Wood Products
Paper, Paperboard & Pulp
Australians consumed 4.2 million tonnes of paper products in 2004-05 - about 200 kg per person. Although the production of paper and paper products has increased by over 30% in the past ten years, imports of paper and pulp products still account for an average of 69% of the total value of Australian imports of wood and wood products. One of the challenges facing both industry and government is to improve the competitiveness of Australia's pulp and paper industry in order to replace imports and take advantage of export opportunities.
Photo: Publishers National
Environment Bureau
The paper-making process begins with removing bark from tree logs. The logs are then sent through a series of chipper machines, which have blades to break the logs into smaller pieces. Before high quality grades of paper can be made, fibres need to be taken from the wood. The fibres are stuck together in the wood by a ‘glue’ called lignin. To separate the fibres, the wood chips are either pressure-cooked in a ‘digester’ with chemicals which dissolve the lignin, or the fibres are mechanically torn apart using a machine called a ‘refiner’.
The method of obtaining the fibres, or ‘pulping’, depends on the type of paper being made. Pulp for lower grade, short term paper products such as newspapers and advertising material is usually made mechanically, while higher grade, long term products require chemical pulping to ensure that the lignin is removed and the paper does not go brown and disintegrate with age. Pulp used to make recycled paper products usually contains a mixture of wood fibre and recycled paper fibre.
rolls up to 8 metres wide and
weighing 20 tonnes
Photo: istock
The pulp is cleaned, refined, bleached, washed and mixed with water to make a thin slush. This slush is sent through a series of screens to remove any contaminants, then pumped onto a flat, fast-moving wire screen. As the slush travels down the screen, excess water is drained off for reuse. (Modern paper mills can reuse water up to 20 times before it needs to be treated).
The paper sheet is then squeezed between rollers to remove the remaining water and make the paper a uniform thickness and smoothness. It is run through a series of heated rollers and spooled onto large rolls, then cut to size for transportation. The finished paper rolls are sent to manufacturers of office paper, magazines, notepads, paper bags, tissues and other paper products.
An important feature of paper products is that they can be easily recycled a number of times. Australia has a high paper recycling rate, with 50% of the total fibre we use to make paper products coming from recycled paper.
Case Study: Upgrading Australia’s Newsprint Capacity
Norske Skog’s paper mill at Albury is now in the final phase of a $130 million upgrade to increase production capacity by more than 20 per cent by the end of the year. The mill is one of Forests NSW major customers drawing upon the state’s valuable pine resource in the south west slopes and providing a reliable long term market for plantation thinnings.
Mill manager, Guy Mycroft, said that it was anticipated that the upgraded paper machine would be running at the new rate of 1600 metres a minute, up from the existing 1300 metres a minute, to produce 265 000 tonnes of newsprint a year.
Norske Skog’s Albury mill
Photo: Norske Skog, Albury
For more information about this new plant technology read the Bush telegraph magazine on the Forests NSW website.
