Polyphenylsulfone (PPSF or PPSU) is a type of moldable plastic often used in rapid prototyping and rapid manufacturing (direct digital manufacturing) applications. Polyphenylsulfone is a heat and chemical-resistant material. It is typically used in automotive and aerospace applications. It has virtually no melting point, due to its amorphous nature.[1] It offers tensile strength up to 8000 psi. Its commercial name is RadelR.