Blow Molding: the route, the tolerances it holds, materials and design tips, with an indicative cost. One of 56 processes in the free finder.
PolymerFamily
+/-0.3mmTypical tol.
5Route steps
70Parts in finder
Blow moulding inflates a hot plastic tube (parison) against a mould cavity with air, forming a hollow one-piece part.
At a glance
When to use it, and when not
Best for
Bottles, tanks, containers and ducts in high volume.
Watch for
Hollow parts only; wall thickness varies and is hard to hold precisely.
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.
Preform
Injection-mould the preform.
Tooling Preform mold Tolerance - Lead -
Reheat & blow
Reheat and stretch-blow against the bottle cavity.
Tooling Blow mold Tolerance - Lead -
Trim
Trim the neck.
Tooling - Tolerance - Lead -
Leak test
Leak/pressure check.
Tooling - Tolerance - Lead -
Decorate
Label, print or sleeve.
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
PET
Clear, strong, recyclable
HDPE
Opaque, chemical
rPET
Recycled
Design
Design tips
A few general pointers for Blow Molding. The full, part-specific DFM list is in the dossier.
Over-weight bottle.Light-weight the preform.
Non-standard neck.Use a standard closure finish.
Cost
What it costs
Bottles and hollow parts; pennies at scale, resin weight is the biggest lever. Blow near the filling line.
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.
$0.38 to 0.64per part at 1,000 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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Blow moulding inflates a hot plastic tube (parison) against a mould cavity with air, forming a hollow one-piece part. The typical route is: Preform; Reheat & blow; Trim; Leak test; Decorate. Bottles, tanks, containers and ducts in high volume.
What does Blow Molding cost per part?
It depends on size, tolerance and volume. As a rough ballpark it starts around $0.38 to 0.64 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 Blow Molding hold?
Typically about +/-0.3 mm, tighter with extra finishing operations at higher cost.
What materials suit Blow Molding?
Common choices are PET (Clear, strong, recyclable); HDPE (Opaque, chemical); rPET (Recycled).
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.
