Physical Constants of Urethane Elastomers

Physical Constants of Urethane Elastomers   Compound Specific Gravity Thermal Conductivity -32°F to +32°F (-35°C to 0°C) 32°F to 75°F (0°C to 24°C) 75°F to 212°F (24°C to 100°C) GC1085 1.08 .92 – 1.1 x 10-4 – GC1090 1.11 .92 1.4 x 10-4 .95 x 10-4 .95 x...

Polyurethane Stoichiometry

Polyurethane Stoichiometry Urethane Stoichiometry is the chemical relationship of the amount of reactive elastomer polymer to the amount of curing agent used. Selection of proper stoichiometry is our responsibility, it plays an all-important part in compression set...

Hysteresis in Urethane

Do you understand how hysteresis works? Let’s examine the compression-deflection curve for a given compound at a given shape factor and record the stress-strain relationship. As the piece is loaded, we arrive at one reproducible curve after three or four cycles. Now,...

Impact Shock Force Reduction with Polyurethane

A urethane bumper can be designed by equating the kinetic energy of a moving body to the total work the bumper does as it brings the moving body to a stop. The work done is represented by the area under the force-deflection curve. Unlike steel springs, the dynamic...

Polyurethane Shape Factor

Polyurethane Shape Factor ​Let’s look at the shape factor and how it applies to polyurethane. The compression-deflection relationship is modified by the shape of the part. The shape has only a minor effect in tension and shear. For example, consider two blocks...

Effect of Loading Conditions on Polyurethane

Effect of Loading Conditions on Polyurethane Designing Polyurethane Products Given an elastomeric shape (where the top and bottom surfaces are flat and parallel) which is compressed between parallel plates, the loaded surfaces of the elastomer want to spread or slip...