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   PROPERTY COMPARISON

1. Chemical Structure: PTFE - homopolymer, FEP - copolymer
2. Continuous Use Temperature:  PTFE - 500 deg F  FEP - 399 deg F
3. Melt Temperature:  PTFE - Does not melt, softens at 625 deg F   FEP - 500 deg F
4. PTFE, being a homopolymer has the best thermal and chemical resistance compared to copolymers.
5. Tensile Strength at 23 deg C: PTFE - 2500 psi - 3553 psi* (See Ref. below)
   FEP 100 - 3335 psi*
   In general PTFE has a tensile strength 15% to 20% lower
   than FEP; however this difference 
   may narrow at higher operating temperatures due to the
   higher sensitivity of FEP to increased to temperature.

                         TYPICAL PROPERTIES OF FLUOROPOLYMERS

                                         [1]   [2]      [3]    [4]     [5]      [6]    [7]
                                       (TEFLON)                               (KEL-F)
Property      Method        Units        PTFE   FEP     PFA    ETFE   ECTFE    PCTFE   PVDF
                                                     
Specific       D792           -          2.17   2.15    2.15   1.74   1.7      2.12    1.78
Gravity
                                                     
Melting        D223         deg F        621    518     581    527    464      410     352
Point          
                                           
Tensile        D638         psi          2,900  4,350   4,570  6,960  6,960    6,060   7,830
Strength                                                     
                                                          
Yield          D638         psi          1,450  1,740   2,250  3,480  4,500    5,800   6,670
Strength                                                     
                                                           
Elongation                   %           200-5  250-3   300    200-5  200-3    80-25   20-15
                    
Tensile        D638         psi          87     72.5    101.5  217.5  240      218     348
Modulus 
                                                    
Flex           D790         psi          98     101.5   95     203    261       -      333.5
Modulus 
                                                    
Izod           D256         ft-lbs/in    3.2     -       -      -      -        -      2-4
Impact                                                  
                                                         
Hardness       D224         Shore D      60     57      62     75     75        90       79
                                                   
Heat DT,       D648         @66psi deg C   250    158   164    219    240      248      300
                                                  
Heat DT,       D648         @66psi deg C   122    129   118    160    169       -       239

[6] Specifications: AMS 3650, Mil-P-46036, ASTM-D-1430-95 Type 1 Grade 3 , FDA Regulation 21 CFR 177.1380

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