Choice of Material

Choice of Material

1. Method and scale of production

   • Maximum economy
     • Precision
       • Best finish
   • Some suit mass production
     • some easier to mould than others

2. Ecominic requirements

   • quality of product determind by material
   • expensive material justified by low processing cost
   • wide range of alternations
     • paper cup
     • glass cup
     • china cup

3. Physical Properties

   • Fusibility
     • metals and some plastics change into liquids when heated to cetain temperatures -melting point.
   • Density
     • mass per unit volume
   • Electrical Conductors
     • offer low resistance to the flow of an eletrical current
       • good conductors
         • silver
         • copper
         • gold