The SW-600 applicator from Baumer hhs enables precision control of the amount of folding liquid applied to packaging materials.
Advanced water scoring solutions for packaging production now make it possible to fold and glue even corrugated and solid cardboard with high bending stiffness while maintaining unmatched process stability. The Xact Easyfold system from German-based Baumer hhs enables users to meet very close tolerances in folding-gluing operations on multipoint gluers, even when processing the most demanding materials. The high dimensional accuracy achievable with this efficient water scoring solution, even with complex folding and gluing, benefits the entire process chain, but especially filling and packing.
„Increasingly stiff substrates are being processed today on multipoint gluers, and the variety is virtually endless. As a result, precision has become an even greater challenge in the folder-gluer process. At the same time, error tolerance is shrinking because brand owners are placing rising demands on the quality of their packaging. With the high-end technology behind our Easyfold system, packaging manufacturers can reduce bending stiffness along score lines and temporarily increase elasticity. Their multipoint gluers can then execute consistent folds with virtually no force – and without affecting the surface quality of the materials they process for customers”, explains Thomas Walther, head of Corporate Strategy & Innovation at Baumer hhs.
High process reliability
A core component of the water scoring solution from Baumer hhs is the SW-600 Easyfold precision applicator. Developed specifically for this application, it boasts very high reliability. A two-stage filter assembly effectively prevents the nozzles from clogging, including nozzles of very small diameter. Seals minimise the risk of drip formation even after extended periods in operation. These features also benefit the reliability of the overall process. Thanks to its compact dimensions, the SW-600 Easyfold applicator can be installed even in confined spaces in multipoint gluers and folder-gluers.
The folding liquid is supplied to the system by a pressure-regulated feed unit with an infinitely variable working range of 1 to 5 bar. With such a wide control range, application of the folding liquid can be calibrated to the machine speed and volume of liquid required. Baumer hhs likewise designed the feed unit to work hand-in-hand with the Easyfold system.
The very user-friendly Xact Easyfold controller connects the two components into a compact water scoring solution capable of operating up to four SW-600 Easyfold applicators. Any number of different application patterns can be set up easily and quickly on the controller. “With all of these features, our Easyfold water scoring solution can be integrated in various machine configurations to suit the existing process”, says Walther, emphasising the flexibility of the innovative technology.
Consistent and high-precision glued joints
To reduce the bending stiffness of packaging materials, the SW-600 Easyfold precision applicator applies very narrow streams of scoring fluid along the edge of fold lines. At low machine speeds, it can optionally apply dotted lines to avoid excessive wetting.
The scoring fluid consists of water with an added surfactant which reduces the surface tension of the packaging material along the edge of fold lines. Instead of just remaining on the surface, the liquid can immediately penetrate the fibres of the substrate, significantly reducing bending stiffness in a defined area – but only temporarily. The multipoint gluer or folder-gluer can then precisely fold a carton along the wetted lines, adhering to even the tightest dimensions.
In many cases, this method even enhances the appearance of a packaging product, especially if it is made from dry, brittle material with low elasticity. In the folding process, a lack of elasticity can cause cracking on its surface, but this too can be avoided with water scoring.
Water scoring also considerably reduces the spring back forces of the glue flaps, stabilising glued joints and preventing unwanted opening of the flaps, even if they are of small dimensions. Water scoring significantly increases both the precision and reliability of folding operations.
“With our Easyfold system, customers can avoid asymmetrical folds, which cause deviations in the inner and outer dimensions of the packaging. This issue often causes problems in the filling process, particularly when thin materials and close tolerances are involved. Under some circumstances, it can even make packaging unusable. Both cases lead to complaints that are not only costly for packaging manufacturers, but also outmoded in view of today’s sustainability concerns”, Walther explains.
A tool for customer loyalty
Because water scoring reduces the spring back forces of the glue flaps, packaging manufacturers can also use it to optimise adhesive consumption. Until now, manufacturers often compensated for these forces by applying more adhesive, especially when processing corrugated and solid cardboard with high bending stiffness. But this method did not always work reliably. Water scoring spares packaging manufacturers all the experimentation.
By delivering symmetrically folded boxes, they can enhance their image as a reliable partner to customers, because perfectly folded and glued boxes function as expected in packing and filling processes. There are fewer disruptions. In short, water scoring increases efficiency and productivity along the entire value chain.
The folding liquid does not impair the stability of finished boxes in any way. Baumer hhs has verified this in studies. But the company’s customers also confirm this. Strength is reduced locally and only temporarily because the liquid penetrates the packaging materials uniformly and dries quickly. Absolutely no delamination has been observed to date in corrugated cardboard.
Baumer hhs invites customers and anyone interested in this technology to visit its hhs solution-center in Krefeld, Germany, where they can test the Xact Easyfold water scoring system on their own original packaging materials.