Melt
Granules are melted by the extruder screw.
Manufacturing services · Chapter B · Method 12
Plastic extrusion
Thermoplastic is melted and pushed through a die to make continuous profiles, tubes and sheet, then cooled and cut.
How it works
Plastic extrusion, step by step.
A labelled schematic of the process (not to scale), and the four steps every job goes through.
Die
Melt is forced through a shaped die.
Calibrate & cool
Vacuum sizing and water tanks set the profile.
Haul-off & cut
A puller draws the profile; a saw cuts to length.
Reference figures
What to expect.
Typical industry values to help you plan. We agree the figures for your part on the drawing.
Tolerance±0.25–0.76 mmFor 3–25 mm features
Wall±10 %Typical
Angularity±3° rigid / ±5° flexibleTypical
Straightness≤0.64 mm per 300 mmCamber and bow
| Materials | PVC (rigid and flexible), PE, PP, ABS, PC, PMMA, TPE and co-extruded combinations. |
|---|---|
| Finishes | Ra 3.2 µm or better; gloss, matte or co-extruded coloured skins. |
| Design guidance |
|
| Best suited to | Trims, channels, tubing, light diffusers, frames and edge protection. |
| Watch-outs | Constant cross-section only; complex hollows need special tooling. |
More in chapter B
Other methods in Plastics & polyurethane
Next step
Not sure this is the right route?
Send a sketch, photo, sample or CAD file with your quantity and target date. We will recommend the most sensible route and explain the trade-offs before quoting.
Reference figures are typical published industry values for planning, not a guarantee; final tolerances, materials and finishes are agreed in writing for each project.