Ferrous metals Ferrous metals include: mild steel, high carbon steel, cast and wrought iron. Availability of stock forms such as sheet, bar, tube and angle. Applications for ferrous metals such as car body panels, tools, white goods and machine parts. POLYMERS Non-Ferrous metals Non-ferrous metals include aluminium, copper, zinc, gold, silver and titanium Availability of stock forms e.g. sheet, tube, ingot Applications for non-ferrous metals such as kitchen ware, jewellery, food wrapping, cans and electronics Alloys Ferrous alloys include: Stainless Steel, High speed steel and Die (tool steel) Applications for ferrous alloys e.g. kitchen ware, street furniture, cutting and press tools Non-ferrous alloys include: Bronze, Brass, Pewter, and Duralumin/aluminium alloys Applications for non-ferrous alloys such as ornaments, valves, boat fittings, sculpture, coins and jewellery Biodegradable polymers Degradable polymers (Oxo-degradable) Biodegradable polymers ( bio-batch additive mixed polymers) Compostable polymers include: cellulose based polymers such as Biopol, and corn starch based polymers such as Polylactide (PLA) Applications for biodegradable polymers : carrier bags, plastic bottles and detergent sachets Absorbable/water soluble polymers including: lactide, glycolide, ( Lactel ) and Ecofilm Medical applications such as slow release medication, bone repair fixings, detergent washing liquid sachets. Elastomers Common Elastomers: Thermoplastic Elastomers (TPE), Thermoplastic Rubber (TPR) and Liquid Silicon Rubber (LSR) Applications for elastomers such as car bumpers and trims, and product grips (over mouldings)
Injection moulding A metal Die casting uses a metal mould is used and softened or molten plastic is forced into the mould by pressure from a screw thread or pneumatic plunger. The mould is made in two parts to allow the moulding to be removed. Injection moulding is used extensively in industry mould that can be very detailed. The mould is made in two parts to allow the casting to be removed. Die casting is a very important industrial process used for many different types of products. Blow moulding is used to shape plastics, mainly for making bottles, plastic buckets and similar shapes. Extrusion moulding is used to produce long, but fairly thin products such as pipes or curtain tracks. Both plastics and metal can be extruded. The material is forced through a die, which contains a hole which is the same shape as the required product. Steps: 1. Parison inserted into mould. 2. Base of parison squeezed by mould. 3. Air blown in to parison, parison expands to fill mould. 4. Finished product. Press or compression moulding Vacuum forming is used for food and confectionary packaging, trays, shop fittings and baths. This process uses a wooden mould or form. A sheet of thermoplastic is heated, then shaped by creating a vacuum underneath it. Air pressure then forces the plastic over the mould. A mould is made in two halves. Sheet plastic is placed between the two halves, which are then heated and pressure applied, enabling the plastics to assume the new shape.
Paper thickness is measured in grams per square metre (gsm). This is the weight of one square metre of the paper. Most paper is manufactured from recycled boards and paper. Virgin paper is made from 100% wood pulp and contains no recycled material. Bending Metals can be bent in a vice or in folding bars. The material is marked where it is to be bent, and clamped to the line in the vice or folding bars. To prevent damaging the material as you hit it with the mallet, place a piece of wood next to it and hit that instead. Layout paper Thin metal may be bent whilst cold, while thicker metal may need heating or annealing. Larger pieces of metal may also need to be heated first. Tracing paper Laminating Wood is usually bent by laminating. This is done by cutting thin strips of wood, putting glue on the strips and clamping them into a mould. Cartridge paper Bleedproof paper Coloured paper Grid paper Shaping by wasting means cutting away material to leave the desired shape. It gets its name because the material which is removed is usually thrown away. Shaping by wasting can be done on any type of material. - lightweight, thin white paper - used for initial ideas - takes colour media well - low cost - thin, translucent paper - making copies of drawings - high cost - good quality white paper - available in different weights - general purpose work - can be used to make simple models - medium cost - smooth, hard paper - used with water-based and spirit-based felt-tip pens - medium cost - many different types - available in different thicknesses - used for mounting finished work - used to apply coloured surfaces to models - low to medium cost - printed square and isometric grids in different sizes - a guide for quick sketches and model-making - low cost Board (sometimes called card or cardboard) thickness is measured in microns: one micron is one thousandth of one millimetre. Sometimes the thickness of board is given in sheets. This refers to the number of pieces of paper that have been glued together to make a sheet of board.
