Answer to Question 1
FEP is a copolymer of tetrafluoroethylene and hexafluoropropylene . It has the advantage of being melt processable with only minor decreases in many of the excellent physical and chemical properties of PTFE.
Answer to Question 2
Sanitary, won't react with the milk, stiffness is good so that the container will uphold its shape, easily blow molded and moderately impact resistant.