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Testing and inspecting the complete package

Ensuring a product reaches the end user in perfect condition is of paramount importance to suppliers. It comes as no surprise then that manufacturers continue to develop new and efficient ways to test and measure the integrity of a product, finds Tim Sheahan

A brand’s reputation on the market is, arguably, everything. In the age of social networking and online media, the ability to communicate with the masses almost instantaneously has empowered consumers to make their feelings on a product known immediately.

The fallout following the launch of Apple’s latest iPhone resulted in thousands of users converging online to pour vitriol on the perceived poor quality finish that adorned the device that could set you back as much as £700.

Whether the substandard appearance was a result of poor packaging or an inadequate iodized aluminum finish is a moot point, but it was an example of brand reputation taking a literal dent among some of its most loyal followers.

Therefore, packaging testing can provide a raft of benefits to the full life cycle of a product. Testing can measure a number of factors such as a package’s level of recyclability or its ability to ensure its contents reach the end-user in the desired state, especially in the fresh food and drinks sectors. It is therefore unsurprising that manufacturers continue to develop new and efficient ways for suppliers to test the effectiveness of their packaging.

One such supplier active in the field is UK-based RDM Test Equipment, which has recently released new online seal inspection technology that instantly rejects compromised seals.

The systems are claimed to "revolutionise" quality assurance for packaging in the food, beverage and healthcare sectors that place a particular emphasis on seal integrity to maintain the quality and shelf life of their products.

Inspection and integrity

According to RDM, the Seal-Scope and Seal-Cam inspection systems can integrate into most existing packaging machines, without the need for any modification of the user’s equipment setup.

Supplied by RDM, the technology has been developed by researchers at the University of Leuven in Belgium. Capable of detecting incomplete seals, wrinkles and folds, the systems can pick out creases, holes, and product or contaminates that could be found in the seal.

Phil Neal, sales director at RDM says the technology generates a unique fingerprint for each package processed, which is then compared, using statistical data, as to whether the unit can be passed or failed. Those units that fail then trigger a signal to an ejector unit.

The Seal-Scope system analyses the vibration burst signal from a sensor on the sealing bar, making it suitable for a range of both vertical and horizontal form fill seal machines. RDM’s Seal-Cam is used to capture an infra-red image of the residual heat at the seal, which is suited to a diverse range of packages that include trays as well as blisters.

One key selling point, according to Neal, is that the system can be switched either on or off without disrupting the parent machine’s production. The initial statistical data for each product is generated in just 30 seals. "Since this technology does not leverage ultrasound or use standard cameras, it is unaffected by varying light conditions, and the type of product being packaged is irrelevant, while opaque packaging also presents no issues," he says.

"While there are competitor systems on the market that can get the job done, the requirement for ultrasound and a strict set of parameters limit their flexibility. The fact that the Seal machines can be retrofitted onto existing technology without interference is another key selling point."

According to Neal, the Seal-Scope and Seal-Cam machines have already had successful initial installations in Europe, primarily at companies in the food sector. While he would not be drawn on pricing, he says those customers have reported that the systems "pay for themselves quickly" by saving on waste costs and by improving quality control.

Oxygen analysis

Another product recently launched into the test and measurement space was OpTech-O2 Platinum from US-based manufacturer Mocon. Demonstrated by Lippke at November’s Emballage show in Paris, OpTech-O2 Platinum is a multi-application oxygen analyser aimed at beverage, biopharmaceutical and food sectors that rely on maintaining the barrier integrity of a product.

The technology leverages optical fluorescence to non-destructively measure oxygen content in a package’s headspace. According to the manufacturer, this method means the oxygen test can be repeated over a period of time to determine O2 permeation and analyse the shelf-life of an oxygen sensitive product.

A platinum sensor, which comes specified in a ready to use sticker format, is placed inside the package using the manufacturer’s vacuum pen. The product is then sealed and interrogated in a non-destructive fashion with the external detector. According to Mocon, this sensor type is ideal for package permeation studies, shelf life analysis and distribution studies.

Recent developments to the OpTech system are a portability kit that enables mobile testing outside the laboratory environment, as well as a new sensor that can work with opaque packaging materials.

