PTFE (Polytetrafluoroethylene) is known for its excellent chemical resistance, but adding fillers like glass or carbon can slightly impact its chemical compatibility. Virgin PTFE is resistant to most chemicals, with exceptions like molten alkali metals and some fluorine compounds. Filled PTFE, while maintaining most of PTFE's resistance, can have slightly increased permeability and may be affected by the specific filler used.
PTFE (Virgin PTFE)- Excellent Chemical Resistance: PTFE is highly resistant to acids, bases, alcohols, detergents, and solvents.
- Exceptions: It is not resistant to molten or dissolved alkali metals (like sodium, potassium), fluorine gas, and certain fluorine compounds at elevated temperatures.
- Ideal for Corrosive Environments: PTFE is suitable for use with highly corrosive and reactive chemicals due to its inertness.
- Contamination-Free: PTFE is insoluble and can be manufactured to be ultra-pure, making it suitable for sensitive applications.
- Impact of Fillers: Fillers like glass, carbon, or graphite can slightly affect PTFE's chemical resistance, but it generally retains most of its properties.
- Increased Permeability: Filled PTFE can have higher permeability than virgin PTFE due to the lack of chemical bonding between the PTFE and the filler.
- Dependence on Fabrication: Permeability in filled PTFE is highly dependent on the method of fabrication, and careful techniques can minimize permeability.
- Specific Fillers:
- Glass-filled PTFE: Good for creep resistance and improved wear and friction properties, but may discolor under certain conditions.
- Carbon and Graphite-filled PTFE: Good for chemical resistance and wear.
- Selection Guide: A guide for selecting between virgin and filled PTFE is available, based on specific application requirements, according to a PTFE material supplier.
- Specific Chemical: When choosing between virgin or filled PTFE, carefully consider the specific chemicals involved in the application.
- Filler Content: The higher the filler content in filled PTFE, the more important it becomes to consider the impact of the filler on chemical resistance.
- Fabrication Method: The method of fabrication plays a crucial role in the performance of filled PTFE, especially regarding permeability.
- Exceptional Resistance: Virgin PTFE is known for its remarkable chemical inertness and stability in the presence of most aggressive and corrosive media.
- Limitations: It is important to note that virgin PTFE is not chemically resistant to molten or dissolved alkali metals (such as sodium, potassium, rubidium, cesium, and francium), fluorine gas, or certain fluorine compounds and complexes at elevated temperatures.
- Enhanced Performance: In general, PTFE compounds filled with materials like carbon and glass demonstrate superior performance in chemical service compared to virgin PTFE.
- Permeability Considerations: The permeability of filled PTFE is highly dependent on the manufacturing methods used. Due to the lack of chemical bonding between PTFE and the fillers, the permeability can be greater than that of unfilled PTFE.
- Filler Specifics:
- Glass Fiber Filled PTFE: Offers improved creep resistance at varying temperatures and is chemically stable, except when exposed to strong alkalis and hydrofluoric acid.
- Carbon Fiber Filled PTFE: Provides superior resistance to pressure under load and is particularly effective in strong alkali and hydrochloric acid environments, where glass fiber may fail.
- Bronze Filled PTFE: Exhibits excellent creep resistance and high thermal conductivity.
- Glass + MoS2 Filled PTFE: Creates a rigid, chemically unreactive material with reduced friction.
- Stainless Steel Filled PTFE: A harder, stiffer material that is particularly suitable for high-pressure chemical handling equipment.
Let’s Build Better with PTFE Solutions
From standard sheets to custom components, we're ready to deliver quality you can rely on.
Contact Us