Spray head assembly

Purpose and effect of stretching

Stretching is an essential step in the manufacturing process of polyester fiber. It is often referred to as the second stage of the forming of the polyester fiber, or the two forming process. It is not only a necessary means to improve the physical and mechanical properties of the fiber, but also to test the way to get good or bad. In the stretching process, the large molecules or aggregates of the structural elements are stretched and aligned along the fiber axis. The orientation change at the same time, often with similar state, and other characteristics of the institution changes.

As a result of the fibers within the macromolecules of stretching process oriented along the fiber axis, formation and increased the hydrogen bonding and dipole bond, and other types of intermolecular force fiber under external tension of chain molecules increase in the number, so that the breaking strength of the fiber significantly increased, elongation decreased, abrasion resistance and on a variety of different types of deformation fatigue strength also obviously increased.

Drafting principle

The main purpose is to improve the tow drafting of molecular chain orientation, which has a certain strength and elongation. Drawing is produced in two between the drafting mechanism. Between before and after the two drafting mechanism is due to differences in tow, stretching and stretching roller surface speed. The surface velocity of two tension roller drafting mechanism defined as the stretching ratio. In fact, the tow in the drawing roller surface slipping phenomenon, the actual draft will be lower than the values of its theory. Due to tow the total denier number is large, up to 100 ~ 200 million Dan, or even higher, the required traction tensility is also a great help drafting mechanism must be very strong.

Drawing machine's main role is under certain conditions in the axial direction of tow subjected to external force, the tow in the single fiber elongation, increase the degree of orientation, make the single fiber by low strength, high elongation of the plastic state variable for high strength, low extension of the elastic state.