According to Doug Lindemann, vice president at Mocon, customers had demonstrated the demand for a portable version of the OpTech oxygen test system following "significant success as a laboratory instrument.

"By pairing the lightweight and ergonomic reader with a 9-inch tablet in a carrying case, we are pleased to announce that users now have the ability to test production line samples on the fly," he says.

Impulse testing

Mocon has also introduced a new sensor it calls ImPulse, which enables the system to work with opaque materials or retort packages. This is carried out through a pin that carries the fluorescent sensor material, which punctures the package then adheres itself thanks to a self-sealing adhesive.

Lindemann says: "When the package is punctured, a small hole is created. Oxygen from inside the package is now exposed to the sensor, which is sealed from the external environment.

"A reading is then taken through the transparent head of the pin. This system allows for measurements to be taken over a period of time to determine the longer term effects of oxygen in a package."

The Systech Illinois Oxygen Permeation Analyzer 8700 has been designed for oxygen permeation tests on multiple bottles, packages or films and is claimed to be ideal for production testing by customers using high speed bottle forming lines.

Suitable for products such as PET bottles, coated PET bottles, barrier films, bottle closures, pet food packages and juice containers, the system uses the manufacturer’s Turbopurge technology. This is said to ensure the fastest possible stabilisation time for permeation measurement.

One company that has recently tested the Oxygen Permeation Analyzer 8700 is global mineral water supplier S Pellegrino, which has experienced "excellent stability" in its results during initial usage.

The Italian beverage business has integrated the Systech Illinois machine to its quality control line in order to test oxygen permeation of its plastics bottles to help measure the shelf life of the product. The machine can complete up to 11 sample tests simultaneously, as well as providing statistical data in periods that can range from between three and 12 hours.

Driving leak detection

UK manufacturer AutoCoding Systems has recently revealed the details of a tie-up with Dairy Crest, Davidstow to design a vision system which tests, analyses and identifies vacuum failures on the company’s sealed packs of 20kg blocks of cheese.

Dairy Crest, Davidstow, which produces cheese under the leading Cathedral City brand, vacuum seals its 20kg blocks in order to prevent any air leaking into the product before the cheese has matured for a period of 12-18 months.

The vision system from AutoCoding replaced the firm’s existing in-house setup and was tasked with the criteria of testing for leaks across the 120 tonnes that are processed on a daily basis.

It comprises camera-driven software that helps analyse the reflected light from the surface of the vacuum-sealed cheese block, and the system rejects blocks that fail to meet the pre-defined criteria.

Dairy Crest automation engineer Neil Flood says the food business is already benefiting from cost savings following the installation. He adds: "Any blocks of cheese with faulty seals that slipped through our old system and were stored for maturation would result in us having to downgrade contaminated product.

"We now have an efficient and reliable system that gives us meaningful and useful data, which allows us to continually improve our sealing and packing process. In addition, we have been able to refocus one of our operators on other tasks rather than checking for failed seals."

Test of strength

While AutoCoding Systems has been developing technology within the vacuum vision space, UK-based Lloyd Instruments manufactures and supplies universal testing machines and tensile testers. One area the company has been extensively involved in is the peel strength of containers with peelable sealed lids. While the ASTM test method F88, which tests mechanical peel strength, has been in use since the 1960s; the major negative of this process is that it only checks one section of the seal.

According to Lloyd Instruments, the newer ASTM F2824 method goes some way to addressing this problem by testing the whole container as it would be used by a consumer. It describes the method for the measurement of mechanical seal strength while separating the entire lid from a rigid or semi-rigid round container.

This enables the manufacturer to collect data for the entire product in a bid to improve manufacturing processes, or for research and development to aid the investigation of new materials or bonding processes.

Lloyd Instruments’ Nexygen Plus material test and data analysis software ties together the supplier’s materials testing system, which primarily comprise the LS1 and LS5 materials testing machines.

The data analysis software, now on version three, enables the user to analyse, in-depth, the whole characteristic of the peel graph. This is carried out by selecting the whole peel test, individual sections or averages, with user defined markers as well as parameters

Typically performed at a 45-degree angle and at a rate of 304.8mm/min, testing can determine the continuous or average peel strength of the product, as well as the maximum and minimum force applied during the testing process.