PTFE is also known as Teflon, a non-stick material comm […]
PTFE is also known as Teflon, a non-stick material commonly used in cooking utensils and protective clothing. This versatile material also has many industrial uses. Polytetrafluoroethylene is widely used in aerospace, food and beverage manufacturing, pharmaceutical and telecommunications industries, to name a few.
Pure PTFE is a low-friction material that can withstand great temperature changes and is ideal for cooking utensils such as non-stick pan. Physically, PTFE is very soft and very dense; therefore, the PTFE coating on the machine parts makes it more durable. Chemically, it is extremely reactive and insoluble in most chemicals and is itself non-toxic and gives further advantages in the context of laboratories, pharmaceuticals and food manufacturing. Together, these properties make PTFE an extremely useful material that is widely used in almost all industrial applications.
Because it is highly flexible, PTFE can be creep and deform under heavy loads. By adding a filler, this potential drawback can be eliminated in order to benefit from the nature of the two materials. Fillers can also add properties such as improved thermal conductivity for applications that require good heat dissipation. The most common filler material is glass, but other materials give certain advantages to certain applications. These alternative additives include carbon, graphite, stainless steel, molybdenum disulfide, bronze and polyimide.
Adding glass to PTFE makes it stronger and more durable, as well as reducing flexibility and likelihood of creep. Glass filled PTFE can operate at the same temperature range as virgin PTFE and is similarly chemically inert. Fluorotec offers glass filled PTFE ranging from 5% to 60% glass content. Increasing the glass filler content results in an increase in durability and compressive strength. Optionally, glass filled PTFE can be inert gas sintered. This further reduces the material's tendency to creep as well as its porosity. Glass filled PTFE is more abrasive than PTFE, meaning that it can be abrasive to adjacent surfaces.
Carbon-filled PTFE facilitates improved compressive strength, reduces stress under heavy loads, and provides better wear resistance than raw PTFE. Since the carbon is electrically conductive, it is suitable for applications requiring higher thermal conductivity than PTFE alone, and becomes dissipated due to its electrical conductivity. The carbon may be added in the form of powder or fiber. It can be abrasive, but not equal to the degree of glass.
Usually used with glass or bronze, molybdenum disulfide as a PTFE sheet will lead to more slippery and harder materials. MoS2 also improves compression and abrasion resistance. The resulting material is very useful for dynamic sealing.