Sheet in PTFE MG 1000x1000 mm natural

A sheet in PTFE MG is pure, unfilled PTFE that has been compression molded into a disc and sintered. MG stands for molded, that is compression molded; unlike skived or extruded PTFE, the sheet is built up in a mold, which gives an even structure in every direction and makes it possible to produce thick formats with low internal stresses.

The chemistry is the whole point of the material. PTFE is a fully fluorinated polymer where the strong carbon-fluorine bonds make the material inert in practice; it withstands concentrated acids, bases and almost every solvent without being affected. The temperature range runs from about minus 200 °C to plus 260 °C, wider than any other common engineering plastic, and the combination of cold and heat in the same part is a classic PTFE niche.

Friction is among the lowest measured on any solid engineering material, with a coefficient of friction against steel usually given at around 0.05 to 0.10, and almost nothing sticks to the surface. Two properties that on their own explain why PTFE is found in every process plant.

The density is around 2.15 g/cm³, heavy for a plastic, and the material does not burn under normal conditions. Water absorption is effectively zero, so the dimensions are not affected by moisture. Electrically, PTFE is among the best insulators there are, with stable dielectric properties across both frequency and temperature. That holds from low frequency power to high frequency signal applications.

The grade in this sheet is unfilled and compression molded, and that matters when you choose. Skived film from block suits thin thicknesses and liners; compression molded sheet is chosen for blanks that will be machined into gaskets, slide plates, insulators and spacers, and it is surface ground to tight thickness tolerances where needed. Compared with filled PTFE grades, pure PTFE has the best chemical resistance and the lowest friction, but also the greatest tendency to creep under load.

Creep deserves a paragraph of its own. PTFE deforms slowly under constant pressure, so bolted joints around PTFE gaskets need retightening after commissioning, and heavily loaded sliding surfaces should be dimensioned for low surface pressure. A gasket that has settled can rarely be saved with more torque; plan the retightening from the start instead. If the part has to carry more load, a glass, carbon or bronze filled grade is the right way forward.

Typical uses in Swedish industry are gasket and seal blanks in process plants, slide plates under heavy structures and bridges, liners in vessels and chutes where nothing is allowed to stick, insulator parts in electrical power, plus spacers and shims in aggressive chemical environments. What they all have in common is that the material was chosen because it handles the medium, the temperature or both, when simpler plastics have given up.

The food and pharmaceutical industries also like unfilled PTFE, thanks to the smooth, inert surface that neither takes on taste nor gives anything off; the surface is easy to clean as well. If you need certification for product contact, the compliance documentation for the grade is held by the manufacturer.

Machining calls for sharp tools and a light hand; the material is soft and tends to move away from the cutting edge. Keep cutting pressure low, support thin sections properly and expect more generous tolerances than for stiffer plastics such as POM or PEEK. Milling and turning work fine in ordinary machines, as long as the feed is adapted to how soft the material is. The sheet is of course cut into smaller blanks if you want.

Do you need a different thickness, or do you want to check whether unfilled PTFE handles the load? Contact us.