Inspection system for all types of labels
For the decoration of bottles, jars and cans, there are more different types of labels available today than ever before. Producers have the choice: established pressure-sensitive labels, indestructible IML decoration, or an outstanding sleeve solution? For the inspection of these decorations, companies are then also spoiled for choice.
Why not a “one for all” solution?
Some suppliers of vision inspection rely on universal solutions that cover different label types. A customer should then be able to perfectly inspect several label types with the same kind of vision system, for example sleeves as well as pressure-sensitive labels. On first impression, this may seem tempting to many customers, as it is assumed that these solutions can be flexibly used for different label types.
“At first glance, such solutions certainly look attractive to some customers due to their low initial price,” knows Janina Orlowski, Team Leader of Product Management and Marketing at Intravis. “But at second glance, these solutions come with enormous disadvantages. For instance, you need at least one absolute expert in the company to adjust the system to the ever-changing types of labels. As a company, you are therefore dependent on a well-trained employee. If this employee is absent, this can immediately have a noticeable impact on the quality of the inspection process – and thus on the quality delivered.”
And this is not the only disadvantage of an ”one for all” solution. Janina Orlowski continues: “The decisive disadvantage of these solutions, however, lies in their inspection accuracy and the data determined. The systems may sort out defective parts, but they cannot tell you exactly which defect caused a part to be sorted out. So, as a customer, they know they had a bad part, but how to prevent that from happening again is something they have to painstakingly check in the quality lab and then draw their conclusions with a time lag. In that time, you may have already produced half a production slot with inferior quality. If this happens more often, the initial advantage of the low price is used up very quickly.”
Special solutions for quality products
Therefore, Intravis has chosen a different path for many years now. The Aachen-based company offers specialised systems for the various types of labels. “With our systems, producers ensure, on the one hand, that high quality is delivered to their customers. On the other hand, in the event of a defect, they learn directly which defect types have caused rejects and to what extent,” reports Markus Juppe, Chief Marketing Officer at Intravis.
The company accomplishes this thanks to two factors. Firstly, each system is equipped with hardware explicitly designed to detect the typical defects of the particular labelling process. This includes specific illuminations that are necessary due to different surface conditions of the various label types. For example, this avoids annoying reflections that would otherwise result in false ejection or at least a restricted inspection area. Moreover, the integration of high-resolution cameras is claimed to support an optimal and detailed evaluation of the labels.
The second decisive factor is the IntraVision inspection software. The software has specific modules which, on the one hand, have been developed directly for the different label types and, on the other hand, are additionally adapted explicitly for each customer product. This has the advantage that special label geometries or product shapes can be precisely addressed. In conjunction with high-resolution industrial cameras, the integrated inspection modules are then able to find defects and identify which type of defect it is. Thanks to an interface between the vision system and the customer’s ERP or MES system, this information can also be directly transmitted. Thus, line operators and plant managers can see immediately and at a glance which processes they need to check in order to keep their production quality high in the long term.
The IntraVision software also solves the problem of the image processing specialist that the company has to keep on hand when using “one for all” solutions. This is because, on the one hand, the systems are completely commissioned by an Intravis service technician. They are ready-to-use, which means they are already optimally set up to meet the customer’s requirements. On the other hand, the easy-to-use software requires no time-consuming programming by the operator. Usually, the setup of a new product is already fully automated with the touch of a button.
Automatic readjustment possible
With the right integration of the Intravis system, the whole inspection process can even be automated. Intravis has already implemented such a solution at a German global player for many years. Markus Juppe presents it in more detail: “Essentially, the solution is that we use one of our inspection systems to detect any misalignment of the label relative to a predefined optimum position. If such an offset is detected, then our system sends a signal to the labelling machine, which automatically readjusts its dispensing head based on the detected offset.”
The ingenious aspect is that even in the event that a label is dispensed from two different dispensing heads, the Intravis system can trace the offset back to the respective dispensing head, and only this head is then adjusted. According to Markus Juppe, such a solution can be implemented with both linear and rotary labelling machines in case of producing with pressure-sensitive label. However, this technical approach can also be transferred to IML labels in the injection moulding process or to a shrink or stretch sleeve application.
