A PROCESS FOR COATING OF ROOFING BOLTS WITH ZINC PHOSPHATE AND LOW DENSITY POLYETHYLENE FOR BETTER RUST PREVENTION AND IMPROVING MECHANICAL PROPERTIES OF COATING

摘要

A process for coating of roofing bolts with zinc phosphate and low density polyethylene for better rust prevention and improving mechanical properties of coating like abrasion resistance, peel off force and malleability of the coat, comprising dipping the bolts into zinc phosphate solution which is heated between 80 to 85 °C for achieving uniform zinc phosphate coating, the said bolts with uniform coat of zinc phosphate, are further heated in an oven to a temperature between 325 to 350 °C which is critically maintained with the help of specially designed thermister control and after attaining the desired temperature, keeping these bolts at attained temperature for about 30 minutes and then the virgin polymer powder like low density polyethylene, specially ground to 65 micron mesh is sprayed upon the body of the bolts with the help of specially designed spray gun to get the desired uniform fusion coating of minimum 0.5 mm thickness of the said polymer powder.