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).
Main features: 1  highly transparent. 2  crack-, curl-, break-, scratch- and yellow-resistant. 3  non-smelling and dirt-resistant. 4  free from toxic chemicals, totally recyclable. 5  suitable for underfloor heating. 6  approx. 7  not as many UK manufacturers as PVC chair mats.