The shoe press is a critical component of a paper machine that significantly influences paper quality and energy saving. However, to fully realize these benefits, the shoe press must be tailored to the specific operating conditions of each paper mill.
In the case study we are presenting the customer was operating a single-piston shoe press with varying paper widths up to approximately 3000 mm, running multilayer paperboard at speeds around 200 mpm.
The fact of having a fixed load width create problems of dry edges once the paper width was less than the loading widths, affecting overall paper quality.
Following a thorough feasibility study, Techso proposed to upgrade the load system by replacing the single-piston with an advanced multi-piston hydraulic system. This innovative solution allows precise control of the hydraulic load at the edges, ensuring uniform pressure distribution and optimal edge moisture control on all range of paper width.
Techso supplied the complete components for the rebuild consisting in new pistons, new pistons holders, sealing and new shoe. After the delivery the on-site implementation for this upgrade required no modifications to the existing hydraulic unit, while a new control system was integrated to operate the hydraulic valves of the edge pistons. The entire on-site retrofit, including testing and startup, was successfully completed under Techso supervision within five days, minimizing machine downtime.
As a result of the rebuild, the moisture profile across the paper was significantly improved. According to the customer technician, “We had never experienced such uniformity in the moisture profile,” highlighting the positive impact on paper quality and production consistency.
This shoe press rebuild demonstrates a cost-effective and efficient solution to enhance paper quality by addressing edge moisture variability—delivering tangible operational improvements with minimal disruption to production and limited investment.