Open to two or more interpretations; or of uncertain nature or significance; or (often) intended to mislead. Synonyms: ambiguous; equivocal. Context examples:
Polypropylene, also know as polypropene is a form of plastic just as polyethylene is. What separates polypropylene from polyethylene for starters is the fact that polypropylene can be molded in essence becoming pliable above a certain temperature. When it cools it will return to its solid state.
The previous three plastic pipe variants are all rigid whereas PB (polybutylene) and PE (polyethylene) are flexible; the former being rigid and used for the same purposes as CPVC and the latter being low cost. Both of these types are not joined with solvents but are instead formed with mechanical and clamped couplings.