Mould-making silicone (addition cure)
Frequently asked questions
Can Mould-making silicone (addition cure) be laser cut?
No: Mould-making silicone (addition cure) is not suitable for laser cutting. However, it releases toxic fumes — machining is not recommended.
Can Mould-making silicone (addition cure) be CNC machined?
No: Mould-making silicone (addition cure) is not suitable for CNC milling.
Is Mould-making silicone (addition cure) food safe?
Mould-making silicone (addition cure) is food safe only after a suitable finishing treatment.
Physical properties
| Density | 1100.0–1200.0 kg/m³ |
|---|---|
| Tensile strength | 5.0 MPa |
| Thermal expansion | 300.0 µm/m·K |
| Moisture absorption | Negligible |
Laser processing
Thermal decomposition releases abrasive mineral crystalline silica fumes, formaldehyde, and irritating volatile organic compounds. Not suitable for laser.
CO₂: ❌ Not recommended. Laser processing destroys the machine optics: the CO2 beam vaporizes the silicone, releasing extremely fine and highly abrasive silicon dioxide (SiO2) powder that deposits permanently on lenses and mirrors, scratching them irreversibly.
Diode: ❌ Strongly advised against. The smoke generates immediate abrasive mineral deposits on the diode lens.
Fiber: Not applicable.
CNC / milling processing
Being an extremely soft and elastic elastomer, it cannot be CNC-milled or cut as it deforms and tears under the action of the rotating bit.
Post-processing
Sanding: Impossible to sand: the elastic rubber bounces against the abrasive, heating up and deforming. Any imperfections or casting flash must be removed solely by hand using very sharp scalpels.
Primer: Nothing chemically bonds to cured silicone, except liquid silicone itself.
Gluing: Bondable or repairable only using fresh liquid silicone or silicone sealants. Cyanoacrylate or epoxy glues detach immediately with no mechanical grip whatsoever.
Over time: Exceptional durability and chemical-physical stability. Resistant to extreme thermal cycling (–50 °C to +200 °C), UV radiation, ozone, and atmospheric ageing for decades.
Common defects
- Cure inhibition (rubber stays liquid/sticky) if cast in contact with sulphur (common plasticine), cyanoacrylate glues, condensation silicones or not-fully-cured UV resins
- Air bubbles trapped in the final cast — preventable with a vacuum bell degasser or by pouring in a very thin stream from height
Safety
Recommended PPE: gloves_nitrile
Addition-cure (platinum) silicone is extremely sensitive to contaminants from mixing tools. Use clean plastic or glass containers and nitrile gloves (latex gloves inhibit curing).
Availability and formats
Commercial formats: two-part A+B liquid kit
Related materials
Sources
- FDA Regulation 21 CFR 177.2600 — Rubber articles intended for repeated food use
- Schede tecniche gomma siliconica platinica per stampi
Information on compatibility, processing parameters and safety is purely indicative. MakerSpecs accepts no liability for damage to persons or property arising from the use of this data. Always check the safety rules and the manufacturer's official manuals before carrying out any processing.