Metal detection systems were long considered the industry standard for product inspection; however they do not address non-metallic contaminants such as glass, stone and calcified bone.
There are two typical types of metal detection equipment used industry wide for these applications: pipeline based system and aperture based systems. Pipeline systems are used to check for contamination prior to filling. This approach is cost effective but leaves the possibility of the product becoming contaminated during filling or having glass introduced via glass breaks in the capping process.
Additionally, pipeline systems are difficult to audit and regulate in a HACCP procedure as a contaminant should be placed and rejected in the product stream itself. When pipeline systems reject for HACCP test verification or when a contaminant is detected, a large quantity of product is released to ensure a contaminant is rejected every time, thus resulting in product waste.
The second industry standard metal detection option is an aperture-based system. Aperture based systems are placed directly after the filler and before the capping process. Again, this method leaves an opportunity for product contamination prior to the product being sealed and/or during the capping process itself. X-ray inspection technology is the only inspection technology on the market that can detect and automatically reject products contaminated with metal, stone, calcified bone or glass in a sealed package.
Specific to this application, the ability to detect glass in glass while running online was the biggest driver for the customer to purchase the QuadView X-ray inspection system.The customer packages the majority of their baby food products in glass jars that have a crown in the bottom of the jar and are sealed with a metal lid.
The customer used standard metal detection equipment for quality control purposes but were looking for increased contaminant detection capabilities, specifically the ability to detect glass contaminates within their glass-packaged products. This application, glass in glass inspection, has unique requirements and requires a specialised solution.
One baby food manufacturer investigated multiple X-ray system manufacturers and selected the Smiths Detection Eagle QuadView system as the preferred inspection technology; the system is named the QuadView based on its function - it analyses each product that passes through the system from four different viewpoints.
Evaluating the product from four different angles is essential in a glass jar application as the crown of a jar creates a blind spot in any given view - the only way to see the entire jar bottom is through a 4-view system.
Over the course of two years, this baby food manufacturer has purchased 18 Eagle QuadView systems supplied with high-speed reject mechanisms. While evaluating each jar from four different angles, the Eagle QuadView analyses products at online productions speeds of 850 to 1250 jars per minute. Since four images of each jar are analysed, the system is able to process 5000 images per minute (1250 x 4) showing the power of the Smiths' SimulTask.
The manufacturer is now able to fully inspect a sealed container for metal, stone, calcified bone and glass while running at production speeds without the expense of multiple systems or manual labour. In addition to the operational benefits of enhanced detection over standard metal detection systems, several jars were rejected after the QuadView was installed online due to the jars having metal inclusions deposited during the recycling process.
The metallic inclusions that form during the recycling process form a weak spot in the jar and could lead to broken product during shipment or as the jars bump into each other on the production line.
As an added value to the customer, compared to other inspection technologies, the Eagle QuadView is installed over the existing conveyor line, eliminating the need for costly line integration expenses.
Smiths Detection is based in Alcoa, TN, USA. www.smithsdetection.com
