Fraunhofer Institute for Process Engineering and Packaging IVV
Increased requirements for heat contact sealing of monomaterials
The sealing of flexible packaging for food, cosmetics, pharmaceutical and technical products predominantly involves heat contact sealing. Ensuring product safety places the highest demands on the quality of the sealing seams, in particular their tightness and freedom from contamination. However, insufficiently adjusted sealing parameters, air pockets, wrinkles and contamination in the seam area can lead to sealing seams in the production process that do not meet quality standards.
The increasing replacement of multi-layer composite films with recyclable monofilms in the interest of a circular economy is increasingly leading to problems with heat contact sealing due to narrow processing windows. This increases the need for continuous seam inspection in production to prevent the transport of defective products to the consumer and to reduce rejects by detecting the defects at an early stage while the products are still with the producer.
Seam inspection methods used to date do not meet these requirements, as they are usually only suitable offline for random samples and the packaging is destroyed in the process. Inline methods used, such as CO2 test gas tests, again do not achieve the speed required for seamless testing of all packages produced. In addition, most methods do not allow localization and classification of defects based on features to evaluate critical defects.
Inspection system for timely, end-to-end inline seam inspection during ongoing processes
The aim of this research project is therefore to develop a novel inspection system for 100% continuous inline inspection of sealing seams. Optical coherence tomography (OCT) is used as a target-oriented method for defect detection. This makes it possible to detect and quantify defects using three-dimensional joining seam images. Within the scope of the project, the OCT method and the hardware for measurement data collection will be further developed for application in the inline quality control of sealing seams and a demonstrator system will be integrated into a packaging machine in order to carry out a validation of the system under practical conditions. This will also ensure that the system can be applied in production operations.
Quality assurance, resource efficiency and the basis for adaptive sealing processes
By using the inline inspection device, manufacturing companies can ensure prompt, completely end-to-end inspection of their sealed film packaging and thus its quality assurance without restricting machine output. The inspection system thus helps to increase product safety for consumers and improve process efficiency. At the same time, the option to detect faulty packaging during the packaging process and to reintroduce the packaged goods back into the process through repackaging significantly saves resources.
In addition to the immediate benefit within the packaging process, the system is a valuable tool for increasing the automation of the packaging process. It enables process data to be collected and internal process-specific databases to be created for process analysis purposes. As a result, it creates the starting point for developing adaptive sealing processes through prompt defect detection and intelligent adaptation of the process parameters in the sealing process.
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Additional project information
| Project duration | July 1, 2022 to June 30, 2025 |
| Cooperation partners | Fraunhofer Institute for Ceramic Technologies and Systems IKTS, Kallfass Verpackungsmaschinen GmbH, IMM electronics GmbH |
| Grant number | 13N16375 |
| Project sponsor/Grant authority | VDI Technologiezentrum GmbH / German Federal Ministry of Education and Research (BMBF) |