PaperMac

and Computer Modelling of Paper and Paperboard

Computer software programmes are today available for modeling of single-ply, multiply and multilayer paper and paperboard. By building and using paper models, people engaged in product development can simulate the influence of papermaking variables on important paper properties. PaperMac is a modular programme developed in 1991 for dynamic simulation of single-ply or multiply structures up to 9 plies. The impact of furnish recipe,separate or mixed refining, addition of filler and broke, wet pressing, calendering and strength orientations of the different plies on important paper properties such as bending stiffness,opacity ,brightness, whiteness and shade, can be studied.

There is now a separate library named PaperMac available in FlowMac which means that process and product quality can be modelled in the same flowsheet - togehter with economy! This opportunity is unique to the world of simulation.

PaperMac can be used in paperboard mill projects for modelling of Liquid Carton Board, Bleached Multiply Board, Duplex and White lined Chipboard. The furnish recipe is modified and paperboard properties such as brightness, reflectivity, strength, bending stiffness, caliper and furnish costs are studied. Modelling of pigmented and coated singleply base papers to develop new paper grades for a current papermachine has been done in a mill project.

The influence of different process variations on important paper properties can be studied by use of PaperMac blocks. Actions taken for improved process stability are tested and compared. Mass balance of fines is of interest for many paper grades.

PaperMac runs on MacOS or Windows. Both programs can establish warm links to spreadsheet programmes in which complementary programmes can be developed.

To companies and people engaged in the pulp and paper industry, not yet familiar in the use of computers and advanced papermaking theories, PaperMac opens a new window to the area of computational work and carrying out computer experiments.

The plan, to combine FlowMac and PaperMac to one software strong in both process and product modelling, has since end of 1998 been realized.