Stainless steels are selected for applications where their inherent corrosion resistance, strength and aesthetic appeal are required.
However, dependent on the service conditions, stainless steels will stain and discolour due to surface deposits and so cannot be assumed to be completely maintenance-free. In order to achieve maximum corrosion resistance and aesthetic appeal, the surface of the stainless steel must be kept clean.
Provided the grade of stainless steel and the surface finish are correctly selected, and cleaning schedules are carried out on a regular basis, good performance and a long service life will result.
Get more information on stainless steel from the British Stainless Steel Association.
Galvanisation is a method of protecting certain metals – usually iron and steel – from corrosion.
There are two common methods of galvanisation; hot-dip galvanisation or electro galvanisation.
When an object is hot-dipped it’s passed through a bath of molten zinc which adheres to the surface of the object. When an object is electro galvanised, it’s electroplated with a thin layer of zinc in a process similar to chrome plating. The zinc oxidises when exposed to the elements and eventually produces a compound called zinc carbonate on its surface, which sticks to the underlying zinc very well and protects the object from corrosion, similar to the way aluminium and stainless steel react to oxidization.
Visit www.hdg.org.uk for further technical data on galvanisation.
What is Polyester Powder Coating?
Definition: Powder coating is the process of coating a surface in which a powder material is applied using an electrostatic or compressed air method. The applied powder is then heated (cured) to its melting point, after which it flows to form a smooth film which dries to a firm, durable finish very resistant to scratched, cracking, peeling, UV rays and rust.
The entire powder coating process involves several steps.
Polyester Powder Coating (often referred to as simply Powder Coating) is the process of coating a surface with a powder material, applied using an electrostatic or compressed air method. The applied powder is then heated, or cured, to its melting point, after which it flows to form a smooth film which dries to a firm, durable finish very resistant to scratched, cracking, peeling, UV rays and rust.
The entire powder coating process involves several steps;
- Blasting, stripping and/or solvent cleaning, to ensure the substrate is free of any oils, dirt, rust, mill scale etc.
- Pre-treatment (an important step not done by all coaters), during which the product is treated with a pre-treatment chemical or conversion coating, usually phosphate- or zinc-based, to further protect it and improve the surface for powder adherence.
- Rinse, rinse, rinse. Followed by thorough and complete drying
- Powder coating, usually done with an electrostatic gun, but sometimes applied in a fluidized bed.
- Finally, the powder is fully cured in the oven, generally at 375-400 degrees Fahrenheit, for between 15 and 20 minutes, making sure the oven’s preheated to temperature.
Advantages of Powder Coating
Powder coatings have become the coating technology of choice for consumable goods from toolboxes, bicycles, office furniture and lawn furniture to widespread markets such as appliance and automotive for the reasons listed below.
Quality: The unique characteristics of powder coating provide superior consistency and uniformity of finish without sags, drips, runs or bubbles. They provide extremely tough, durable films, offering the high quality, value-added image associated with premium products. In general, the performance properties, such as impact resistance, flexibility, and corrosion resistance of powder coatings are better than with liquid paints.
Economics: Powder coatings are frequently a cost-saving alternative to liquid paints with respect to energy savings, labour cost, rework costs, material usage, waste disposal, and overall line efficiency. So the advantage to you is a coated part with a superior quality finish at a reasonable cost.
Environmental: Unlike many liquid paints, powder coatings are compliant with environmental regulations. Liquid paints often contain solvents, which can contribute to air pollution and, in some cases, ozone depletion. Powder coatings are free of such pollutants. Wet painting processes can generate sludge which must be disposed of into hazardous waste landfills. Properly formulated powder coatings don’t generate a hazardous waste. You can feel good about using a powder-coated finish which is environmentally responsible.
Visit www.interpon.com for further technical data on powder coating.