PACKAGING INSPECTION
What is the most suitable vision technology for each type of packaging?
When selecting the most suitable technology for the inspection of packaging, we must take into account the defects to be detected but above all the type of packaging of our product.
In this post we explain which are the most common types of packaging in the food industry and which are the most suitable vision technologies for the inspection of these packages.
In terms of vision technologies for packaging inspection, we will focus on the three main ones:
- RGB/Monochrome: Detectable defects by comparison of colour shades.
- Artificial intelligence: Defects detectable by comparison of shape and colour shades.
- Hyperspectral Vision: Defects detectable by comparison of spectral signature by chemical imaging.
THERMOFORMED PACKAGING
Thermoformed packs are formed on the machine itself, usually automatic horizontal packaging machines, from two reels of film, usually of different material. These packs have a modified atmosphere and can be flexible or rigid, and the films can be transparent or opaque.
The detection of contamination on the sealing band of thermoformed packaging can be done by comparing colour shades, by RGB vision, through the grouping of shades into regions. Depending on whether the film is opaque or not, backlighting or direct illumination is used.
Suitable for packaging:
- Transparent/opaque films
- Transparent tray
Valid for product trapping:
- Any contrasting with film background in case of opaque film
- Any non-transparent in case of transparent film
Detection of lean contamination in thermoformed packaging
Another technology that can be used for the detection of contamination on the sealing band of thermoformed packaging is hyperspectral imaging, using chemical imaging by spectral signature comparison.
Valid for packaging:
- Opaque films
- Transparent/opaque tray
Valid for trapping:
- Product that does not contrast in tone with the film or tray.
- Transparent products (rendered fat, whey,…)
Detection of grease contamination in thermoformed packaging
HEAT-SEALED PACKAGING
The sealing of this type of packaging is carried out on trays or trays with automatic horizontal packaging machines. They are modified atmosphere packs, usually transparent trays with transparent or partly polychromed films.
Detection of contamination on the weld band can be done by comparison of shades of grey, by monochrome vision, by clustering of shades into regions. If the weld band does not have a fixed position in relation to the container, artificial intelligence can be used to locate it.
Valid for packaging:
- Transparent films
- Transparent trays
Valid for trapping:
- Any that is not transparent and contrasts with the weld.
Trapping detection in heat-sealed packaging
Other types of packaging film defects that manifest themselves on the sealing band, such as wrinkles in the film or other types of anomalies, can be detected by RGB vision and artificial intelligence.
Valid for packaging:
- Transparent films
- Transparent tray/opaque
Valid for defects:
- Wrinkles, tears, film creases and any other type of anomaly that manifests itself as an anomalous wrinkle in the film.
Wrinkle detection in heat-sealed packaging film
STAND UP POUCH PACKAGING
The vertical pouch packaging is used for high production of bulk products. The packaging is made with a single film reel and up to 4 seals by means of automatic vertical packaging machines. Transparent or opaque flexible packaging with modified atmosphere.
For the detection of welding faults in stand-up pouch packaging, we capture and process images using monochrome machine vision technologies for grey tone comparison and artificial intelligence.
Valid for containers:
- Transparent films
- Transparent trays
Valid for entrapment:
- Sealing defects
Detection of defects in vertical bag seals
DOYPACK TYPE bags
Doypacks are packs formed by means of automatic horizontal packaging machines. Part of prefabricated pouches of complex material, with or without ZIP. They can have nozzle and lid, and are used in high production for liquid products.
For the detection of product entrapment in sealing bands and zips, as well as the detection of filling faults in doypack containers, images are captured and processed by means of hyperspectral vision and chemical imaging, by comparison of the spectral signature.
Valid for packaging:
- Plastic opaque
Valid for entrapment:
- Sealed product
- Entrapment in zip
Entrapment detection and filling in Doypack packaging
FLOWPACK PACKAGING
Packaging used for high production. This type of packaging is made from a single reel of film using automatic horizontal packaging machines. These packs are flexible, transparent or opaque, and have a modified atmosphere/vacuum.
For the detection of roll-up faults and irregular welding faults in flowpacks, we capture and process images using RGB vision technology and artificial intelligence.
Valid for packaging:
- Transparent / translucent
Valid for defects:
- Sealing entrapment
- Sealing defects
Detection of roll-up defect in flowpack packaging
CANS
Packaging formed by means of automatic can sealing and closing machines. They are used for products of high production and which are normally liquids or solids.
For the inspection of cans and the detection of defects originating during the production process, we also carry out the capture and processing of the images taken using RGB vision and artificial intelligence.
Valid for packaging:
- Cans of any type
Valid for defects:
- Packaging
- Packaging
- Shape and shade anomalies
Detection of dents in cans