In the process of rolling, the textile calendering roller mainly passes the shearing force generated between the rollers, so that the material can be squeezed and sheared many times, thereby increasing the plasticity, and extending on the basis of further thin plasticization products.
During the calendering process, the material of the textile calendering roller is mainly subjected to the shearing force and the tensile stress during the operation of the calender roll. The high polymer will follow the rolling direction. Oriented, so that the product is characterized by anisotropy in physics.
The calendering effect of the textile calendering roller causes a difference in properties of the article, one of which is that the tensile strength of the calendered film (sheet) in the machine direction (in the direction of rolling) is greater than the transverse tensile strength, such that the transverse elongation at break is greater than the machine direction.
When the temperature change is too large, the size in each direction changes, the longitudinal direction shrinks, and the more serious is the rupture, at which time the lateral and thickness directions expand. This is the anisotropy of the product in physical mechanics.