Hygienic, leak-proof, efficient: innovative bagging of potato starch
In the industrial processing of potato starch, error-free filling and sealing processes are crucial for product safety, hygiene and efficiency. At Danish starch manufacturer AKD Toftlund, part of the KMC Group, this is ensured by the combination of a high-performance air packer, precise bag inspection and patented ultrasonic sealing.
High demands on accuracy and hygiene
AKD Toftlund produces potato starch as well as numerous modified starches and exports to more than 80 countries. Production runs at high throughput with a BVP air packer system from Greif-Velox, which bags up to 800 bags of 25 kilograms per hour. During operation, however, a recurring problem became apparent in the past: a number of valve bags were not being opened or positioned correctly. This led to incorrect filling, product loss, dust formation and increased cleaning effort.
Faulty bag valves, for example due to sticking to the bottom of the bag, were only detected late in the standard process - often after the filling process had started. This resulted in unnecessary interruptions, rejects and quality defects. The aim was to sort out these bags at an early stage and increase overall process reliability.
Early detection and ejection with the ValvoDetect sensor system
To minimize incorrect filling, the existing filling system was expanded to include the ValvoDetect feature from Greif-Velox. Sensors are used to check whether the bag valve is properly opened before the filling process. Faulty bags are thus sorted out in advance. This check ensures that only correctly filled and properly sealed bags end up on the pallet.
Analysis of faulty bags
After commissioning Valvo-Detect, AKD Toftlund launched a systematic analysis project together with Greif-Velox and other partners in order to not only identify the causes of faulty bags, but to eliminate them permanently. Over an extended period of time, all discharged bags were logged, categorized and examined in detail. Three main causes occurred particularly frequently: Firstly, it was found that valves on some bags were sticking to the bottom and therefore could not be placed correctly on the filling spout. Secondly, an unfavorable valve length meant that the valves buckled or twisted easily during handling. In addition, some batches had faulty bonding or material tension, which had a negative impact on the opening behavior.
Significant reduction in waste
Based on these findings, alternative bag designs were tested in several series of tests. The combination of a shortened valve length and an adhesive dot modification, which fixed the valve in a defined position and thus ensured problem-free opening, was particularly successful. This optimization reduced the reject rate by up to 90 percent; the rate of faulty bags was reduced from the original 0.4 to 0.8 percent to just 0.04 to 0.08 percent. In combination with ValvoDetect, faulty welds practically no longer occurred. "There are no more bags that are not correctly sealed. ValvoDetect is a real benefit for the trouble-free operation of the system," says project manager John Skriver Kloster, summarizing the results.
Maximum tightness thanks to ValvoSeal
ValvoSeal is also used at the site to ensure that the final process stage - the sealing of the valve bags - also meets the highest safety standards. The patented ultrasonic welding technology uses structured, waffle-patterned weld seams. Compared to conventional methods, it offers up to 60% greater strength (in accordance with DIN 55571-2) and reliably prevents dust from escaping.
In the revised and patented "ValvoSeal Safe" version, the system works with a double seam, ensuring absolute tightness even with critical products. In addition to protecting the product and employees, this contributes to consistently high packaging quality and an improved brand reputation.
Holistic process reliability from filling to welding
The combination of ValvoDetect and ValvoSeal ensures a consistently safe and clean filling process at AKD Toftlund - from the detection of faulty bags to the absolutely tight sealing of the valve. This minimizes product loss and cleaning effort, reduces reject costs and reliably meets the hygiene and packaging safety requirements of international customers.