390 is the stiffest grade giving it better dimensional stability.
Grade 390 rubber is a high tear strength rubber for the casting of polyurethane resins.
Its high tear strength permits castings to be made with larger than normal under cuts. When cured, it is stiffer that 370 and 380 giving it better dimensional stability.
Pale blue (when mixed) Comes complete with hardener – mix-ratio is 5 parts of hardener to 100 parts of rubber. (For casting in Clear PU please use Grade 400.)
- Pot Life: 45-120 minutes
- De-mould: 8 hours
- Mixed viscosity: 19,500 mPas
- Shore A hardness: 22°
- Elongation at break: 497%
- Tensile strength: 3.64 MPa
- Tear strength: 26.24 kN/m
- Young’s modulus: 1.5 MPa
- Linear shrinkage: 0.4% Min
- Service temperature: -50°C Max
- Service temperature: 200°C