Ahead of FAKUMA 2024, Wittmann examines direct current (DC) solutions for injection moulding, offering potential energy savings, reduced carbon emissions, and lower operating costs compared to traditional AC-powered systems.
Key Highlights:
- Since it acquired Battenfeld in 2008, Wittmann has been innovative in manufacturing all injection moulding cells and has also led the drive for each piece of equipment to be as transparently low-energy as possible.
- The creation of DC networks parallel to the existing AC power supply offers the processing advantage of providing the generated DC power unconverted for direct use.
- The new Wittmann Tempro Plus DC reaches exactly the same high-performance rates as the equivalent conventional Tempro Plus AC-powered models.
Wittmann
EcoPower DC
The environment, the circular economy, can now safely be considered the most topical factor in business today. Net Zero, energy efficiency, carbon footprint, traceability and sustainability are all concepts that have taken root in today’s world.
The ISO 140001 standard is now probably the minimum requirement for any injection moulder doing business in any market, and other environmental validation systems such as EcoVadis are steadily gathering up customers.
The emerging environmental ‘food chain’ is connected like never before: everything counts – from the smallest business practices to the behaviour of billion-dollar corporations. Simply put, in this chain you pass on your environmental credentials to others; your environmental successes, failures, and resulting numbers become part of your customers’ - right up to the consumer or end-user. Every business depends therefore on the environmental performance of the previous link in the chain (its suppliers) before attempting to add environmental value of its own.
In these circumstances, the primary factors of production cannot be altered throughout the chain and are where the most environmental gains (and losses) can be established. In this world, your factory ideally wants to take delivery of equipment, components or material already low-carbon; carbon-neutral or carbon-negative.
Enter equipment supplier Wittmann: Since it acquired Battenfeld in 2008 Wittmann, has been unique in manufacturing all of the equipment required in injection moulding cells and Wittmann has also led the drive for each piece of equipment to be as transparently low-energy as possible.
Wittmann is very conscious that many of its plastics processing customers are on the front line when it comes to the role of environmental legislators. By 2050, for example, the EU wants to be climate-neutral. The resulting Green Deal will make it mandatory for manufacturing companies to gradually reduce their CO2 emissions.
The idea of product carbon footprint (PCF) is therefore coming into sharp focus as it eventually would. As part of the quotation process, companies will increasingly be asked to quantify the energy that will mould products, parts and components – and on a per-unit basis.
The benefits of DC power
Wittmann has accordingly designed new software to help - part of the company’s Manufacturing Execution System (MES) - which will launch next month at the FAKUMA show in Southern Germany, October 15-19.
The new software will provide answers as soon as a Wittmann production cell is switched on. The processor will receive a complete overview of the production progress. Key figures will be displayed for each individual cycle and the CO2 emissions can now be added in at that point – each indicated in grams per cycle.
Wittmann
Tempro plus DC
The calculation of CO2 emissions is based on two values. One is the energy consumption of the injection moulding production cell and the other is the shot weight, i.e. the amount of raw material processed per cycle.
The role of temperature control – an integral part of the cell – will be critical in managing this task. Processes that require the management of an unvaried pattern of 220 C over lengthy production schedules are energy-intensive, by definition.
Moulders are therefore enabled to compute the PCF of each moulding - but how can this number be further reduced?
This question has spurred Wittmann to investigate all the options in the power supply itself which has yielded bicycle-powered Wittmann robots to solar-powered Wittmann injection moulding machines (IMMs). The key finding is that Wittmann has found that substituting direct power, or direct current (DC) to moulding cells instead of alternating current (AC) can deliver a rise in energy efficiency and profitability of up to 15%.
The creation of DC networks parallel to the existing AC power supply offers the processing advantage of providing the generated DC power unconverted for direct use. The conversion losses incurred on the way from an in-house photovoltaic system through direct voltage converters to the processing machine are by comparison to AC absolutely minimal.
Until this year, the role of the temperature controller had been the missing piece in the Wittmann DC jigsaw.
Efficient solutions
At the K2022 exhibition, Wittmann presented for the first time a DC-powered all-electric EcoPower injection moulding machine as a conceptual study. A robot from the WX series, also directly supplied with DC current via a joint interim circuit, handled the finished moulded parts.
However, June 2024 saw Wittmann extend the range of injection moulding components available for use in DC networks by adding temperature controllers. The new Wittmann Tempro Plus DC reaches exactly the same high-performance rates as the equivalent conventional Tempro Plus AC-powered models. The Tempro plus D90 DC presented in Vienna in June is suitable for temperatures of up to 90°C and has a heating capacity of 9 kW with 750 V DC. The cooling capacity is 40 kW for a differential temperature of 75 K.
This DC Temperature Controller version already comes with a 1.1 kW synchronous motor and an inverter as part of the standard equipment package. The motor drives a seal-less submersible pump with a maximum working pressure of 7.5 bar and a maximum flow quantity of 60 l/min. The inverter enables direct connection to the machine’s interim circuit as well as speed control in line with the desired process parameters. In this way, power conversion loss is prevented and the pump speed is adapted to the requirements of the process. The net result is a hefty two-fold increase in energy efficiency.
Now that the concept has been tried and tested, Wittmann is ready to roll out the solutions to the marketplace: The FAKUMA 2024 exhibition will be the platform for Wittmann to demonstrate DC energy as a power source for injection moulding systems.
On an EcoPower B8X 180/750 DC Insider cell with an integrated WX142 robot in DC version from WITTMANN and also a DC-compatible Tempro plus D temperature controller, the housing of a plug-in connector for DC technology will be manufactured using a 2-cavity mould supplied by Harting, Germany. A Harting Han Lock & Light connector will securely connect the temperature controller, with a safety feature that prevents disconnection until the machine's power supply is turned off. An additional lighting element on its base serves as a visual status indicator.
The system will be powered by an ultra-modern sodium-nickel battery from Innovenergy. The battery has a total capacity of over 45 kWh which can provide uninterrupted power for the machine throughout an eight-hour workday.
Future solutions always present initial hurdles and doubts for early adopters. However, these carbon-saving numbers at source will present impeccable credentials to OEMs looking to source the lowest possible PCF numbers for their products and components.