Elevating packaging integrity: the latest in inspection and detection 

The role of inspection and detection technologies is undergoing a remarkable transformation within the packaging industry. By Laura Syrett.

Inspecting and detecting packaging plays a vital role in safeguarding against contamination or harm and upholding brand loyalty. Credit: Leah-Anne Thompson via Shutterstock

With packaging manufacturers facing increasingly tight regulatory and industry standards, the role of inspection and detection technologies to ensure packaging meets industry requirements is becoming ever more important.  

Different products have to adhere to different standards – for example, the International Featured Standard (IFS), a Global Food Safety Initiative (GFSI) benchmarked standard, applies to food packaging; packaging for pharmaceuticals and veterinary products has to conform to nationally-set pharmacopoeia standards and World Health Organisation guidelines; and cosmetics packaging must conform to specific ISO (International Organization for Standardization) standards; and, in the European Union (EU), rules set out in the EU Cosmetics Regulation.  

Most manufacturers also have to follow Hazard Analysis and Critical Control Points (HACCP) management systems when making and filling packaging with perishables to comply with regulatory requirements, as well as meet individual supplier policies set by customers.  

But beyond compliance motivations, brands are also looking to ensure the quality of their packaging insulates them from other risks.  

If packages with defects slip through quality control, this can lead to reduced shelf life, product safety problems, customer complaints, returns or call-backs and brand damage – all carrying significant financial costs to manufacturers.  

Modernising packaging quality control 

Delivering quality-assured packaging requires checking for a number of potential hazards before the packaged product is provided to customers, such as detecting for metal, label position and recognition, expiry date check, bar code reading and seal inspection.  

“Traditional” quality control methods such as visual monitoring, vision cameras and old-style x-rays have until recently constituted the main approaches to inspection and detection for packaging, but these have a “variable success rate”, said Renaat Van Cauter, marketing director at Engilico, a Belgian company specialising in in-line sealing inspection and monitoring technology for packaging in the food, pet care and other industries.   

Accordingly, specialist companies are coming up with new inspection and detection solutions, such as infrared, thermal imaging and high-resolution print imaging, to reduce the risk of faulty packaging making it to market.  

According to Van Cauter, unreliable package sealing is one of the biggest issues brands face, particularly in the food and pharmaceuticals industries where regulation is strict and contamination can have serious consequences.  

He told Packaging Gateway that the evolution of packaging design and production processes has made checking the integrity of package seals more difficult.  

“Because many food producers use printed films for attractive-looking packaging, this makes it harder to see any contamination in the sealing area. In the case of transparent films, there may be too little contrast between the contamination and the film – for example in the case of water or fat [to allow the faulty seal to be detected],” said Van Cauter.  

“High production speeds (…) make it difficult for vision systems to recognise the exact boundaries [of the packaging],” he added.  

Engilico has developed inspection solutions based on hyperspectral cameras that create a spectral profile of packages using different wavelength bands, from visual to infrared, at a rate of up to 160 packs per minute, combined with artificial intelligence that is able to recognise which products have faulty seals.  

Van Cauter noted that not many inspection and detection systems offer wholly reliable one-size-fits all solutions, however, and hence different providers have focused narrowly on solving specific packaging issues.  

For instance, Lake Image Systems, a New York, US-based company, has developed DISCOVERY PQExpress – a print quality inspection software solution that enables printers to monitor barcode printing, detecting for errors such as missing labels, label matrix residue, die-cut errors, ink smudges, streaks and surface imperfections such as creases, bubbling and wrinkles.  

“As demand for precise variable data on labels and packaging continues to surge, robust print inspection processes have become indispensable for label and packaging production workflows,” said Martin Keats, managing director at Lake Image Systems.  

Challenges in metal detection and thermal imaging for packaging 

Detecting misplaced metal in packaging is another major issue manufacturers need to tackle.  

“Metal contaminants turn up in food products in a variety of ways - from buckshot in red meat to metal shavings from a machine in the production line,” explained Christy Draus, marketing manager at Florida, US-based Eagle Product Inspection Systems.  

She explained that metalized film is a popular food packaging solution due to its ability to increase a product’s shelf life and appearance because of the moisture, oxygen and UV-light barrier advantages metal has over clear products such as plastic film. However, metalized film poses product inspection challenges for manufacturers who are trying to screen out metal contaminants.  

“Unlike metal detectors, x-ray machines are simultaneously capable of measuring mass, inspecting product seals for trapped foods, detecting gross under and overfills and spotting missing components,” Draus said, adding that these machines allow manufacturers to save and export valuable production data, as well as save rejected product images for off-line review.  

Markus Tarin, president and CEO of MoviTHERM, an advanced thermography solutions for packaging business, located in California, US, explained that thermal imaging of packaging allows intelligent inspection technologies to ascertain the “thermal fingerprint” of sealing technologies, to ensure the temperature required to seal a certain type of package has been reached.  

He said that the inspection process is complicated by the fact that sealing temperatures are “very product and machine-specific,” so finely tuned technologies are required for individual product manufacturers.  

Dr Claire Koelsch Sand, owner and founder of Minnesota, US-based Packaging Technology and Research, LLC and Gazelle Mobile Packaging Inc, and adjunct professor at Michigan State University, explained that the chief aim of packaging for most food products is the safety of the packaged food, so packaging is designed to prevent oxidation, moisture loss or gain, and microbial growth.  

Faulty packaging can allow these processes to take place more quickly than the product’s shelf life is designed to tolerate, causing food to spoil and resulting in more food waste.  

Ensuring the integrity of sustainable packaging 

Dr Sand said that while virgin plastic can be chemically bonded through melting to provide efficient but unsustainable packaging solutions, the introduction of new sustainable packaging alternatives and lower cost packaging require rigorous testing using exacting inspection and detection methods.  

“Alternate structures such as monolayer recyclable flexible packaging are being explored, so ensuring that the seals for these structures maintain their strength is essential (…). The integrity of seals on packaging for new product introductions and alternate distribution, such as via e-commerce, also needs to be assessed,” she said.