Fagor Hydraulic Presses are developed to give all the features required by SMC and other composites processing in order to obtain high quality parts
Technical plastics and composite materials continue to increase their market share at a good rate in the following sectors: automotive, industrial vehicle (trucks, buses, farm and urban management vehicles, etc.), renewable energy, maritime and aeronautics given their excellent features regarding:
Given these advantages it is hardly surprising that since they emerged in industry in the mid-1970s (although the technique had become known a little before World War II), the market in 2010 had already reached 18,000,000,000 USD, with estimates it might reach 40,000,000,000 USD in 2020, with highly significant inter-annual growth. In the car sector, turnover is expected to double in the same time period, for the standard car sector alone. If one took into account the potential effect of the electric car, the advance of composite materials would be greater, since the combination of light weight and robustness for this kind of cars is critical.
Composite materials may be classified according to matrix type:
For the last type, there is the following sub-classification:
* CFRP (CARBON FIBER REINFORCED PLASTICS).
* CFRTP (CARBON FIBER REINFORCED THERMOPLASTICS)
* GFRP (GLASS FIBER REINFORCED PLASTICS).
Fagor hydraulic presses are designed to provide all the required SMC pressing requirements to produce high quality parts. Firstly, a high uniform pressing force is required. It is usual to have capacities between 10,000 KN and 37,000 KN. Furthermore, this force must be applied with extreme precision over the entire sheet, length-ways and width-ways on all its points over a large surface area, performed at a slow well-controlled speed, and once position has been reached it is held with extreme parallelism. This is clear because otherwise the gap between the upper and lower part of the mould would vary slightly modifying the heat and pressure transmission at that point leading to non-uniform thicknesses, mechanical resistances and surface finishes. These requirements are achievable with hydraulic presses but not with mechanical ones.
In addition, both the upper and lower parts of the tool can be heated to different temperatures, to improve part quality or to give it different characteristics on each face and above all to ensure both parts of the die fit together as it is essential to ensure the upper part has not been heated and dilated more than the lower part (as this might damage the tool). It is essential when manufacturing parts of this kind to be able to control the slide movement in very special cycles which include downtimes and intermittent reverses. To do this quickly and efficiently in mechanical presses is complicated and this is even true in servo presses. So, for example, one often has to descend at high speed, brake while tightening with a certain tonnage, wait a moment until the gas that is spontaneously generated by the composite mixture is created, slightly raise (10-15 mm) the slide to evacuate these gases, close the press again immediately afterwards at a certain speed and then increase or reduce the pressure as the curing cycle continues. Moreover, depending on the parts, sometimes a large table is required but with a relatively low pressure per square millimetre, which also makes the hydraulic press an ideal cost-effective solution for this application. Another important requirement is that the presses must have a very big Shut Height which means the space prepared for operators when the slide is in the upper position must be very large. This is because manual operations are usually required to prepare the composite inside the die and the operator must be inside the machine. This is very difficult or expensive to achieve in mechanical presses. Fagor Arrasate hydraulic presses are optimized for all these features.