In South Africa, special trees – namely eucalyptus and pine – are planted, grown and harvested for the purposes of making paper products. It takes trees anywhere between 25 to 30 years to mature before they are harvested. Only 9% of the plantation is harvested annually and this area is then replanted with new trees. This is what makes trees, wood and paper renewable resources.
In South Africa, paper can also be made from recycled paper and bagasse (sugar cane waste).
There are three main stages in paper production, from when the timber arrives at the mill as a raw material right up to the stage when it becomes the final packaged product.
Fibre for papermaking is also sourced from sawmills in the form of wood chips from off-cuts as well as from the recovery of used paper of all types. This “recycled fibre” ensures that the cellulose content, carbon, remains in a form that postpones degradation, (and hence carbon dioxide generation), for as long as possible.
In addition to fibre, a number of chemicals are used to convert the raw cellulose into a form that can be converted into the plethora of paper grades required by the end user:
Other materials used in the paper making process are listed below:
- Pulping chemicals consisting of sodium hydroxide, sodium sulphate, sodium carbonate and calcium oxide are the main constituents. The bulk of these chemicals are recovered in the recovery section of the pulp mill and re-used in the process.
- Water – the bulk of the water is used in the paper making process to dilute cellulose fibre to be formed on the paper machine. Virtually all this water is recovered and recycled back to the machine
Paper making chemicals – such as starches, dyes, and strengthening and water proofing agents – impart a number of different and important properties to the sheet of paper being formed on the machine.