Learning aim B: Understand the selection of specific materials for use in the components that make up an engineered product Met? P2Describe the engineering properties, qualities and environmental impact of materials in two components of an engineered product and suggest alternatives Component: Lens Material used? Acrylic Student name: Ryan Stephenson Properties  The material is water resistant due to molecular structure and therefore can be used in the outside environment.  Acrylic is quiet brittle. It can easily become scratched on its surface and easy to shatter if dropped  it can also be easily formed into shapes and it will retain its shape once formed. The nature of the material will allow it to be flexible without breaking, this allows the back of the light to clip inside the lens  Acrylic is available in a wide range of colours and has a the properties of being a lightweight, yet a strong thermoplastic. Its available as opaque, translucent and transparent material. The material has a smooth but also a shiny surface.  It also is an electrical insulator which makes it very hard to conduct electricity, this is important because a bike light contains a circuit  It has a low melting temperature this allows it to be manipulated into shape Qualities  It’s very long lasting and is durable however it becomes scratched over time. It can go cloudy- in the sun It’s less likely to break than glass-less sharp edges it is readily/easily available.  As it is a thermoplastic and it can be recycled to be less wasteful in the environment  Safety can be an issue as it is a brittle material and when it breaks it can leave sharp edges  To source the material it can be quite low cost therefore it can be inexpensive to manufacture in acrylic. The manufacturing of the shapes is done at low temperature and therefore uses less energy  The material can be chipped and recycled into other products Environmental  Acrylic is a plastic made from oil, mixed with other chemicals. Oil is not a renewable fossil fuel and eventually this resource will run out. Energy is used to refine crude oil  Energy is used in the refining process of getting crude oil and other chemicals from the fossil fuels  Energy is used in the forming / shaping process of thermoplastics Acrylic is a thermoplastic which can be heated and softened to reform its shape  It can be recycled and made into other products Possible alternatives Glass – because it will let light through and it can be red Advantages  It is long lasting  It will not go cloudy  The material is transparent or translucent and will allow light to pass through it so it will be seen.  Alternative material could be glass Disadvantages  It is more dangerous if broken because it has sharp edges  It is more limited with shapes it can be formed into.  It will not flex like acrylic would let the casing clip in and it would be thicker and will not break easily

Component: Casing Material used? ABS Student name: Ryan Stephenson Learning aim B: Understand the selection of specific materials for use in the components that make up an engineered product Met? P2Describe the engineering properties, qualities and environmental impact of materials in two components of an engineered product and suggest alternatives Properties  ABS is strong, and it doesn’t break if it gets hit or dropped. It has got to be rigid so it can bend slightly to clip into the lens  ABS is available in a wide range of colours and has a the properties of being a lightweight, yet a strong thermoplastic. Its available as opaque material. The material has a smooth surface.  It is not damaged by water  It can be easily formed into shapes at low temperature  It’s shock resistant/impact resistant (if dropped).  It’s an electrical insulator Qualities  It’s low cost it’s also readily available.  It doesn’t break/shatter or leave sharp edges this means it is durable.  It can be recycled for benches/garden furniture Environmental  Acrylic is a plastic made from oil, mixed with other chemicals. Oil is not a renewable fossil fuel and eventually this resource will run out. Energy is used to refine crude oil  Energy is used in the refining process of getting crude oil and other chemicals from the fossil fuels  Energy is used in the forming / shaping process of thermoplastic which can be heated and softened to reform its shape  The plastics can be recycled. Only a certain percentage can be included in recycling material. The Styrene gases are toxic. Possible alternatives Advantages Material used is aluminium Advantages:  - Impact resistant and is less likely to break  - It is very strong and is more durable Disadvantages  It is more expensive and has a higher processing cost  Not as complex shapes can be formed  Material is more expensive Similar  it is impact resistant  It is very strong and is water resistant  The casing will not rust Different  It can be melted down or reformed and recycled  It can be painted/polished