01 / APPEARANCE
Design reviews and presentation samples
Compare shape, color, texture and the way visible edges meet.
Cosmetic samples. Small-batch replication.
Vacuum
casting.
From an approved master to repeated polyurethane parts. Plan the resin, appearance and critical interfaces around the purpose of your samples.
Master → Mold → PartA controlled route to repeated samples
Appearance & assemblyAgree the details the sample must represent
Resin-specific performanceMatch the data sheet to the intended test
A SMALL RUN. A CLEAR PURPOSE.
Explore the look.
Check the fit.
Vacuum casting uses a master pattern and a silicone mold to reproduce parts in polyurethane resin. It is a route to assess when you need several consistent samples before committing to production tooling.
02 / ASSEMBLY
Enclosures and mating components
Evaluate packaging, handling and assembly. Mark the interfaces that need dimensional control.
03 / SHORT RUNS
Repeated samples from an approved master
Review quantity, design stability and mold reuse together. A design change can require a new master and mold.
FROM MASTER TO REPLICA
The surface starts
with the master.
Part geometry and appearance pass through several stages. Review the master, mold split and final part requirements before making repeated samples.
Prepare the master
Use a suitable CNC-machined or printed pattern. Resolve texture, cosmetic faces and geometry before replication.
Make the silicone mold
Plan the split, resin entry and venting around the component and its visible surfaces.
Cast, finish and check
Cast the selected resin, cure and remove the part, then complete the agreed finishing and inspection.
SELECT THE PROPERTY. THEN THE RESIN.
“ABS-like” describes
a comparison.
A polyurethane that resembles a thermoplastic is still a different material. Select against the test purpose and the exact resin data sheet, including thermal, chemical and aging conditions.
| Desired behavior | Typical sample purpose | Define in the request |
|---|---|---|
| Rigid / ABS-like | Housings and general assembly samples | Stiffness, impact needs, heat exposure and finish |
| Clear or translucent | Covers and appearance models | Clarity, tint, surface condition and viewing requirements |
| Flexible / PP-like | Compliant features and handling checks | Deflection, recovery and expected flex cycles |
| Rubber-like | Grips and compliant interface samples | Target hardness, compression and contact environment |
Match the test to the material.
PU samples do not establish the long-term performance of an injection-molded ABS or PP part. If the test requires the production resin, discuss prototype injection tooling.
AGREE THE ACCEPTANCE CONDITIONS
Define what the
sample must prove.
Part size, geometry, resin shrinkage and mold condition influence the result. Critical requirements need drawing review rather than a single tolerance applied to every feature.
| Requirement | Include with the model | Review together |
|---|---|---|
| Size and geometry | Overall envelope, walls, ribs and internal spaces | Master preparation, mold handling and casting feasibility |
| Critical fit | Datums, tolerances and mating components | Shrinkage, measurement conditions and secondary operations |
| Color and appearance | Reference sample, color target and show surfaces | Resin, master finish and an agreed cosmetic approval |
| Quantity and repeats | Initial samples, quantity breaks and expected reorders | Usable mold life, replacement tooling and batch consistency |
DESIGN DETAILS
Small features.
Important decisions.
Show the complete assembly context. Identify what can change and what must remain controlled before the master is approved.
Walls, ribs and geometry transitions
Flag thin sections, large flat areas and abrupt thickness changes. Review resin flow, cure and distortion around the complete geometry.
Split lines and visible surfaces
Mark cosmetic faces and permissible mold split locations. Discuss trimming and any witness marks before approving the appearance.
Holes, threads and inserts
Identify loaded threads, close-fit holes and inserts. Agree whether a feature is cast, finished afterward or made through another route.
Undercuts and flexible features
Silicone mold flexibility does not make every undercut practical. Deep returns and delicate features need demolding and mold-life review.
APPROVE THE SAMPLE. DEFINE THE CHECKS.
Inspect against
the intended use.
Agree the revision, resin, cosmetic reference and critical dimensions. Request the inspection records or sample-approval gate your project needs before the order is confirmed.
Dimensions
Identify functional datums and measurement support, especially for flexible parts and large thin walls.
Appearance
Set the viewing conditions, color reference, surface texture and acceptable visible marks.
Repeat batches
Reconfirm the approved revision and resin, plus mold condition or replacement needs, before reordering.
BEFORE YOU ORDER
Questions worth
settling early.
Send the model, drawing revision, intended tests, quantities and target date. Add color or surface references where appearance matters.
Is cast polyurethane the same as injection-molded ABS?
No. “ABS-like” describes selected similarities. The resin chemistry and performance differ; use the exact data sheet and your test conditions to assess suitability.
How many parts can one silicone mold produce?
Useful mold life depends on geometry, undercuts, resin and the required appearance. Share the initial and repeat quantities so mold replacement can be included in the plan.
Can I request clear parts or a specific color?
Include the clarity or color target, visible faces and a reference sample if available. Resin and surface finish affect the result; agree an appearance sample when it governs acceptance.
Can the samples be used for functional testing?
Some tests may suit the selected resin. State load, temperature, chemical exposure and test duration. A successful PU sample does not validate a different production material.
What happens if the design changes?
The master and mold reproduce a specific revision. A geometry change can require replacement tooling. Confirm design stability and any likely revisions before committing to repeated parts.
What determines the price and lead time?
Master preparation, mold complexity, resin, quantity, finishing and inspection all contribute. The quotation should confirm manufacturing time separately from shipping.