The evolution of paper machines has been interesting. The Fourdrinier brothers' continuous process was a gigantic leap forward. After that came steam dryer cans and other innovations. Early machines were notable in that the process was largely atmospheric. In other words, it took place in conditions open to the atmosphere. Hence and necessarily, papermaking was dependent to a certain extent on seasonal weather conditions.
In the last fifty years, there has been much progress in enclosing the process and hence making it more controlled. However, I can still report that it was not that long ago I visited mills in northern climates in the wintertime where large ice bridges had built up at doorways. It seems just days ago I was in machine rooms that had no hoods (it was longer than that, but not so far back it is a distant memory). Open vats, open tanks, standpipes and other such atmospheric exposures are still in existence.
Can we fix these? Should we fix these? The questions are many, but it seems that if we tightly control the process, we can make better paper. By better paper, I mean paper that consistently meets tight performance specifications at the lowest possible costs.
Come with me as we explore some of the unit operations that may need to be rethought as we move forward.
