Compression Molding: the route, the tolerances it holds, materials and design tips, with an indicative cost. One of 56 processes in the free finder.
PolymerFamily
+/-0.2mmTypical tol.
5Route steps
87Parts in finder
Compression moulding presses a measured charge of material into a heated mould that closes and cures or sets it, common for thermoset and rubber parts.
At a glance
When to use it, and when not
Best for
Rubber seals, composite panels, electrical parts and silicone moulds in medium volume.
Watch for
Longer cycle than injection; flash to trim and limited fine detail.
Step by step
The typical route
Raw material to finished part. Steps vary with material, volume and tolerance; this is the free route from the finder.
Charge
Place the compound charge in the open mold.
Tooling - Tolerance - Lead -
Mold & cure
Compression-mould and cure under heat and pressure.
Tooling Mold Tolerance - Lead -
Deflash
Remove flash.
Tooling - Tolerance - Lead -
Post-cure
Post-cure elastomers/thermosets as specified.
Tooling Oven Tolerance - Lead -
Inspect
Check hardness and dimensions.
Tooling - Tolerance - Lead -
Precision
Tolerances it can hold
TYPICAL TOLERANCE IT CAN HOLD
Where this process typically lands. Tighter is possible with extra operations like grinding, at higher cost.
Materials
Materials it suits
Grade
Why it suits this
NBR (nitrile)
Oil resistant
EPDM
Weather, water
Silicone
Temperature, food/medical
Design
Design tips
A few general pointers for Compression Molding. The full, part-specific DFM list is in the dossier.
Rubber seals and thermoset parts; robust molds, good for mid-to-high volume elastomer/thermoset parts.
PER-PART COST vs VOLUME
Per-part cost drops as volume spreads tooling and setup over more parts. The exact figures for your part at your volume, in your currency, are in the dossier.
MODEL EST.
$4.3 to 10per part at 100 off
A rough ballpark only. The dossier gives should-cost at your exact volume and currency, with the full breakdown.
GET THE FULL DOSSIER
Everything you need to quote and source it
The free route above is yours. To actually put a number on this process and buy it well:
Should-cost at your exact volume in 12 currencies, with the material, processing, tooling and overhead breakdown
Who to source from, typical MOQ and lead time, and the exact RFQ checklist to send
A quote checker that tells you if a supplier quote is fair, and the red flags to watch
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Compression moulding presses a measured charge of material into a heated mould that closes and cures or sets it, common for thermoset and rubber parts. The typical route is: Charge; Mold & cure; Deflash; Post-cure; Inspect. Rubber seals, composite panels, electrical parts and silicone moulds in medium volume.
What does Compression Molding cost per part?
It depends on size, tolerance and volume. As a rough ballpark it starts around $4.3 to 10 per part at low volume and falls with quantity. The dossier gives should-cost at your exact volume and currency. Model estimates, not quotes.
What tolerance can Compression Molding hold?
Typically about +/-0.2 mm, tighter with extra finishing operations at higher cost.
What materials suit Compression Molding?
Common choices are NBR (nitrile) (Oil resistant); EPDM (Weather, water); Silicone (Temperature, food/medical).
See the exact route and should-cost for your part
The free finder maps your part to its process and full route. Pro adds should-cost at your volume, sourcing and an RFQ draft.
