Sheet in POM H+PTFE 3000x620 mm brown

A sheet in POM H+PTFE is acetal with a PTFE filler blended in, a compound where the PTFE particles are spread evenly through the POM matrix. The result is an internally lubricated material with much lower friction and improved wear resistance in dry running compared with standard POM, while the stiffness and dimensional stability of the POM base are kept. It is a combination that is hard to reach with external lubrication alone.

The density is around 1.41 g/cm³ and the continuous service temperature reaches up to 105 degrees. The material copes down to -40 degrees without losing toughness. Water absorption is low, around 0.8 percent, which keeps the tolerances stable even in a damp environment. The flammability rating is HB according to UL 94. The high dimensional stability makes the material dependable in duty with changing temperatures as well, where other plastics would wander outside the tolerance.

The PTFE filler lowers the dynamic coefficient of friction markedly. That shows clearly in applications where two surfaces slide against each other without lubricant. The wear surface ploughs more slowly, the temperature of the counterface rises less and so called stick-slip behavior disappears in most situations. The additive moves stiffness and hardness somewhat toward the softer side, but that is a deliberate compromise for the sliding properties. The PV value (the product of pressure and speed) the material takes in dry running is higher than for pure POM grades, which opens up more applications where oil or grease is not wanted.

In sheet form POM H+PTFE is the first choice for milling slide plates, wear surfaces, guide rails, slide washers, cams and running surfaces that work without lubrication or with a limited oil supply. The material is used a great deal in packaging machines, conveyors, food equipment and in assembly fixtures where moving parts are to slide quietly and cleanly. In workshop mechanics the sheets are used for slide strips in hydraulic cylinders, guide elements in pneumatics and as a wear surface against steel in lightly loaded bearings. Quiet running is often a bonus in environments where noise from conveyors would otherwise be a nuisance.

In machining terms POM H+PTFE behaves in principle like ordinary POM. The material is turned, milled, drilled and cut with standard tools for plastic or brass. Count on short chips, a shiny surface and dimensionally safe tolerances. Thermal expansion is around 0.11 mm per meter and degree, which should be weighed in when press fitting against steel or aluminum. Use sharp tools with a positive rake angle; blunt edges give heat and spoil the surface on the finished part.

The material is not friendly to adhesives in the classic sense, which is typical of both POM and PTFE. Parts are screwed, clamped or assembled mechanically. Welding works poorly since the PTFE filler disturbs the melt. For a measurable friction improvement over standard POM, thin sliding surfaces are enough; a sheet a few millimeters thick gives the same sliding property through the whole thickness. That means thin wear linings work perfectly well, which saves both material and weight in the construction.

Chemically the material takes most organic solvents, mineral oils, fuels, weak acids and alcohol. Strong acids, concentrated bases and oxidizing media should be avoided over time. The material is not UV stable in natural color, so for outdoor or sunlit placement darker versions or a protective surface treatment are recommended. When choosing a counterface, hardened steel or anodized aluminum works best; soft or roughly ground metal wears the plastic down faster.

The sheets are supplied in natural color (slightly brownish from the PTFE additive) in a range of standard thicknesses and format sizes. Cutting to finished size is done to order, and for larger series we can also pre-cut blanks that are ready to go straight into the next machining operation, which saves both time and material waste.

Choosing between POM H+PTFE and oil filled POM or standard POM, the sliding requirement is often what decides. If the part has to take high PV values in dry running, the PTFE grades are the first choice. If the part stands still and is loaded statically, standard POM with plain stiffness is often enough. For slide plates in a food environment where oil must not get into the product, the PTFE filler is particularly valuable, since the lubrication is enclosed in the material and cannot migrate out in service. In larger series production it is also worth working out the material cost against the service life; a POM H+PTFE sheet costs more per kilo than pure POM, but the longer life in a sliding application often makes up for the price difference. If you need help comparing and picking the right grade for a specific sliding surface, send over a sketch or a description of the application and we will come back with a proposal.

The 3000x620 mm format in brown, homopolymer with PTFE blended in for drier sliding in bearings and strips.