Teflon® (PTFE) Fasteners
Teflon® (PTFE) fasteners include screws, hex nuts, hex head cap screws, flat washers, etc. It is also used to fabricate custom parts. However, this material can only be turned, or made into parts on a CNC machine. It can also be compression molded. But it cannot be injection molded. It is not thermoplastic.
These fasteners and custom parts are used in applications where high heat and chemical resistance are required. The downside is that PTFE is not very strong. For instance, it is so soft you can make an imprint in the material with a fingernail.
Discovery of Teflon®
Teflon® (PTFE) or polytetrafluoroethylene was accidentally discovered in 1938. A DuPont chemist named Roy J. Plunket was attempting to produce chlorotrifluoroethylene, a refrigerant. Instead, he made a happy discovery. The inside of one bottle was coated with a waxy and very slippery material. Teflon® became a registered trademark in 1945. By 1948, a DuPont company, Kinetic Chemicals, partnered with General Motors. They produced over 900 tons of Teflon® per year. One of the early uses of the material was in the Manhattan Project. It was used to coat valves and seals in pipes at the uranium enrichment plant in Oak Ridge, TN.
What is Teflon®
PTFE is a solid fluorocarbon and synthetic fluoropolymer. In other words, this material is wholly made of carbon and fluorine atoms. It has a high molecular weight. It is also hydrophobic therefore it does not absorb water.
The only substances to affect the carbon-fluorine bonds of PTFE include alkali metals (molten or in solution.) Also, rare fluorinated compounds at high temperatures and/or pressures such as xenon difluoride and cobalt (III) fluoride can attack these bonds. Aluminum and magnesium at high temperatures will also damage them.
Coefficient of Friction
PTFE has one of the lowest coefficients of friction of any solid. Therefore it is almost impossible to glue something to Teflon® (PTFE). It does not matter what the material is or what glue is used. Because it is resistant to van de Waal forces, it is the only material that a Geeko cannot stick to.
Teflon® is a polymer with a melting point of 326ºC or 620ºF. In addition, it also maintains its properties such as high strength, toughness, and self-lubrication at very low temperatures of -268ºC or -450ºF. At temperatures above 650ºC or 1200ºF, PTFE will undergo depolymerization. Teflon® is nonflammable.
While nonstick Teflon® cookware had been sold in France since the early 1950s, it was not until 1961 that it was introduced in the US. An American, Marion A. Trozzolo, introduced “the Happy Pan.” It was cookware coated with PTFE We all have Teflon® coated pans in our kitchens today. Brands include Swiss Diamond International® and Caphalon®. The sole plates of some clothes irons are also coated with the material.
What Else is Teflon Used For
PTFE is used in so many applications it would not be possible to list them all here however below are some of the more common ones.
PTFE has excellent dielectric properties. In other words, insulating properties. 50% of Teflon® production is used in wiring for aerospace and computer applications because of this insulating property.
It is used in industrial applications because of the material’s low friction. It is fabricated into bearings, gears, gaskets, bushings, and other parts that must operate in a sliding action. This results in energy savings for the operation of some machinery.
In medicine, PTFE is often used as a graft material. Additionally, it is used as a coating on catheters. This coating helps reduce the ability of bacteria and other infectious agents to adhere to a catheter. Therefore hospital-acquired infections can be reduced.
PTFE parts are used in the semiconductor industry as it is chemically resistant to the strong acids used in the photoresist process.
Parts, Prints, Problems? Give us a call at Craftech® Industries, Inc., and we will help you with your fastener and component requirements.