IsoCast RCR 731

IsoCast RCR 731 is used to make castings from rigid and flexible molds. Some of the most common uses of IsoCast RCR 731 are point-of-purchase displays; rapid prototypes; special effects; and sculpture reproductions. However; IsoCast RCR 731 can be used for any application that requires a lightweight; hard plastic.
IsoCast RCR 731 is a two-part polyurethane casting system. IsoCast RCR 731 is mixed one-to-one by volume and cures at room temperature. IsoCast RCR 731 produces a higher exothermic temperature than our other IsoCast RCR products; begins to gel in 1.5 minutes; and cures to an off-white color.



  • Point of Purchase Displays
  • Rapid Prototypes
  • Sculpture Reproductions
  • Special Effects


  • Convenient mixing ratio (s)
Product Types

Casting Resin


Product Testing

Test PerformedTest Results
Color - ISOBrown  
Color - POLYellow  
Color of PartOff White  
Compressive Strength - ASTM D6954994.1 psi 
Compressive Yield Strength - ASTM D6954994.1 psi 
Cure Time30 Minutes 
Demold Time8-15 Minutes 
Elongation - ASTM D41210 % 
Flash Point - ASTM D92 - POL305 °F 
Flash Point - ASTM D93 - ISO325 °F 
Gel Time - 100 gram sample, 74°F90-150 Seconds 
Hardness - ASTM D2240 - Shore D71-75 Shore D 
Heat Distortion Temperature - ASTM D648145 °F 
Izod Impact Notched - ASTM 256A.28 
Izod Impact Unnotched - ASTM 256E6.2 
Izod Impact-Notched, Four Specimens - ASTM D256-93A.31 
Linear Shrinkage - ASTM D2566.0065  
Modulus of Elasticity - ASTM D7901085.8 MPA 
Pot Life - 100g45 Seconds 
Ratio by Volume - ISO:POL1:1  
Ratio by Weight - ISO:POL1.12:1  
Rebound, Bayshore % - ASTM D263230 % 
Reversion Temperature270 °F 
Shrinkage0.28 % 
Specific Gravity - 74°F, ISO1.08-1.13  
Specific Gravity - 74°F, POL.97-1.02  
Specific Gravity - ASTM D792.99  
Stress - ASTM D790 - at 5% Strain40.6 MPA 
Tensile Strength - ASTM D4124700 psi 
Viscosity - ASTM D-2196 - 74°F, ISO10-90 cps 
Viscosity - ASTM D-2196 - 74°F, POL100-300 cps 

Posted on

December 18, 2020