper, computer paper, offset paper, cover paper, writing paper, and paper bag paper. Unbleached chemical pulp is used for high-strength industrial paper such as kraft paper, paper bag paper, etc.

3. Semichemical pulp

Semi chemical pulp is a combination of mechanical and chemical methods. Divide into neutral semi chemical pulp, cold soda pulp, and chemical mechanical pulp. Semi chemical pulp is generally used for packaging paper.

Nowadays, most commonly used pulp is bleached chemical thermal mechanical pulp (BCTMP), which has the advantages of mechanical pulp and chemical pulp.