You have most likely experienced purchasing a food product, only to discover that it has decayed long before its time, resulting in the necessity to throw out the product. The decay is most frequently due to flawed sealing. Apart from the economical waste it causes the customer, it is also potentially dangerous if the tainted product is consumed.
The task for the X-ray technology is to secure that the final product conforms to a long list of specifications, among others:
- That the plastic container conforms to the tolerances (+/- 0.2 mm)
- That the plastic container has an acceptable thickness as well as density, and that the variation within each container is according to the tolerances established;
- That the plastic container is intact, not deformed or otherwise damaged or dented;
- That the sealing foil is positioned correctly within the defined seal zone;
- That there are no folds or defects within the foil, especially in the sealing zone;
- That there is no product within the sealing zone
- That product or product remnants are not present next to the seal zone
- That the product filling level is correct and that the distribution is even;
- That the product is homogeneous;
- That foreign objects are absent from the product.
Automatic detection and rejection of sealing imperfections, seal contamination, packaging integrity and package content conformity
Faulty packaging may be caused by a number of factors, including sealing defects due to product, damage to the plastic cup, reels getting out of alignment, faulty materials, failure in processes, etc. The problem is that such defects often are discovered only upon final handling. This leads to significant waste, loss of revenue, at best. At worst, the products reach the retailer shop, and ultimately the end user. This leads to call backs, to potential accidents, and complaints that must be handled.
The HYMCIS system allows the on-line, automatic and real-time assessment of:
- Determination of the aluminum jar/can/pouch being undamaged
- Determine that the plastic/aluminum foil is correctly placed within the acceptance seal zone
- Determine that the seal zone conforms to the defined area for the welding
- Determine that the plastic/aluminum foil is free of folds and other similar defects
- Determine that there is no product lying in the seal zone
- Determine if there is product lying outside the seal zone
- Determine that there is no contamination of the product
- Determine that the right amount of product is filled into the plastic/aluminum jar/can or pouch
- Determine that the distribution of the product within the jar/can/pouch is homogeneous
- Determine that the density of the product corresponds to acceptance criteria
- Determine that the homogeneity of the product meets acceptance criteria
The usage of X-rays with a very low energy (15-20 kV) in on-line applications facilitates imaging of very small composition, density and/or thickness differences. This is the fundamental basis for making it possible to inspect and detect in real-time seal imperfections and leakers in e.g. plastic pouches, plastic cans with plastic or aluminum foil, and many other packaging types. Deviations in the seal thickness down to fractions of a micron can thus be detected and the object rejected, at production speed up to 180 units per minute.
EXAMPLES OF USAGE
The value adding effect the systems provide for is particularly due to the fact that the X-ray technology is not only used as an end control, but also as a process control. Hereby, errors due to process machines are found momentarily, the downtime is reduced and the number of errors is decreased. The seaming of cans is particularly essential in the case of the durability of the product. The development of an online system now enables a 100% control of the can seam with a speed of up to 300 cans per minute. Meanwhile, the content and possible foreign particles are assessed.Especially companies that handle food packed in plastic cups and packages where integrity is of big importance to the appearance and durability have focused on improving the process control, and the low energy X-ray technology may be of particular interest here.
Vision systems have previously gained wide acceptance for industrial quality control. The present X-ray detectors with speed of up to 300 images per second allow, together with faster computers, that X-ray data is usable for the control of processes in industrial production. The starting point is the quantification of information of the X-ray images.
The incorporation of PLC-based control in the X-ray systems enables a more complex and safe online quality control.
There are surprisingly many application areas – from an X-ray based measurement of flow in pipe systems for off-shore research to quantification of internal structure in micro-mechanical components. The applications set demands to high speed, high resolution, and high sensitivity. Advanced imaging is integrated with intelligent system control so that an effective utilization of the inspection of the product for controlling the quality is achieved.
One of the main applications for low-energy X-ray systems is within food and pharmaceutical packaging and the like. Depending on the product, shape, size, and packaging material, low-energy X-rays can be used to control and measure many different aspects of the product:
- Is the package intact?
- Are labels placed correctly?
- Is the package correctly closed (is the plastic weld free of foreign particles etc.)?
- Is the product correctly placed in the package?
- Are all units in the package?
- Is the distance between packages/objects on the line correct?
- Is the product correct and does it look “normal” (without flaws)?
- Are there any foreign particles – and if so, where in the package?
- Is there a correct amount of the product?
The motivation for the use of low-energy X-ray systems is in this way not solely as a method for detection of foreign particles – but a more complete quality control, online
EXAMPLES OF USAGE
PHARMACEUTICAL DEVICE INSPECTION
Pharmaceutical device inspection
3 PACKAGES PER SECOND
Real-time and online inspection with instant automatic rejection
FOREIGN PARTICLES DOWN TO 0.3 MM
Foreign particles of (almost) any size in (almost) any kind of product
Our X-ray systems help reduce the risk of spoilage and food poisoning
Danish seafood supplier, Bornholms A/S, wanted to ensure a very high quality standard of their large variety of new packaging containers, and therefore invested in an InnospeXion X-ray system. Read their story.