Abstract:
Sixty samples of Enamel powder were prepared and applied on sheet iron pieces. On visual inspection samples were selected for further studies. Blistering, boiling, burning off, chipping, crawling and fish scale defects were noted in most of the samples. Samples having any of these defect were discarded. Remedial measures were not studied because of lack of time.
The objectives of comparability with imported stuff and reduction in the cost of manufacture of enamel powders were kept in mind. Reduction in the cost of manufacture have been done by two methods I.e. by replacing totally or apart of a expensive chemicals by less expensive chemical and lowering the fusing temperature of enamels, the temperature at which the enamel are fired on the ware. Low temperature mean low fusion coast and on sheet iron particularly distortion difficulties are minimised.
The enamel powders selected for future study have the composition shown in the talbe Nos.1, 2, 3 and 4. An interesting development is the idea of extending the work to develop enamel powders with low fusion temperature for Aluminium and sheet iron for use as architectural enamelld sheets is being done in USA and Japan.
Enamel powders Nos. 7,9 and 10 (ground coat) in Table No.2 have been prepared in bulk and supplied to an industrial unit. On these ground coats, cover coat enamels Nos.7, 8, 9, and 11 in Table NO.4 are also being evaluated and the report from the factory is awaited.
