Millable Polyurethane Rubber
Millable urethanes are specially polymers that have found use in applications that need the unique combination of properties that uretahnes offer: excellent abrasion resistance, tensile and tear strength, oil resistance, low temperature flexibility and ozone resistance. Urethanes are inherently very good for resistance to gas permeability as well, but this property was improved upon with development of new polymer which combines excellent nitrogen permeability with excellent low temperature flexibility. Another new polymer filled a gap in the range of commercial polymer by being developed for wet food handling requirements. These two new polymers expand the range of application where millable urethanes could use. Molded parts based on millable polyurethane rubber make a perfect choice for seals, gaskets, O-rings, membranes, CV-boots, dust cover, mounts and bearing for the automotive industry. Millable polyurethane are also widely used at the production of rollers and drive belts for many business machines. Other market includes footwear, mechanical engineering and plant construction, the textile industry, the petroleum industry, and transportation and vehicle construction. Typical applications are tile molds, hydraulics gaskets, diaphragms, seals, belt, roller covering, vibration insulators, bumpers, pump stators, cable jackets, sand blaster and shoe soles.

Castable Polyurethane

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).