Teflon is the common name of a specialised class of a PTFE fluoropolymer engineering plastic that is resistant to practically every chemical known to man.
The spectacular physical qualities of Teflon rod, sheet & cylinders include a surface as slippery as ice, to which no substance will adhere unless specially treated.
But Teflon (Dupont's trade name for PTFE) is only one member of a broader family of PTFE plastics that can be custom-formulated to deliver superb engineering characteristics required by industrial engineers. Just as metals can be mixed to create metallic alloys, and chemicals combined to create new compounds, so PTFEs can be tailored to achieve certain highly desirable benefits under particular conditions.
One branch of the PTFE family that is especially useful as a bearing and wear surface material is the Ticomp family from our company, Dotmar EPP. These aristocrats of engineering plastics are ideal for applications ranging across the industrial spectrum, from delicate chemical, food and beverage tasks to heavyweight materials handling, minerals processing, energy generation, primary processing and water and waste water tasks.
In one demanding recent Australian application, for example, the Ticomp S polymer was used on 370mm (14.5in) diameter shafts as an alternative to conventional filled Teflon PTFE rotary seal arrangements on 14 large recirculating pumps used by an Australian power generating company seeking optimum reliability. After more than 500 hours operation, the Ticomp S seals were removed and inspected. There was no marking of the hard steel shaft, no deformation of the seal itself and little evidence of wear on the seal. The Ticomp S seals continued to perform with exceptional wear life, with fewer maintenance shutdowns required as a result.
Before considering the Ticomp family for particular applications, however, it is important to know that there is no one ideal PTFE compound (because, as we know, each is tailored to achieve certain benefits under particular conditions).
Selection of materials should be examined in partnership with specialists (such as Dotmar EPP on www.dotmar.com) but it is helpful to know at the outset that the Ticomp range of materials includes five outstanding materials each with particular attributes:
This material was the result of the search for a material with chemical inertness similar to PTFE, with FDA-approved constituents that offered no formation of debris, low wear, low friction and low abrasion against soft mating surfaces, such as stainless steel.
• Excellent wear properties • Excellent Chemical resistance • Constituents FDA approved. • For high PV and rotary seal application
Applications include pump valves, valve seats, rotary seals, food and pharmaceutical dosing seals, mixer bearings and LNG seals.
This material combines the adhesive wear transfer properties of Ticomp S with improved memory and resistance to deformation under load. (Adhesive wear is the mechanism whereby the polymer composite is sliding against smooth steel and a transfer layer of polymer is deposited on the counter face).
• Excellent chemical resistance, closely matching that of virgin PTFE, with outstanding resistance to hot concentrated sulphuric acids, hot caustic soda and concentrated sulphuric acid. • Service temperature under load rated up to 210C, depending on media, loads and speed • Excellent ductility of the alloy combined with low friction, which optimises adhesive wear resistance
Fluoro-polymer composites are now being used increasingly as engineering materials or applications in which tribological properties are important. Suitable for use with foodstuffs, typical products include high duty seal, low deformation gaskets and bearings up to 240 deg C.
This unique synthetic polymer offers
• Good chemical resistance, similar to virgin PTFE • Not abrasive, suited to hard and soft metal counter faces • Excellent creep and deformation resistance at high temperature • Dissipates heat • Used for high temperature applications where deformation resistance is required, such as Deckel Seals
Applications include gaskets, valve seals (ball and gate), bearings, piston rings – non lubricated, hydraulic/pneumatic seals, Deckel seals and bearing pads. When used as an advanced Deckel seal material for sheet extruders, it offers extended seal life, fewer tool changes and custom dimensions.
A newly available synthetic polymer alloy ideal for sealing in high-pressure, high temperature settings that also require low wear and friction.
• Excellent creep and deformation resistance at high temperature • Chemical resistance similar to virgin PTFE • Dissipates heat • Also not abrasive, suited to hard and soft metal counter faces
Applications include gaskets, valve seals (ball and gate), bearings, piston rings – non lubricated, hydraulic/pneumatic wear bands, spring-energised seals.
These specialty formulated polymers offer high strength over a wide temperature range, from -270 C to 275 C with short-term application to 300 C.
• Excellent long-term stability • High purity with low out gassing in vacuum • Excellent electrical insulation properties • Outstanding wear resistance • Good chemical resistance • Low specific gravity
These five Ticomp materials often command a higher price per kilogram than less effective materials, naturally enough. However, this is offset with greatly improved life and performance when correctly specified for a particular application.
Dotmar EPP Pty Ltd is a privately owned Australian & New Zealand business focused on the application of plastic materials, polyurethanes & conveyor products in engineering
Established in 1967 and ...