PROCESS CONTROL & CONFORMITY
The unique high sensitivity is connected with a limiting pixel resolution of 0.1 mm, which gives real-time X-ray images of an extraordinary quality. The production speed can reach 30 m/min (limit 200 m/min), and products can be sorted into different quality categories. A powerful PLC, connected to a powerful computer, manages the data processing in real-time. High-speed communication ensures the correct activation of the sorting mechanisms, via a series of I/O terminals. The number of quality categories to sort into are un-limited, yet the standard system has 10 I/O terminals for reject/sorting arrangements.
- Optional conveyor width to 2000 mm
- Multiple lane solutions
- Production speed to 200 m/min
- Detection down to 0.2 mm
- Ultra high sensitivity
- Sorting into different quality categories
Traditionally, X-ray technology is used as a final reject, especially for contaminants detection in the food sector. During the last years, InnospeXion has developed a unique real-time X-ray imaging technology, based on using a part of the X-ray spectrum not used in other X-ray imaging systems. At the same time, a substantially higher resolution (0.1 mm) and a very fast imaging speed has been achieved. This means that on-line X-ray images today may have an information content that enables the X-ray system to continuously measure and verify conformity of even very thin and very small details relevant for modern production. Thus, the InnospeXion X-ray systems may be used as on-line process control stations where significant product parameters are continuously measured, verified, and reported. The benefit is to enable a contingency action prior to deviations ending as faulty products.
Bakery product X-ray inspection – biscuits & cakes process and product control
Modern manufacturing lines require a strict control of the correct distribution, dimensions, and mass of the dough, in addition to e.g. contamination inspection. High contrast X-ray imaging online enables the fast and reliable control of the product conformity before the baking process. This leads to immediate action-taking when there are issues with the performance of the dosage system. Consequently, downtime is largely eliminated and discard of non-conforming products is minimized.
The InnospeXion technology enables the compactness and robustness required to insert X-ray inspection during the forming process.
However, the X-ray technology also is applied to inspect the baked products and to secure that the products are packaged correctly, with the correct, uncontaminated, and un-damaged amounts in the package. This also gives additional value to the product and safeguards a minimum of recalls and customer complaints.
- Tailored, ultra compact design
- Ultrafast inspection capability: Line speed up to 180 m/min
- Fast signaling cycle: Approx. 15 ms or better
- High precision in marking of defect – better than 0.1 s precision (depending on local layout of network and control/handshake)
- Detection capability 0.1 – 0.8 mm, speed dependent
- Ultra high sensitivity – high contrast images
- Suitable for multiple products in one system (multiple lines per system) (total width < 100 mm)
- System product coverage 100 mm in width, optional larger width
- 2 m distance (cable connection) between control compartment and inspection compartment
- Standard off-the-shelf systems for contamination and product conformity inspection
Detection of contaminants in large cheese blocks
The distribution of voids and holes in cheese may have a large influence on the quality of the cheese. For certain cheese types, a void development may result in failure to sell the cheese. This concerns e.g. cheeses based on sheep milk and others, as well as other cheeses with a long maturity requirement. The problem is, that the voids may develop near the surface, causing fungi to enter the cheese cavity. This makes the cheese to develop as a blue cheese which impedes that it can be sold. Such void development may occur at any stage during the long maturation process, thereby causing significant waste and loss for the manufacturers.
The ability to scan the cheese at regular intervals may facilitate that the cheese can be sold when a hole is developing critically near the surface.
The objective was, therefore, to develop, test and install an X-ray system which can determine when the cheese is ready for the market.
Development, design, testing, and installation of a prototype high sensitivity and high-resolution tomographical scanning system suitable for the inspection of cheese.
A commercial tomographical X-ray system for cheese inspection with the following specifications:
- Automatic in- and out-feeding of cheese and automatic scanning and decision-taking of critical hole development in cheese
- High contrast, high resolution imaging with tailored X-ray scanning detector;
- Operating at maximum 70 kV, at very high flux, and with large output stability
- Lead-free radiation cabinet with integrated conveyor section
- Software package for general assessment of cheese, automatic operation
- System control and safety system complying to European and US regulations
- Cycle time 1-4 cheeses/min
- Hygienic design suitable for cheese producers
- Automatic/semi-automatic decision taking and sorting
On-line inspection of chocolate and candy is advantageous due to the ability to detect non-conforming production that may compromise automatic packaging or may pose quality issues of the product itself (e.g. layer thickness deviation, filling imperfections, form/shape deviation, etc). Tailored X-ray systems that can offer the possibility of inspection across the entire production conveyor width is a requirement to improve the yield.
X-ray systems are also ideal for inspection of the packaged products and the detection inside the parcel of a variety of defects, including foreign objects.
