Preamble
The completely fluorinated polymer PTFE is the most widely used fluoropolymer and based on its unique properties established as an undispensible construction material in modern industries.
The extraordinary properties of PTFE are due to its resistence to most chemicals, its broad service temperature range, the excelent electrical properties, the persisting to embrittlement, the ageing resistance and its high purity.
This technical brochure informs about the quality requirements and test conditions, which are necessary to assess semi – finished goods made from PTFE resins, which are essential for high quality PTFE products.
This brochure replaces in parts respectively augments the brochure „quality requirements, test guidelines and tolerances“ for PTFE products edited in 1993 by the „Gesamtverband Kunststoffverarbeitende Produkte (GKV). This technical brochure is edited by the Fluoropolymergroup of pro-K and provides the present state of knowledge as by January 2020. It replaces the brochure from July 2014, September 2017 and March 2019.
Table of content
1. Field of application
2. Specific gravity
2.1 Test method
2.2 Minimum and maximum requirements
2.3 Comments
3. Tensile strength and elongation at break
3.1 Test method
3.2Mechanical machining of test specimen
3.3 Minimum requirements
4. Ball hardness and Hardness Shore D
4.1 Test methods
4.1.1Ball hardness
4.1.2Hardness Shore D
4.2Typical values
5. Voids
5.1 Test method
5.1.1 Stabilized DC-voltage
5.1.2 Indicator for voids
5.2Maximum limits
6. Dielectric strength, volume resistivity and surface resistivity
6.1 Test method
6.2 Minimum requirements
7. Semi finished goods made of filled PTFE (PTFE Compounds)
8. Detection of Melting Point, Crystallinity and filler content for PTFE and PTFE-compounds
8.1Differential scanning calorimetry (DSC)
8.2Thermal Gravimetric Analysis (TGA)
8.3Sample for temperature regime
9. Deformation under load
9.1 Test method
9.2 Analysis