This thesis addresses the design and implementation of a control system for a plastic extrusion
blow moulding machine. The extrusion blow moulding process is complex, as it involves
continuous melting of plastic granules, formation of a parison, mould closing, air inflation, and
cooling of the final product.
The main objective of the work was to develop a fully functional electrical control system for
an existing machine, including the design of the control cabinet, component integration, and
programming logic. The two core problems addressed are the lack of appropriate control on the
original machine and the need to automate production cycles that were previously performed
manually or only partially automated. The solution was built around a Fatek programmable
logic controller equipped with expansion modules, a thermocouple temperature acquisition
module, and a pulse width modulation module. A complete control program was developed in
the WinProLadder environment, divided into safety logic, output management, and automated
sequences for the mould, blow pin, and cutting knife. The system also includes a Samkoon HMI
panel, enabling process parameter control, manual operation, state visualisation, and fault
diagnostics. Within the project, electrical wiring, component parameterisation, communication
configuration, and automatic cycle testing were performed.
The results demonstrate that a properly designed control system enables stable machine
operation, repeatable automatic cycles, and significantly improved process control. Moreover,
the system allows quicker adjustment of parameters (pressure, temperature, time), improving
machine efficiency and product quality. The structured logic design also enables further
expansion and upgrades. In conclusion, the developed control system successfully solves the
initially defined problem and provides an effective technical solution for automating extrusion
blow moulding. The work confirms the importance of synchronising mechanical, hydraulic,
and control functions and demonstrates that modern automation significantly contributes to
machine productivity and safety.
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