Powder coating is a highly versatile method for providing a decorative and protective finish to different types of metal.
One of the aspects of this versatility is the use of powder coating across a broad range of industries, including food production.
Using food grade powder coating on food production surfaces and equipment ensures that they are easy to clean and to sanitise.
Of course, to apply powder coating in this way, it must be thoroughly food safe.
Food grade powder coatings have several distinct advantages for food production:
• They are able to withstand very hot and very cold temperatures
• They are non-stick
• Coatings make surfaces resistant to hot oils and fats, steam and water
• They help restrict the growth of mould
• Powder coatings protect equipment involved in food preparation.
Powder coatings help reduce downtime in food production, since equipment is then much easier and faster to clean.
Food manufacturers can rely on powder coatings to simplify their cleaning and maintenance processes, protect their equipment and lengthen its working life.
Coating metal in this way helps ensure it stays hygienic. Powder coating gives it a smooth, even finish, so that there are no abrasive areas or cracks which can collect food and therefore lead encourage bacterial growth.
You apply powder coating via an electrostatically-charged gun. This gives an even, complete coverage, and ensures that the powder adheres to the surface.
Once applied, you then cure the coating, by baking it in a special oven.
This transforms the powder, so that it reaches flow out. At this point, the powder ingredients merge together in a chemical reaction.
This forms a tough, resilient outer shell.
There are different types of powder coating, some of which are ideally suited for use in food-related applications. These powder coatings are known as food safe.
One of the most popular non-stick powder coatings for food-related applications is PTFE.
PTFE stands for polytetrafluoroethylene, a synthetic fluoropolymer of tetrafluoroethylene. As a powder coating it has a range of benefits:
• It offers an excellent degree of tolerance to high temperatures, with a high thermal stability and flame resistance
• It is resistant to chemicals
• PTFE is a good electrical insulator
• It protects against corrosion and is resistant to weathering
• It is non-stick, with low friction
• You can achieve a smooth surface finish with it
• It won’t age or go brittle
• PTFE is non-wetting.
As a versatile powder coating application, PTFE has several applications related to food, particularly its non-stick properties.
Belts and conveyors in the mass production of food have PTFE coatings. The coating creates a non-stick, durable surface that enables a high volume throughput of commercial food processing.
Industrial bakeries rely on food safe coatings such as Teflon, which is a PTFE trade brand.
The maximum continuous use temperature for PTFE is 260°C.
FEP powder coatings are also food safe. FEP stands for fluorinated ethylene propylene, and it is part of the same family of polymers as PTFE.
Some formulations of FEP powder coating can achieve a high level of smoothness, with good non-stick properties. It does, however, tend to be softer than PTFE and may require multiple coats to achieve a longer life. It also has a lower continuous temperature use than PTFE.
The maximum continuous use temperature for FEP is 205°C.
Another powder coating used extensively in food-related applications is nylon.
Nylon powder coating is tough, long lasting, offers high performances at low temperatures and is anti-microbial.
This makes it ideal for food storage.
The anti-microbial action of the coating helps prevent or slow down the growth of unpleasant odours and moulds.
Powder coating production involves blending polymers and resins with a range of additives.
Some food safe powder coatings are actively anti-microbial, while others are passive, preventing microbes from adhering to surfaces or damaging cell walls.
Next comes an extrusion process, followed by grinding down the blended mixture into fine particles.
Like other powder coatings, you apply food safe coatings using an electrostatically-charged gun. This coated surface is then cured in an oven at a temperature high enough to cause the particles to fuse together and form a smooth, film surface.
To find out more about food safe powder coating, please contact us.