Technical basis for selecting press felt

According to the technical conditions of paper machine production.

1. Line pressure and mechanical load: 

The line pressure and mechanical load in the press area of paper machine are proportional to the strong requirement of press felts. The greater the line pressure, the higher the selected paper-making blanket can withstand the life cycle of the compressive performance, while requiring good elasticity of the press felt return performance, so that the press felt can maintain good water filtration performance and water tolerance space for a long time. The greater the mechanical load, the greater the elastic return of the bottom mesh layer and the greater the tensile (fracture) strength when transmitting power, and the smaller the elongation and shrinkage rate. Generally, the manufacturers of old press felt will design different bottom nets with different organization structure according to different press line pressure and mechanical load to meet the demand of different line pressure and mechanical load.

2.The size of vacuum degree :

 The vacuum degree of the papermaking system and the vacuum system setting state directly determine the water content size, cleanliness and dewatering performance state of the papermaking felt, especially the bottom net papermaking felt. If the vacuum degree is too small, it will lead to poor water dragging of wet paper sheet, large water content of press felt, pressure of pressure zone can not be added up, difficult to lead paper and unclean press felt washing problems. Vacuum degree is too large, will lead to paper machine transmission load increases, the net felt wear aggravated, energy waste and other problems

3.Washing conditions: 

washing conditions include the configuration of the washing device, washing water quality requirements, washing water pressure and vacuum settings, etc. Washing conditions are good or bad and washing effect is proportional. Under normal circumstances, the requirements of each paper machine should have good washing conditions to meet the requirements of the network, blanket, but the actual situation is that each paper machine varies, and each paper machine in different periods of time. Therefore, when choosing press felt, it is completely necessary to adjust the variety, quantitative, structural ratio and production process of press felt and the degree of stereotypes to cater for the needs of paper machines within a certain range.

4.Pulp: 

The quality of the material not only affects the quality of the paper to be copied, but also plays a vital role in the water filtration state and service life of the paper felt. Pulp  degree, filler viscosity and impurity content and paper blanket water filtration performance is inversely related, in addition to chemical fiber resistance to weak alkali, avoid acid, the pulp PH value of high and low on the paper blanket also has a certain impact. When choosing the matching paper blanket, we must pay attention to the ratio of pulp, the pulp pulp degree and wet weight, the use of chemical products, the acidity and alkalinity of pulp and other parameters, which directly affect the water filtration performance and service life of press felt, and also affect the surface sticky pulp state of press felt.