Related Legal Terms & Definitions. 1  COMPETENT WITNESS One who is legally qualified to be heard to testify in a cause. 2  RESPECTABLE WITNESS One who is competent to testify in a court of justice. 3  CREDIBLE WITNESS A credible witness is one who is competent to give evidence, and is worthy ofâ¦.
In general, combustibility of polymers depends on their chemical structures. Polymers with more carbon atoms in their macromolecular structure (e.g., PE, PP, PS, PMMA) are more combustible than polymers containing halogen atoms (e.g., PVC, PVDC, PTFE).
PVC or vinyl decking has become a popular alternative to composite decking in recent years. Some composite companies have created new products that encapsulate the composite material with a thin layer of PVC capstock for a hardened exterior shell that protects the material from stain, mildew, scratching and UV fading.s the material is extruded it is usually given a textured surface for slip resistance and appearance. Some products have reversible boards that have a wood grain side and a brushed finished side. Most low maintenance decking materials can be machined and cut just like wood decking.