Currently the size press application utilises oxidized corn starches. The equipment for starch preparation is designed for fully automatic operation with an exception for manual starch loading into a boiler due to usage of starch delivered in 25 kg bags. The starch boiling process is based on 8 bar live steam used for direct heating of 20-25 % slurry.
This technological equipment comprises three primary subgroups: an atmospheric (opened) discontinuous starch boiler, a storage tank for boiled starches with an on-line diluting loop intended for attainment of required starch concentration and an own size press working station. The entire line is controlled by an independent control system based on the Simatic S7-300. The control procedures consist in automatic control of boiling processes, automatic diluting of the starch solution to operating concentration intended for the given size press and automatic starch dosing directly into the size press in required volumes. Besides these primary functions the equipment enables to control starch temperatures in the storage tank of the working station in accordance with technological requirements.
This technological line operates with capacity from 200 to 400 kg/h of the given product. Its operating concentration can be set up to 8-12% according to the customer's technological requirements.
The control panel of the working station is built in the main control stand of the size press thus the operator has immediate supervision not only over the starch dosing and diluting process in the size press but also over the starch boiling, stored volume available and, of course, over the entire size press station while in duty.
One-side starch application on the paper web surface in the size press is ranging from 1 to 3 g/m2 a.s; this parameter can vary through changing concentration connected with changed viscosity of the starch solution.
This equipment was manufactured in compliance with the EU standards and delivered with all applicable certificates. The manufacturer provided warranty on this equipment for a period of 24 months. The on-site commissioning phase included also necessary training of attendants under assistance of translation services of the starch supplier.