Experience paired with new ideas
The system used for the automatic readjustment of label dispensing heads is a LabelWatcher. It has already been in the Intravis product portfolio for 20 years. It is the solution for the inspection of pressure-sensitive labels on bottles, jars and cans. Regardless of whether only one side is decorated with a label or two, the LabelWatcher can be specifically adapted to all requirements. The inspection scope includes standard inspections such as presence and positioning of the label, contaminations, wrinkles and bubbles, as well as artwork inspections, and even reading codes – no matter whether barcode, QR code, data matrix code, or plain text codes.
Intravis has also introduced two enhancements to its proven system this year. First, the LabelWatcher is now also available in the so-called washdown design. Janina Orlowski says: “With the washdown design of the LabelWatcher, we are once again significantly expanding the application possibilities. Each component is individually enclosed. Thanks to the specific design, the inspection unit and the control cabinet are splash-proof from all sides and meet the hygiene requirements of the producers. In addition, this makes cleaning much easier, even with aggressive cleaning methods.”
The second innovation is that the LabelWatcher can now also inspect unoriented products with any object shape. The LabelWatcher 360°, the official name for this solution, is an inspection system particularly designed for the quality control of products with 360° labels in any rotational position. Thanks to a newly developed imaging as well as a referencing procedure specially developed for the LabelWatcher 360°, it can now be used to inspect unoriented products just as reliably as customers have been used to with the established LabelWatcher for oriented products. Due to the characteristic of the wrap-around label, the inspection scope of the LabelWatcher 360° is additionally extended by an inspection of the label joint line.
IML on the rise
IML decorations are increasingly being used on cups and jars. The IMLWatcher is a system for the quality inspection of products with in-mould labels that has already been established in the market for years.
“We realised more than 10 years ago that IML labels require special handling and inspection and could only be insufficiently checked with a solution like our LabelWatcher,” reports Janina Orlowski. Due to the special manufacturing process, IML-labelled products also come with special types of defects. For example, the IMLWatcher is one of only a few inspection systems available on the market that can inspect for short shots as well as blow byes. This ensures not only the quality of the decoration itself, but also of the decorated object.
And the system also addresses the peculiarities of the IML process during daily handling. “We are aware that rapid product changes are the daily routine, especially in productions using IML labels. That’s why we equipped our IMLWatcher with a quick reference mode,” Janina Orlowski tells. This functionality helps the operator to create a new, ready-to-use reference within seconds and fully automatically. The subsequent reference evaluation also helps to find out the effects of an adjusted reference compared to the previous one. This ensures that only perfect references are activated.
In addition to the already established solutions in the household chemicals and food industries, new industries are also increasingly experimenting with how they can incorporate IML decorations for their purposes. In this regard, Intravis recently announced with several partners that a new solution for IML-decorated medical products will be presented at this year’s Fakuma trade show.
Sleeve labels with special requirements
Compared to the other types of labels, sleeves pose special challenges for the vision systems currently available on the market. For this reason, Intravis decided to develop a system specifically designed for sleeved products, the SleeveWatcher. Undoubtedly, a major challenge is the glossy surface of sleeves. Compared to pressure-sensitive or in-mould labels, sleeve labels often lead to high reflections if illuminated incorrectly. These reflections, in turn, can result in the ejection of faultless products that actually meet all quality requirements.
Intravis meets this challenge with a lighting technology. It illuminates the entire inspection area and, consequently, produces a very homogeneous light. This significantly minimises the risk of reflections but still detects typical defects like folds and holes.
Another challenge presents the huge number of possibilities that can arise with sleeved objects. A large selection of object shapes with diverse combinations of colours, patterns and transparent label parts provides a particularly high degree of variation for sleeve labels.
These elements, which make the sleeved product attractive to the end consumer, are often highly challenging for vision inspection. Due to the specially arranged hardware as well as a completely new developed inspection module for the IntraVision software, the SleeveWatcher is optimally adjusted to the challenging characteristics of sleeve labels. Thus, the system enables a comprehensive 360° inspection of the entire label.
Once the SleeveWatcher is installed, it inspects 100% of the product flow at a speed of up to 15 parts per second. Thus, the system can easily keep up with even the fastest sleeve labelling machines, says Intravis. Its six side cameras inspect sleeves for common label inspection criteria such as presence, identity as well as horizontal and vertical offset. In addition, the system inspects for sleeve-specific defects such as smiling and frowning effects, folds, distortions, and holes. On request, code reading is also possible – with the same code range as known from the Label Watcher.
Click here to learn more about the Sleeve Watcher
Click here to learn more about the IML Watcher
