Polyurethane is available in several different forms such as thermoplastic, thermoset, coatings and foams (flexible, semi-rigid and integral skin). A variety of processes are used to produce parts, including injection molding, extrusion, RIM, spray and casting. Most can be supplied in polyether or
polyester base formulations. The ethers are generally better for use in contact with water and have higher heat resistance. The esters have higher abrasion and oil resistance.
Thermoset and some foam types are supplied in standard shapes (sheet, rod, bar and tube) as well as custom molded parts. Advantages of the cast types are low cost tooling and short production runs.
Injection and extrusion will generally result in lower piece prices, but tooling can be quite expensive.
Polyurethanes are versatile engineering materials designed to provide properties not available in conventional rubbers, metals and plastics.Typically they have higher oil and solvent resistance, along with greater abrasion and tear resistance. Impact strength, low compression set and superior load bearing capacity are also important engineering characteristics.