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Materials and components
News Release from: FTL Seals Technology | Subject: PTFE materials and parts
Edited by the Engineeringtalk Editorial
Team on 06 March 2008
PTFE materials provide new properties
FTL Technology offers state-of-the-art technology in PTFE, including cost-effective injection moulded parts in PTFE, tubes and components in PFA, porous PTFE and PTFE foils and films.
Polytetrafluoroethylene (PTFE) is a partially crystalline substance obtained from the monomer tetrafluoroethylene (TFE by polymerisation The macro-molecules created in this process have a linear structure
This article was originally published on Engineeringtalk on 5 Jun 2008 at 8.00am (UK)
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PTFE's chain structure has two interesting characteristics.
The carbon chain is almost completely shielded by fluorine atoms, and so is protected from external influences.
The carbon-fluorine combination is one of the strongest bondings in organic chemistry (dissociation energy 460kJ/mol).
This gives PTFE its exceptionally high chemical and thermal resistance.
Modified PTFE is obtained from the monomer, tetrafluoroethylene (TFE) and a modifier (which is perfluorinated as well), perfluoropropylvinylether (PPVE).
The shorter molecular chains (compared with PTFE) have a higher tendency to crystallise, and this would degrade the mechanical properties of the material.
The modifier effectively inhibits crystallisation, which means that with modified PTFE it is possible to combine thermoplastic property components - due to the shorter molecular chains - with the good mechanical properties of standard PTFE.
Unfilled PTFE is characterised by a combination of properties that make it unique in the family of plastics.
These include an exceptionally wide thermal application range from -260 to +260C (short-term up to +300C) and a virtually universal chemical resistance.
Additionally the material is lightweight and resistant to both weather and hot water vapour.
It has very good sliding properties and is anticombustible.
Unfilled PTFE has good electric and dielectric properties and exhibits no absorption of water.
It is physiologically harmless (with BgVV, EU and FDA approvals for use with foodstuffs).
As well as retaining the positive properties that are typical for PTFE, modified PTFE has additional benefits.
Cold flow is reduced by the factor of 3, with reduced permeation of chemicals and gas down to half of the PTFE value.
Porosity is half that of PTFE, and there is a minimum tendency for pore formation during drawing processes.
Modified PTFE is suitable for welding, using special methods. Request a free brochure from FTL Seals Technology ...
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