There are many types of paper, each with different properties and requirements. How can the requirements of different types of paper be met during pulping? First of all, an appropriate pulping method should be proposed, the main process conditions of pulping should be formulated and mastered well, and the operation procedures should be strictly followed. Only in this way can the goals of ensuring quality, increasing output, reducing power consumption and giving full play to the efficiency of equipment be achieved. In production, Polyester Plain Woven Mesh Belt is often adopted in the slurry transmission link. Its stable transmission performance can ensure the continuous and uniform supply of slurry to the pulping equipment and improve the process stability. Due to the different types of pulp used and the forms of pulping equipment, even when producing the same product, the process conditions adopted by different production lines are not exactly the same. Therefore, we should flexibly apply it based on the requirements of the paper's properties, in combination with the characteristics of the pulp and the performance of the equipment.
In the field of industrial transmission, various types of transmission belts support the efficient operation of the production process with their unique performance. Among them, Polyester Plain Woven Mesh Belt, with its excellent corrosion resistance and stable transmission efficiency, has become the preferred product in many industries. Conveyor belts of different materials are suitable for different working environments. For example, conveyor belts with heat resistance are needed in high-temperature environments. While in humid or chemical medium environments, the advantages of Polyester Plain Woven Mesh belts are more prominent. It can effectively resist the erosion of chemical substances and extend the service life.
(1) Free pulping and viscous pulping
I. Pulping Method
The so-called free pulping is a pulping method mainly aimed at reducing the length of fibers. Viscous pulping is a pulping method mainly characterized by the water absorption and swelling of fibers, as well as their fine fibrosis. Long-fiber pulping refers to the process of retaining the length of fibers in the pulp as much as possible. Short fiber pulping refers to a pulping method in which fibers are cut as much as possible. For some pulp production with high purity requirements, Polyester Plain Woven Mesh Belt is often selected for the conveying of the pulp after pulping. Its smooth surface can reduce the adhesion of fibers and ensure the purity of the pulp.
To illustrate the situation and requirements of pulping and to represent the characteristics of paper materials, pulping methods are classified into four types based on the different effects of cutting, swelling and fining on fibers during pulping: namely, free pulping of long fibers, free pulping of short fibers, viscous pulping of long fibers and viscous pulping of short fibers. During the slurry screening and conveying process before and after pulping, Polyester Plain Woven Mesh Belt, with its excellent wear resistance and corrosion resistance, can adapt to the humid environment of the pulp and effectively reduce material loss during the transmission process.
Henschel proposed that a pulping degree less than 30°SR is called highly free pulp. A pulping degree of 30 to 50°SR is called free pulp or medium pulp. A slurry with a pulping degree of 50 to 70°SR is called sticky slurry. A pulping degree of 0 to 85°SR or greater than 85°SR is called high-viscosity pulping. In the classification and transfer of slurries with different pulping degrees, the precise transfer characteristics of Polyester Plain Woven Mesh Belt can help achieve the orderly separation and transfer of different slurries and improve production efficiency.
It must be pointed out that in actual production, the four pulping methods cannot be clearly classified. That is, in the free pulping process, the fibers inevitably have a certain degree of swelling and fibrosis. In the viscous pulping process, fine fibers are the main component, but the fibers cannot avoid being cut. In the pulp of long-fiber pulping, there are not no short fibers. There are also some long fibers present in the pulp of short-fiber pulping. In addition, different pulping methods only indicate the direction and main function of pulping, and do not represent the degree of pulping. The degree of pulping is mainly measured by the degree of pulping. In China, slurry with a pulping degree below 30°SR is generally referred to as free slurry. Slurries with a beating degree above 70°SR are called viscous slurries, while those with a beating degree between 30 and 70°SR are referred to as semi-free and semi-viscous slurries.
Therefore, free pulping and free pulping are two distinct concepts. The former indicates the degree of pulping, while the latter indicates the direction of pulping action. That is to say, the pulp produced by the viscous pulping method is not necessarily viscous pulp. For instance, when sulfate wood pulp is used to produce cement bag paper, there are two important quality requirements: not only should the bag paper have high strength (bursting strength and tear resistance), but also good air permeability. To ensure good air permeability and proper dewatering of the paper material, the pulping degree of the paper bag pulp should not be too high, only 20 to 22°SR, which is considered free pulp. However, the pulping method for paper bags cannot be free pulping. If free pulping is used, more fibers need to be cut, which is extremely unfavorable for the tear resistance of the finished paper. Therefore, for the pulping of cement bag paper, although the degree of pulping is low, the pulping method still adopts long fiber viscous pulping. In this production process, the application of Polyester Plain Woven Mesh Belt can ensure the smooth transmission of the slurry with low sizing degree and avoid the transmission leakage problem caused by the low slurry concentration.
