- Created by: mackerss
- Created on: 23-10-17 14:28
CAD - Computer Aided Design (designing products on a computer rather than by hand). CAD packeges can be 3D or 2D.
CAM - Computer Aided Manufacture (manufacturing products with the help of a computer). CAD software works out the coordinates of each point on the drawing. These are the x,y,z coordinates- x - left/right y - forwards/backwards z - up/down. The point where x,y and z meet (0,0,0) is called the datum. CAM machines are computer numerically controlled (CNC). CAM machines are useful for manufacturing at different scales:
- Individual items - laser cutters are used to produce single items like student projects or one-off prototypes
- Batches - you can draw your design in CAD then copy and paste the image so the CAM machine will cut out more than one shape from your material
- Large quantities - a CAM lathe works quickly and accurately to make large numbers of identical products
Some CAM machines are 2 axis - they only follow the x and y coordinates to cut out 2D shapes. Others are 3 axis - these use x, y and z axis to cut out 3D shapes.
- CNC routers can cut out 2D or 3D shapes from a block of material using different sized cutting tools. They are either 2 axis or 3 axis and can also be used to engrave things. CNC routers can be used on plastics, metals and woods.
- Laser cutters are used to cut and engrave plastic, wood, cardboard, fabric and some metals. Laser cutters are only used on sheet materials because they are 2 axis and so can only cut out 2D shapes.
- Die cutters are used to press out a net (for packaging) from a sheet of material. You have to make a blade specially shaped to the particular net and so die cutting is expensive but is great for making large quantities of nets with complicated designs.
- Vinyl cutters are used to cut out 2D shapes from sheet materials like vinyl and card. They are 2 axis and are often used to make signs and stencils.
- 3D printers can be used for rapid prototyping - they convert your design from an onscreen image to a 3D model so they are 3 axis machines.
Materials used for packaging - paper, card (boxes), textiles (bags), metals (cans), plastic (bottles, bags, bubble wrap), glass (jars and botttles).
Functions of packaging - to contain and store products, to protect products, to preserve products, to display products and to inform consumers about the products.
- Containment and storage - packaging is needed to contain small parts e.g a board game. It also makes it easier to store packing e.g fitting side by side or on top of each other.
- Protection - when products are transported, packaging protects them from damage by using bubble wrap, air pillows etc. It is also used for security e.g anit theft devices and tamper -proof seals.
- Preservation - many products (especially food) deteriorate when exposed to oxygen and so use airtight packaging like glass jars, tin cans, plastics and composite materials like card and aluminium foil laminated together.
The environmental impact of packaging
Packaging has an environmental impact -
- Producing packaging uses up materials - most plastic is made from crude oil which is a finite resource (it will run out eventually)
- The processes used to make packaging also has an impact - moulding plastic uses energy that comes from fossil fuels which cause air pollution, contributing to global warming.
- Packaging produces waste - it is disposed in landfills and if it's not biodegradable it will be there for centuries.
The environmental impact can be limited by:
- Recycle old packaging and use recycled materials when making new packaging
- Reuse an existing product's parts or material to make a new one
- Rethink the materials and processes we use to make products
- Reduce the amount of material and energy used to make a product
- Refuse to use unsustainable materials and products
- Repair products that break down instead of throwing it away
Paper and card
The process of making paper - Trees are cut down and taken by lorry to a paper mill then the bark is stripped off and the wood is cut into small peices by a chopper. The small bits of wood are heated with chemicals to turn them into a mushy pulp. The pulp is washed and bleached. Then it's pressed flat between rollers, dried and cut.
Types of paper:
- Cartridge paper - high quality, textured surface, good for sketching with pencils and pastels
- Layout paper - strong, thin, slightly translucent, used for general design work
- Grid paper - a square or isometric pattern printed on it, useful for presentation drawings
- Tracing paper - translucent, used to copy images
Types of card: (paper is measured in gsm and above 20 gsm it's card/board not paper)
- Solid white board - high quality bleached surface ideal for pinting, used in primary packaging
- Corrugated board - secodary packaging, fluted inner core sandwiched between two layers
- Duplex Board - different colour and texture on each side, only one side is seen
Paper sizes go from A0 (area - 1m2) to A1, A2, A3 and so on, halving in size each time.
If you laminate paper by adding a layer of another material, you get a composite material.
A combination of paper and aluminium foil is often used to package foods (e.g juice). This keeps flavours in and air out, and you can print onto the paper.
Foam core board is made by laminating polystyrene foam between card. It's stiff but lightweight, and used for mounting posters and making models.
Paper can also be coated with polythene to make it waterproof. Then it can be used for things like paper cups, and it won't go soggy.