The blow molding process is designed to produce canisters and containers for household chemicals and cosmetics, for which there is a very high demand worldwide: high-capacity blow molding machines have outputs of 60 to far in excess of 120 million hollow articles annually at the moment.
At first glance, the blow molding process looks simple: Plastic granulate is plasticised and processed to an endless tube. This tube is filled with air pressure so that it takes the shape of the mold cavity.
Regardless of the simple processing principle, this modern technology poses considerable challenges to the processors. To produce the highest possible piece numbers per time unit, an appropriately high melt flow must be ensured, which can make costly machine heating or cooling necessary. The diverse heating zones of the blow molding machine, in particular, must, therefore, be constantly monitored.
It is not only extruders and blows molding heads that are becoming increasingly sophisticated due to the growing demands of more complex processes: retrofitting them on existing machines demands the highest degree of expertise. These components and their condition must also be monitored by software during the blow molding process and ideally visualized. Increasingly intricate sensor systems for monitoring the normal operation of blow molding machines are gaining in importance. The control software of modern blow molding machines is, therefore, becoming increasingly important.
W. MÜLLER GmbH, Troisdorf near Bonn, is regarded by many operators in the blow molding industry as a leading machine retrofitter and retrofit expert with decades of experience. Extruders and blow molding heads from this company are used by operators who are no longer able to satisfy the requirements of their customers with standard machines or who want or need to produce less waste or achieve higher throughputs. W. MÜLLER offers internally developed control software that has been used successfully for many years: The MÜLLER Extrusion Retrofit Control, MERC.
At first glance
The new 2.0 system version features a modern, touch-sensitive 21.5″ flat screen mounted on a trolley in the standard version; up to now, operators had to communicate with the control software via a much smaller 15″ display. The hardware buttons that were previously arranged on the MERC console have been replaced by touch-sensitive icons on the right side of the new screen layout.
Moreover, this purely software-based solution facilitates remote access by W. MÜLLER experts for service purposes: faults can be located and corrected more effectively than before from Troisdorf. Provided this obviates the need for a qualified service team on-site, this saves time and costs for operators.
More space at last!
The second important, immediately recognizable change is the omission of the space-consuming tab system via which, in the previous MERC version, operators had to navigate through the individual pages. It features now a homepage which can be accessed from all submenus; this represents a global level and enables direct access to secondary system components via intuitive icons – for example, to the page that shows an overview of the parameters of the selected Extruder.
Touching one of the component icons directly displays a subpage showing the machine components in more detail. More space was also provided here by omitting the tabs on the generously dimensioned screen for clearer display of the respective machine section with all its controllable components.
The most important process parameters for extruders such as speed, torque, melt pressure and melt temperature are always displayed directly on the main page. They represent the entire machine configuration; a corresponding number of icons is provided for machines with several extruders.
Detailed values only on request: This provides clarity
A further advantage of this approach: until now, operators found virtually all machine parameters in a separate window on the right half of the component page. As a rule, these values do not have to be constantly monitored by operators – as long as all parameters are displayed in “green”. The version 2 MERC system only displays the most important parameters on the main and component subpages. Touching the touchscreen opens a small input window showing all parameters.
The extruder flushing programs have now also been better integrated into the overall system. These largely automated programs help to ensure that no problematic material residues remain behind in the extruder after shutting down the machine. In difficult cases, they can harden in the cooled extruder, which involves costly manual removal.
This function is also only visible to operators if flushing is actually required. This also reduces the complexity of the software and prevents maloperation. Notable is that the software functions without any purchased components. This offers the blow molding experts at W. MÜLLER the option to adopt the system quickly, tailored to specific customer requirements.
For more information, please visit www.extrusionhead.com