First, the temperature
Temperature is the most important factor affecting the quality of heat setting of Hot Air Stenter .
Because the fabric is heat-set, the degree of wrinkles that have been eliminated, the improvement of surface flatness, the thermal stability of the fabric and other performances are closely related to the heat setting temperature.
The setting time is another major process condition for heat setting. After the fabric enters the heating zone, the time required for heat setting can be divided into the following parts:
Usually referred to the type of time, often refers to the time required for the first three items, not including the fourth item. If the first item is regarded as a kind of preheating, then the setting time refers only to the time required for the second and third items, namely the time required for heat penetration and molecular adjustment.
The time required for heating and heat infiltration depends on the properties of the heat source, the weight per unit area of the fabric, the thermal conductivity of the fibers, and the moisture content of the fabric.
Third, the tension
The tension experienced by the fabric during the heat setting process has a certain influence on the setting quality, including the dimensional thermal stability, strength and elongation at break of the fabric.
The thermal stability of the warp direction increases with the increase of the warp overfeed during the setting, while the thermal stability of the weft dimension decreases as the degree of stretch of the web increases.
After sizing, the average single yarn strength of the fabric is slightly higher than that of the unshaped, and the latitudinal change is more obvious than the warp direction.
After the styling, the elongation at break of the fabric decreases, and the latitude decreases as the degree of stretching increases, while the warp direction increases as the overfeed increases.