Features Equipment & Systems Paper Pulp
Case study: Reducing web breaks with monitoring and inspection

Improving high-quality output and efficiency in paper and print applications
It’s a matter of high concern for paper manufacturers to keep web breaks at minimum level. Whether a pulp, paper or board producer, the target is always to achieve excellent paper quality at high speeds without suffering excessive process downtime.

Procemex provides camera technology to check for problems – its core competencies are web monitoring and inspection systems (WMS and WIS).

Papier- und Kartonfabrik Varel is a manufacturer of packaging paper especially for the food secto, and produces cardboard and corrugated board for the international packaging industry. In 2013, while converting machine 4 (PM4) into a multi-functional-machine, Varel replaced its old web monitoring system with one from Procemex.

“Our objective was to deliver only first quality paper to the slitter winder to avoid possible breaks and therefore, to reduce downtime in the further process steps” says Holger Droege, project manager at Varel.

The choice was made for the web inspection and web monitoring system from Procemex. “Good light distribution, wide image range coverage and light sensitivity [were] crucial for our decision,” says Droege. “The integrated web monitoring and inspection system offer now the possibility to track our products through the process within one system. Additionally, [the] Procemex solution could be integrated easily into our IT environment.”

Reducing web breaks by understanding the root causes
The cooperation between Procemex and Varel has evolved ever since. It started with the implementation of a Piccolo system (a small WMS with few cameras for web break monitoring) on PM4 in 2013 and continued with PM5 in 2014.

At that time, both paper machines were equipped with the web monitoring system for paper web and break monitoring. In the next expansion step in 2017, Varel commissioned a Procemex web inspection systems for both PM4 and PM5. The purpose of web inspection system delivery was to reduce slitter winder downtime; they now had a camera system installed to discover defect and the root-cause of those defects.

“If we discover defects, we can now detect them at an early stage and reduce winder downtime,” says Thomas Müller, production manager at Varel.

Both paper machines are today equipped with 12 to 16 web monitoring cameras. The web inspection beams have a defect detection capability of 0.50 mm2. The slitter winder 5 has three cameras and it is further planned to equip the new slitter winder 4 with web monitoring cameras as well.

For the employees at Varel, it was important to carry out the project implementation efficiently with short stillstands in order to keep any interruptions of the production to a minimum.

“Procemex led the preparation with experience so that the installation of the web inspection beam could be completed within one short maintenance shut,” Droege explains. Further demands of Varel were mill-wide access to the system and server virtualization as well as the capture of the tambour diameter. “At the end, we have seen a notable rise in production volume due to the significant 30 per cent decrease of unknown web breaks at slitter winder, which also enabled our team to take action against and to prevent these breaks more efficiently.”

A new air-saving concept
A special feature of the cooperation between Procemex and Varel was to have cooling of technical elements, because web monitoring cameras usually require a high amount of air, especially for the cooling of the components within the dryer section. The amount of previously installed cameras at Varel already showed a great air requirement, which Varel did not want to increase with the implementation of further components.

“The opportunity for us was to develop a solution to reduce the air consumption of the system,” says Mika Valkonen, CEO at Procemex. A lot of measuring and testing has been performed with Varel on site to finally develop and implement a new cooling concept, which allows the use of water to cool the components as well as a series connection with the cameras. We are particularly pleased that the system is also applicable for other customers and can be adapted. In this way, we can also help other paper companies to lift their production to a new level.”