Problem

At a corrugated cardboard manufacturing factory, winter brought the challenge of cardboard cracking along score lines. Seeking a solution, they turned to us, renowned for our extensive track record in humidification for cardboard manufacturing processes. From the very first meeting, the factory manager, production manager, packaging process manager, and senior managers were all present, engaging in lively discussions and inquiries.

What Does Score Line Cracking Cause?

One major issue is that the cardboard sheets themselves can crack during the scoring process when they dry out, resulting in a critical defect. Another frustrating problem is that reducing the scoring pressure to avoid these cracks can lead to failures during the lamination process.

Additionally, if the raw materials for the cardboard sheets were changed, the sheets could become even more prone to cracking. Therefore, the project started early to implement measures.

Solution Proposal

Based on the past experience, IKEUCHI proposed installing a humidification system to increase the moisture content of the sheets, thereby reducing score line cracking.

Since the facility interior was very large, we focused on the specific areas that required humidification. By adopting a layout that surrounded these target areas, we designed a system capable of providing powerful spot humidification.

Additionally, the high ceiling requiring the humidifiers to be installed at a relatively high position led us to anticipate a considerable burden on workers during maintenance after installation. Therefore, we proactively devised a system to keep the maintenance frequency to a minimum.

For the Dry Fog humidifier AKIMist planned for installation, we selected the “AE-04E” type, which is particularly clog-resistant within the series. Additionally, we placed a reverse osmosis water purifier to treat the water before it reaches the humidifiers to remove as many impurities as possible that could cause nozzle clogging. These approaches significantly reduce maintenance efforts at the site after installation.

The humidification system in operation at TAKEUCHI HI-PACK, which served as a model case for this project.

Product Demonstration

Demonstrating the humidifier with the relevant persons on the actual production line proved that no wetting occurred with the cardboard sheets or the facility. The portable humidifier was purchased on the spot for the customer to continue monitoring its impact on the sheets and other interiors.

Since the extended testing, with no issues such as wetting observed, clearly demonstrated its effectiveness in addressing the problem, the decision was made to officially implement the humidification system before the winter season.

Benefits

The defect rates of cardboard cracking along the score lines at the position where the humidification system was installed have reduced from the range of 10% down to 1% or less. Furthermore, the reduction in score line cracking has decreased the issues in the lamination process, thereby significantly mitigating the workload. These benefits have been highly praised not only by those involved in the implementation of the system but also by the on-site operators.

We have received feedback that the results exceeded expectations, and there are considerations for future expansions to other lines and installations at other factories.

In addition, the customer has also signed a contract for an optional service that allows us to perform regular maintenance, ensuring the system can be used with peace of mind over the long term. IKEUCHI will continue to work on solving issues in corrugated cardboard manufacturing plants.