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Machining Teflon/PTFE: Tips, advantages & applications

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    April 19, 2023 10:58 PM EDT

    Machining Teflon/PTFE: Tips, advantages & applications

    Polytetrafluoroethylene (PTFE), most commonly known by the brand name Teflon, is a synthetic fluoropolymer thermoplastic that can be used for a range of applications, from non-stick frying pans to medical devices.To get more news about machining teflon tips, you can visit runsom.com official website.

    Resistant to chemicals and stable even at high temperatures, Teflon is one of the popular CNC machining and milling materials for many specific applications, despite its so-so mechanical properties. As is the case with non-stick frying pans, it is sometimes used as a coating rather than a base material, and it can be manufactured in several ways.

    One of the best ways to fabricate Teflon parts is CNC machining. This article looks at the ins and outs of machining Teflon: its material properties, the advantages of machining it, common applications, and more.
    What is Teflon?
    PTFE is a thermoplastic and a fluoropolymer of tetrafluoroethylene. The name ‘Teflon’ is a brand name of American chemical company Chemours, a spinoff from chemical giant DuPont (now DowDuPont). Interestingly, the material was initially discovered by mistake.

    A white solid at room temperature, PTFE consists of carbon and fluorine only. It is hydrophobic, has incredibly low friction, and is non-reactive due to the very strong bonds between carbon and fluorine, one of the strongest existing bonds in organic chemistry. Due to its low friction — it is the only surface a gecko cannot stick to! — Teflon is often used as a lubricant.

    The melting point of PTFE is 327 °C, and other material properties include strength, toughness, and self-lubrication at low temperatures.
    Applications of Teflon machining
    Teflon is not the most versatile material for CNC machining, but it has some important niche applications due to its desirable properties like thermal stability and a low friction coefficient.

    About half of all PTFE in the world is used for wire insulation, but wiring and its insulation is not made using CNC machines. The other most well-known use of Teflon is for non-stick coatings on aluminum cookware; in this case, Teflon in its liquid form is sprayed or rolled onto the etched metal surface. In general, Teflon-lined cookware is not machined.

    Nonetheless, CNC machining is useful for manipulating Teflon in its solid form. Teflon parts suitable for machining include industrial components like gears, bushings, fittings, and valves.
    Teflon machining tips
    Teflon parts must be designed to suit the properties of PTFE; it does not behave like common machinable thermoplastics, and is not easily substituted in for more common materials.

    That being said, Teflon is suitable for a variety of parts and components if proper care and precaution is taken by both designer and machinist. An achievable tolerance for Teflon parts is around 0.13 mm — tighter than this may be difficult without stress-relieving the material in advance.

    When CNC machining Teflon, very sharp tools combined with water-soluble coolants such as pressurized air and spray mists work well to produce the best surface finishes and tolerances. Non-aromatic coolants are also preferable.

    Another key consideration when machining Teflon is deburring. Because PTFE is so soft, even fine, sharp cutting tools can produce undesirable marks that require post-processing treatment.

    Common surface finishing techniques like sanding can be used to remove burrs, although a more advanced method involves freezing the machined Teflon to make it less soft during the deburring process.