First U.S. production facility for Sappi to convert from paper pulp to dissolving pulp for viscose
Cloquet (Minnesota), Lenzing (Austria), October 2012 – Increasing its total annual capacity from
800,000 to 1.3 million metric tons, South African pulp and paper group Sappi is reacting to
rising global demand for dissolving pulp, which is used for viscose fiber manufacture. Twothirds
of Sappi’s expansion program (330,000 tons p.a.) involves its pulp plant in Cloquet
(Minnesota). The facility will be converted from paper pulp production to the manufacture of
dissolving pulp for viscose. Sappi is investing approx. EUR 130mn (USD 170mn) in the
project. At the same time, Sappi is purchasing more than EUR 2mn (USD 2,6 mn) worth in
technology and engineering from Lenzing Technik GmbH for digester house and its fiber line,
the plant’s key processes. The basic engineering work has just been completed. The newly
equipped facility is anticipated to start operation in May 2013. From then onwards, the
Cloquet plant has the capability to produce dissolving pulp for viscose fibers under the
patented, state-of-the-art pulp cooking process developed by Lenzing Technik.
Viscose fibers are cellulose fibers man-made from wood, a natural raw material. The properties of
viscose fibers are similar to cotton, and far superior to textiles made of crude oil as far as wearing
comfort is concerned. Viscose is a very soft, extremely absorbable and breathable natural textile that is used for both clothing as well as hygiene products and wound dressings. As the global area under cultivation for cotton stagnates, demand for textiles continues to grow. The production of cotton consumes enormous amounts of water, pesticides, and land which is lost to food production. Thus the manufacture of viscose fibers is becoming more and more important.
Pioneer project in the USA“The fact that a large multinational company such as Sappi relies on the engineering know-how of
Lenzing Technik for such a project in the U.S.A is an honor for our team”, says Herbert Hummer,
Managing Director of Lenzing Technik. In any case, Cloquet will be the first U.S. plant for Sappi to
produce dissolving pulp for viscose. In addition to technology, simulation and balancing, process
engineering, mechanical equipment, instrumentation, automation and programming solutions, the
spectrum of services offered by Lenzing Technik also includes coordination and supervision of
erection works as well as startup, subsequent process optimization and project management. “Our teams are repeatedly on site to ensure smooth operation”, Herbert Hummer adds.
The Lenzing process as an international benchmark. In terms of purity and quality of the pulp, Lenzing Technik has defined a worldwide benchmark. “One can certainly claim that Lenzing’s patented cooking process has set an international standard. We want to ensure that this standard is met at the plant in Cloquet”, says Project Director and Managing Director Mike Schultz, Cloquet Mill, Sappi Fine Paper North America explaining the reason for collaborating with the engineering specialists from Austria. The patented “Viscose Continuous-Batch Cooking” of dissolving pulp for viscose fibers (VISCBC) enhances the quality of the produced pulp, reduces overall cycle times in the production process, maximizes the capacity of the modified plant and minimizes energy consumption at the same time.
Logistical challengesDue to conversion of the entire digester system and of the fiber line including washing, screening and bleaching, the project management of the entire Cloquet facility has turned into a special challenge. “A project of such dimensions is very complex and it is necessary to coordinate many subcontractors and service providers. For this reason, progress checks and resource planning are extremely important factors of success,” Lenzing Technik Project Manager Berndt Cupak explains.
All steps of the project must be planned and coordinated with precision for plant erection and start-up to proceed on schedule. “In addition to understanding the processes involved, this task requires a high degree of skill and consistent project management”, says Lenzing Technik’s Managing Director Hummer in clarifying what is involved.
Source - Lenzing press release