Almost nothing runs today without electricity. Plastics processor Ruch Novaplast has demonstrated that electricity can do more than just run the machines; it can optimize manufacturing using an integrated manufacturing execution system (MES).
The fog has begun to dissipate for Mathias Schmälze, Comptroller at Ruch Novaplast and the man responsible for the introduction of the HYDRA manufacturing execution system from MPDV. The recording of real-time data in manufacturing has enabled calculation of key data, such as OEE (overall equipment effectiveness) and ensures greater transparency and efficiency at the production facilities in Germany and in the Czech Republic. Ruch Novaplast, a mid-sized plastics company, has produced molded parts from EPS and EPP particle foams since 1960; with its 180 employees, it is one of the market leaders in this sector in Europe.
Range of functions in the integrated MES solution
The basic manufacturing process is simple: particle foam granulate is blown into the hollow cavity of a closed tool using compressed air and injector fillers. Hot water steam flows across the steam chambers and the tool to weld the raw material. The beads expand and fuse at their surfaces to form a homogeneous foamed part. This is followed by additional steps for stabilizing the molded part until the finished part is ultimately demolded, using ejection, compressed air, or handling systems.
The HYDRA MES supports Ruch Novaplast along the entire value added chain: the incoming raw material is inspected and provided with a unique batch number in receiving. The data generated here is available during later process steps due to the central production database. Order planning is carried out in the ERP system, which is linked to the MES via a bidirectional interface. Using this interface, the orders are downloaded, while data recorded on the shop floor is reported back in compressed format. The operators use MES module functions, operating data, and machine data for this purpose.
Like all suppliers to the automotive industry, Ruch Novaplast is obligated to document the complete manufacturing process, including the material batches, machines, and tools used. The tracking & tracing module in the MES supports them in this. An automated inspection is also useful: it carries out inspections during production and files the results from the linked scale system in the MES. Faulty parts are immediately dealt with in a standardized way by the integrated complaint management. To minimize the number of IT systems on the shop floor, the parts manufacturer also uses HYDRA functions for staff work time logging, time management, and access control.
When asked about his experiences over the last few years, Schmälze explains, “Using the MES is as natural and indispensable for our colleagues in manufacturing as the ERP system is for management. The HYDRA MES offers all the functions we need in order to monitor and control our production. The key productivity data are automatically generated by the MES. In just the first 24 months after introducing the MES, we were able to significantly improve our OEE index. This corresponds to a savings potential in the high six-figure euro range. The investment in HYDRA has already paid for itself several times over.”
Easily capture data in the field
Extending the existing MES installation by adding the energy management module was a quantum leap forward. Ruch Novaplast requires both compressed air and steam during production. While compressed air is generated using a compressor, as in most factories, the steam results from water heated by a gas burner. The amount of steam and compressed consumed varies according to the shape of the item to be manufactured. In total, the energy costs account for up to 15% of total expenditures. Using numerous evaluations and operating figures, the HYDRA energy management system provides the conditions for recording and optimizing energy consumption. The less time that the employees on the shop floor have to spend learning a new software solution, the more willing they are to accept it. Therefore, a system that records energy consumption in a highly automated fashion is recommended. Ruch Novaplast met these challenges using WAGO automation technology. To record the use of steam in kilograms and compressed air in cubic meters, an I/O module with signal inputs is linked to an ETHERNET controller at each machine. In addition, gas consumed during steam generation and electrical consumption to generate compressed air are recorded centrally. To simplify things, all parameters are also assessed as euro amounts.
The use of steam and compressed air varies depending on the item; however, a consistent level develops over several consecutive cycles, which enables detection of a fault in the system when excess consumption occurs. Thus, for example, a leaky valve or a crack in a line in not just visually detected, but it is also recorded in the MES so that service can occur in a timely fashion.
Compare, optimize, visualize
HYDRA uses evaluations to correlate specific energy consumption with the machines, the job registered to the machine, and the machine status. Conclusions can then be drawn as to which machine manufactures an item most efficiently and when a machine should be switched off instead. The energy consumption during stand-by operation held significant savings potential. Evaluations of this type are, however, only possible because Ruch Novaplast records their energy consumption in the integrated MES. Connections between the data obtained, which enable a subsequent visualization and evaluation, are already produced during the recording process.
As in other sectors, key performance indicators simplify the overview of complex connections. For example, the energy consumption per part provides information about the efficiency of a manufacturing step, provided that there is a target setting. The consumption per machine hour or in stand-by operations allows machines to be compared. However, even meaningful operating data are useless if no one knows them. This is why Ruch Novaplast visualizes them for context directly at the machine on the shop floor terminal, and also on large flat screens placed around the production hall where they are easily visible. The transparency gained this way increases employee awareness about their own work and provides extra motivation. Ultimately, it comes down to improving a little bit every day, recognizing errors a little earlier, and introducing counter measures a little faster.
Electrical energy – more than just a consumable resource
In the end, electrical energy is not merely a necessity for a business like Ruch Novaplast, or even just a very expensive consumable resource, it is a means to an end for optimizing production processes. As Schmälze confirms, “HYDRA energy management has brought a fresh outlook to our production halls and enables us to continue offering function solutions with added value to our customers. In addition, we are not only increasing our savings potentials, we are expanding our environmental management abilities.” Therefore, energy management now has three relevant optimization aspects: economical, ecological, and organizational.
Text: MARKUS DIESNER, MPDV MIKROLAB
Photo: RUCH NOVAPLAST