Compounds and Semi-Finished Products Made from PTFE. The exceptional compound for custom-tailored functionality

Compounds and Semi-Finished Products Made from PTFE: Properties and Principles Properties Performance Porous PTFE for optical applications and media separation Laminates Xymon Semi-Finished PTFE products Films/sheets, plates, rings, circular blanks, solid rods, tubes PTFE – Tailored for Top Performance and Functional Reliability Innovations in Plastics PTFE – the material that provides Modified PTFE the basis for technical solutions in For over 50 years, ElringKlinger a wide range of applications. Derived from standard PTFE, a new Kunststofftechnik has been a technol- Tailor-made by the specialist....

Our Products Made from PTFE Pages 36 – 42 • uide band for pistons and rods G • adial shaft seals (oil seals) with PTFE sealing lip R • ealing elements in large dimensions of up to S 3000 mm diameter • ngineering design elements E • embranes/diaphragms with a PTFE elastomer M Approvals and Regulations (Product Stewardship) ATEX, food contact, BAM, IMDS Processing Instructions Compression molding and sintering, Ram extrusion composite • pring-energized seals S • emory packings M • TFE hoses P • iston rings for compressors P • omposite seals C • Bellows • orous PTFE for media separation P • orous...

PTFE – Cost-Effective and Versatile Special Plastics Thanks to their exceptional properties PTFE and modified PTFE as well as the compounds made from these materials offer new tech- Despite higher material costs nical problem-solving approaches compared to conventional, mass- produced plastics, PTFE parts may well be the more cost-effective Typical Uses These unusual properties make • Sealing and anti-friction elements PTFE perfectly suited for use as a special-purpose plastic material When used in critical applications, for a wide range of applications. PTFE offers longer service life, higher...

Synthesis Polytetrafluoroethylene (PTFE) is a partially crystalline substance obtained from the monomer tetrafluor­ oethylene (TFE) by polymerization. The macro-molecules created in this process have a linear structure. PTFE’s chain structure has two interesting characteristics: PTFE The carbon chain is almost completel ­ y shielded by fluorine atoms, thus being protected from external influences. The carbon-fluorine combination is one of the strongest bondings in organic chemistry (dissociation energy: 460 KJ/mol). This gives PTFE its ex­ eptionally c high chemical and thermal resistance. Modified...

Physical and Chemical Properties of Unfilled PTFE Special Characteristics Benefits of Modified PTFE This material is characterized by a While retaining the positive proper- Besides these benefits, unfilled PTFE concentration of outstanding proper- ties that are typical for PTFE, modified has a few shortcomings as well: ties which is unique in the family of PTFE has additional benefits: • Cold flow reduced by the factor of 3 • Relatively low wear resistance • An exceptionally wide thermal • Reduced permeation of chemicals application range from -260°C up to +260°C (short-term up to 300°C) • Virtually...

Compounds Based on PTFE and Modified PTFE Fillers are incorporated into PTFE for • If required, the electric properties of the PTFE matrix may be modified • Wear resistance is increased sig- • Cold flow under load is significantly reduced • In addition, the choice of filler influences wear behavior of the • Depending on the type of filler mating surface used, thermal conductivity may The influences on the ultimate increase by a multiple • Thermal expansion is reduced properties of the compound, which may be influenced by both the PTFE matrix and the filler, have been summarized in the following...

The Most Commonly Used Fillers and their Influences on Compound Properties: PTFE-Type Filler Content in % of Weight PTFE filled with glass fibers • higher pressure and wear resistance as well as better thermal conductivity resistant to organic solvents, non-resistant to alkaline solutions and acids carbon fibers are chemically inert up to 35%, also in combination with graphite compound is brittle, filler may be attacked by oxidizing media typically up to 5%, in exceptional cases up to 15%, also in combination with glass fibers or carbon high abrasion when used with hard metals, is attacked by...

ermal Properties Thermal Resistance The thermal resistance of PTFE ranges from -260°C up to +260°C, with short-term resistance helium at -269°C). This temperature range is not achieved by any other plastic. Permanent service temperatures, however, depend on the respective load and stress factors. With regard to field applications, this means that PTFE exposed to moderate mechanical stress can be used at temperatures from -200°C up to +260°C. Temperature Limits of Selected Fluoroplastics® Melting ranges: PTFE Mod. PTFE PFA FEP ETFE PVD

Thermal Expansion of PTFE and Modified PTFE When designing assembly components the relatively high thermal expansion of these materials must be taken into consideration: If PTFE assembly components are cooled down from +20°C to -260°C this will result in an app. The development of the linear expansion coefficient shows two conspicuous ranges: • At 19°C there is a transformation within the crystal lattice (<19°C triclinic, >19°C hexagonal). • At app. 327°C there is an even higher degree of unsteadiness, the crystal melting point Relative change in length of unfilled PTFE Relative length change...

Thermal Properties Thermal expansion of unfilled PTFE and PTFE compounds, measured lengthwise Test piece: diameter 16 mm, length 40 mm I crosswise I lengthwise M crosswise = lengthwise PTFE virgin PTFE with 60% bronze

PTFE with 10% glass fibers and 10% graphite PTFE with 25% carbon PTFE with 30% carbon and 3% graphite