PTFE Technical Specification

PTFE Technical Specification - Fluoropolymer Properties


Item Unit ASTM Test
Method
PTFE
(4F)
PFA PCTFE
(3F)
PVDF
(2F)
FEP
(4-6F)
PEEK
Physical
Properites
Density   D792 2.14~2.2 2.12~2.17 2.1~22 1.75~2.17 2.12~2.17 1.31
Melting Point oC   327 302~310 210~212 170 253~282 340
Mechanical Properties Tensile Strength Kg/cm2 D638 280~350 320 315~420 400~520 200~320 1142
Elongation % D638 200~400 280~300 80~250 100~300 250~330 20
Compression Strength Kg/cm2 D695 120 -- 320~520 600 150  
Impact Strength Kg*cm/cm D256 16.3 Not Damaged 13.6~14.7 19.6~21.8 Not Damaged Not Damaged
Hardness Rockwell Hardness D782 R25 -- R75~95 R100~115 R25 R126
Hardness Shore Hardness D1706 D55 D60 D90   D55 D85
Static Friction Coefficient -- 0.05 -- 0.25 D80 --  
Kinetic Friction Coefficient   -- 0.1 0.2 0.37 0.1 0.3 0.4
Heat Properties Heat Conductivity 104cal/cm.sec. oC C117 5.9 6.2 4.7~5.3 0.39 6  
Coefficient of Linear Expansion 106/oC D696 9.9(23~66oC) 12(21~100oC 4.5~7.0 3 8.3~10.5(-17~71oC)  
Operating Temperature oC   260 260 150~180 8.5 200 300
Electrical Properties Volume Resistivity .cm D257 >1018 >1018 12*1018 150 >1018  
Surface Resistivity   D257 >1016 >1016 -- 20*1014 >1016 >1013
Insulation Resistivity 1/8" thick Kv/mm D149 16~4 20~24 20~24 -- 20~24 24
Durability Chemical Resistance   D543 Excellent Excellent Good Good Excellent Good
Flammability % D635 Non-Flammable Non-Flammable Non-Flammable Self-Digested Non-Flammable Flame Resistant
Permeability % D570 <0.01 0.03 0 0.04 <0.01 0.1
Note : PEEK is not a Fluropolymer, it is listed only for comparison purposes under high pressure and temperature operating environment.

Types of Fluoropolymers and Chemical Resistance Comparison
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. The commonly known brand name of PTFE-based compositions is Teflon™ by Chemours, a spin-off from DuPont, which originally discovered the compound

Category (Name) Molecule Structure
(Fluorine per molecule)
Melting Point and Operating Temperature Chemical Resistance
PTFE

ptfe-chemical-formula

m.p. 327oC
W.TEMP(MAX) 260oC

Excellent chemical stability;
PTFE don't interact with the vast majority of chemicals and solvents.
However, it is vulnerable to molten alkali metal.
PTFE also interacts with fluorine gas and fluorine compounds, such as CIF3. OF2, under high temperature and high pressure environments

ETFE

etfe-chemical-formula

m.p. 270oC
W.TEMP(MAX) 150oC

Similar to the chemical resistance of PTFE, but easily corroded by nitric acids. Has chemical resistance on par with PTFE, but easily corroded by certain chemicals such as nitric acid.

ECTFE

ectfe-chemical-formula

m.p. 240oC
W.TEMP(MAX) 150oC

Highly crystalline, high polymer material, with superior permeability properties. 

PFA

pfa-chemical-formula

m.p. 302~310oC
W.TEMP(MAX) 260oC

Similar to the chemical resistance of PTFE, with superior mechanical and sanitary properties.

FEP fep-chemical-formula
m.p. 253~282oC
W.TEMP(MAX) 160oC
Similar to the chemical resistance of PTFE, but has slightly lower operating temperature.
PVDF

pvdf-chemical-formula

m.p. 170oC
W.TEMP(MAX) 130~150oC

Easily dissolved by fuming sulfuric acid, high temperature sulfuric acid, or caustic soda above 100oC; also bloats or dissolves when interacting with strong solvents such as acetonketoneDMA, acetamide or extremely alkalic primary amine such as n-butylamine.