Foreign Particle Analysis Methods and Observation/Analysis During Inspections
The contamination of food, medicine, or their packaging with foreign particles is a serious problem on the market. The identification of foreign particles by way of fast analysis as well as investigation to determine the cause of the problem and the prevention of future occurrences are all required from the point of view of quality assurance.
This section introduces foreign particle analysis methods and application examples of KEYENCE’s latest 4K Digital Microscope, which solves conventional problems for more advanced and faster foreign particle analysis.
- Problems Caused by Contamination With Foreign Particles and Increasing Response Speed
- Foreign Particle Analysis Methods and Conventional Problems
- Application Examples of a Microscope that Enables Accurate and Fast Foreign Particle Analysis
- Observation of three-dimensional foreign particles
- Observation of foreign particles contaminating a multi-layer film
- Observation of insects
- Low-magnification/high-magnification observation of fibres
- Observation of hair cuticles
- Foreign particle analysis of cotton swabs
- High-definition observation of metal fragments
- Observation of small insects adhered to a food surface
- Observation of foreign particles contaminating a transparent film
- Observation of mould at the curved surface of food
- A Multi-Function Microscope that Makes Foreign Particle Analysis More Advanced and Efficient
Problems Caused by Contamination With Foreign Particles and Increasing Response Speed
These days, consumers spread information instantly over social networking services. As such, the contamination of food, medicine, and similar products with foreign particles has been distinguished as a serious problem. Consequently, there has been a rise in consumer awareness and concern regarding the safety of food and medicine.
Also, food served regularly to many people at schools, hospitals, and similar facilities has especially severe requirements for safety and quality assurance. When a problem occurs, it is necessary to quickly clarify the location responsible for the problem, to use analysis to investigate the cause of the occurrence, and to implement countermeasures against reoccurrences of the problem.
There is not a little amount of cases where analysis is outsourced to one of the many analysis trustee companies, but analysis speed is especially important when a problem occurs due to contamination with foreign particles, so there is an increasing trend toward companies having their own analysis equipment and systems in the food and medicine industries.
Foreign Particle Analysis Methods and Conventional Problems
Most often, foreign particles contaminating a product have a composition that differs from that of the product itself, so the common method of foreign particle analysis is composition analysis. However, consider the case of an insect contaminating a product that contains protein. It may not be possible to designate or identify this insect as a foreign particle just with composition analysis.
Therefore, foreign particle observation and analysis by way of an appearance inspection using a microscope is just as important as composition analysis. In other words, ensuring the accuracy of foreign particle analysis requires not just a composition analysis device but also an optical microscope that is capable of observing a microscopic outer appearance with high accuracy.
However, conventional foreign particle observation and analysis pose the risk of overlooking foreign particles due to the following problems:
- The image only focuses on a part of the target due to the foreign particle and product being three dimensional.
- Foreign particles contaminating glossy metals or packaging films made of plastic are difficult to observe due to reflected light.
Application Examples of a Microscope that Enables Accurate and Fast Foreign Particle Analysis
KEYENCE has repeatedly improved and reformed its digital microscopes for over 30 years by making use of the information obtained from on-site customers. The result of this process is the VHX Series high-definition 4K Digital Microscope. Its high-resolution lens, 4K CMOS, proprietary observation system, and advanced image processing not only enable observation of microscopic shapes with easy operations and high-definition 4K images but also allow for high-accuracy 2D and 3D measurements. It solves various problems while also enabling more advanced analysis and evaluation in an easy and fast manner.
This section introduces application examples of foreign particle analysis using the VHX Series.
Observation of three-dimensional foreign particles
The VHX Series 4K Digital Microscope has a deep depth of field. Also, the real-time depth composition function can be used to quickly obtain high-definition images in which the entire target is fully focused even in the case of three-dimensional targets. Obtaining such images makes observation accurate and improves the efficiency of work regardless of the shapes of the foreign particles.
Observation of foreign particles contaminating a multi-layer film
In this example, foreign particles contaminating multi-layer films, which are used in the packaging of food and medicine, are observed. Conventionally, it was not possible to determine the shape of a foreign particle because ring-shaped reflections occurred at the location where the foreign particle causes a bump in the film.
With the VHX Series 4K Digital Microscope, the ring-reflection removal function—which instantaneously obtains multiple images with varying ring illumination lighting directions at the push of a button—can eliminate these ring-shaped reflections. Eliminating ring-shaped reflections enables clear observation of foreign particle shapes by preventing the effect of reflections from the film surface.
Observation of insects
Among all foreign particles, insects have extremely complex three-dimensional shapes and often have low colour contrast.
