Papermaking machinery is a combination of various devices that handle everything from raw material preparation, pulping, and papermaking to the final production of rolls or sheets. It can also process paper and paperboard. So, what are the main components of a papermaking machine and what are their functions?
Before being cooked or refined, papermaking raw materials undergo pretreatment and processing according to the cooking or refining process. This is divided into non-wood fiber preparation equipment and wood fiber preparation equipment. The former includes straw cutters, reed cutters, and sugarcane depigmenters, while the latter includes peeling machines and chippers.
A wood chipper is a machine that chips logs into wood chips of a certain size for the production of wood pulp. It is divided into two types: disc type and drum type.
A digester is a device that dissolves lignin in papermaking raw materials into a cooking liquor, thereby separating the raw materials into fibers. It is divided into two types: batch and continuous.
Wood grinders are equipment used to produce wood pulp. They can be classified into two types according to the production method: intermittent and continuous. They can also be classified into two types according to the method of pressurizing the logs: hydraulic pressurization and mechanical pressurization.
Pulping equipment is used in the process of separating plant materials into fibers. Pulping methods can be divided into chemical, mechanical, and chemimechanical methods, and the corresponding pulping equipment includes digesters, wood grinders, thermomills, washing machines, bleaching machines, beaters, and waste liquor recovery equipment. Pulp made by preheating wood chips with steam and then grinding them under high pressure is called thermo-ground wood pulp, and the machine used to produce thermo-ground wood pulp is called a thermomill. A washing machine is a mechanical device that separates the cooked pulp from the black liquor; based on the black liquor extraction rate, it is divided into two main categories: high-concentration and low-concentration extraction.
The purpose of pulp bleaching is to remove residual lignin and pigments from the pulp after cooking, thereby increasing its whiteness and giving the pulp a clean white color. A bleaching machine is a commonly used bleaching device, consisting of a bleaching tank, a screw propeller, a washing drum, and other components. The pulp and bleaching agent are placed in the tank, and wash water is continuously added. The bleaching agent circulates the pulp within the tank, completing the mixing and chemical reaction process. The water, containing bleaching products and residual bleaching solution, is discharged through the inner cavity of the washing drum, resulting in clean pulp.
The above is the main content introduced by the editor of China Paper Industry Network. Each part of the paper machine has its own unique function. These functions combined make up a complete paper machine. Everyone should do a good job of maintaining each part in order to improve the service life of the paper machine.
