Engineering plastics can have many attributes or qualities, below are plastics that are particularly good for low friction

PTFE co-efficient of friction = 0.10
PTFE has one of the lowest co-efficient of friction of all materials and is the lowest of any man made material and is also simular in levels to that of ice. This engineering plastic is also commonly known as Teflon® which is a trade name applied to it by manufacturers Du-pont. PTFE is a little softer in comparison with other plastics.

UHMWPE co-efficient of friction = 0.29
UHMWPE or "Ultra High Molecular Weight Polyethylene" to give it is long name is also a very low friction material and simular in levels to PTFE. This is a dense plastic with a "waxy" feel and a member of the polythene family.

HDPE co-efficient of friction = 0.29
HDPE or "High Density Polyethylene" is a low friction material commonly used in high volume food processing factories for wear strips to guide cans or bottles around high speed production lines. It has a waxy feel, is another member of the Polythene family and is also commonly used as food chopping boards in domestic kitchens.

Acetal co-efficient of friction = 0.32
Acetal is a very slippy and a comparatively hard material that is excellent to machine. Acetal is also known by its homopolymer trade name of Delrin® and can be found in limitless applications from gears to motorcycle crash pegs.

Nylon co-efficient of friction = 0.35
Nylon is the most popular of all engineering plastics, this is because it is a good all round performer and can be found in bearings, bushes, pulleys and gears etc. Nylon does not have the lowest co-efficient of friction levels but they are very good and Nylon has other attributes.