Optical sorting performs best with a uniform product that is evenly distributed across the conveyor. But products like confectionery and chips behave differently. They tend to stick together, overlap or spread unevenly, which can lead to good product being rejected unnecessarily by your sorting machine. The issue often lies not in the product itself, but in how it is presented to the machine.

A Defect Return System (DRS) is designed to solve exactly that. Instead of discarding wrongly rejected product, the system automatically recirculates it for a second inspection. This reduces food waste significantly and helps recover valuable product that would otherwise be lost, improving both yield and overall process efficiency. In this article, we take a closer look at how the system works and how it can be applied in real production environments.

What does a DRS module bring to your process?

A Defect Return System (DRS) introduces an additional sorting stage focused on recovering good product. During the first pass, the sorter inspects the product stream. Material that falls outside the defined specifications, such as deviations in colour, size or shape, as well as foreign materials, is typically directed to the reject stream. In confectionery applications, however, many rejects are not actual defects. Typical examples include:

• Overlapping gummies,
• Clusters of sweets sticking together,
• Incorrect product presentation to the cameras.

In these situations, perfectly good product can be rejected unnecessarily, resulting in avoidable product loss. The DRS module addresses this by recirculating rejected product instead of discarding it, returning it via a separate conveyor to the infeed for a second inspection. During this second pass, the product is more evenly distributed, clusters separate, and presentation to the cameras improves. This allows previously misread or unclear data to be evaluated correctly. The result is a significant increase in sorting accuracy, reaching up to 95–99% depending on your product type and machine settings.

How does a DRS module work?

A Defect Return System from Optimum Sorting is typically integrated with a Novus belt sorter, with both systems working together to deliver consistent performance. The sorting process consists of a series of clearly defined steps, while ensuring optimal product flow and minimizing unnecessary product loss throughout the process. It enables producers to maximize yield while maintaining consistent product quality throughout the line.

1. Infeed of candy: at the start of the sorting process, the product (candy mix) is mechanically split into two separate lanes on the infeed system. Approximately 80% of the product flow is fed into the first scan.
2. First scan: the cameras inspect the product for foreign materials and defects in colour or shape, capturing the majority of visible deviations. Accepted product is then directed to the accept stream at the end of the machine.
3. Accepted products: approved candy is conveyed via the accept conveyor to the next processing stage (packaging).
4. Rejected products: candy that does not meet the set criteria is recirculated by the DRS module via a separate conveyor, returning it to a narrower lane on the infeed shaker  (approximately 20% of the feeder width).
5. Second scan: during this stage, the candy is more evenly spread across the conveyor, allowing previously rejected good product to be recovered. At the same time, any true defects are identified more clearly and permanently removed via a separate conveyor or reject bin.

By sorting the product twice, a Defect Return System already minimizes defects, although a small number may still reach the accept stream. An Accept Return System (ARS) removes these in a final step, re-inspecting the output and ensuring that remaining defects are effectively eliminated. This results in a consistently high-quality, virtually defect-free product that is ready for packaging. The video below shows step by step how a DRS module works, clearly illustrating each stage of the process.

Why DRS makes a difference for candy producers

For producers of candy, chips and other snacks, getting the most out of every batch is essential without compromising final product quality. In many processing lines, however, confectionery doesn’t behave perfectly: overlapping, sticky or irregularly shaped sweets often lead to unnecessary product loss and quality variations. With DRS, in combination with ARS, you can tackle exactly that challenge. Let’s have a look at some of the key benefits:

• Significant reduction in food waste: good sweets that would otherwise be unnecessarily rejected are recovered and reintroduced into the process. Every gram you save increases yield while also improving profitability and supporting a more sustainable operation.
• Consistent, high product quality: ARS removes the final remaining defects from the accept stream, ensuring that only confectionery meeting your quality standards makes it through. The result is a highly consistent, virtually defect-free end product.
• Stable process with minimal manual intervention: the system continuously self-corrects through multiple inspection stages, allowing deviations such as clusters or uneven distribution to be quickly identified and resolved. This results in fewer manual adjustments and a more stable production line, even with variations in the product or infeed conditions, helping to maintain consistent performance over time.
• Seamless integration with existing Novus setups: the modular design allows easy integration with your existing Novus sorter. You can quickly improve yield and sorting accuracy without major changes to your line.
  

Maximum defect detection with a single machine

With Optimum Sorting, there’s no need to compromise on defect detection. By combining camera inspection, laser detection and metal detection in a single system, the Novus by Optimum Sorting offers full inspection capability within one machine. This 3-in-1 approach delivers consistent quality control without the complexity of multiple separate systems, while ensuring reliable detection across a diverse variety of products and applications.

With a wide range of scan widths, the Novus is suitable for both smaller production volumes and high-capacity processing lines. Its ultra-fast lasers, operating at up to 3,333 scans per second, deliver an optical resolution of 0.3 mm, making it possible to detect even the smallest structural deviations. Multispectral laser technology identifies foreign materials such as wood, plastic, glass and stone, while high-resolution cameras detect colour deviations and irregularities in shape or size.

When camera and laser inspection reach their limits, the integrated M-TEC metal detection takes over. Using an array of small coils, the system detects extremely fine ferrous, non-ferrous and stainless steel particles, even when they are embedded in or beneath the product. Below are some of the most common defects the Novus sorter detects in confectionery, from colour and shape imperfections to fused clusters and foreign materials.

A unique module designed for maximum yield

A Defect Return System is a valuable solution for confectionery and snack producers aiming to maximize yield from every batch. By recovering unnecessarily rejected product and removing missed defects, it improves both yield and final product quality. The result is a more efficient process with reduced food waste, a highly pure accept stream and significantly less need for manual inspection. For producers of gummies, wine gums, jelly beans and chips, this means more saleable product and a more stable, consistent product quality.

Interested in a free demo?

Get in touch with the sales team of Optimum Sorting and have your candy, chips and other snacks tested at one of our demo centers around the globe.
Experience firsthand the benefits our machines can bring to your business!