Castable Polyurethane
Cast Polyurethanes are a versatile family of elastomers that can be molded to optimize a combination of the following properties, depending on the application:
- Excellent Resilience (high or low )
- Extra Toughness and Durability
- Very high load bearing capacity
- High Tear Strength and Cut Resistance
- Low Compression Set
- Very good impact resistance
- Outstanding Abrasion resistance
- Good machinability
- Oil, solvent, water and ozone resistance.
- Non-marking
- Mold, mildew , fungus resistance
- Flex fatigue resistance
- Good Electrical properties
- Friction (high or low)
Mechanical Properties:
Cast Polyurethanes have an extraordinary combination of many of the above properties in the same material, unlike any other engineering material. The molder has the ability to vary the ratio between the resin and the curative to optimize some of these properties ( and some times it may be at the cost of some other properties ). So, a properly engineered compound can outlast an identical hardness part by a factor of several times.
Types of Polyurethanes:
Cast Polyurethanes based on TDI, MDI,PPDI, polyethers, polyesters and polycaprolactones as building blocks, offer a wide variety of application possibilities and advantages.
Polyethers perform well in dynamic applications and in hydrolytic environments. They are extensively used in applications such as die-forming pads, press brake dies, die springs, fork lift tires, roller coaster wheels, rolls for steel and paper mills.
Polyesters have superior cut, tear and abrasion resistance as well as better resistance to oil and solvents. Typical applications include hydraulic seals, scraper blades, rolls for graphic arts, pipeline pigs, chute liners, etc.
Cast polyurethene is outstanding over other O-Ring elastomers in abrasion resistance and tensile strength. Additionally, Cast polyurethene surpasses the performance of millable polyurethene in its higher tensile strength, grater elongation, wider temperature range, and lower compression set characteristics
The heat resistance of standard compound Cast Polyurethene (to 225°F) shows a decides improvement over the lesser heat resistance of standard compound millable polyurethene (to 175°F).