Topics & Information
The History of Technological Developments of the Paper Industry in Japan after World War II
Part 3 Hardwood as a New Pulp Resource
2017 Volume 71 Issue 6 Pages 649-660
Details
2017 Volume 71 Issue 6 Pages 649-660
Until the 1950s, pulp was manufactured from softwood. As Japan did not have enough softwood, it was necessary to use hardwood as an alternative.
Then, USA, which was the largest paper manufacturer but scarce in good softwood resource, studied on using hardwood and developed SCP and CGP processes. Japan suffering from softwood shortage quickly adopted them and blended CGP up to 30% in its newsprint furnish. The key technology was the refiner of high power that was developed in Sweden and USA.
The effort continued and one paper company manufactured printing paper of high grade from hardwood bleached kraft pulp （LBKP）. As its quality proved to be fine and the demand for that type of paper increased quickly, many paper companies in Japan started to produce that kind of paper. With technological advances that followed such as introducing chlorine dioxide for bleaching, perfecting continuous digester, and surface sizing for vessel troubles, fine grade printing paper of LBKP, invented in Japan, has become a world standard.
Japan, however, could not keep up against increasing paper demand with its domestic wood supply, and started to import wood chips overseas by chip carriers. It greatly changed the structure of the industry which will be discussed in the coming issue.
