There are, of course, too many types of surface coatings (a much better description than paint) for an attempt to be made to mention them all but as a guide it can be said that the qualities most generally encountered in everyday usage fall under the following headings:-
- Building and Decorative Paints.
- Industrial Finishes
- Metal Protective Coatings.
1) Building and Decorative Paints
This is the largest group of products and used for the protection and decoration of all classes of buildings. Materials such as wood and metal primers, undercoating and enamel finishes are used on doors and windows whilst emulsion paints in a variety of qualities and prices are used for walls and ceilings.
2) Industrial Finishes
Virtually, all articles fabricated in industry are painted before they find their way to the consumer and the paints required in this field are usually tailor-made to suit individual requirements of gloss, hardness, flexibility, impact resistance, chemical resistance and colour. Manufactured articles such as refrigerators, air conditions, light fittings, etc are coated with stoving finishes which have to be baked at high temperatures to cure the film to produce the insoluble mark proof surface associated with such articles. Other types of stoving finishes are used on steel furniture, office equipment, metal containers and a vast miscellany of other goods.
Other surface coatings which may be considered under the heading of industrial finishes are air drying materials such as quick drying machinery and tractor enamel; cellulose lacquers for wooden furniture and other articles, pencils for example, where the extremely rapid drying time is advantageous; hammer finishes, both air dying and stoving, commonly used on electrical switchgear, and many other specialized items.
3) Metal Protective Coatings
The corrosion of metal is the biggest problem facing the paint industry and constant research is being carried out to find the most suitable method of protecting metal from the effects of the atmosphere, moisture and chemical attack. The application of anti-corrosive primers and weather resistant finishes to metal structures such as bridges, pylons, etc., serve to protect the metal and, therefore, increase the life span of the structure by preventing damage and possible collapse by rusting. Red Lead, Metallic Lead, Calcium Plumbate and Zinc Chromate are among the most important pigments used in metal primers and lamellar finishes such as aluminium or micaceous iron oxide paints are extensively used as weather resistant protective top coats.
Apart from the above mentioned types of surface coatings, many other outlets exist for specialized products. Ship paints, including anti-fouling composition, car paints, both air drying and stoving, insulating varnishes, petrol resisting coatings, road marking paints, etc.
|
