Packaging line retrofit: less product loss and easier to operate

Challenge

On the one hand, medical compression stockings, a product that must be sterile packed with great precision.

On the other, a packaging line on which operators still have to manually adjust the settings with dials. And where every adjustment only comes through after twenty or thirty products.

That combination resulted in a large error rate for this manufacturer of medical compression stockings. As a result, too many products ended up in the trash.

The goal of this packaging line retrofit: to make the packaging quality operator-independent. So that fewer products would be lost.

Solution

The products are wrapped in a film.

First, the machine cuts the film into two pieces. One piece for the bottom of the package, the other for the top. The medical stocking is placed in the middle. Lastly, the machine folds the package together and welds the seams together.

A crucial step in those processes is the alignment of those two pieces of film.

We have automated that alignment. We replaced the old rotary knobs with a system that constantly adjusts itself automatically. To do this, we integrated fork sensors and replaced the old motors with new servo motors.

These fork sensors continuously keep track of both films’ position. This allows the servomotors to control the fine-tuning of the alignment. By constantly making small adjustments in a control loop, they position the top and bottom films perfectly.

An additional challenge with this packaging line retrofit had to be able to cope with the variability of the film rolls. Because every roll is just that little bit different. There are always small differences.

We also took care of the electrical control panels during the retrofit of this packaging line. The customer chose to keep the previous cabinet – the cabinet itself was still relatively new, the dimensions and cooling were good. So we replaced the old platine one-to-one with a board we newly engineered and assembled. We also replaced the machine cabling.

We also advised our client on their spare part management. Certain machine parts and electrical components turned out to be obsolete. We replaced them with new components. We also made an overview of the critical components they need to keep in stock at all times.

Finally, during this packaging line retrofit, we also integrated a new safety and a new HMI. Thanks to that interface, the operator can monitor the process and check the quality.