Teflon® Compression Molding

PTFE / Teflon® Compression Molding

PTFE (polytetrafluoroethylene) is a high-molecular-weight fluoropolymer that consists entirely of carbon and fluorine atoms.  PTFE is best known by the brand name Teflon®.

Thermech manufactures compression-molded PTFE stock shapes:

1. •PTFE sheets
   

2. •PTFE plate
   

3. •PTFE rods
   

4. •PTFE tubes
   

5. •PTFE rings
   

6. •PTFE discs
   

7. •PTFE near-net shapes, which reduce scrap and save money
   

We also manufacture compression-molded PTFE parts that are precision machined to our customers’ exacting specifications.

We compression mold and machine both virgin PTFE and filled PTFE compounds.  Various fillers are blended with PTFE to enhance particular properties.  Some fillers include carbon fiber or carbon powder, glass fiber or glass bead, bronze, molybdenum disulfide (MoS2), polyphenylene sulfide (PPS), Ekonol® and many different pigments.

PTFE / Teflon® Properties

1. •Unsurpassed chemical resistance, only molten alkali metals and a few fluorine-containing compounds at elevated pressures and temperatures will attack its surface
   

2. •Not affected by any solvents
   

3. •Ultra-high purity
   

4. •Exceptional flame resistance, rated UL 94 V-0
   

5. •Extremely low coefficient of friction
   

6. •Excellent insulator
   

7. •Low dielectric constant over a wide frequency range
   

8. •May be used in food contact applications in compliance with FDA 21 CFR 177.1550
   

9. •Fillers can enhance PTFE’s mechanical properties
   

10. •Suitable for outdoor use with no degradation from exposure to the elements
    

PTFE / Teflon® Applications

When the ability to withstand high temperatures is required, compression-molded and machined PTFE is often used to make seals and other parts for aircraft, rockets and missiles.  PTFE is also used to make seals that can withstand cryogenic temperatures.

Because PTFE is chemically inert from cryogenic temperatures to very high temperatures, PTFE is used in components for transferring ultrapure, aggressive fluids, such as seals, valves, laboratory equipment, pipes, liners, fittings, connectors, and pumps.  Contaminants will not adhere to the surface of PTFE.

The semiconductor industry uses ultra-pure PTFE for its extreme inertness and wide operating temperature range.

PTFE is one of the best insulating materials and is often used in electrical applications.  Because it is non-wettable and absorbs only negligible amounts of water, it retains its high resistivity in damp, polluted environments.  Its superior nonstick properties prevent the accumulation of conductive deposits.

The construction industry uses PTFE bearing pads because they resist weather-related degradation.

Virgin PTFE complies with FDA regulations for use in the food, beverage, cosmetics and pharmaceutical industries.

Compression-molded PTFE / Teflon® Parts

1. •PTFE O-rings
   

2. •PTFE seals
   

3. •PTFE mechanical seals
   

4. •PTFE seal rings
   

5. •PTFE bushings
   

6. •PTFE bearings
   

7. •PTFE piston rings
   

8. •PTFE gaskets
   

9. •PTFE skived film and sheet
   

10. •PTFE valves
    

11. •PTFE valve seats
    

12. •PTFE mixing impellers and agitators
    

13. •PTFE wafer carriers
    

14. •PTFE washers
    

15. •PTFE sleeves
    

16. •PTFE balls
    

17. •PTFE membranes
    

18. •PTFE diaphragms
    

19. •PTFE pressure transducers
    

20. •PTFE funnels
    

21. •PTFE piping systems
    

22. •PTFE manifolds
    

23. •PTFE stopcocks
    

24. •PTFE beakers
    

25. •PTFE dough molding rollers
    

26. •PTFE strips
    

27. •PTFE guide rails
    

28. •PTFE slides
    

29. •PTFE slide bearings
    

30. •PTFE slide plates
    

31. •PTFE slide pads
    

32. •PTFE bridge and pipeline bearing pads
    

33. •PTFE slide assemblies for piping systems
    

34. •PTFE high-voltage encapsulation devices
    

35. •PTFE standoff insulators
    

PTFE Compression Molding Resins

Teflon® PTFE from DuPont™

1. •Teflon® PTFE 7A X
   

2. •Teflon® PTFE 7C X
   

3. •Teflon® PTFE 8A X
   

4. •Teflon® PTFE 807N X
   

5. •Teflon® NXT 70 Modified PTFE
   

6. •Teflon® NXT 75 Modified PTFE
   

7. •Teflon® NXT 85 Modified PTFE
   

POLYFLON™ PTFE from Daikin America

1. •POLYFLON™ M-12 PTFE
   

2. •POLYFLON™ M-15 PTFE
   

3. •POLYFLON™ M-15X PTFE
   

4. •POLYFLON™ M-18
   

5. •POLYFLON™ M-111
   

6. •POLYFLON™ M-112
   

Dyneon™ PTFE from 3M™

1. •Dyneon™ PTFE TF 1620
   

2. •Dyneon™ PTFE TF 1641
   

3. •Dyneon™ PTFE TF 1645
   

4. •Dyneon™ PTFE TF 1750
   

5. •Dyneon™ TFM™ 1600 Modified PTFE
   

6. •Dyneon™ TFM™ 1700 Modified PTFE
   

7. •Dyneon™ TFM™ 1705 Modified PTFE
   

Algoflon® PTFE from Solvay Specialty Polymers

1. •Algoflon® F 5/5 PTFE
   

2. •Algoflon® F 5 PTFE
   

3. •Algoflon® F 7 PTFE
   

4. •Algoflon® F S 121 PTFE
   

Fluon® PTFE from AGC Chemicals Americas

1. •Fluon® G110 PTFE
   

2. •Fluon® G155 PTFE
   

3. •Fluon® G163 PTFE
   

4. •Fluon® G204 PTFE
   

PTFE / Teflon® Compression Molding Process

PTFE is molded by applying high pressure (typically 3,000-4,500 psi) to powdered PTFE resin in a mold at room temperature to create a preform shape.

After the preform is removed from the mold, it is slowly heated to approximately 685-720 °F to sinter the PTFE particles into a solid form, and then the temperature is slowly lowered back to room temperature.  Dwell times in the oven vary based on the size and shape of the part.

Optimizing the mold pressure and the oven cycle maximizes the end-use properties of the PTFE, such as:

1. •Physical properties
   

1. 1.specific density
   

2. 2.tensile strength
   

3. 3.elongation
   

4. 4.flex life
   

5. •Electrical properties
   

6. •Permeation resistance
   

7. •Chemical resistance
   

For finished PTFE components we machine sintered shapes to customer specifications.