Paper Machine Press Felt
Paper machine press felt is important for removing water of paper sheet in paper machine press section, and it has some properties to ensure work efficiency.
Paper Machine Press Felt Properties
Strength: Press felt has a certain strength. The periodic stress and fatigue in the process of pressing can cause the felt elongation, compression and horizontal direction strain. When felt is used too long, the deformation will reduce the felt quality and reduce felt service life.
Void Volume: The void volume refers to the measured value of water capacity of press felt, especially the maximum water capacity of the press felt under the load effect. Felt shall have a certain volume of voids to absorb the water pressed out of the wet paper sheet.
Permeability: Permeability refers the performance of water or air through felt under certain pressure or vacuum conditions. Press felt must have good permeability. The fluid pressure in pressure zone is too high to cause wet paper embossing. Fillers, binders, fine fibres and other impurities can clog felt pores and reduce felt permeability. So the felt must be cleaned regularly to keep felt clean. And as far as possible to avoid impurities to block felt pores, maintain its smooth, water permeable and large enough void volume to play the auxiliary dehydration of felt.
Compressible Properties: Felt must be kept in a certain degree of compressibility. After the felt is used, the pore volume decreases gradually, and the diameter of the capillary pipe becomes smaller. The result is that the channel of fluid flow and the penetration of the felt are reduced, and the pressure of pressed zone increases.
Wear Resistance: The felt play the role of transporting power, driving the action roller in press section. Because the felt will produce friction with some fixed element surface, such as felt suction tank or suction pipe, so the felt must have good wear resistance.