What is surface coating technology?
Surface coating technology covers all mixtures of binders, pigments, solvents and other additives which form decorative or functional films on surfaces after drying or curing. Surface coatings include paints, dying oils and varnishes, synthetic clear coatings, chemical surface treatments and other products whose primary function is to protect the surface of an object from the environment. These products can also enhance the aesthetic appeal of an object by accentuating its surface features or even by concealing them from view.
Composition of surface coatings
Most surface coatings for industrial and consumer use consist of synthetic polymers. They are industrially produced substances composed of extremely large, often interconnected molecules that form tough, flexible, adhesive films when applied on surfaces. The other component materials of surface coatings are:
- Pigments which provide colour, gloss and opacity
- Solvents or liquid carrier (such as water or oil) to give the film forming components a liquid form
- Additives for a number of special properties
Chemical surface coatings
Surface coating through chemical reaction is also possible and very common in pre-treating metals. The chemical coating means include:
These kind of coatings are thus placed on the surface through a chemical process such as electrolysis. Furthermore conversion coating, where a substrate is chemically converts into another material, is a surface coating technology. Conversion coating is also only suitable for metals or other materials that have gone through an appropriate preparation treatment.
Advantages of surface coating technology
Surface coatings for industrial use include those with decorative and functional (protective) properties. These coatings exist as liquid paints and powder coatings. Both of these have several significant advantages even though not every coating is suitable for every application. The choice of surface coating should always be based on the substrate material and the requirements for the coating.
- Corrosion prevention and in general reduction of environmental impact
- Increased resale value
- Improved durability and therefore reduced costs for maintenance
- VOC: Powder coatings emit zero or near zero volatile organic compounds
- Environmentally friendly and durable; energy and material efficient
- Powder coated items generally have fewer appearance differences between horizontally coated surfaces and vertically coated surfaces than liquid coated items