Technological conditions of stenter setting machine
Aug 16, 2023
After the fabric enters the heating zone, the time required for heating and setting can be roughly divided into the following parts:
1. Heating time: After the fabric enters the heating zone, it takes time for the surface of the fabric to be heated to the setting temperature.
2. Heat penetration time: After the surface of the fabric reaches the setting temperature, the heat penetration time required to make the fibers in the inner and outer parts of the fabric have the same setting temperature.
3. Molecular adjustment time: After the fabric reaches the setting temperature, the time required for the molecules in the fiber to adjust according to the setting conditions.
4. Cooling time: the time it takes for the fabric to come out of the drying room and the size of the fabric to be fixed for cooling.
The setting time usually referred to by the stenter setting machine often refers to the time required for the first three items, and the fourth item is not included to a certain extent. If one is regarded as a preheating effect, then the setting time only refers to the time required for the second and third items, that is, the time required for heat penetration and molecular adjustment.
The time required for heating and heat penetration depends on the performance of the heat source, the weight per unit area of the fabric, the thermal conductivity of the fiber, and the moisture content of the fabric. The tension of the fabric during the heat setting process has a certain influence on the quality of the setting, including the dimensional thermal stability, strength and elongation at break of the fabric.
The thermal stability of warp direction increased with the increase of overfeed in warp direction, while the thermal stability of weft direction decreased with the increase of web stretch. The average single yarn strength of the fabric after setting is slightly higher than that of unshaped fabric, and the change in weft direction is more obvious than that in warp direction. The elongation at break of the fabric after setting, the weft direction decreases with the increase of the stretch degree, while the warp direction increases with the increase of overfeed.
https://www.hans-machinery.com/
