The choice of injection
The injection is an industrial process for implementation of plastics allowing to obtain in a repeatable way and in large series workpieces of different shapes.
The choice of plastic material to be used strongly depends on the nature, the structure and the final use of the workpiece to be produced.
That is why it is essential to associate as soon as possible in the design of the product a Design Office specialized in plastic injection to make the good technical choice from the beginning. The economic model of the project is also very important, because it will help to define the mode of financing of the necessary equipments (moulds, means of control and\or of recovery …).
The choice of plastic injection will start to become interesting for higher volumes of workpieces up to 1000 units. Below that, the use of prototyping techniques is often more economically advantageous.
However, depending on the added value of the product and its anticipated evolutions, the injection may be the right choice.
The use of an expert advice will help clear up these points.
The Injection Press
Once the mould is made, it will be mounted in an injection moulding machine having strong technical characteristics adapted to the shape of the workpiece, to its size and the material selected.
The main characteristic will be the press closing force, which allows to keep the mould closed regarding the pressure carried on by the plastic material injected therein.
The 30 Plast’avenir presses have clamping forces extending from 35 tons for the smaller to 1100 tonnes for the biggest. This allows the production of workpieces from few grams to several kilograms.
The Injection Cycle
During the injection phase, the melted plastic balls are driven by a loading screw inside the mould. Plast’Avenir has a centralized supply system of plastic presses. More efficient than an individual distribution, this system is also cleaner and secured.
Once the material is fully injected, the mould will open to permit demoulding of the workpiece. It can be extracted by a robot, put on a carpet to be worked again, assembled or conditioned. The mould is then closed to restart a new cycle. These cycles can range from a few seconds to several minutes, again according to the workpiece characteristics (shape, size, material).