Do You Know The Type of Paper Making Felt?

The Usage Location of Press Felts in Paper Machine

According to the use position of paper machine, the paper making felt can be divided into wet felt and dryer felt, the wet felt including forming felt and press felt.

Forming Felt

Forming felt are mainly used in the forming section of paper machines. Forming felts are mainly used in the forming section (wire section) of single cylinder paper machine, multi cylinder paper machine, and super forming paper machines, but traditionally, they can also be classified as press felts. The forming parts of this type of paper machine have high requirements for the paper (tape) performance, water filtration performance, breaking strength, and dimensional stability of the paper making felt.

Press Felt

The press felt is mainly used in the press section of paper machines and plays a key role in the entire wet paper pressing and dewatering process. According to the structure and dehydration conditions of the pressing device, press felt can be divided into: ordinary press felts, composite press felts, support press felt, vacuum return press felt, calendering press felt, groove press felt, vacuum suction press felt, large roller press felt, shoe press felt, and hot press felt; According to the upper and lower parts of the felts used, it can be divided into: top press felt and bottom press felt; According to the order of use of the felt in the press section, it can be divided into: first press felt, second press felt, back press felt, etc.

Function of Press Felt

• Dehydration function: By using mechanical pressure to break the water fiber bond, it achieves pressure from the compression zone.
• Structural reinforcement: The squeezing force increases the hydrogen bonding area between fibers
• Process connection: The dryness of the wet paper web needs to be increased from 15-25% to 35-45% in order to meet the process requirements of the dryer section.
• Surface finishing: Squeeze the compressible (arithmetic mean deviation of contour) value to improve the surface roughness caused by mesh marks.

Dryer Felt

In order to distinguish between the forming felt and the press felt mentioned above, we refer to the felts used in the dryer section of the paper machine as a dryer felts. During the drying process, the paper sheet is tightly pressed against the surface of the dryer by the dryer felts, which accelerates the drying process, improves the drying speed and efficiency, and can also make the paper sheet flat and the surface smooth. According to the different types used for dryer cylinders, dryer felts can be divided into group cylinder dryer felt and MG felts (glossy cylinder dryer felts with rollers).