POLISHING

 

POLISHING

 

 

Polishing is the important phase of mould construction because the  final finish given to the moulding determines the finished obtained on the piece part of the casting.

 

ADVANTAGES OF POLISHING

1)      Easier ejection of the component .

2)      Reduce risk of corrosion

3)      Reduce risk of fracture and cracking of component during ejection.

4)      Imparts high surface finish to the moulding.

5)      Easy flow of plasticised material in the cavity.

 

  Surface smoothness that can be achieved depends on some factors such as:

1)    Polishing technique.

2)    Tool steel grade.

3)    Heat treatment

      

First the rough machining marks are removed using oilstone or emery cloth, the part is then polished with rough emery paper. Then going from coarse grit to intermediate and then to fine grit results in good polishing. Mirror finish is obtained by finest grade of emery paper or diamond paste.