Conventionally, time-consuming lighting adjustments must be made in order to properly observe the target.
The VHX Series 4K Digital Microscope is equipped with a multi-lighting function that quickly obtains multiple images with various types of lighting from all directions at the push of a button. This function enables users to simply select the image that is appropriate for observation from among all the obtained images. This function eliminates the time and effort that were conventionally spent on extracting lighting conditions and can be used to quickly observe and identify the three-dimensional shapes of insects with high-definition images.
Furthermore, image data with different lighting is automatically saved even after the observation image is selected or saved, so images can be loaded immediately even when it is necessary to perform observation with a different lighting. This function can eliminate the time and effort that were required to set the sample on the stage once more and to reproduce conditions such as the lighting and the focus.
Low-magnification/high-magnification observation of fibres
The high-resolution lenses and the motorised revolver of the VHX Series 4K Digital Microscope enable a seamless zoom function that automatically switches between lenses according to the magnification. This seamless zoom eliminates the time and effort that were required to replace lenses and enables magnified observation from 20x to 6000x with intuitive operations.
The cutting-edge optical system and 4K CMOS enable clear observation of fibre structures and foreign particles with high-resolution 4K images even at high magnifications.
Observation of hair cuticles
The high-resolution lenses and the motorised revolver of the VHX Series 4K Digital Microscope enable a seamless zoom function that automatically switches between lenses according to the magnification in the range of 20x to 6000x. This seamless zoom enables smooth high-magnification observation with intuitive operations.
High-resolution 4K images can even be obtained at high magnifications. Hence, clear observation of cuticle shapes is even possible with hair samples. This clear observation makes it possible to quickly identify whether contaminating hair belongs to a human or an animal or is actually a fibre from a piece of clothes.
Foreign particle analysis of cotton swabs
With the VHX Series 4K Digital Microscope, foreign particles can be clearly observed and analysed even in the case of cotton swabs and other such targets having three-dimensional structures.
Former, it was only possible to bring a part of a three-dimensional target into focus at a time due to the limitations of the depth of field. Hence, it sometimes was difficult to observe microscopic foreign particles due to insufficient resolution.
The VHX Series can obtain high-definition images of the structure of and foreign particles present in three-dimensional cotton swabs with the entire target fully focused. These images enable smooth foreign particle analysis in which nothing is overlooked.
High-definition observation of metal fragments
Metal fragments with uneven surfaces are difficult to focus, so, conventionally, foreign particles on these surfaces are difficult to observe and identify.
The VHX Series 4K Digital Microscope uses a high-resolution and low-noise 4K CMOS and a high-resolution lens that supports a deep depth of field and 4K images. High-definition images in which the shapes of the uneven surface are in focus for the entirety of the metal fragment can be obtained, so it is even possible to clearly observe the surface shapes of metal fragments.
Observation of small insects adhered to a food surface
Releasing to the market food to which foreign particles have adhered is a serious problem that harms the safety and reliability of the product.
Even in the case of small insects adhering to food that has uneven surface shapes, the VHX Series 4K Digital Microscope can be used to quickly perform clear observation with high-definition images in which the entire target is fully focused.
Observation of foreign particles contaminating a transparent film
Light reflections made it difficult to observe foreign particles in plastic film, which has a high degree of transparency.
The VHX Series 4K Digital Microscope can also be used to perform high-definition observations and analyses of foreign particles contaminating a transparent film.
Observation of mould at the curved surface of food
Foreign particles are sometimes overlooked because it is only possible to bring a part of the sample into focus at a time. Targets with curved surfaces are particularly hard to inspect.
The deep depth of field of the VHX Series 4K Digital Microscope enables it to obtain high-definition images in which the entire target is fully focused in the case of, for example, the observation of microscopic mould occurring on the curved surfaces of donuts. The result is not only the elimination of the time and effort required to adjust the focus but also the prevention of overlooked foreign particles thanks to the entire target being in focus.
A Multi-Function Microscope that Makes Foreign Particle Analysis More Advanced and Efficient
In addition to the functions introduced here, the VHX Series high-definition 4K Digital Microscope is also equipped with various other functions including the ability to perform observations from a variety of angles using the free-angle observation system, highly accurate 2D and 3D measurements performed with easy operations, and the automatic counting and calculation of the area of foreign particle (contamination) samples. Furthermore, it is even possible to output reports using observation images and measured values with user-specified templates. A single VHX Series microscope is all that is needed to seamlessly and quickly complete an entire series of work operations.
For details on the VHX Series, click the button shown below to download the catalogue. For inquiries, click the other button shown below to contact KEYENCE.
