[Practical] Experts help you quickly master and use the basic concept of forming net (II) polyester forming net


Release time:

2023-10-26

The code and representation of polyester forming nets are the People's Republic of China national standards in China, GB/T 26454-2011 "Single-layer forming nets for papermaking" and GB/T 26455-2011 "Multi-layer forming nets for papermaking".

Product Model of Polyester Forming Net

The code and representation of polyester forming nets are the People's Republic of China national standards in China, GB/T 26454-2011 "Single-layer forming nets for papermaking" and GB/T 26455-2011 "Multi-layer forming nets for papermaking".

① Single-layer forming net

The product model is expressed as follows:

 

② Multi-layer forming net

The type of forming net for two-layer and two-layer and half-layer papermaking is expressed as follows:

 

Example 1:

 

Three-layer papermaking with forming net model representation method is as follows:

 

Example 2:

 

Determination of forming wire for paper making

Determination and definition of warp (weft) density, tensile strength, fixed force elongation, air permeability, water filtration, thickness, dehydration index (DI) and fiber support index (FSI) of forming webs for papermaking.

① warp (weft) density

Measure the number of warp threads per centimeter in the weft direction of the net structure, and call it warp density, root/cm; Measure the number of weft threads per centimeter in the warp direction of the net structure, and call it weft density, root/cm.

② Air permeability

The air permeability is defined as the amount of air flowing vertically through the paper-making net per unit area per unit time under the pressure difference condition of 100Pa or 124.5Pa. Expresses in m3/m2 · h or ft3/(ft2 · m)(CFM).

③ Filtration degree

Filtration is defined as the time required for 5L of water to flow through a unit area of the paper web at a specified constant differential pressure, expressed in seconds/5 liters (s/5L).

④ Dehydration Index (DI)

Dewatering Index (DI) is defined as DI(Drainge Index), which is the calculated value of the air permeability of the forming net and the effective coefficient of the weft line, which is related to the structure, weft line density and air permeability of the forming net.

⑤ Fiber support index (FSI)

FSI(Fiber supporting Index) is used to evaluate the count value of the number of effective support points for the fibers of the forming net, which is related to the structure of the forming net, the warp density and the weft density.

Relationship between the thickness of polyester forming wire and the speed of paper machine

The choice of polyester forming net, not only to consider the net structure, fiber support point, air permeability and other related parameters, but also according to the different paper machine speed and the thickness of the forming net, the final determination of the use of the net model.