There are numerous ways to increase energy efficiency in production, and Gira is working continuously to ensure this. Just one example of this is the cylinder heating on the machine that melts the plastic to be processed. This maintains a constant heat of 300 to 450 C°, which requires extremely large amounts of energy. In order to make this indispensable procedure more energy-efficient, the system's insulation was improved even further – an investment with long-term effects that will have paid for itself in around just 18 months.
Additional success was achieved in the vacuum generation of a manufacturing cell. Previously a mechanical rotary vane vacuum pump was used, which had to be kept in continuous operation. Now, a Venturi nozzle and thus a pneumatic vacuum generator is used, which can be turned off even for short periods when not in use. Thanks to this conversion, energy costs of more than 1,000 Euros per year are saved. A valuable side effect: the noise level was also reduced by 10 decibels.
One area of production that has particularly high energy consumption is plastic drying. "Here, the focus is exclusively on the energy balance," explains Andreas Höller, Head of Technical Plastic Production Facilities. Until now, a wide range of materials were heated in a central dryer that had to be designed for the maximum possible temperature and material capacity. If the dryer was not optimally utilised, valuable energy was wasted. "Today, we use several dryers that enable drying temperatures and material capacities to be set in accordance with the process. Unnecessary dryers can be switched off. This achieves significant energy savings, since only the energy that is actually needed is used," summarises Höller.
Optimisations are currently also being implemented in material transport. In line with this, granulated plastic is transported through pipes to the corresponding machine based on the vacuum cleaner principle. Although not all machines require the maximum capacity, the entire system was previously set at the highest level and needs-based grading was not possible. Now, frequency converters enable the selective adjustment of the system, which operates faster or slower depending on current requirements. For the distance from the silo to the production building, the more variable and thus also more efficient technology is already in use. The routes from the building entrance to the corresponding machines are currently being equipped to ensure further energy savings.
