The forming fabric of the paper mill forming department is a key component of the paper machine, which has a direct impact on the quality, production efficiency, and operating costs of the paper.
Single layer fabric: With a relatively simple structure, it is interwoven with a set of warp and weft yarns, which has a lower cost. However, it has certain limitations in terms of drainage performance, fiber support capacity, and service life, making it suitable for situations where paper quality is not high.
Double layered fabric: usually composed of upper and lower horizontal threads, with the threads of the two layers overlapping in pairs. The fabric layers are connected by longitudinal threads that are almost interwoven in the upper layer, with only a portion of the longitudinal threads additionally interwoven in the lower layer. The interwoven threads are generally thicker than the longitudinal threads, providing better drainage and support performance.
Three layer fabric: consisting of two sets of machine oriented yarns and two sets of machine horizontal yarns, forming a fine mesh paper side fabric layer and a thicker machine side fabric layer. The two fabric layers are usually joined together by additional stitching yarns, providing good fiber support, drainage, and resistance to interlayer wear.
The three-layer formed fabric produced by our company is not only suitable for producing low-end paper products on low-speed and medium speed looms, but also for producing high-quality paper products on high-speed paper machines. Especially, a wear-resistant thread was added in the middle of the weft yarn, and the mesh structure was adjusted to make the polyester formed fabric more prominent. It has the advantages of long service life, wear resistance, anti-aging, low net consumption, fatigue resistance, etc
During the papermaking process, the dewatering of the press section causes the paper web to pass through a series of pressure zone rollers, which squeeze water out of the pulp pad. At this stage, the moisture contained in the paper is removed by pressing it onto a large sleeve (pressing a fabric with fine synthetic fibers on the surface). This pressure also compresses the fibers, causing them to interweave and form dense, smooth sheets. At this stage, the moisture content has decreased to between 45% and 55%.
There are two options for squeezing blankets: seam and endless. Traditional paper-making blankets mostly adopt an endless circular structure. The blanket with this structure is a continuous ring without obvious seams or endpoints. Its advantage is that it can provide more uniform pressure distribution and better paper surface quality. During the papermaking process, the endless blanket can run smoothly on the paper machine, avoiding paper quality problems such as surface scratches and uneven thickness caused by uneven seams.
However, the endless circular blanket also has some limitations, and for large paper machines, the installation process may require more time and manpower. There is a seam paper blanket. Our seams use a specific connection method to connect blankets with open ends into a circular structure, which reduces the difficulty of machine operation to a certain extent, saves machine time and labor.
There are mainly spiral dry mesh and woven dry mesh.
Spiral dry mesh has higher breathability, which can quickly remove moisture from paper and improve drying speed; The spiral structure endows the dry web with good flexibility and elasticity, enabling it to better adapt to the complex operating environment of the paper machine drying section and reduce the risk of wear and breakage of the web.
The use of flat yarns in weaving dry nets increases the contact area between the net and the paper, transforming the traditional point contact of round yarn dry nets into surface contact, greatly promoting heat transfer between the dryer and the paper surface and improving drying efficiency; At the same time, the flat wire mesh body is relatively thin, and the resistance to water vapor passing through is small, reducing the chance of water vapor condensation and further improving the drying performance of the paper; In addition, the use of hydrolysis resistant polyester materials to make flat yarns has extended the service life of the dry mesh.
