Sheet in POM+PTFE 1000x610 mm natural

Sheet in POM+PTFE combines the stiffness of the acetal matrix with the extremely low friction of the fluoroplastic. The density is about 1.52 g/cm³, higher than pure POM because PTFE is a heavy material. The continuous working temperature goes up to around 105 degrees and the material is functional down to -20 degrees. Water absorption stops at around 0.65 percent, somewhat lower than pure POM because of the PTFE addition, which keeps tolerances stable in damp environments. The fire class is HB according to UL 94. The raised density is a direct result of the weight of the fluoroplastic and something to allow for on large parts, since the weight lies noticeably above both POM C and POM+PE.

What separates POM+PTFE from other sliding plastics is the friction level. In dry running against steel the PTFE domains give one of the lowest dynamic coefficients of friction that can be reached in a matrix that carries a technical load. Wear is low and stick-slip disappears more or less completely. That makes the material suitable where surfaces have to slide silently and without jerking, for example in precision mechanics, optics mounts and linear guides with periods of standing still. The PV value is considerably higher than for unfilled POM, which opens up heavier loads and higher sliding speeds without the sliding surface starting to melt. For designers who have previously used bronze bearings with grease lubrication, POM+PTFE is often a direct replacement, with the advantage that the maintenance cycle gets longer and lubricant can be removed completely.

Mechanically the material sits somewhat below POM C in hardness, since the PTFE phase is softer than the acetal. Impact strength is good and the material is not brittle. Creep under long-term load is lower than for pure POM, which means a pressed wear plate keeps its shape longer under continuous load. Thermal conductivity is low, so the material does not help to lead friction heat away, but since the friction is so low, the heat from the sliding surface is still manageable in most applications. Chemically the material takes the same media as POM, plus a wider tolerance against solvents in the surface layer thanks to the fluoroplastic. Against strong oxidizers and concentrated acids the same limitations apply as for other POM grades, though, and the material should not be chosen for permanent exposure in such environments.

Typical uses are slide strips in conveyors, wear plates under heavy moving loads, base plates in press tools, stuffing box parts and backing pieces in hydraulic cylinders. The material works well against steel, stainless steel and hard chromed shafts. In packaging lines POM+PTFE often replaces metallic lubrication completely, which keeps production clean and the maintenance cost down. In the tool industry the sheet is used as a stop part where the surface has to take many cycles without changing dimension. At very high PV values where ordinary POM would overheat, POM+PTFE handles considerably more before the sliding surface starts to soften. In pharmaceutical and cleanroom environments the material is used as a slide support for dosing robots and movable station parts, since particle release is low and cleaning does not affect the surface. For construction solutions with a moving load, for example expansion bearings on bridges, thick POM+PTFE sheets are sometimes chosen as a bearing between steel and concrete.

The sheet is machined in CNC and water jet cut. The cutting edge holds up well, but the PTFE phase gives a slightly softer surface that easily picks up polished marks if the feed is too low. Thin strips are milled safely with sharp inserts and frequent cooling. Gluing is difficult, mechanical fastening is recommended. The sheet comes in standard formats and is cut into strips, blocks or finished blanks to drawing. For laser engraving, power and speed need to be adjusted, since the fluoroplastic phase reacts differently than pure acetal. For larger series, carbide inserts with a polished chip face are recommended so that the fluoroplastic does not tend to stick to the edge. When mounting in load-carrying fasteners, bolted joints should be tightened with a controlled torque, since soft sliding plastics otherwise risk creeping under the head and losing preload over time.

In series production a fixture that holds the sheet without building up stresses saves both time and scrapped parts. When mounting in structures that vibrate, a thin rubber shim between the sheet and the load-carrying structure can dampen shocks and extend the service life further.

Unsure whether POM+PTFE or POM+PE suits your wear situation best? Describe the load case and the mating surface and we will give a concrete recommendation based on real operation and what maintenance is possible.

At 1000x610 mm in natural, the sheet gives a little more width for slide strips with lower friction.