The advantages and classification of the net former in the paper machine

The sandwich former in the paper machine represents a type of former in which the headbox jet is sprayed between two converging meshes.

1. The paper web formed on the ordinary Fourdrinier wire or round wire is not uniform in the thickness direction, and the fiber composition and interweaving state of the web surface and the carpet surface of the paper web are different. The two sides have different properties (for example, in terms of printing performance, the carpet side of the paper is easier to shed). Because the double-sided dewatering of the sandwich former overcomes the above shortcomings to varying degrees, the two sides of the paper have nearly the same properties, the outer surface of the paper web has a better fiber interlacing state, and the physical properties and quantitative properties of the paper web are both More evenly.

2. Another advantage of the former of the paper machine is the closed forming, and there is no free surface of the suspension in the former that is exposed to the air.

3. At the same time, compared with the traditional single-sided dehydration, the dehydration rate can be increased by about 4 times. Because the dewatering capacity of the sandwich former meets the requirements of high-speed paper machines, and its excellent paper-forming properties, it gradually dominates high-speed paper machines.

There are many structural forms of the paper machine's mesh former, which can be divided into vertical, horizontal and inclined types from its installation position. According to the forming and dewatering element used at the beginning, there are three main types of mesh former: Gap blade for-mer, Gap roll former and Gap rol/ blade former.