Teflon coating – the non-stick accident to solve sticky accidents
Some discoveries are the result of years of experimentation and striving for just the right combination of luck and determination. Others, however, are pure luck. So it is with Teflon coating. In 1938, Roy Plunkett was busily beavering away at DuPont, attempting to make a new chlorofluorocarbon refrigerant. Plunkett was running an experiment with a gas under high pressure when he found that the bottle he was using was oddly heavy. When he pulled it apart its interior was coated in a strange, slippery substance – Plunkett had accidentally discovered Teflon.
Though DuPont registered the Teflon trademark in the 1940s, it would be a decade before it first appeared performing the role for which it is best known: non stick cookware. Now a household name, Teflon finds application in aerospace, communications, electronics, industrial processes, architecture, architecture, cookware, medical implants, even windshield wiper blades. In this article we look at the science behind Teflon coating, its applications, and Teflon coating specialists in New Zealand.
What is Teflon? – The science behind non stick coating
Teflon coating is actually the brand name of a particular type of fluoropolymer. Fluoropolymer coatings include Teflon, Xylan, Excalibur, and Fluon, and are known for their highly inert nature. Teflon’s scientific name is Polytetrafluoroethylene (PTFE), which doesn’t roll off the tongue quite so easily. As the name suggests, polytetrafluoroethylene contains fluorine, and it is this atom which is the secret to the fluoropolymer’s properties. The fluorine atoms surround the molecules of PTFE, forming a barrier which prevents them interacting with anything they come into contact with. It is this action which makes Teflon so inert and thus low-friction and slippery.
If nothing sticks to Teflon, how does it stick to the pan?
Everyone knows that smart alec who, with a smirk, says “ah yes, but how if Teflon is so non-stick, how does it stick to the pan?”. There are two techniques to make Teflon stick to other surfaces. The first is “sintering”, a process in which the Teflon is heated to very high temperatures and then pressed onto the surface to which it needs to adhere. The other technique is to chemically alter the side of the Teflon that you want to stick to a surface by bombarding it with ions in a high vacuum under an electric field – this causes the fluorine atoms at the surface to break away, leaving the bonds open for other substances that will adhere.
The benefits of Teflon coating – more than just non-stick
Fluoropolymers such as Teflon coating are known for their non-stick properties, but they have many properties beyond slipperiness. It is the combination of these properties that make fluoropolymers such powerful coatings. These properties include:
- Non-wetting – Fluoropolymer coated surfaces are hydrophobic and oleophobic, and cannot be wetted. This also makes them easy to clean.
- Chemical resistant – Fluoropolymers have a high resistance to solvents, acids, and bases.
- Corrosion resistant – Because it is waterproof and chemical resistant, fluoropolymer coatings are a barrier between a substrate and corrosive elements, protecting it from damage.
- Electrical resistant -Fluoropolymers work as insulators, and have a high dielectric strength and high surface resistivity. This makes them especially useful in electrical applications such as light fittings and connectors.
- Anti galling and low friction – Due to the non-stick, low friction properties of fluoropolymer coating it prevents galling (a form of wear caused by adhesion between sliding surfaces) and provides excellent bearing properties. It can achieve very low coefficients of friction, so is ideal for shafts, bearing surfaces, moving mechanisms, stud bolts and fasteners.
- Temperature resistant – Fluoropolymers are highly temperature resistant, and can function at temperatures of +260°C. They also have cryogenic stability and can maintain their physical properties down to -270°C.
The top applications of Teflon coating – cookware to industry
PTFE coatings can be used on a wide range of metallic and non-metallic substrates, including carbon steel, aluminium, stainless steel, steel alloys, brass, and magnesium, glass, fiberglass, some rubber, and plastics. Below is a look at the top uses of Teflon coating across industries.
Cookware and food processing
The most recognised use for Teflon coating is non-stick cookware. Pots, pans, and bakeware have all benefited from a Teflon coating. These non-stick benefits can be expanded into the food processing industry. Using Teflon on commercial equipment can allow the same equipment to make a wider range of food products (due to the hygienic, easy-to-clean nature of the coating) as well as cutting down on maintenance and issues with wastage and corrosion. With easier cleaning comes less downtime and fewer harsh chemicals, increasing productivity. Surfaces that may benefit include vats, mixing hoppers, transfer buckets, moulds, rollers, blades, and process pipes.
Industry and manufacturing
Corrosion is a big issue facing the world of industry and manufacture. Teflon coating is a common corrosion protection coating, particularly where thin-film coatings that can deal with extreme high temperatures are required. As well as corrosion, substrates in the chemical, manufacturing, or oil and gas industries require protection from chemicals, water, acids, temperature, and weathering. Teflon is used to provide a protective lining for hose assemblies and industrial pipelines as well as in reactor vessels and storage tanks. The low friction surface is used in valves, pumps, hydraulics, and more.
The range of substrates in the medical industry which can benefit from a coating that prevents biofilm and creates an oleophobic and hydrophobic surface which is easy to clean is endless. Surgical tools, life support equipment, needles, electrodes for diagnostics, medical clothing, gowns, sheets, bones prostheses, stents, tubes… the list goes on. Fluoropolymer coatings such as Teflon help provide surgical tools that create easier and cleaner surgeries, medical implants that are electrically insulated, clothing and equipment that diminishes the chances of infection.
The insulating properties and high dielectric strength of Teflon, added to the fact they are hydrophobic, heat resistant, and can form around objects like circuitry, means that they are used in almost all industrial sectors, from aviation and aerospace to telecommunications and automotive. Just a few of the applications of fluoropolymer coatings are insulating wiring and cables, protecting printed circuit boards, moisture-proofing LCD displays in televisions, computers, and other screens.
Where to find Teflon coating services in New Zealand
There are a number of PTFE Coating specialists in New Zealand. The table below is a selection of Teflon Coating services in the country. If you need Teflon coating for a project and aren’t sure where to start, our experts are here to help! Get in touch through the “Request a Quote” button beneath this article or through our contact form and we will connect you with the coating specialists for your needs.
|TEFLON COATING NZ SPECIALIST||LOCATION||SPECIALTY|
|Canterbury Powder Coaters||156B Antigua St, Addington, Christchurch 8024||Non-stick Teflon powder coating applicator|
|Dotmar Engineering Plastics||111 Wrights Rd, Addington, Christchurch 8024||Teflon Coatings distribution, technical support, material selection and applications development|
|DuPont||Level 1, 14 Ormiston Road, East Tamaki, Auckland 2016||Teflon coatings supplier|
|Siltech Industries||48 Andromeda Cres, East Tamaki, Auckland 2013||DuPont licensed applicator|
|Thermo Polycoating||2C Ashfield Rd, Glenfield, Auckland 0627||Release coatings for the food industry|