Polyurethane Elastomers (Cold Castables)
Cold cast polyurethane elastomers and foams are used in a wide variety of applications from flexible polyurethane resin or foam to very hard plastics. These systems are formulated for application at room temperature and do not require heat for post-curation, making them simple and fast to produce.
Our medium/high performance polyether urethane elastomer (polyurethane) is designed to be used with flexible moulds, concrete moulds, stamp pads, cast in place linings, sound dampening applications and casters. It can be readily processed and cured at room or elevated temperatures. The convenient mix ratio and low viscosity allow for easy processing.
Bespoke formulas available
We work closely with our suppliers to provide optimised formulas for specific applications. Please contact us if you have a bespoke need. We can provide bespoke solutions for your desired physical properties.
Cold Castable Polyurethane Elastomers
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Eracast RT70A
Eracast RT70A is a medium performance cold castable polyurethane elastomer. The product is free from MOCA (methylene-bis-ortho-chloroaniline) and flammable solvents, which produces an economical elastomer with good toughness and high elongation and good chemical resistance.
It offers advantages in that it can be readily processed and cured at room or elevated temperatures. The convenient mix ratio and low viscosity allow for easy processing.
Applications
Flexible moulds, concrete moulds and stamp pads, cast in place linings, sound dampening applications and casters.
Product Specifications
Flexible moulds, concrete moulds and stamp pads, cast in place linings, sound dampening applications and casters.
(Swipe left/right to reveal table columns on mobiles)
| Product Specifications | ISOCYANATE PREPOLYMER (A) | POLYOL CURATIVE (B) |
| Specific Gravity at 25°C | 1.08 | 1.04 |
| Viscosity at 25°C (cps) | 4700 – 5300 | 360 – 600 |
| Appearance | Clear, Light Amber | Clear, Amber |
(Swipe left/right to reveal table columns on mobiles)
| Mixing and Curing Conditions | |
| Isocyanate Prepolymer (A) | 100 (pbw) |
| Polyol Curative (B) | 65 (pbw) |
| Prepolymer (A) Temperature | 25 30°C |
| Curative (B) Temperature | 25 30°C |
| Mixed Viscosity at 25°C | 2000 – 4000 (cps) |
| Pot Life at 25°C (Based on 200 grams sample) |
12 – 18 mins |
| Cure at 25°C | 24hrs at 25°C will result in an 80% cure. Fully cured att 7 days at 20°C.Alternatively a 70°C cure for 4-6 hrs will result in 80% cure. |
Eracast RT70A can be mixed by hand or readily processed through suitable polyurethane dispensing equipment.
Note: Both part A and B components are moisture sensitive. Once opened, containers should be purged with nitrogen, if they are to be stored for a period of time.
Processing Procedure
- Carefully weigh the correct proportions of the two components together in one container, mix thoroughly. Be careful not to entrap air while mixing.
- Pour the mixed material into moulds that have been prepared with release agent, being careful to avoid trapping air.
- Allow casting to cure before demoulding.
Handling Precautions
Eracast RT70A should be used in a well-ventilated area. Avoid breathing in vapours and protect skin and eyes from contact.
In case of skin contact, immediately remove excess, wash with soap and water. For eye contact immediately flush with water for at least 15 minutes. Call a physician.
If nose, throat or lungs become irritated from breathing in vapours, remove exposed person to fresh air. Call a physician.
Eracast RT90A
Eracast RT90A is a medium performance cold castable polyurethane elastomer. The product is free from MOCA (methylene-bis-ortho-chloroaniline) and flammable solvents, which produces an economical elastomer with good toughness and high elongation and good chemical resistance.
It offers advantages in that it can be readily processed and cured at room or elevated temperatures. The convenient mix ratio and low viscosity allow for easy processing.
Applications
Flexible moulds, concrete moulds and stamp pads, cast in place linings, sound dampening applications and casters.
Product Specifications
Flexible moulds, concrete moulds and stamp pads, cast in place linings, sound dampening applications and casters.
(Swipe left/right to reveal table columns on mobiles)
| Product Specifications | ISOCYANATE PREPOLYMER (A) | POLYOL CURATIVE (B) |
| Specific Gravity at 25°C | 1.08 | 1.2 |
| Viscosity at 25°C (cps) | 4800 – 5200 | 500 – 540 |
| Appearance | Clear, Light Amber | Clear, Amber |
(Swipe left/right to reveal table columns on mobiles)
| Mixing and Curing Conditions | |
| Isocyanate Prepolymer (A) | 100 (pbw) |
| Polyol Curative (B) | 20 (pbw) |
| Prepolymer (A) Temperature | 25 30°C |
| Curative (B) Temperature | 25 30°C |
| Mixed Viscosity at 25°C | 2000 – 3000 (cps) |
| Pot Life at 25°C (Based on 200 grams sample) |
8 – 14 mins |
Processing Procedure
- Eracast RT90A Part A should be heated to 30°C (the temperature may be increased to a maximum of 80°C) and thoroughly degassed at -95 kpa of vacuum until excessive foaming stops.
- The Part B (Curative) should be added to Part A (Prepolymer) and processed at room temperature. After adding the curative, mix thoroughly, being careful not to introduce air into the mixture.
- Pour mixed Erapol RT90A into moulds, which have been pre-coated with Eralease (release agent).
Adhesion
Adhesion of Erapol based elastomers to various substrates is at best marginal if a primer is not used. Please consult Era Polymers for specific recommendations to improve adhesion.
Handling Precautions
Eracast RT90A Part A contains a small amount of free TDI. Therefore, the product should be used in well-ventilated areas. Avoid breathing in vapours and protect skin and eyes from contact.
In case of skin contact, immediately remove excess, wash with soap and water. For eye contact immediately flush with water for at least 15 minutes. Call a physician.
If nose, throat or lungs become irritated from breathing in vapours, remove exposed person to fresh air. Call a physician.
Physical Properties
The properties presented below are an average based on several determinations and should not be used for specification purposes.
| Physical Properties | RT70A | RT90A | Test Method |
| Hardness (Shore A) |
70 ± 4 | 90 ± 3 | AS1683.15 |
| Tensile Strength (%) |
13 | 14 | AS1683.11 |
| Elongation (%) |
910 | 450 | AS1683.11 |
| Rebound Resilience (%) |
57 | 41 | DIN 53512 |
| Abrasion Resistance (mm3) |
130 | 196 | AS1683.21 |
| Cured Specific Gravity (g/cm3) |
1.08 | 1.12 | AS1683.4 |
| Linear Shrinkage at 23°C (%) (500mm length x 46mm width x 16mm thick) |
0.1 | 0.2 |