Compliant Materials Composites Fibre Reinforced Polymers include: 1. Glass Fibre (GRP) 2. Carbon Fibre (CFRP) 3. Kevlar Applications for Composite Fibres are such as boat building, sports car manufacture, performance sports equipment and body armour. Particle based composites include: 1. Concrete 2. Cermets such as tungsten carbide. Paper: including layout paper, bleed proof, photo quality cartridge and watercolour. Applications such as design drawings, presentations and graphic products. Card including carton board, multi-sheet, laminated, corrugated, metal effects, and mount board. Applications such as model making and packaging. Reflective films and holograms: Applications such as reflective/warning patches, jewellery and security holograms Polymer based sheet and films including: foam board, fluted and translucent polypropylene sheet, acetate, Styrofoam, modelling foam, low density polyethylene sheet, and plastazote foam. Applications such as packaging, point of sale displays, and model making Applications for concrete such as structural building components, garden ornaments and paving. Applications for cermets such as cutting tools.
Materials and the ENVIRONMENT One way to reduce impact on the environment is to use less material in the product. This might mean asking questions about what is needed or whether it could be made smaller (or thinner) and still do the same job. It could also mean using an alternative material with better properties, so that not as much of the material is required. Wood Timber is a renewable resource, which means that if forests and woodlands are carefully managed, we will never run out of it. Timber is easy to reuse and can be burnt to produce heat when at the end of its natural life. It is also biodegradable. Metals Most metals are relatively easy to recycle and reuse, and there are advantages for manufacturers. It is 20 times more efficient to recycle aluminium cans than to make new ones. Plastics Although most plastics are not biodegradable, they can be recycled and reused. Polystyrene vending cups can be recycled to make items such as pencils and rulers, and plastic carrier bags can be reused. Consumer rights and legislation For many products, society has laws and standards that the designer must meet. These help to protect the users, by specifying that products meet certain requirements and have suitable levels of safety. The Laws also allow consumers to get their money back if goods are found to be faulty or if products do not perform in the way claimed by the manufacturer. A law is a formal rule adopted by Parliament and enforced by the government. A standard is a guideline which is widely accepted. Standards do not necessarily have the force of the law. The Consumer Protection Act 1987 This protects the public by: 1. Prohibiting the manufacture and supply of unsafe goods making the manufacturer or seller of a defective product responsible for damage it causes 2. Allowing local councils to seize unsafe goods and suspend the sale of suspected unsafe goods 3. Prohibiting misleading price indications The Trade Descriptions Act 1968 The Trade Descriptions Act makes it an offence for a trader to make false or misleading statements about goods or services. It carries criminal penalties and is enforced by Trading Standards Officers, making it an offence for a trader to: 1. Apply a false trade description to any goods supply or offer to supply any goods to which a false trade description has been applied 2. Make certain kinds of false statement about the provision of any services, facilities or accommodation In the UK, standards are regulated by the British Standards Institution (BSI). Products which meet these standards can be marked with the KiteMark. There are also separate standards for the European Union. If a product meets these, it can be given a CE Mark. The marks show government officials that the product conforms to a standard, which enables it to be legally placed on the market within their country.
Components are the smaller parts that make up a product, often used to join materials together. Different kinds of component are used to join plastics, woods and metals, and adhesives are used to join materials together by glueing. Components made from resistant materials are usually bought ready-made. The most common components are nails, screws, hinges and catches. Nails Generally used where appearance is not important or where a quick job is needed. Made of mild steel. Panel pins and veneer pins Used to fix backs onto cupboards and bottoms onto boxes. Veneer pins are finer (or thinner). Made of mild steel. Wood screws Used to join metal or plastic components to wood, or to join two pieces of wood to make a strong joint. Machine screws Have a screw thread to fit into a threaded hole or a hexagonal nut. They can be used to join two or more pieces of metal or plastic. Bolts Have a screw thread which fits into a threaded hole or a hexagonal nut, and are normally used to join two or more pieces of metal or plastic. A bolt is only threaded for part of its length. Bolts normally have hexagonal heads. Set screws Have a screw thread along the whole or most of their length, and normally have hexagonal heads. Pop rivets Originally designed for use in the aircraft industry but are now used in many different products. They are often used where there is only access to one side of the material. Hinges, catches and locks Used on boxes, cabinets and cupboards. They can be used on products made from wood, metal or plastic. They are normally fixed to the product with wood screws or machine screws and nuts. Metal joints can be made by brazing, soldering, welding or using rivets. Brazing Brazing is a way of bonding materials by melting a filler metal or alloy between the components. The filler metals used in brazing must have a lower melting point than that of the material being joined. Brazing forms very strong, permanent joints. Soldering Soldering is a type of brazing which works at lower temperatures. Soft soldering is used to make permanent joints between copper, brass, tin-plate or light steelwork, and is normally used to join components to electronic circuit boards. Hard soldering is used for stronger joints. Welding A man uses a welding torch to join two sheets of metal. In welding, two pieces of metal are melted along the joints - fusing together as they cool. No filler is used. A filler rod may be used for a really strong joint. Rivets are used to join metal, plastics and plywood. The rivet is placed in a hole drilled through both pieces of material, and its end beaten into a dome. A tool called a rivet set or a rivet snap is used to to finish the joint. Some rivets are countersunk. Pop rivets are used where there is only access to one side of the work. They are used to join thin sheets of material together.
