The papermaking press felt is an indispensable industrial cloth in the papermaking industry. It has the functions of transferring wet paper sheets, keeping the paper surface flat, pressing and dewatering, and drawing paper machines.
1. Papermaking felts are classified according to different parts of use
1) Wet felt. Running with water on the paper machine, its function is to accept the paper blank from the forming part, make it dewatered by pressing, and the paper surface is smooth and based on the press felt, it drives the guide roller, bears the traction force of the paper machine, and runs continuously. Needle-punched papermaking wet felt has good water drainage, good elasticity, high strength, low elongation and shrinkage rate, and wear resistance. Resistance to acid and alkali and bacterial corrosion.
2) Top felt. It is used for Fourdrinier wire or rotary wire Yankee paper machine. Because the used part is above the wet blanket, it is called the top felt, and a small part of it contacts the drying cylinder, which plays the role of collecting paper, ironing and drying. Acupuncture top felt has the properties of flatness, stiffness, good elasticity, wear resistance and high-temperature resistance.
3) Dry felt. Used in the dryer section of a paper machine, operating in moist heat and dry conditions. On the paper machine, the drying cylinder is covered, the paper blank is set off, and the paper is ironed and dried. Acupuncture dry felt has the characteristics of firmness, good elasticity, wear resistance and high-temperature resistance.
2. Papermaking felts are classified by forming method
1) Woven papermaking felts. Traditional papermaking felts are woven fabrics, which are woven on wide looms using coarse-count yarns. Dry felt is a heavy canvas woven with cotton yarn, which has the characteristics of high strength, small elongation, good air permeability, smooth surface, high elasticity and good water absorption. The warp and weft yarns are made of multiple strands of high-quality cotton threads or wrapped with multiple strands of high-quality cotton threads] 0% to 25% polyester filament to increase the strength and make the product heat-resistant, wear-resistant, acid and alkali resistant.
2) Needle-punched papermaking felt. Needle punching papermaking felt is papermaking felt made by the needle punching method, which is used for dewatering wet paper sheets and smoothing and drying paper. Acupuncture methods generally include double-sided acupuncture and single-sided acupuncture, which have good water drainage. It has the characteristics of wear resistance and high strength. There are general acupuncture felt, thin weft needled felt, no-weft needled felt, bottomless needled felt, and composite needled felt spun with mesh felt.
3. According to the different classification of raw materials
There are general needle-punched felts made of wool and chemical fibers in different proportions, heat-setting needle-punched felts with high chemical fiber and full chemical fiber, and full-chemical fiber composite needle-punched felts with high-strength multifilament base cloth monofilament plying.
