First, the temperature
Temperature is the most important factor that affects the heat setting quality. Because the fabric after heat-setting, the original existence of the degree of wrinkles to be eliminated, the surface roughness increases, the dimensional thermal stability of the fabric and other taking performance, are closely related with the heat setting temperature.
Second, the time
Set time is another major heat setting process conditions. After the fabric enters the heating zone, the time required for heating and setting can be roughly divided into the following sections:
Heating time: the fabric into the heating zone, the fabric surface heated to the required temperature for the time required.
Heat penetration time: After the fabric surface reaches the setting temperature, the fibers inside and outside each part of the fabric have the same heat penetration time required for the setting temperature.
Molecule adjustment time: After the fabric reaches the setting temperature, the time required for the molecules in the fiber to be adjusted according to the setting conditions.
Cooldown: The time it takes for the fabric to cool out of the oven to hold the fabric in place.
Usually refers to the setting time, often refers to the time required for the first three, not including the fourth. If we consider the first term a preheating effect, then the setting time refers only to the time required for the second and third items, ie, the time required for thermal penetration and molecular adjustment.
The time required for heating and heat infiltration depends on the performance of the heat source, the weight of the fabric per unit area, the thermal conductivity of the fiber, the moisture content of the fabric, and the like.
Tensile properties of the fabric during heat setting have some influence on the quality of the finished fabric, including its dimensional thermal stability, strength and elongation at break.
The warp dimension thermal stability increases with the overfeed by setting, while the dimensional stability of the dimension decreases with the degree of stretching of the width.
The average single yarn strength of the fabric after the setting is slightly higher than that of the un-shaped fabric, and the change of the weft direction is more obvious than the warp direction.
After setting the fabric elongation at break, the latitudinal direction decreases with the degree of stretch increases, while the warp along with the increase of overfeed becomes larger.