Choosing what Millathane® millable polyurethane grade you need, but not sure where to begin? Let’s start by first discussing what Millathane is and how it is manufactured. Millathane is a reaction product of a diisocyanate with a polyol and a chain extender, and it is processed using standard rubber processing equipment. It can also be crosslinked using sulfur or peroxide cure systems.
From there, Millathane is broken down further into TWO main categories or Grades, polyether-based or polyester-based. These millable polyurethane grades are determined by the type of polyol used. While both Polyether and Polyester Grades offer excellent abrasion resistance and strength properties, there are very distinct differences between the two. Polyether grades offer better resistance to water and humidity. Polyester grades offer better resistance to oil, fuel, and solvents.
Choosing the best Millathane grade comes down to which compound properties are most important for your application. Is water or humidity resistance critical? A polyether grade is a better choice. Are oil, solvent, and fuel resistance more important? Polyester is a better choice. Different Millathane grades within these two categories offer other unique properties, too. There are thousands of Millathane formulas, but the below list should guide you to the proper grade and get you on your way!
Polyester: Best Choice for Heat, Oil, and Compression Set Resistance
Properties: Oil, fuel, and chemical resistance, excellent low and high temp performance, mechanical strength
Uses: Seals, gaskets, O-rings, membranes, CV-boots, dust covers, bearings for the automotive industry, hydraulic or pneumatic applications, drive belts, rollers
Properties: Excellent dampening and vibration control, excellent oil and fuel resistance, abrasion resistance
Uses: Automotive parts, O-rings, seals, gaskets, seals, diaphragms, bushings, test pads, suction cups, rubber-covered rollers, and solid tires
Properties: Low-temp flexibility, excellent oil, fuel and solvent resistance, high strength and abrasion resistance, resistance to gas permeability
Uses: Seals, gaskets, O-rings, suction cups, rollers, diaphragms, molded electrical parts, dust covers
Properties: Excellent frictional characteristics, low-temperature flexibility, high abrasion resistance, excellent ozone, weathering resistance, good oil, and fuel resistance
Uses: Printing rollers, paper-handling rollers, and belts
Polyether: Best Choice for Water and Hydrolysis Resistance
Properties: Meets FDA regulations for wet and dry food contact (21CFR 177.2600), hydrolysis resistance, good strength
Uses: Belting, rollers, seals, gaskets, lining, curtains, hoses
Properties: Excellent abrasion resistance, low-temp performance, hydrolytic stability
Uses: Rollers, belts, seals, gaskets, military, aeronautical
Properties: Low viscosity, high hardness, excellent water, abrasion, ozone resistance, hydrolytic stability
Uses: Rollers, belting, industrial wheels, seals, footwear
Properties: Excellent wear properties, excellent transparency, high coefficient of friction, very good UV stability
Uses: Shoe soles, roll covers, or where transparent, brightly colored, or decorative products are desired
Properties: Abrasion and water resistance, excellent low-temperature properties
Uses: Rollers, military, aircraft, belts, bushings, seals, rollers
Properties: Outstanding hydrolytic stability, water and abrasion resistance, low-temp flexibility
Uses: Rollers, seals, footwear, belting, gaskets, industrial wheels
Download our Millathane Polymer Selector Guide for even more details including density and Mooney viscosity levels of the different grades presented above. You can find even more information including specific Millathane formulas and safety data on our website.