Howard Forryan, Harting, explains the benefits of digitally retrofitting real-time production monitoring to plastic injection moulding manufacturing lines.
Digital factory
One of the key issues facing today’s manufacturing industry is how to improve the productivity of existing production lines for minimum cost outlay. A ‘digital retrofit’ of integrating additional intelligent devices and sensor technology into a well-established production line of plastics injection moulding machines can help to achieve these objectives.
Introduction
An important element of Industry 4.0 is the ability to apply digitalisation to the production environment by adding more intelligence into the existing process. Initially manufacturers have been wary of Industry 4.0, on the assumption that effective implementation would require expensive changes to production lines. However, through a digital retrofit, it is possible to smarten existing processes for minimal cost over a short period of time, resulting in a fast return on investment and immediate productivity gains.
Digital retrofit provides four different ways to improve production processes, increase cost savings and extend the lifetime of different types of machinery: Legacy machine protocol conversion; condition monitoring / energy measurement; asset management; and predictive maintenance.
Legacy machine protocol conversion
Central machine monitoring and process optimisation offer the best way to ensure that production lines and their associated constituent parts operate more effectively and economically. Many machines in well-established production lines, which may be between 15 and 30 years old, can still perform their main functional tasks successfully. However, they do so much less efficiently than their modern-day counterparts. For example, they do not have the same level of computing power, enough memory capacity to record and store relevant data, or the ability to communicate with their modern equivalents. In many cases, these machines also use data formats and operating communication language protocols from the 1980s and 1990s, which are no longer used by today’s PLCs and industrial PCs.
A prime example of a production environment that accommodates mixed protocol legacy machines would be a plastics injection moulding machine (PIMM) line. Such machines, when well maintained, can attain as much as a 30-year operational life. However, some of the older software protocol operating languages (eg. EUROMAP 15), cannot be directly connected to a factory MES (Manufacturing Execution System) without expensive annual custom software licensing charges. In a lot of factories these machines still require individual programming by an operator, which can be very time consuming for reasonably large installations and therefore potentially requiring input from multiple personnel.
An MES keeps track of all manufacturing information in real time, receiving up-to-the-minute data from robots, machine monitors and employees. Although manufacturing execution systems used to operate as self-contained systems, they are increasingly being integrated with enterprise resource planning (ERP) software suites. The goal of a manufacturing execution system is to improve productivity whilst reducing cycle-time and the total time required to produce an order.
Harting now offers a new solution to these challenges. MICA (Modular Industrial Computing Architecture) is an edge computing device in the form of a digitally retrofittable IP67 package with Linux-based open-source software. Its modular software and hardware architectural design platform permits the user to choose the programming language and development environment they are most familiar with.
For the PIMM specific plastic moulding component manufacturing environment, Harting has developed the MICA Euromap 15 variant, which converts the legacy Euromap 15 TCP/IP machine operating communications protocol into OPC UA for example, via an intermediate JSON software format.
Condition monitoring
Additional real-time condition monitoring of legacy machine key operating processes can help to reduce downtime and extend lifetime, achieving manufacturing productivity improvements. This can be accomplished by digitally retrofitting additional stand-alone MICA devices to store, analyse and process data from existing or extra retrofitted sensors.
Predictive maintenance
Critical operating parts of a plastic injection moulding machine which are subject to continuous wear and tear include the plasticising screw pump and associated check valves. As wear increases, this can result in a significant number of rejected parts and expensive financial losses. This situation can be resolved by monitoring the changes in the operating power curve characteristics of the screw pump and the pressure loading at the check valves.