High speed metal detection ensures quality control, claims Mettler Toledo
The X-ray machinery supplier said that the new CanCheK system is applicable for sectors such as baby food, tinned fruit and vegetables, processed meat and fish, ready meals, soups, snacks and tinned desserts.
It sits over the processor’s conveyor and can be retrofitted into new or existing production lines as a result of its compact size, said the company.
The technology employed in the CanCheK system is unique, according to the manufacturer, and offers several advantages over the single beam method employed in conventional X-ray equipment.
“CanCheK utilises a split beam method where the two beams are arranged at angles in order to eliminate blind areas at the edges of the can,” said a spokesperson for the company.
In traditional vertical beam inspection systems, said Mettler Toledo, contaminants lying next to the sidewalls or flat on the bottom of the can are extremely difficult to identify, whereas due to the angle of the beams in the CanChek system contaminants are pulled away from the sidewalls, increasing visibility in the X-ray image and detection probability.
The detection system also automatically rejects any cans containing foreign bodies such as metal, glass, stone and bone, which the company claims optimises quality and safety and avoids costly and brand damaging recalls.
“A high speed short stroke pusher device is used to nudge the can from the production line onto a parallel reject conveyor,” explained the spokesperson.
According to the manufacturer, the CanCheK system uses a high speed computer processor to ensure that each can is scanned and checked in fewer than 50 milliseconds.
“This equates to a throughput of 1,200 cans per minute. Also, the scanning speed of the sensor is capable of working at line speeds of up to 120 metres per minute with a minimal gap between cans,” said the spokesperson.
The company said the new system is also capable of measuring mass and check fill levels.
“Mass is achieved by using a known weight can and setting this as the reference point, effectively achieving a mass calibration. The can itself is not included in the mass calculation, so only the product inside is measured. This optimises the accuracy of the check,” claims the spokesperson.
It said that the fill level is achieved by placing a vertical measurement axis over the image.
The company said that the CanCheK system can also detect missing or damaged products, thus providing processors with a holistic inspection system.
“If some of the contents are missing, either fill level or mass will recognise this by detecting a ‘low fill’ level or a ‘low mass’ level. A damaged (dented) can will typically appear as contamination, due to the dented or creased area having a higher density than the rest of the can,” said the spokesperson.
The firm added that as downtime and changeover times are also kept to a minimum on the CanCheK through ease of set up and operation, an overall low cost of ownership is achieved.