PRODUCTS
THE PRODUCT RANGE
SUITABLE FOR CAST IRON AND LOW CARBON STEEL APPLICATION
- High quality ground coats.
- High quality cover coats in a full range of colourfast colours.
- Cover coats for economical items.
PRODUCT SUPPLIED FORMS
- Frit – Frit is the basic ingredient of porcelain enamel. Frit is most commonly a borosilicate glass and is formulated to incorporate desired properties like chemical resistance, heat resistance, colour, clean ability and more. Frit is made by melting raw materials together at about 2400°F (1315°C). The molten glass is quenched to provide flake particles that are used to make porcelain enamel coating.
- Ready-to-Mill (RTM) – RTM material is a composto of frits and sometimes mill additions that are pre-weighed at Porcelain Enamels so the applicator needs only load them into a mill to grind into enamel slurry for application.
- Ready-to-Use (RTU) – RTU powders are “cake-mix” powders that are fully ground porcelain enamels and ready to be reconstituted with water into enamel slurry on a high-shear mixer. Ready-to-Use porcelain enamels supplied as a liquid slurry are also available.
- PERC® Powders – PERC® is porcelain enamel powder applied dry electrostatically and offers automation and efficiency required in modern mass production. The powder is charged and sprayed on the steel parts. There is no waste water in the coating process. Over sprayed powder is re-circulated back to the feed hopper, making powder 99% efficient.
APPLICATION
Porcelain enamel coatings are either applied as wet slurry or dry onto metal that has been cleaned, degreased or shot blasted. They are then fired in a high temperature furnace which bonds the small glass particles into a solid glass coating on the substrate.
If wet application is used the glass has to be ground into a water based slurry, flow coated, dipped or sprayed onto the metal. The water is allowed to evaporate in a dry environment before being fired in a furnace.
The firing temperature for porcelain enamel on aluminium is 560⁰C and from 800-850⁰C on low carbon steel, which is dependent on the final process. Cast iron enamels, wet processed, are fired at 760⁰ to 800⁰C.
In the case of dry application for steel, porcelain enamel is prepared and supplied in a dry powder RTU form. Special additives are incorporated in the preparation of the powder to ensure that it can be applied electrostatically to the metal surface. The advantage of this application is that a smooth finish is achieved resulting in a more attractive finish which will be less prone to chipping.
Dry applications are also used on cast iron substrates i.e. bath tubs where the entire bath is preheated up to 900⁰C and then the powder is sprinkled onto the hot surface where it fuses to form a solid coating. Multiple firings and coating may be needed to obtain the optimum finish.
