BS 6564 is a British Standard that discusses polytetrafluoroethylene (PTFE) materials and products. The main aim of the BS 6564 series is to provide best industry guidance on the manufacture of PTFE materials and products such that they are fit for its intended use.
BS 6564-3 is the third part of the BS 6564 series that provides the composition and physical property requirements for E glass fibre filled PTFE fabricated products. The style of the designation follows closely the designation introduced into BS 6564-2 for unfilled products. In BS 6564-3, the requirements are specified in three grades of product which are designated grade G5, G15 and G25 containing a nominal 5 %, 15 % and 25 % of E glass fibre filler.
BS 6564-3 specifies requirements for fabricated E glass fibre filled polytetrafluoroethylene (PTFE) products which may occur in several forms, available in the grades, subgrades and types as indicated in Table 1 of the standard.
Note: BS 6564-3 does not include any detailed information on machining tolerances but it should be noted that some difficulty in achieving closely controlled dimensions may be experienced when working with PTFE.
BS 6564-3 on E glass fibre fillers for PTFE is relevant to:
Fabricated unfilled PTFE, whilst having many advantageous properties making it a material of wide applicability, suffers from relatively poor resistance to wear and high deformation when subjected to compressive loads. These deficiencies may be improved by the incorporation of fillers such as glass fibre. In order that such enhancements may be realized, up to 25 % (m/m) of E glass fibre filler, milled typically to an aspect ratio of 10 : 1 (length : diameter), is intimately compounded into the PTFE before fabrication. The addition of such amounts of E glass fibre filler gives improved wear, performance and resistance to compressive forces.
In this regard, BS 6564-3 provides guidance on designations, composition and appearance, dimensional tolerances along with performance requirements and physical properties. It also covers forms and their corresponding, grades, subgrades and types.
Thus, you can demonstrate the performance, quality and durability of E glass fibre filled PTFE by complying with BS 6564-3 requirements and guidance.