Technical Issue

Shrink film characteristic

There are many basic shrink films characteristic.
 
  • Visual properties such as Clarity, Gloss and Haze, are first noticed by end-user and the buyer. A premium shrink films should have a better visual properties (greater clarity, gloss and lower haze). Good visual properties of products have an advantage when displaying to customer.
  • Low Temperature Flex is the ability of film to perform at low temperature without any fracture. PVC has a high temperature flex and easily fracture at low temperature.
  • A modulus is used to describe the shrink film elasticity or stiffness. Higher the modulus value, the film is stiffer and resistance to bending.
  • Some films have a slip performance that permits it to move easily over metal, plastic or against another piece of film. Some films have a tack performance that adherence to metal, plastic or against another piece of film.
  • The material molecules that stretching and aligning below its melting points is called Oriented. When the material molecules are oriented equally in both longitudinal direction (LD) and transverse direction (TD), the film is called balanced oriented (Biaxial). Unbalanced oriented (preferential shrink) is the molecules oriented unequally in LD and TD. The film which is moniaxial oriented will shrink only or more in one direction, longitudinal or transverse, depend on the molecules orientation. A monoaxial shrink, shrink only in one direction; can be achieved since the molecules arrangement is designed during manufacturing.
  • Transverse Direction is parallel to the film width and Longitudinal Direction is perpendicular to film width.