PTFE specific weight. Types of PTFE and their characteristics

PTFE, better known to consumers as “Teflon”, was discovered by the American company Kinetic Chemicals back in 1938. Tetrafluoroethylene in gaseous form was accidentally discovered by chemist Roy Plunkett. When the gas was pumped into a cylinder under pressure, polymerization formed a white powder with unique properties.

Characteristics and area of PTFE use

Its main purpose was determined by its unique dielectric ability. At the same time, additional characteristics such as:

• low specific weight of PTFE;
• wide range of tolerated temperatures;
• plasticity;
• strength;
• moisture resistance;
• low surface adhesion, meaning self-cleaning ability;
• resistance to ultraviolet and ionizing radiation;
• resistance to wear and abrasive action;
• bioinertness;
• ease of processing

made it possible to use the material in many different areas. It is widely used in everyday life, the food industry, automotive production, medicine and other manufacturing areas. Many surrounding items are made from PTFE, including:

• wire insulation, hoses, pipes, various containers and fishing lines;
• nonwoven noncombustible materials, technical fabrics, protective films;
• heat-resistant membranes, bearings, car-part elements;
• parts of pump and mixer stations, valves, plumbing components;
• products for cable installations and capacitors;
• high-pressure pipelines for chemically active media and other products.

Under permitted operating conditions, PTFE is chemically stable and is usually considered safe for normal use. However, the working temperature range of the specific grade must not be exceeded. Negative qualities include:

• the need to use expensive equipment for mold fusion;
• the need for strong extraction ventilation during material processing;
• after exceeding extremely high temperatures, the polymer becomes dangerous to human health.

Types of PTFE

Several grades of this polymer are distinguished depending on the number of monomers in the chain and molecule size. The specific weight, or density, of PTFE ranges from 1700 to 2240 kg/m³ depending on type. The following PTFE types are distinguished:

• F4 is the densest, low-porosity, hydrophobic material, resistant to temperatures up to +260 degrees.
• F3 is less chemically and thermally resistant, but denser than F4; it melts, which makes it more convenient to use in casting and pressing, has good adhesion to metals and is often used as an anti-corrosion coating.
• F2 is abrasion-resistant, contains no plasticizers, is strong and is used for aggressive media and the production of pipes and containers.
• F40 is strong, resistant to boiling acids and some solvents, does not burn and does not transmit UV radiation or radiation.

PTFE forms can be very diverse. They include rounds, plates, sheets, films, rods, granules and powders.

The most widespread are:

• Sheet PTFE. The weight of a 1000 mm x 1000 mm sheet with a thickness of 1 mm is 2.5 kg.
• PTFE rods are convenient as semi-finished products for making various parts. The approximate weight of PTFE, a rod 1000 mm long and 10 mm in diameter, is 0.18 kg.