MANUFACTURE
Theory Answers. Veneer Veneer refers to thin slices of wood. 1. Describe any two of the following: Veneer, Plywood, Laminating Veneer What are they ? Veneer refers to thin slices of wood. How are they made? A Natural Veneer is produced as a thin sheet of wood of the same thickness by peeling or slicing logs. One method has been illustrated bellow: Rotary Cut The log is mounted centrally in the lathe and turned against a razor sharp blade, like unwinding a roll of paper. Where are they used. Veneer layers are usually glued and pressed onto panels of different materials, to make products such as; Kitchen worktops ,unit doors and furniture
Theory Answers. Laminating Why do we need laminating? Forming wood by bending can produce strong shapes, however it is difficult to bend thick pieces of wood. How are they made? An answer to this is to use thin veneers that can be bent easily. These layers are glued together and placed in a jig or former. When the glue is set, the shape is removed from the jig and the veneers retain their shape. The chair bellow is an example.
Theory Answers. Plywood How are they made? Plywood is made up of a number of layers of veneer, each layer glued with its grain at right angles to adjacent layers for strength.
Theory Answers. Casting 2. Name and briefly describe two methods of shaping metal: Casting What is it? Casting is a metal-forming process. Molten metal is poured into a mould, when cooled it solidifies and takes on the characteristic shape of the mould. Where are they used. Casting is used to produce intricate shapes in metal and is used for mass production. Such as car engines and workshop vices. Products made
Theory Answers. Extrusion What is it? The principle of this process is very similar to squeezing toothpaste from a tube. Extrusion is a manufacturing process used to create long objects of a fixed cross-sectional profile. How is it done? A material, often in the form of a billet, is pushed through a die of the desired profile shape. Extrusion may be continuous (producing indefinitely long material) or semi-continuous (producing many short pieces).
Theory Answers. Blow Moulding 3. Name and briefly describe two methods of shaping plastic: Blow Moulding FEED BACK Parison How are they made? Blow moulding of plastic bottles. A molten polymer is extruded into a hollow, tube-shaped parison. A split mould is closed around the parison, which is expanded against the sides of the mould by a stream of air. Once the plastic has solidified, the mould is opened and the shaped bottle released.
Theory Answer. Injection Moulding Polystyrene, nylon, Materials used: Polystyrene, nylon, polypropylene and polythene. Products made: Electronic cases, mp3, Wii, etc, How it works. Granules of plastic are poured into a hopper. 2. A motor turns a thread which pushes the granules along the heater section which melts then into a liquid. 3. The liquid is forced into a mould where it cools into the shape. 4. The mould then opens and the shape is removed.
Theory Answers. Vacuum Forming How is it works? FEED BACK
Theory Answers. 4. Name and briefly describe 1. A smart material, 2. A composite material. Smart materials have been developed to change their properties in response to changes in their environment. 1. A smart material What is a Smart material? Shape Memory Alloy (SMA) Shape Memory Alloy (SMA) is a smart material that is able to remember its original shape. It can be easily bent when cool, but when heated returns to its original shape. For example ‘Smart Wire’ changes shape when electricity passes through it . It is used in robotic hands to make the fingers grip objects. How is it works? A robotic hand has ‘stretched muscle wires’ attached to the base of each finger. When current is applied to the muscle wire it contracts to its ‘natural’ length, pulling on the ordinary wire ,making the fingers look as if they are moving.
Theory Answers. Name and briefly describe 1. A smart material, 2. A composite material. 2. A composite material. Fibreglass Carbon Fibre Fibreglass (glass reinforced polyester, GRP) is made from thin glass fibres stuck together with polyester resin. It is a very strong material that can be formed into complex shapes. Carbon Fibres are stronger than glass fibres and produce a material which is strong and lightweight. Carbon fibre is used for racing car bodies, crash helmets and bullet proof vests. Products made: Products made: Surf boards, boat hulls, swimming pool water chutes and some car bodies
Theory Answers. Name and describe THREE methods of production: One Off Production A one off product, means what is says, one product is produced, to suit an individual customers needs. Quantity Advantages The look and function are tailored to suit the customers needs. Disadvantages One off products are usually very expensive and production is very labour intensive. It takes time to produce a one off and highly skilled workers are needed. One off production suits complex products or luxury items. Products made: Surf boards, guitars, hand made furniture and bridges.
Theory Answers. Batch Production Quantity In batch production, small quantities of identical products are produced. The size of a batch can vary hugely, from twenty to a few thousand. Advantages The machinery used is adaptable and small changes can be made to the product, from batch to batch, variations on a theme. Products made: Batch produced include aircraft, CD’s, and books.
Theory Answers. High Volume Production (Mass Produced) Quantity Products are manufactured in very large quantities Advantages Cheaper than one off or batch produced items as materials and components are bought in bulk which makes them cheaper. . Production is often continuous, running 24 hours per day. Mass production suits products for which there is a high demand and affordable to a wide range of people. Disadvantages This type of production often uses expensive, specialised equipment and machinery, including CAM and industrial robots. Products made: Mass produced items include cars, fridges, washing machines and electrical goods.