Superior quality paper after rebuild - Sappi Gratkorn PM11
Sep 7, 2017
Continuous improvement in both cost and quality is always top of mind for Sappi Gratkorn Mill. They take pride in having a strong relationship with their customers and make a point of understanding their needs. To ensure that the mill is fit for the future, the commissioned a technology upgrade that aimed to increase the quality of coated printing papers produced.
The upgraded PM11 started in late 2014. The achieved quality enhancement completely meets Sappi’s expectations. The production of paper meeting all quality standards began almost immediately after the startup of the rebuilt machine.
One target of the PM 11 rebuild was to achieve a lower tensile strength ratio. We also wanted to maintain good runnability by eliminating free draws. We started talking with Valmet about different technical solutions and the pilot process gave us the advantage of being able to test two alternative concepts on two pilot machines.
Manfred Tiefengruber, Paper Production Manager at Sappi Gratkorn
Need to improve the quality of the coated woodfree printing papers.
Main target was to decrease tensile strength MD/CD – ratio and to improve formation at the same time. Second target was to widen the basis weight window and add new products to product portfolio.
Solution
Paper machine rebuild for improved end product quality.
Rebuild concept was optimized and validated in the series of pilot trials at Valmet Paper Technology Center in Jyväskylä.
Existing headbox was modified to deliver required jet quality and jet properties to the forming section
Center roll press section rebuild with novel transfer belt application known from linear press sections. Closed sheet transfer and targeted runnability now possible also with center roll presses
