Polymer birefringence is predominately the result of manufacturing processes. Most polymer plastics are inherently isotropic and as such would not show birefringence in an unstressed state. However, when these materials are subjected to stresses from extrusion, stretching and injection, blow molding processes, or even post manufacturing unintentional damage, the induced stress shows up as birefringence in the finished materials.
Evaluating the nature of the high and low birefringence areas of a material can help development scientist and engineers improve process parameters and consequently yield for both high volume plastics (e.g. liquid containers, packaging films, consumer product packaging) and high performance plastics (e.g. automotive parts, mobile and communication device covers, camera lenses). Hinds Instruments' systems and components can be used to measuring this polymer birefringence.
Biopolymers are polymers, films and bulk plastics sourced from agricultural or biological materials rather than petrochemical sources. Historically, most plastics came from petrochemical sources but with the development of sustainable and environmentally friendly materials, more and more biopolymer plastics are becoming available for a wide variety of applications. These polymers are subject to the same handling stresses as petrochemical plastics and as such will exhibit polymer birefringence in the same way. Using birefringence to understand the physical properties of these new materials can help establish usage parameters and lifetime predictive characteristics.
Exicor® MT for inline manufacturing of bulk polymer films process and quality control
Exicor® 150AT for the quality control or research laboratory setting
Exicor® product line - Kerr Constant measurement system for evaluation of block co-polymers
FURTHER READINGPolymer Stress
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