UHMW plastic is the highest quality polyethylene (PE) available, with extreme toughness and high abrasion resistance that makes it perfect for a wide range of industrial applications. When it comes to manufacturing UHMW, machining is the go-to solution as UHMW can’t be transformed by conventional methods such as injection molding. When you need a durable plastic with great versatility that is engineered for extreme performance, UHMW is the go-to solution.
UHMW stands for Ultra High Molecular Weight. This high-density polyethylene resin has a molecular weight ranging from 3 to 6 million, compared to 300,000 to 500,000 for high molecular weight (HDPE) resins. An ultra high molecular weight gives this plastic a unique combination of high abrasion resistance and impact strength along with a low coefficient of friction, allowing it to outperform lower density plastics. But this high weight means it will not melt or flow as a molten liquid, which is why UHMW can’t be processed through injection molding or thermoforming.
Low coefficient of friction
Self-lubricating
Extremely low moisture absorption
Odor and stain resistant
Suitable for machining and fabrication
Highest impact strength of any thermoplastic
Resistant to UV radiation and micro-organisms
High abrasion resistance (up to 15 times that of carbon steel)
High wear resistance, especially in contact with metals
Noise reduction
Good chemical resistance (very resistant to corrosive chemicals, concentrated acids and alkalis, as well as many organic solvents)
Corrosion resistant
Performs well in extremely low temperatures (-482°F)
This low-cost plastic can be found in a wide range of applications, from hip and knee replacements to skis and snowboards. It is also used in hydraulic seals and bearings, body armor, high speed conveyors, dock bumpers, and chute linings. With an absorption rate of less than .01%, UHMW is popular for marine applications as well as applications that require exposure to high levels of moisture and humidity. There are several grades of UHMW available, including grades for enhanced bearing and wear, and grades that are FDA compliant.
UHMW is very hard to machine, especially for shops that are not familiar with the material. This is due in part to the fact UHMW starts to lose its properties over 200°F, and partly due to the material’s instability: UHMW’s expansion rate is 12x that of steel. Therefore heat levels have to be strictly controlled during UHMW machining with the right tools and coolants. Care must also be taken to keep cutting tools sharp as UHMW can quickly dull blades, resulting in part distortion. For UHMW parts with even surface finishes and tight tolerances, it’s important to choose a machine shop experienced in UHMW machining.
When it comes to high-wear operations, UHMW is the perfect affordable solution. With our ultra-precise cutting tools and decades of experience, Reading Plastic can deliver the high-quality parts you need right on time. Call us today at (610) 926-3245 to learn more.
