Introduction to PTFE Diaphragms

PTFE diaphragms are thin film materials made from pure polytetrafluoroethylene (PTFE) resin through special processing techniques. They exhibit excellent chemical stability, temperature resistance, and low friction characteristics, making them an ideal choice for high-performance sealing and isolation applications.

 

 Core Characteristics

Characteristic	Description	Advantages
Exceptional Chemical Inertness	Resistant to all strong acids, alkalis, and organic solvents.	Suitable for extreme chemical environments.
Wide Temperature Range	Continuous use from -200°C to +260°C.	Ideal for alternating high and low-temperature conditions.
Extremely Low Friction Coefficient	Dynamic friction coefficient of only 0.04-0.07.	Suitable for dynamic sealing applications.
Non-Stick Properties	Very low surface energy, does not adhere to any substance.	Easy to clean, excellent anti-fouling properties.
Excellent Electrical Insulation	Dielectric strength up to 100-200 kV/mm	Suitable for electrical insulation applications.

 

 Manufacturing Processes

Process Type	Characteristics	Applicable Products
Compression Molding and Sintering	Thickness 0.5-10 mm, high density	Sealing gaskets, sheets.
Biaxial Stretching	Thickness 0.01-0.5 mm, high strength.	Microporous membranes, filter materials.
Skiving	Thickness 0.1-3 mm, flexible processing.	Custom-sized sealing components.

 

 Performance Parameters Table

Performance Indicator	Value Range	Test Standard
Thickness	0.01-10 mm	ASTM D374
Tensile Strength	20-40 MPa	ASTM D638
Elongation at Break	200-400%	ASTM D638
Density	2.1-2.3 g/cm3	ASTM D792
Air Permeability	0.1-10 L/m2·day	ASTM D1434

 Application Fields

1. Sealing Industry:

   · Pump and valve seals

   · Pipeline flange gaskets

   · Reactor seals

2. Filtration Field:

   · Chemical filtration membranes

   · Air dust removal filter materials

   · Liquid filtration media

3. Electrical Insulation:

   · Cable insulation layers

   · Capacitor dielectrics

   · Motor insulation materials

4. Non-Stick Applications:

   · Food machinery non-stick layers

   · Heat sealer non-stick tapes

   · Mold release films

 

Selection and Usage Guide

1. Selection Considerations:

   · Chemical properties of the working medium

   · Temperature and pressure range

   · Friction and wear requirements

   · Installation space limitations

2. Installation Requirements:

   · Ensure sealing surfaces are clean and flat

   · Avoid over-compression (recommended 20-25%)

   · Use appropriate tightening torque

   · Consider thermal expansion factors

3. Usage Precautions:

   · Avoid surface damage from sharp tools

   · Regularly check compression set

   · Observe pressure limits at high temperatures

   · Avoid heavy pressure and folding during storage

 

 

PTFE diaphragms, with their unique chemical inertness, wide temperature adaptation range, and excellent dielectric properties, are the preferred material for high-end sealing and isolation applications. Although they have limitations such as cold flow and poor wear resistance, reasonable structural design and correct usage methods can fully leverage their performance advantages, providing reliable sealing solutions for industries such as chemicals, power, and food.