Page 344 - BOLA Catalogue

PTFE – Polytetrafluorethylene
Discovered in 1938 by research-chemists of the DuPont (USA) it was not introduced to the market until 1946.
A partly crystalline fluoroplastic that belongs to the family of thermoplastics (but not suitable for injection
moulding). The strong bond of the fluorine atom to the carbon atom as well as the almost complete shielding ...CC... of the unbranched carbon chain by fluorine atoms result in a remarkably high chemical and thermal load.
PTFE has a thermal resistance ranging from -260 °C up to +250 °C, at short term up to +300 °C (e. g. no
brittleness in boiling helium at -269 °C). This temperature range is not reached by any other plastic material.
The continuous operating temperature depends on the load. This means that PTFE can be used from -200 °C
to +250 °C at moderate mechanical load. PTFE labware has a white appearance and a non-adhesive surface
which is easy to clean. Furthermore, this material has excellent slip characteristics. A lubrication of turning
steel or glass shafts is not necessary. Semi-finished PTFE rods are fabricated by isostatic pressing processes
or extrusion. The final products are produced by machining the semi-finished materials.
TECHNICAL INFORMATION
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PTFE - TFM
A further development of the classic Polytetrafluorethylene (PTFE) with additional modifier (PPVE).
Due to a five times lower molecular weight going along with a lower melting viscosity, the single particles merge to an almost pore-free polymer structure. Compared to PTFE, the tightness as well as the barrier effect at the same wall thickness are doubled. The flowing under pressure load, so-called cold flow, is reduced by factor three. This is particularly advantageous at high working temperatures. PTFE-TFM has an almost universal chemical resistance. Sticking of any contaminations is prevented by an extremely smooth surface. Special methods allow a simple and safe heat seal. This material is ideal for e. g. digestion vessels or gaskets. As a consequence of the excellent barrier function, chemicals cannot penetrate the material. Instruments and components made of PTFE-TFM are therefore especially suitable for frequently changed products.
FEP – Tetrafluorethylene-Perfluoropropylene
A molten copolymer of tetrafluorethylene and perfluoropropylene with a high-molecular, partly crystalline structure which had been introduced on the market in 1960. Its mechanical and chemical properties are com- parable with those of PTFE, however, the upper limit of the permanent working temperature is 50 °C lower (max. +205 °C). FEP is a typical thermoplastic material, which can be processed with the known production methods for this kind of material. New types with lower melting viscosity (= high melt flow index MFR) allow the processing at higher speed. FEP labware is translucent to transparent and non-porous.
PFA – Perfluoralkoxy Copolymer
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Fluorinated hydrocarbon with a high-molecular, partly crystalline structure. Compared to PTFE, it has additio-
nal side chains consisting of perfluorated alkoxy groups. ...CCCCC...
Trade names
3MTM DyneonTM PTFE by Dyneon
Teflon® by Chemours Fluon® by AGC Chemicals Europe
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Trade names
Teflon® FEP by Chemours DyneonTM Fluorothermoplastics FEP by Dyneon
Neoflon® by Daikin
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PFA can be processed using thermoplastic production methods and offers chemical and thermal properties equal to those of PTFE. PFA labware is translucent to transparent, non-porous and particularly useful in high- purity work. Big components with a total weight of several kilograms can be fabricated in a „single shot“ by using transfer moulding.
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By the way: BOLA offers custom manufacture. From 1 piece. Hotline +49 (0) 93 46-92 86-0
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Trade names
Teflon® PFA by Chemours DyneonTM Fluorothermoplastics PFA by Dyneon