Modern Materials Smart Materials Shape Memory Alloy (SMA), such as Nitonol (Nickel-Titanium alloy). Applications such as flexible spectacles (superelastic wire), heat activated cable connectors, muscle wires, and fire sprinkler control. Thermochromic pigment (Smart colours). Applications such as thermometers, baby feeding products, kettles, steam irons, thermal warning patches, and hi-tech jewellery. Thermochromic sheet Applications such as thermal warning patches, battery condition indicators and jewellery Photochromatic pigment Applications such as sunglasses, anti-flash visors, sun-blocking products and radiation indicators Phosphorescent pigment Applications such as emergency exit signs, jewellery and toys Polymorph Applications such as modelling grip prototypes Metal based, including: coated metals e.g. anodised aluminium sheet, nickel plated steels, polymer coated aluminium, Alu composite(polythene cored aluminium sheet) Aluminium foam and titanium Wood based-including: flexible MDF, flexi-ply, aircraft grade plywood, Hexaboard and paper backed veneers Difference between Smart & Modern Materials Smart materials respond to differences in temperature or light and change in some way. They are called smart because they sense conditions in their environment and respond to those conditions. Modern materials are developed through the invention of new or improved processes.
Know your Joints Frame joints Strong, permanent and neat-looking joints in wood are achieved using one of the many types of frame joint. Frame joints are right-angled, jointed frames common in furniture, boxes and many other types of assembly. When making several identical products or parts, jigs, formers, templates, patterns and moulds are used to ensure the parts are all the same. 1. A jig is used to make sure that parts are made exactly the same, without the need for marking out. For example, when drilling through a block of wood with two holes in, it will make sure that the holes are drilled in the same place in each component. 2. A former is used to make sure that parts are shaped or bent to exactly the same shape. Knock-down (KD) joints are commonly used in flat-pack furniture, which is assembled by the customer at home. Usually KD joints are made from a plastic, such as nylon. 3. A template is something that you can draw around to mark a shape onto material, so that it can be cut or shaped. 4. A pattern is used to make a mould when casting in metal or plastic resin. It is a replica of the finished object and may be made in wood or another soft material. Patterns are also used when shaping plastics in a vacuum-forming machine. 5. A mould is a hollow shape used when casting metal or plastic resin. Moulds for casting metal can be made in a special type of sand, in metal or in plaster. Moulds for casting resin can be made of plaster or rubber.
One-off production In one-off production a single product is designed and made to a client's specification. Labour and material costs are high, and a high level of design and manufacturing skills are needed. An example of one-off production would be a made-tomeasure wedding dress. Batch production In batch production set quantities of a product are manufactured to order. Batch production requires a high level of design, pattern making and sampling skills. Materials are cost-effective and manufacturing costs are lower than one-off production. Garments are designed to fit a range of standard sizes and shapes. The quantity varies from a set of four cushions made by a designer/maker to 20,000 jumpers made for a department store. Mass production Mass production is the industrial-scale manufacture of large quantities of products, usually on a production line. Standardised production methods mean it is suitable for products that rarely need to be redesigned. Mass production is used for products that are needed in very large numbers, eg socks or jeans. Often, products are made overseas where labour costs are lower Just-in-time manufacturing is when materials are ordered so they arrive just as they are needed. Market PULL Technology PUSH The opportunity for new products arises from developments in technology or customer need. The effective design of these products does not just consider how they work. It also has to take into account a broad range of issues, including social, cultural, market and environmental factors. Market pull is when product ideas are produced in response to market forces. Examples of market influences include: - A demand from consumers for new or improved products. - A competing product is launched by another manufacturer. - A manufacturer wants to increase their share of the market. Technology push is when products are re-designed because of changes in materials or manufacturing methods. This might mean that new materials have become available, with improved properties; or that improvements in manufacturing processes mean a manufacturer can make the product cheaper or more efficiently, which reduces manufacturing costs. Production methods