PTFE (Polytetrafluoroethylene) low-shrinkage crimped chopped fiber for filter needled-punched felt and manufacturing method of PTFE low-shrinkage crimped chopped fiber

Abstract

The invention discloses a PTFE (Polytetrafluoroethylene) low-shrinkage crimped chopped fiber for a filter needled-punched felt and a manufacturing method of the PTFE low-shrinkage crimped chopped fiber. The manufacturing method comprises the following steps of: preparing, mixing, fueling, curing, compacting, extruding, calendaring, rolling, depositing, unreeling, deoiling, sintering, drafting, film-splitting, carding, high-strength variable-speed crimping, hot-air oven sizing, natural annealing of air and cutting-off. According to the invention, by the adoption of the low shrinkage which is achieved after the mechanical crimping under a thermal state and the thermoforming of fibers, the cohesive force among the fibers is enhanced, and thus convenience is provided for the carding and the felting of a rear channel.

Description

technical field [0001] The invention relates to a functional manufacturing method for making polytetrafluoroethylene fibers for environment-friendly filter needle-punched felts. Background technique [0002] Polytetrafluoroethylene (PTFE) chopped fiber material has been widely used in the manufacture of needle felt as a filter material in recent years. Needle-punched filter felt is a key component in bag filter (solid-gas separation). Polytetrafluoroethylene fiber material has broad market prospects because of its wide temperature resistance (-190°C-260°C), chemical corrosion resistance, oxidation resistance, strong adaptability to working conditions and excellent functions. However, since PTFE is an ultra-high molecular polymer, the molecular chain does not have a plane saw-point conformation, but a helical conformation (as shown in Figure 1). Therefore, it has the lowest friction coefficient, high non-adhesion and self-cleaning properties at the same time, resulting in w...

AI Technical Summary

Problems solved by technology

Therefore, it has the lowest friction coefficient, high non-adhesion and self-cleaning properties at the same time, resulting in weak cohesion between fibers during the carding process, uneven carding and laying, and difficult web formation. The hooking force between the fiber and the base fabric is low, so the thickness of the needle felt is different and the strength is low

Secondly, the thermal expansion coefficient of PTFE is relatively large, and the thermal conductivity is relatively low. The PTFE fiber produced by the membrane splitting process has a large elastic plastic change under the condition of continuous heating and drawing. After the bundle is cut into short fibers, there are fibers Large shrinkage and other unstable physical properties cause the filter material to creep after being heated in use, resulting in bag swelling and bag damage after friction, especially because of its poor cohesion, when carding 100% PTFE fiber , it is necessary to modify the equipment, and spray a large amount of silicone oil, Pingping plus "0" and other additives

These methods lead to low carding efficiency, fiber agglomeration, and irreversible quality problems such as hair particles, which restricts the selection of PTFE, an excellent fiber material, by filter material companies.