FINISHES Flashcards
What are the three types of material finishes
Self finsihes
= a material (acrylic) that has an adaptable finish after processing
Self coloured
= a material that has an acceptable colour after processing
Applied finish
= a substance applied to the material after
How is pigment used in finsihing
Polymer finishing
Adding a colour during the moulding process, colour therfore goes all the way through
Usually a smooth mirror-like finish, can be textured or frosted
The edges are also not very sharp
How are acrylic spray paints used for finishing
Polymer finishing
Fast drying, can be applied by spray or hand, water resistant when dry
Readily available in various colours
Acrylic paint is fairly expensive
What is overmoulding
Polymer finishing
A polymer is moulded over a specific part of a product
Usually silcone over a product eg. toothbrush
Two ways of producing
1. use two injection moulds
2. twin shot injection moulding = one mould set than another set on top
How are cellulose and acrylic paints used on metal
Metal finishing
Provides colour and soemtimes a textured finish to metals
Provides a barrier against corrosion for metals like steel and iron (ferrous)
Surface must be cleaned, degreased so areas adhere properly
a clear laquer is often applied on top of the paint to make it shiny and protect it
How is elctroplating used for finishing
Metal finishing
Cathode and anode in an elecrolyte solution, uses a donor material to mimic the finish of one metal onto another
The donor metal is usually more expensive, and coats a cheaper metal
What is galvanising
Metal finishes
= the application of a protective zinc coating onto metals such as iron and steel
The iron or steel parts are submerged into a vat of molten zinc
This protecets the metal from corrosion and corrosive substances
= more cost effective than stainless steel or aluminium
What is polymer dip coating
Metal finsihing
usually used on ferrous metals
Metal parts are heated then dipped into a tank of polymer powder which has air circulated throughout the particles, this ensures that the coating is even and not too thick
