Something about UHMW you may want to know

UHMW-PE stands for Ultra High Molecular Weight Polyethylene. It is the highest quality polyethylene (PE) available, engineered for tough jobs and a wide range of applications. It delivers savings in a number of difficult applications. Ultra High Molecular Weight is the secret of this polymer’s unique properties. Its high-density polyethylene resin has a molecular weight range of 3 to 6 million, compared to 300,000 to 500,000 for high molecular weight (HMW) resins. That difference is what ensures that this material is strong enough to withstand abrasion and impact better than lower level poly products. UHMW-PE’s high molecular weight means it will not melt or flow as a molten liquid. Processing methods are therefore derived from those of powder metal technology. UHMW-PE cannot be transformed and molded by conventional plastic processing techniques (injection molding, blow molding or thermoforming). Compression molding is the most common conversion process used with this resin because it produces a stronger, more consistent product.

UHMW is known for its high abrasion resistance, natural lubrication, high impact strength, chemical-, corrosion-, and moisture-resistance and acoustic impedance.

Due to its abrasion-, corrosion-, chemical- and moisture-resistant properties, UHMW is commonly used in applications where conditions may be too harsh for other materials. It is a cost-effective high performance polymer used to produce low cost, high quality parts.

UHMW is a self-lubricating material which exhibits excellent wear and abrasion properties as well as adding extremely high impact strength. A few of the markets which would utilize these attributes would be snowboard bottoms, package handling, packaging, food processing and automotive.

The high molecular weight is what gives UHMW-PE a unique combination of high impact strength efficient of friction and abrasion resistance that outwears carbon steel 10 to 1 making it more suitable for applications where lower molecular weight grades fail.

There are three tests you can perform:

1. Burn Test – light it with a match and smell the smoke. If it smells like candle wax – that indicates polyethylene. UHMW does not drip as readily as HDPE but it will drip.
2. Oven Test – place it in an aluminum dish in a 300 degree oven. Regular HDPE will slump or melt but UHMW will not change size or shape. However, it could warp or distort due to built in stresses.
3. Saw Test – When cut with a saw, regular HDPE gives sawdust or filings while UHMW gives strings or nothing.