Plei-Tech® custom-molded polyurethanes are frequently used in demanding applications where shock absorption, vibration dampening, and noise reduction are required. Standard urethanes that do not exhibit excellent dynamic performance, low compression set, and high cut and tear resistance will quickly fail in these vibration damping applications.
We can design, mold, and test shock-absorbing polyurethane bump stops and foam bumpers to develop stress/strain (compression/deflection) curves required for bump stops, damping bumpers, and foam bumper systems to your specifications. Shock absorbing applications are both common and highly variable since they can include prosthetics, coal car draft gears, and pump check valve balls. Equipment bumpers can be designed for shock absorption on loads from 1 to 200,000 pounds. The Jobel impact bar is a specially designed impact system for use on conveyor belts to increase belt life at transition points.
Plei-Tech® 15 Foam is used for polyurethane bump stops and foam bumpers where low load and high frequency occur. This molded foam material can be compressed as much as 70% with little permanent compression set. (Compression & Deflection curves)
Before becoming asymptotic, foam products will exhibit linear spring curves over a longer distance than solid elastomers. The spring characteristics can be varied with the foam density.
Polyurethanes under the Plei-Tech® name are based upon PPDI, NDI, and TDI and are typically used in shock-absorbing applications or vibration absorbers. Depending on your requirements, our polyurethanes can vary in durometer, configuration, and chemical makeup to offer the best shock absorption performance.
Shape factor and durometer are the two criteria that most affect the spring rates of elastomers. A wide range of spring curves can be achieved by varying durometer and shape factors. The shape factor is the area in compression divided by area free to bulge.
In compression, it is essential to note that, unlike foam, solid elastomers have a very short linear spring curve before the spring rate dramatically increases. Similarly, spring rates relative to shore A change significantly after 85A and are more linear close to shore D.