When small becomes BIG: from laboratory trial to successful start-up
This article tells the exciting story of a 20 litres trial test turning into an installed 5000 litres turn-key machine.
In autumn 2018, GAW technologies successfully started-up the new dispersing unit for the fabrication of coating colour with application at the paper machine at OOO Mayak-Technocell in Penza/Russia. But the path to this commissioning already started several years ago with a dispersing laboratory test.
OOO Mayak-Technocell Penza is a joint venture company of the Felix Schoeller Group and OAO Mayak. Today it produces decor papers and raw paper for nonwoven wallpaper at the production-site in Penza, about 600 kilometers south of Moscow.
The first contact to this project dates back more than 3 years. After the inquiry was discussed and clarified, Hartmut Schulz, Vice President of Process Chemistry & Raw Materials at Schoeller Technocell, and the research and development team of GAW technologies scheduled a dispersing trial test in the laboratory facilities in Graz/Austria to meet the specific demands. The laboratory dispersing equipment offers the opportunity to test unusual or particularly challenging recipe specifications under real conditions. It also enables the clarification of the parameters in advance in order to bring the desired application to life.
The special recipe, which includes various pigments like calcium carbonate and kaolin, requires very high solids content in the pigment dispersion. This posed the problem that a separate preparation and subsequent mixing of the pigments could not achieve the solids contents ratios requested by OOO Mayak-Technocell. It was decided to conduct experiments with a co-slurry (mixture of pigments) in the laboratory and technical centre of GAW technologies in Graz.
Already the first test showed that it can be critical using classic agitators (dispersing disc or standard rotor/stator), as they were not suitable for this specific application.
To find the successful combination a total of 3 trial-days was necessary: a CDS rotor and a LR stator achieved a coating colour with perfect rheological characteristics – high solids content and low viscosity. This results in a whole lot of advantages for the customer, i.a. because of lower back pressure within the piping.
Christian Stine, R&D at GAW technologies, puts it in a nutshell: „The understanding of raw products as well as chemical and physical processes is essential in the production of coating colour. The recipe always comes from the customer; we only serve as a tool to build the right production plant with the help of the trial results. We find out how the process can be designed and how to produce the colour exactly as it is required.”
The desired results where achieved in both ways – on a small scale as well as months later during the smooth start-up of the actual plant. A special highlight was the extraordinary support of the entire team of OOO Mayak-Technocell in Penza, which impressed the project management as well as the start-up specialists and technicians of GAW and which will remain in good memory for a long time.
Mr. Schulz, why did you choose GAW technologies as a partner for the test series and what were the particular requirements?
We already know GAW from successful cooperation in the Felix Schoeller Group. Furthermore we quickly realized that GAW has good experience in activities on an international stage.
Was it really possible to transfer the gained insights and the process of the trials one-to-one to the large-scale production plant?
The preliminary trials allowed us to define the process limits and to go into the start-up with a ready-to-use recipe, which meets the technological requirements of the paper machine.
From the customer’s point of view: How was the start-up of the dispersing unit on the paper machine carried out?
The results of the pilot tests in the laboratory were the basis of the layout of the plant. Having the conclusions from the trials in pocket, we were able to quickly set the start-up program. Already the second dispersing preparation during the commissioning achieved the set goals. This allowed the employees of OOO Mayak-Technocell to take over the plant without any amendments straight into production.
From "Professional Papermaking/ June 2019"