Ultra High Molecular Weight Polyethylene (UHMW)
Ultra High Molecular Weight Polyethylene (UHMW or UHMWPE) is a high performance engineered plastic used in high abrasion applications where low friction is desirable, including aerospace, rail, material handling, mining, medical devices, and oil and gas exploration. Its incredible durability and versatility make it one of the most utilized materials amongst engineers. UHMW has a long molecular chain giving it numerous characteristics including: high abrasion resistance, low coefficient of friction, and supreme impact resistance even in cryogenic environments.
Until recently, the only disadvantage of UHMW was that it was not moldable with traditional injection molding equipment. UHMW parts needed to be machined from sheet or bar stock or go through a specialized compression molding process that was prohibitively expensive. So, using UHMW in applications with high volume or complex shapes was not feasible. Rebling has taken advantage of new injection moldable UHMW thermoplastics which have about 90% of the abrasion resistance of traditional UHMW materials. This moldable UHMW resin has greater performance in high abrasion applications than other commercially available thermoplastics such as nylon or PEEK. UHMW also exceeds the low friction characteristics of nylon and acetal and has a coefficient of friction almost as low as PTFE (Teflon).
Properties of UHMW material
UHMW molecular weight ranges from 3.1 million to as high as 10 million. While bearing strength is maximized at 3.5 – 4 million, abrasion resistance continues to improve as the weight increases. UHMW is the ideal solution for reducing wear and friction while enhancing efficiency and productivity. UHMW is odorless, tasteless, non-toxic, and highly resistant to corrosive chemicals. Rebling has experienced success in the use of this type of material in high abrasion environments and applications where low friction is required.
UHMW plastic injection molded part design
Injection moldable UHMW parts can be designed similarly to that of other injection moldable polyethylene materials.