Sheet in PTFE GF15 GR10 1000x1000 mm natural

PTFE with 15 percent glass fiber and 10 percent graphite is a compound that keeps the soft sliding surface of PTFE but takes considerably higher load before it deforms. You get a material that fits where pure PTFE turns too prone to creep or wears out too fast, and where a hard metal counterpart would have scored an unreinforced surface.

The material works continuously up to 260 degrees and takes short temperature shocks far down toward cryogenic levels. The density sits around 2.17 g per cubic centimeter, which is typical for the PTFE family. The fire rating is V0. The chemical resistance is close to total: strong acids, bases, solvents and fuels leave the material alone, which is the whole point of PTFE based compounds.

The glass fiber lifts the compressive strength and cuts creep sharply. The graphite does two things at once. It lowers the coefficient of friction further compared with a plain glass fiber filling, and it raises the thermal conductivity so that the friction heat finds its way away from the sliding surface instead of building up locally. The result is a plain bearing material that takes both higher PV values and longer running times before the wear becomes measurable.

The sheet format is used above all for punched seals, slide plates, wear rails and valve seats. Typical scenarios are hydraulics and pneumatics where cup seals and guide bands in pure PTFE do not measure up, chemical pumps that run dry during startup, and stuffing boxes for valves in the petrochemical industry. When a designer wants chemical resistance like a fluoroplastic and at the same time avoids changing guide bands every six months, this is an obvious candidate.

Machining is done with sharp tools and moderate feeds. The material cuts more easily than unreinforced PTFE because the fillers give the chip a little more body. Note that the glass fiber is abrasive against the tools, so carbide or PCD is preferable to HSS in series production. PTFE moves a fair amount with temperature, roughly an order of magnitude more than metals, which matters for fits in ring grooves and guide bushings. Count on thermal expansion already at the drawing stage.

The sheets are supplied pressed and machined to the format you want. The thickness range covers thin sealing blanks up to thick slide discs. When mounting against a hard mating surface, 0.2 to 0.8 micrometer Ra is a good starting point on the steel, preferably hard chromed or hardened. Surfaces that are too smooth do not hold enough graphite, and surfaces that are too rough wear the sliding layer down early.

At 1000x1000 mm in natural the sheet combines the stiffness of the glass fiber with the dry lubrication of the graphite, good for dimensionally stable sliding surfaces.

Do you need help choosing between graphite, glass, carbon or MoS² as the filler? Get in touch and we will go through what the load, the speed and the environment require.