Candy processor falls for an optical sorter

Hand sorting is out. Automated inspection is in at Swizzels Matlow, one of the oldest confectionery manufacturers in the United Kingdom. Increased demand for its Drumstick Squashies, a chewy candy, prompted Swizzels to forgo manual sorting in favor of using the Nimbus optical sorter from TOMRA, an automated free-fall sorting machine that quickly and  accurately sorts its Drumstick Squashies candy, helping Swizzels to improve throughput while ensuring consistent quality of the product.

Having celebrated its 90th anniversary in 2018, Swizzels is known for its iconic candy brands, including Love Hearts, Refreshers, Drumstick Lollies, Double Lollies, Parma Violets and Rainbow Drops. The family-owned business credits its long run in part to investing in new manufacturing and packaging equipment that have helped it to optimize the efficiency of its operations, which produced 20,000 tons of candy in 2018. That includes installing the TOMRA Nimbus optical sorter to handle the inspection of its Drumstick Squashies.

“We previously used manual labor to remove any imperfect sweets that may have been created during the process,” says Matt Whatcott, business unit manager at Swizzels. “Our desire to provide only product of the highest quality to our consumers drove us to seek an alternative solution to manual sorting in order to improve the effectiveness [of our operations] while also delivering cost benefits to the business.”

Under intense scrutiny

Swizzels has been using the TOMRA Nimbus optical sorter at its plant in Derbyshire for about a year. The sorter separates and inspects products in free fall, allowing the entire surface area of the product to be inspected.

The Drumstick Squashies are fed onto to vibratory conveyor that spreads the candies evenly and in a single layer. They then go into a free fall and pass the scanning area, which uses several sensor technologies to detect different types of defects, such as deformities like misshaped candies or candies joined together, unwanted discoloration, or foreign materials.

During the free fall, the candies are inspected with a laser to identify contaminated products or foreign objects that are not visible to the naked eye. In addition, high-resolution cameras sort the product based on color, outline and shape (length, width, diameter and area). The Nimbus also includes biometric signature identification technology that can sort good product from defects based on certain chemical and molecular differences on the surface and within the product by using light beyond the visible spectrum into the near-infrared region.

When the Nimbus detects a defect in the product, a powerful burst of air removes the imperfect product from the stream. It is then inspected a second time to make sure the company is not rejecting good product.

Sweet rewards

“Before using the TOMRA sorter, we manually inspected the Drumstick Squashies,” Whatcott explains. “The task was challenging due to sweets passing by the manual inspection operators with one side face down on a conveyor. This meant that it was not always possible for them to identify a defect as the inspection only covered 60 percent of the surface area of the sweets. The inspection task was also monotonous, meaning that focus could wane over time.”

“TOMRA’s Nimbus has enabled us to establish a more automated production line with greater rigor around the quality inspection of our product,” he says. “We have much higher confidence in our ability to supply sweets that are only of the optimum standards to our customers. It has allowed us to achieve a more consistent, high-quality product; develop our business; and meet the demands of our customers.”