Urethane Casting
RTV Molding
Ordering Guide
General
Summary of Casting Process
Master Pattern
Utilizing 3D CAD files provided to us or generated by us and one of our rapid prototyping technologies, we create a master pattern
Silicone Mold
Utilizing the master pattern generated in step 1, we create a silicone mold with gating and venting.
Casting
The silicone mold is filled with liquid polyurethane and placed under heat and pressure. The cured part is then extracted and gates and any flash is removed.
Technical Detail
Mold Life
Molds are generally good for about 20 to 25 castings depending on material selected and part features such as under cuts, surface texture, thin features, inserts, etc. Also keep in mind that some urethane materials (i.e. clear) are chemically more aggressive and can reduce the life of a silicone mold.
Accuracy
Standard tolerances are ±0.015" or ± 0.003 inch per inch, whichever is greater. Tighter tolerances may be offered on a case-by-case basis.
Inspection
Overall visual inspection of feature integrity and aesthetics.
Urethane Casting Master Pattern Finishing Options:
Basic
- If SLA, layer lines ARE NOT removed.
- If machined, as machined.
Standard
- If SLA, layer lines ARE removed - leaving a matte finish.
- If machined, tool markings are removed - leaving a matte finish.
Material Selections:
Wide range of material properties available: Shore A, Shore D, Flame Resistant, UL Rate, Optically Clear as well as Foot Grade. If you know the material you desire, you can provide manufacturer and material number.
If you know the final production grade material which will be used, you can specify and we will find a casting material which will mimic it. Please be sure to list any particular property of that material which is important to you such as tensile strength, impact strength, clarity, etc.
Thermoplastic Mimics
ABS-like, PE-like, PC-like, PP-like, Nylon-like, Delrin-like, UL-94VO, High-Impact, High Strength, Optical Clear, Translucent, Opaque
Elastomers
Shore A15 to Shore A90
Standard, High Performance, Clear, opaque
Silicones
Shore A15 to Shore A60
High chemical resistance, medical grade, clear, opaque
Over-Molding
Elastomeric over-molded onto a thermoplastic mimic.
Value Added Services
– EMI/RFI Shielding
– Color Matching
– Decorating
– Metal Inserts