Surface Finishes
Design & Technology: AQA GCSE, topic 7.11.2
Surface Finishes
Products may require a finish adding to it. This will be to improve the function or the aesthetics (look) of the product.
Metal
- Dip coating - air blown on powder to make it act like a liquid and dipping the metal in it.
- Powder coating - metal is sprayed with the powder which is attracted to it as the metal is electrically charged.
Polymers
- Plastics are usually polished to make them bright and shiny.
- Some plastics can have stickers (vinyl) attached.
- Some plastics can be printed onto for example sublimation printing.
Timber: paint
- Paint comes in various forms (water based, oil based, solvent based) and can be applied by a brush or sprayed onto the material.
- Paints make sure that the product is protected and it looks nice.
Timber: varnish
- Varnish is a tough, waterproof and heatproof finish that comes in a range of colours.
- Varnish is usually applied in 3 coats with a brush, it can be smoothed by using a fine glasspaper.
Timber: tanalising
- Tanalising is used for garden furniture and fences.
- The timber is placed in a vacuum which increases the pressure that forces the preservative into the material.
Surface Finishes
Products may require a finish adding to it. This will be to improve the function or the aesthetics (look) of the product.
Textile
- Block and screen printing adds patterns to material.
- Textiles can be dyed or tie dyed to add colour and pattern to material.
- Fabric can also be treated with stain resistant finishes that stop stains from embedding into the material.
Paper and board
- Most papers and board are printed on using techniques like screen printing or block printing.
- Items that are mass produced will be printed using commercial printing techniques such as lithography, flexography, letter pressing and gravure techniques.
Paper and board cont.
- Embossing is when a shape is pressed into the paper or board (a steel die is used) to make it stand out. This improves the visual look of the product
- Ultraviolet varnishing involves putting a glossy coat to the paper or board that is then dried using ultraviolet light.
Electronic and mechanical
- Printed circuit boards (PCB) are lacquered with a clear waterproof layer that protects the tracks and components without affecting how they work.
- Mechanical parts are usually lubricated to reduce the friction, noise and heat.
Test yourself on Surface Finishes
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