How paper is made
Paper manufacture is a fascinating process, whichever way you look at it. Many paper manufacturers have helped revolutionised it, especially in the field of sustainable forestry. At the forefront of paper manufacture are concerns of environmental impact. The best way to address this concern day is through the use of eucalyptus globulus tree in the paper manufacture.
The eucalyptus is a very fast growing species, which helps with Co2 retention and forest replenishment. A tall tree, the eucalyptus can grow up to 180ft, or 55 meters in height making it ideal for mass production purposes and improving forestry efficiency.
Once planted, this evergreen is supported by a straight trunk, which is ideal for logging and transportation purposes. Already, you can see just how many benefits there are to using the eucalyptus over other tree species.
Harvesting the eucalyptus wood
The eucalyptus tree can be harvested after just 4 years, in which time it can grow to an impressive 55 feet. Once the trees have been selected, the logging begins. Full trucks take the trees to specialised industrial units for stripping and chipping.
Bark is first stripped from the trunks, which is then chipped into standard sizes. Once the eucalyptus wood itself has been chipped, it’s time for it to moved on to the next step in the process – Pulping.
Wood pulp manufacturing
Wood chips are first ‘cooked’ in the wood digester. To produce a pulp that is actually usable, it is important to separate the cellulose fibres from the lignin. This can be done in two main ways, but by far the fastest, cleanest and most cost effective way to do this is by dissolving the lignin by using sodium sulphate, heat and pressure. The end result is a brown raw pulp.
Lignin and chemicals are recovered from the process which can then burned at biomass power plants. These plants produce electricity which is then sent the national power grid.
While that is happening, the brown pulp is bleached which can then be used to produce printing and writing paper. Bleaching doesn’t just turn the pulp white, it also removes any lignin that may still be in the pulp. It takes several bleaching stages before the pulp is ‘ready’ but by the end, it has become the bright white that we become accustomed to associating with paper.
The pulp at this stage can either be dried out, for sale on the open market, or kept as it is and pumped directly to the paper production area and the next stage of the process.
Mineral fillers are added, with other additives, to the pulp which improves the strength of the finished product. At this point the pulp is ready to be placed into the machine, by way of the headbox which sits at the front of the line. From here water is removed by a combination of vacuum and gravity. By the time this part is over, up to 85% of the water has been removed.
The pulp then goes through a pressing process which reduces moisture to around 60%. From here, the paper is taken through a series of rollers and a starch is added to the surface which improves ink application to the paper. From here, the paper is heat dried to eliminate the last traces of moisture from the paper.
Finally the paper is fed onto jumbo rolls, which can weigh up to 80 tons. These rolls are processed into smaller reels which can then be sold on to clients.
Paper can be processed ‘in house’ also, before dispatch. This process involves cutting the paper into various sizes such as A4 and A5, before being packed into reams. These reams are made up of 500 sheets of paper.
Reams are then packaged, wrapped and stacked onto pallets with other reams ready for dispatch.
Source: The Navigator Company