To make the industrial filter cloth meet the strength and elongation required for production, the chemical fiber fabric is heat-treated under a certain tension to make its size and shape stable. Most filter cloths are subjected to heat setting treatment. So, what are the main factors of the industrial filter cloth setting treatment process?
There are three main factors of the industrial filter cloth shaping treatment process, temperature, time and tension. The tension and temperature vary according to the application environment of the filter belt.
1. Temperature
It has a great effect on the dimensional thermal stability of the fabric. The dimensional thermal stability of the fabric is generally expressed by the free shrinkage rate, that is, the percentage of warp and weft shrinkage in the warp and weft directions after the fabric relaxes for a certain time at a specified temperature. The smaller the free shrinkage rate, it indicates that the fabric size is hot The better the stability.
The temperature used is generally between the glass transition temperature and the melting point temperature, and the heat setting temperature should be higher than the maximum temperature of the fabric to ensure stability under the conditions of use. Such as polyester: glass transition temperature of 81 degrees, melting point temperature of 230-240 degrees.
2. Time
At the same set temperature, as the setting time is prolonged, the heat shrinkage rate of the fabric decreases, and the warp direction decline obviously, and the weft direction declines after a certain period of time is not obvious or even unchanged. The setting time is: heating time + heat penetration time + molecular adjustment time + cooling time = between 15-30 seconds.
3. Tension
Under certain tension, because the macromolecular chain stretches, moves, and rearranges in the direction of the external force, the fiber is denser and the orientation is higher. Once it is cooled and fixed in this state, the shrinkage rate of the fabric can be greatly reduced and the size is stable. The performance is improved, so a certain tension is applied to the fabric during the set, which helps to improve the setting effect.