Digital control system for PET bottle production from KHS
The KHS Group has developed a digital control system for PET bottle production for more efficient processes and greater bottle stability.
21 August 2020
The digital and automated process control system is used to individually regulate the respective blow moulds of the KHS InnoPET Blomax series. (Image: KHS Group)
Even with the most advanced machine, the stretch blow moulding process can be Differences in material distribution of the PET bottle. This has an impact on bottle quality and production efficiency. In order to optimise these parameters, KHS, in cooperation with the US company Agr International Inc. (Agr), has developed the Unit mould control developed.
With this digital and automated process control system, which is connected to the KHS control system, the respective blowing stations for the InnoPET Blomax series are now regulated individually, thus minimising possible quality fluctuations in the stretch blow moulding process. This enables a Greater bottle stability with simultaneous reduced preform weight realise. This was previously a challenge, particularly for containers with a high proportion of recycled PET.
The blow valves used in a stretch blow-moulding machine can wear differently. This means that the bottles blown with them change over the service life of the stretch blow-moulding machine depending on the station. In the production process, this can lead to deviations in material distribution and thus to varying bottle wall thicknesses.
Previously, parameters could only be adjusted for the entire machine and not for the individual stations. With the new digital control system Unit Mold Control, manufacturers optimise their blow moulding process by Individual settings for each station.
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Frank Haesendonckx (Image: KHS Group)
„This enables more precise control of the material distribution per station, minimising variations in wall thickness from mould to mould by more than 30 per cent,“ explains Frank Haesendonckx, Head of Technology at KHS Corpoplast.
Unit mould control adjusts settings fully automatically
The inspection technology of the KHS Mold Control unit continuously measures the material distribution of each bottle (Image: KHS Group)
The inspection technology of the Mold Control unit continuously measures the material distribution of each bottle and adjusts the settings for the moulding process. Fully automatic optimisation on. „The system identifies deviations in the individual moulding station. Using an algorithm, the variability is reduced without operator intervention and possible incorrect settings are avoided,“ says Haesendonckx
In addition, the data collected from the individual moulding stations provides valuable information for the condition-based maintenance of valves, stretching systems or mould carriers, for example.
The new technology minimises possible quality fluctuations and achieves greater bottle stability while reducing preform weight. (Image: KHS Group)
Particularly with regard to the Growing proportion of recycling in PET bottles, Unit Mould Control offers further advantages. „Process accuracy reaches its limits with these containers,“ explains Haesendonckx. „As the material quality fluctuates when using recycled PET, the bottle becomes increasingly unstable as the preform weight decreases, or manufacturers have to heavier preforms to ensure stability.“
According to Haesendonckx, the new system makes it possible to harmonise weight reduction and bottle stability. „The mould control unit effectively compensates for deviations by detecting unwanted material displacements during wall thickness measurement and automatically counteracting them.“
Cooperation partner Agr is also convinced by the joint new development.
Robert Cowden (Image: KHS Group)
„Our commitment to the global beverage market is to provide innovative process control solutions for the production floor,„ says Robert Cowden, „We help to continuously optimise processes and improve production line efficiency and productivity by reducing unplanned downtime, labour per container produced and energy costs.“
Unit Mold Control is available as an option for the KHS InnoPET Blomax Series IV and V stretch blow-moulding machines and has already been successfully established on the market several times. In addition, the new solution - the property rights for which are held by KHS and Agr - is also available for the InnoPET Blomax. Can be retrofitted in existing systems.
