Minimising waste
Using energy and materials responsibly is an important aspect of designing
A person or company that makes something from raw materials or from an assembly of component parts. will lose money if too much scrap Basic material that goods are made from such as crops, metals, wood and animal products such as wool and leather. is produced during cutting. Profits could be increased if they are able to find ways to lower the cost per product by saving material. Some manufacturers will pass on the savings that they make to the In business, a consumer is a person who uses a product and may also buy it. and lower the cost of the product. During designing, waste minimisation should be analysed in order to reduce unnecessary materials and create effective cutting methods.
Shapes that fit together repetitively. shapes can help arrange items to be cut so that, when fitted together, as many as possible can be cut out of a sheet of material.
A computer-generated cutting pattern designed to minimise the creation of excess scrap during the cutting process. software will automatically fit irregular shapes as close together as possible. A designer could use a The process of creating a 2D or 3D design using computer software. package with built-in nesting tools to try different nested shapes and work out what outputs use the least surface area of material.
How the pattern pieces on fabric should be laid out. are used when cutting fabrics, as fabric has a Short fibres on the surface of fabric.. This means that it has a different appearance when viewed in another direction, and that pattern pieces cannot be Using different shapes to form a pattern with no overlays or gaps. or nested as effectively as wood, metal or plastic.
Calculating surface area and volume
Calculating the amount of material needed can be done by using a A drawing that contains enough information for a third party to manufacture the component or product from scratch. or by measuring a The first working model of a design used for testing, development and evaluation.. Simple measurements can be used to work out the area and volume of shapes. This will help to calculate how much raw material is needed to make a product, as well as how much space would be available inside the product.
Example
Calculate the surface area of all the sides below, to determine how much timber would be needed to manufacture the jewellery box, and the volume of the finished product. In this example, include the lid in the calculation of each face.
Surface area can be calculated by adding together the areas of the six faces.
First, find the total area of the two different-sized faces:
End panels:
Area = 30 cm 脳 30 cm = 900 cm2
Total area = 2 脳 900 cm2
= 1,800 cm2
Side panels:
Area = 60 cm 脳 30 cm = 1,800 cm2
Total area = 4 脳 1,800 cm2
= 7,200 cm2
Surface area = 1,800 cm2 + 7,200 cm2
= 9,000 cm2
Therefore, 9,000 cm2 of timber is required to construct the jewellery box.
= 900 cm2 x 60 cm
= 54,000 cm3
Question
Calculate how much timber would be needed to manufacture the toy box below, and the volume of the finished product. Again, include the lid in your surface area calculations.
100 cm = 1m
Area of end panel = 1 m 脳 1 m = 1 m2
Total area of two end panels = 2 脳 1 m2 = 2 m2
Area of side panel = 1 m 脳 4 m = 4 m2
Total area of four side panels = 4 脳 4 m2 = 16 m2
Surface area = 2 m2 + 16 m2 = 18 m2 of timber
= 2 m2 脳 4 m = 8 m3