pneumatics
Pneumatic systems use compressed air to operate the mechanisms in a machine, instead of using electronic and electrical devices.
Pneumatic systems are particularly useful where a large force is needed. Providing power to the device uses relatively cheap components (air lines), whereas an equivalent power solenoid needs thick copper wires and a large coil to move the armature, which generates heat.
Valves are used to control the flow of air in a pneumatic system. Valves can be switched mechanically, by the pneumatic system itself or more usually, electronically. This means that pneumatic devices can be integrated into a computer control system.
Pneumatics are used a lot on the Cadbury production line, e.g. during the manufacture and moulding of the Cadbury Dairy Milk range, when various fluids have to be pumped around and mixed.
The pipes that the liquid ingredients are pumped along are up to 150mm in diameter and the process valves that control the flow of these ingredients are correspondingly large. Process valves (not to be confused with pneumatic valves) are like taps that can be opened and closed to control the ingredient flow. Each process valve is operated by a pneumatic cylinder that is in turn operated by a pneumatic valve. This pneumatic valve is switched using a solenoid, allowing it to be operated by the electronic control system.
Once the products have been moulded they are placed on a conveyor belt system that carries them through the various stages of cooling and packing. Pneumatic devices are also used here; if damaged products are detected, high pressure air is used to simply blow them off the line into a bin.
