PTFE

Identity and material specification

Ensinger's TECAFLON PTFE natural data give 5 MPa compressive stress at 1% deformation under ASTM D695. Use it as a short-term comparison. A gasket or spacer under sustained preload needs separate deformation or retained-seal evidence over the specified time and temperature. Ensinger PTFE stock-shape data

PTFE is polytetrafluoroethylene; the polymer name does not specify a finished seal, bearing, lining or electrical insulator. Daikin distinguishes molding powders, fine powders, aqueous dispersions, micropowder additives and compounds. Its molding range includes unmodified and modified grades; for example, M-12 targets small-to-medium compression-molded billets, while M-111 is a modified molding powder. These forms are manufacturing choices, not interchangeable feedstocks. Daikin Chemical Europe, POLYFLON PTFE

Match feedstock to process

Daikin's F-series fine powders are intended for paste extrusion. They can fibrillate and be mixed with petroleum-solvent extrusion aids; listed applications include wire insulation, tubing, tape and porous membranes. This is a different process from ordinary melt extrusion. Daikin, POLYFLON PTFE F-series

Its D-111 is an aqueous dispersion of PTFE particles stabilized with nonionic surfactant, intended for gland-packing applications. The technical sheet reports 60 mass% solids; a kilogram of dispersion is therefore not a kilogram of dry polymer. Its values are representative, not guaranteed, and the sheet directs users to the product SDS. Daikin, D-111 technical sheet

For molding and sintering, use the exact resin supplier's process instructions. The Fluoropolymers Product Group (FPG) distinguishes actual polymer temperature from oven/equipment temperature and warns that filled compounds may need different thermal treatment. A published melting or service temperature is not a sintering cycle. FPG, Safe Handling Guide, pp. 7, 14

Unfilled stock: a bounded example

Ensinger's TECAFLON PTFE natural data sheet covers rod, plate and hollow stock. It reports the following guideline values:

The tensile and elongation results use extruded and machined specimens. Ensinger labels the values as comparison guides, not specification minima/maxima, and notes dependence on stock dimensions and orientation. Its listed 260°C application temperature comes with a requirement for individual application review. Ensinger, TECAFLON PTFE natural, version AD

Creep, wear and filled compounds

Flontech explains that PTFE can permanently deform under load through cold flow, and that fillers can improve compression, creep, wear and dimensional behavior. The tradeoffs include changed tensile properties, elongation, friction and chemical resistance. Select the complete compound for the actual loading and counterface; “filled PTFE” is not one standardized behavior. Flontech, PTFE compounds

Daikin's compound guide provides a useful within-document comparison:

Daikin describes the glass-filled entries as improving abrasion and cold-flow behavior, but cautions against soft-metal counterparts unless glass content is very low and notes possible uneven abrasion in water. Its values are representative, not guaranteed. The table is not a ranking of all PTFE suppliers or a design allowable. Daikin, Compound-Series product information, pp. 1, 3

For a sliding bearing, specify load, motion/speed, temperature, counterface material and finish, lubrication and acceptable wear. For a gasket, specify retained sealing performance after time and thermal cycling. Do not solve either problem by applying a universal friction coefficient, bolt torque or pressure limit.

Chemours's selection guide reports typical dynamic friction of 0.05–0.10 under ASTM D1894 for PTFE and explicitly directs users to individual product sheets. It also lists a typical melting point of 327°C under ASTM D3418. Neither number establishes a bearing's lifetime or a loaded component's maximum operating temperature. Chemours, Teflon product selection guide

Chemical and electrical boundaries

Polyfluor identifies exceptions to PTFE's broad chemical resistance, including some alkali metals and fluorinated compounds under particular temperature/pressure conditions. Some organic and halogenated solvents can be absorbed and cause dimensional changes. Its chart distinguishes resistant, limited resistance, not recommended and no data, with separate temperature columns; processing, compound and dimensions can alter performance. Treat a chart entry as screening evidence, then qualify the actual fluid mixture, concentration, temperature, pressure and exposure duration. Polyfluor, PTFE chemical resistance

Electrical values also need specimen conditions. Chemours's typical PTFE dielectric-strength value of 18 V/µm under ASTM D149 is specifically for 100 µm film. It cannot be multiplied by arbitrary wall thickness to guarantee a finished insulator's withstand voltage. Preserve the actual material, thickness, defects, geometry and test arrangement in qualification. Chemours, electrical-property table

Processing safety and source dates

FPG's guide calls for ventilation suited to hot processing and particulate-producing operations, with extraction designed for the process. It warns about polymer-fume exposure and prohibits smoking/tobacco products in fluoropolymer handling areas because trace contamination can generate decomposition exposure during smoking. Obtain the current SDS for the exact resin, dispersion, filler and processing aid; chemical resistance in service does not establish safe processing. FPG, pp. 9, 18

Ensinger's sheet explicitly prints 19 July 2023, version AD, despite a generated filename containing 202610. Daikin D-111 prints ver02_Dec_2020 and ©2018; the compound guide prints ver01_Oct_2022 and ©2022. FPG's guide cover is dated 8 July 2025, independent of its 2026 upload path. Live product pages do not display a technical revision date.

Material selection through production