The low energy X-ray technology is particularly suitable for inspection of unpackaged and packaged products of small thickness and/or low density (low atomic number composition), such as chocolate and candy. For the packaged products, a great advantage is the ability to check not only the conformity of the content but also the integrity of the packaging (sealing, e.g.), as well as positioning of product(s) inside the package.
Detection of plastic pieces from the molds constitutes a major concern since these foreign objects may be elongated and sharp, and therefore constitute a risk for consumers health.
InnospeXion has delivered and installed a large number of systems for online and at-line chocolate and candy inspection, based on the unique low energy X-ray technology. The systems supplied cover single-lane systems at 220 mm conveyor width, up to large systems with 1600 mm conveyor width. The unique sensitivity that allows the assessment of both packaging irregularities and non-conforming product, combined with a 0.1 mm resolution, makes the InnospeXion systems very unique, with second-to-none image quality.
Detection of plastic pieces from the molds is difficult as long as the plastics used are lighter than the chocolate itself, and as lower density fillings (such as nuts) are present. However, the plastic pieces from molds are commonly non-rounded, and they are distinct in the low-energy X-ray image.
Tailored image analysis routines and advanced PLC control makes the systems easily integrated to complex manufacturing lines, enabling complex classification and sorting, with multiple I/O possibilities at line speeds up to 30 m/min. A higher line speed is possible, however at reduced image resolution.
Note also that low energy X-rays stipulate much smaller radiation levels are intrinsically safer than conventional X-ray systems. They use less power and do not include any lead. Hygienic design requirements can be accommodated for, including water jet cleaning. Very importantly, in most applications, lead curtains may be avoided, hence minimizing contamination risks.
Fruit ripeness and seed sprout assessment using X-ray technology
The avocado inspection problem
The quality, price, and overall sales parameters for avocado and other fruits are related to their ripeness and damages that they may have suffered upon transport. Avocado is especially vulnerable to become overripe, a condition which may be difficult to distinguish from ripe fruits, and a condition which makes the fruit worthless.
The seed sprout problem
Expenses on care-taking of seeds with bad sprout capabilities and the cost of farm surfaces or forest land without crops are significant. Therefore, for some crops and types of seeds, the sprout capability assessment has a large value.
The low-energy X-ray scanning of e.g. avocado fruits can be accomplished with the fruit traveling past an X-ray scanner on a conveyor belt, separated into lanes. The speed of the belt is typically about 12 m/min (limit is 27 m/min), and the inspection speed is around 1 avocado per second for each lane or about 4 avocados per second at 12 m/min.
The X-ray images unveil that the ripe fruits correlate with a void development around the inner core, at the early stages of the ripe. Later, an uneven internal structure with cracks seems to correlate with the further ripe of the fruit, and this can also be correlated to a softer feel of the ripe avocado. A sorting mechanism based on the ripe condition and possible damages can be positioned immediately after the X-ray scanner. This sorting mechanism reacts on the basis of the real-time image processing and image quantification of the X-ray scanner.
For seed inspection, they typically are inspected relative to the internal structure, especially the internal density. The inspection may take place with the seeds positioned in a tray. Low density and large internal voids in the seed implies that the seed may not have the sufficient sprout capability, and therefore must be rejected. For some seeds, the proportion of not useful seeds may be substantial.
The low-energy X-ray scanning is a prerequisite for the cost-effective applications of ripe sorting and seed sprout sorting.
The quality assessment of lobster, crab, and other crustaceans, includes the assessment of the meat contents.
High sensitivity X-ray imaging combined with advanced numerical image analysis has made it possible to grade lobsters relative to the meat content. Results have been compared with destructive meat assessment as well as with blood protein analysis and subjective grading processes, such as “squeezing”. Results show a very good correspondence between true meat content and X-ray derived values.
The system is reliable, automatic, fast, and robust. It can provide a consistent and repeatable grading of a lobster, to secure its right price and its correct quality grade.
The basis of the technology is the intensive experience InnospeXion has gained in supplying fish bone detection systems for the fish processing industry worldwide. The system development was targeted:
- Automatic self-contained system for lobster grading
- Reliable, Robust, Reproducible results that match the destructive assessment of meat content
- Fast inspection capability: Line speed up to 30 m/min, 1 lobster per second (max. 2 kg).
- Ultra high sensitivity – high contrast images
- Suitable for different species
- Easily interfaced with reject, sorting and grading machinery
- Hygienic, wash down design
- Tailoring possible
How it works
When a lobster enters the system, an X-ray image will be taken. The X-ray image is then analyzed to estimate the quality of the lobster. The intensity in the X-ray image depends on the attenuation of the X-rays by the product. In the case of the lobster, this attenuation depends on the projected shell thickness and the meat content inside the shell. In the image, the claws are identified, and the software grades the lobsters based on the claw(s).
We are still working on a case story for this application, which will be ready shortly. In the meantime, feel free to flick through our case story on fish bone detection.