Extrusion

Also called: Plastic extrusion, profile extrusion, pipe extrusion, sheet extrusion

Extrusion melts plastic and pushes it continuously through a shaped die to make pipes, profiles, sheet, film, tapes and pellets.

Extrusion is a continuous process in which plastic is fed into a heated barrel, melted and conveyed by a rotating screw, then forced through a shaped die. The emerging shape is cooled and cut or wound. Extrusion makes pipes, profiles, sheet, film, raffia tapes, cable coatings and filaments, and is also the core of pelletising and compounding.

Why it matters when buying recycled plastic

• Pipe and profile extrusion needs low MFI with good melt strength; using high-flow injection-grade material causes sagging and weak products.
• Extrusion is continuous, so lot-to-lot consistency matters even more than in moulding.
• Melt filters can catch solid contaminants but block quickly with dirty material, raising downtime; check contamination.
• For PVC pipe and profile, keep rigid scrap separate from flexible PVC.

Common recycled materials in extrusion

Recycled HDPE and PP for pipes and sheet, rigid PVC for pipes and profiles, LDPE and LLDPE for film, and PET for sheet and strap. See also film blowing.

Before switching to recycled feedstock, run trials and check output rate, surface finish and dimensional stability over a full shift.