Sheet in PTFE MG 1200x1200 mm natural

A sheet in PTFE MG is compression molded, unfilled polytetrafluoroethylene in sheet form: the starting material for gaskets, sliding surfaces, liners and chemically resistant machine parts. PTFE is the most chemically resistant plastic in our range; the material is inert in practice against acids, bases, solvents and oxidizing media, and the known exceptions are exotic, such as molten alkali metals and free fluorine. The grade is pure and unpigmented, hence the natural color.

On temperature the material is hard to beat among plastics. PTFE is used continuously from minus 200 °C up to 260 °C without turning brittle in the cold or softening noticeably in the heat. The density is around 2.15 g/cm³, heavy for a plastic, and the fire behavior is rated V-0 to UL 94. The coefficient of friction is among the lowest measured for a solid material, roughly 0.05 to 0.10 against steel, and the surface energy is so low that practically nothing sticks to the surface.

In short: when nothing else handles the environment, PTFE usually does.

In the 1200x1200 mm format we stock 24 thicknesses from 0.5 to 90 mm. The thinnest, 0.5 to 3 mm, are skived from sintered block to an even thickness; from 5 mm and up the sheets are compression molded.

Out in industry, PTFE sheets sit in more places than most people think of. Gaskets and sealing washers in the chemical process industry are the classic, but the sheets also become slide plates under heavy steel structures, liners in chutes and pockets where bulk material has to slide without building up, insulators in electrical equipment, plus scrapers and guide strips in food lines. We see the material at everything from pulp mills to pharmaceutical producers. Electrically the material is also one of the better insulators among plastics, with high dielectric strength even in thin layers. The unpigmented natural grade is often chosen where cleanliness is a requirement; which approvals apply to your application is stated in the material's TDS.

There are two properties to allow for in the design. PTFE creeps under constant load, what is called cold flow; a heavily pre-tensioned gasket therefore loses preload over time if the joint has no spring element. Thermal expansion is also large compared with metal, so give parts that work across wide temperature ranges room to move in the fastener. Under moderate loads and stable temperature the material is trouble free; the problems only arise when load and heat work together over a long time.

Unfilled PTFE is the base grade. Filled grades with glass, carbon, bronze or graphite improve creep strength and wear resistance considerably, but it costs in chemical purity and friction; for gaskets, liners and cleanliness critical parts it is the unfilled grade that applies, while a heavily loaded plain bearing is often better off with a filled one.

Machining calls for sharp tools more than anything else. The material is soft and tough; with high cutting speed, low feed and a sharp edge you get fine surfaces without burrs, with a dull edge you get a fuzzy edge. Clamp the sheet with light pressure and support it close to the point of machining, because the material springs away. Bonding only works after surface treatment such as sodium etching, so mechanical fastening is almost always the practical route.

If you need dimensions other than the standard format, we cut the sheet to your measurements; add CTS to the cart and enter the dimensions, and you avoid both the offcuts and the cutting job in your own workshop.

Not sure whether unfilled PTFE is enough for your case, or whether a filled grade suits better? Get in touch with us.