Precise temperature control improves quality and productivity
PRIME-tec GmbH in Zella-Mehlis masters the entire process chain of injection moulding technology – from tool making to finishing of the injection moulded parts. The injection moulding machines with clamping forces of 35 to 650 tonnes are equipped with robotic and handling systems. They produce both high-precision technical components and sensitive visible parts for the consumer goods industry (“white goods”). Moulded parts for the automotive industry are also part of the production programme.
When PRIME-tec was planning to purchase a new refrigeration system, the main requirements were very precise temperature control and the lowest possible energy consumption. A constant temperature is important, because it affects the quality of the components. And it also has an impact on productivity, because accelerating the cooling process allows shorter cycle times. Finally, energy efficiency saves operating costs in the long term.
Based on key data gathered on site, L&R Kältetechnik and L&R representative Jurke Engineering designed a dual-circuit refrigeration system that uses an entire array of energy-saving technologies. The system consists of a tool cooling system with a cooling capacity of 140 kW at a water inlet temperature of 15 °C, and a hydraulic cooling system with a cooling capacity of 270 kW at a water inlet temperature of 27 °C.
By means of the “VariKon” control system developed by L&R, the condensing temperature control is variably adapted to the actual outside temperature. This enables significant energy savings for the chiller during most of the running time and reduces the drive energy of the compressor in the chiller by up to 60%.
Another highly effective energy-saving measure is “winter relief” (free cooling) via a self-draining free cooler. The “natural” cold of the environment is used to generate cold. This already significantly reduces the energy requirement of the system during the transitional period. At temperatures of less than or equal to 10 °C, it is even possible to completely dispense with the operation of the refrigeration machines. In addition, PRIME-tec decided to use speed-controlled pumps in the tool and hydraulic circuits, as recommended by L&R.
Initial experience and measurements show that, as a result of the above-mentioned energy-saving measures, cost savings of almost €30,000 per year, as projected by L&R, will be achieved in practice.
PRIME-tec now benefits from the fact that the system, which is installed in a container ready for connection, achieves and maintains the desired cooling temperatures very reliably. This allows a reduction in cycle times and thus an increase in productivity. At the same time, this modern refrigeration technology contributes to the high quality level of the injection-moulded components, especially in the case of complex or warp-sensitive components. And it saves energy costs in the long term.
Sector
Plastics & rubber industry
System solution
Compact chiller