Recycled paper, sustainable forestry and bleaching
By Jay Risbridger, of the Green Stationery Company (http://www.greenstat.co.uk/storefront/evolution_index.html)
How is paper made?
Most paper is made on large machines using a revolving wire mesh called a deckle. A pulp solution of 5% fibres and 95% water is dropped onto the mesh and the water falls through leaving the entwined fibres behind. The fibre mat is dried as it is passed over large heated cylinders and forms into paper. As it runs down the machine, the paper surface is smoothed by adding starch and clay fillers. At the end of the deckle, the continuous sheet of paper is wound onto large rolls, later to be cut into sheets.
Pretty well any kind of fibre can be used for making paper, from silk to plastics. Traditionally, cotton rags were used to make high quality paper, but in the last hundred years rags have been replaced by softwoods – such as spruce, pine, fir, larch and hemlock – as the main fibre source, with the occasional hardwoods, like eucalyptus, aspen or birch. The trees are mechanically crushed to produce a rough quality paper fibre. More often, the wood is cooked with a chlorine or sulphite solution that breaks down the wood fibres by removing lignin, the natural glue that binds the fibres together. Chemically pulped paper is often called ‘woodfree’ because the lignin has been removed. Papers that still contain lignin will tend to yellow as they are exposed to sunlight, so ‘woodfree’ papers are preferred for all quality office and printing grades of paper.
Why use recycled paper?
As over 50% of all landfill waste is paper-based, the act of recycling turns a major waste product into a practical resource. To make recycled paper you do not have to crush or cook wood to get the fibres, as paper has already gone through this process the first time, so there is a large saving in energy and pollution. Used paper can simply be dropped into a vat of water and the fibres will be released for manufacturing new paper. Heavily-inked papers will have the ink skimmed off or dispersed away to make a greyer coloured recycled paper, whilst lightly-inked office papers and printers’ off cuts can produce whiter recycled papers. A single paper fibre can be recycled about five times before it becomes too short to make a strongly woven paper. Yes, in the grand scheme, virgin paper still needs to be harvested and produced to provide a recycled fibre source, but the ratio should be around 20% virgin to 80% recycled, not the other way round, as it is at present.
When calculating the energy consumption/ carbon footprint of recycled paper, some producers include in their calculations the energy spent in the collection of the used paper, to show recycled paper has a higher energy footprint than virgin grades. In reality, the collection of used paper happens anyway, as it is taken to landfill through local waste collections. Therefore, the energy used in collecting used paper is not an additional energy usage derived from the recycling process; instead, the energy used in waste paper collection and disposal should be added to the environmental cost of making virgin paper.
In general, we should all be wary of quantitative assertions that one action or another is more or less environmentally beneficial. All these calculations are open to manipulation by interested parties and reflect current social and market powers. Nature operates through sustainable cyclical processes and we should also make a qualitative judgement about supporting similar cyclical processes, like recycling.
Sustainable forestry
In response to the demand for environmentally responsible papers, virgin paper manufacturers have chosen to certify many of their papers as being ‘sourced from sustainable forests’. As the use of recycled fibre is the most logical environmental option, it would have been better for these manufacturers to start using more recycled pulp – but this would have required considerable investment in new machinery. It would also undermine the advantage that virgin pulp producers have in passing on the cost and responsibilities of disposal. In effect, local council collection services and recycling schemes are subsidising the Virgin paper manufacturers, and so increasing their profits.
The certification of European virgin papers as sustainably sourced changes nothing about how these papers are produced. The vast bulk of virgin paper fibres in Europe come from Scandinavian and North German softwood plantations. These forests are often owned by paper producers and have been a sustainable source of fibre for the European paper industry for over a hundred years. Ironically, even the sustainable forest certification schemes recognise that recycling is the best environmental solution for paper production, and have introduced recycled content papers under their forest certification labels to reflect the environmental value of recycling, even though they can never be sure what forest a recycled fibre comes from. One has to ask why the forestry certifiers are bothering to certify European paper products, when all it is achieving is undermining the demand for recycled papers?
Recently, there has been an increase in imported papers sourced from newly planted eucalyptus trees, prized for its high fibre yields. These are often certified with sustainable forestry and/or zero carbon footprint labels. Eucalyptus itself is a fast-growing, invasive tree originating in arid areas of Australia. Its speed of growth can be attributed to its large root network that draws up tremendous amounts of water and nutrients from the surrounding area, through transpiration. The result is that other vegetation is unable to grow near the tree, and the soil becomes rapidly degraded. Also, due to the volatile and highly combustible oils in the leaves, a densely packed plantation presents a serious fire risk.
There are active environmental campaigns in Portugal and South Africa where Eucalyptus is being grown on agricultural land for paper production. Not only are eucalypts damaging the land for short-term export gains; they also use up land much needed for essential food crops. An important lesson is to be learnt about environmental sustainability here, where we mustn’t just myopically focus on carbon dioxide emissions, but instead we need to think more holistically, and logically: just because a new tree is being planted, this does not mean the environment is benefiting – it depends what the tree is, and where it is planted.
Bleach and secondary whiteners
Many virgin fibre papers carry a ‘totally chlorine free’ (TCF) or ‘elemental chlorine free’ (ECF) environmental label. In paper manufacture, chlorine oxidants were used in the production of paper fibres derived from trees through the ‘woodfree’ process. In the past, many paper mills discharged effluents into rivers that were high in chlorine and sulphite pollutants, and this was the main environmental impact associated with paper production. But in the last twenty years, strict emission controls, and the realisation that the mills were just throwing away costly chemicals that could profitably be reclaimed, has virtually eliminated such pollution. There has also been a move away from sulphates and chlorine-based chemicals (linked to ozone layer destruction) towards more benign oxygen-based processes to extract the fibres. The vast majority of virgin paper is now chlorine free, and choosing a paper based purely on this criterion has very little impact on current paper production processes. Recycled paper cannot presently be classed as chlorine free, though, because you can never guarantee the source of all recycled fibres. Indeed, many recycled papers contain chlorine from used papers that were subjected to secondary bleaching when they were originally made.
Secondary bleaching is the use of bleaches and whiteners to improve the visual appearance of paper. Most recycled papers are not subject to secondary bleaching as it damages the fibres, and the maintenance of good fibre strength is essential to the creation of quality recycled paper. Recycled papers are generally either whiter or greyer depending on the source of the used paper itself. Recycled commercial waste and lightly inked office papers produce whiter recycled sheets. The lower grade waste sources – such as heavily printed magazines and newspapers – produce greyer recycled sheets. The availability of ‘high white’ recycled pulp is fairly limited and we would urge people to use lower grade post-consumer waste papers where possible, to make use of the mountain of waste paper sitting around. In practice though, greyer paper is much easier to read than high white papers that often contain optical brighteners (dyes that absorb light in the ultraviolet and violet region, and re-emit it in the blue region) that reflect light back into the eyes.
So why not lobby your office, business or organisation to use grey papers? Whiter papers aren’t better quality simply because of their colour. Indeed, once upon a time brown bread used to be regarded as poor quality, and white bread was seen as more refined and a premium product. Nowadays, we view white bread as cheap and inferior compared to quality wholegrain healthy brown breads. It’s just a question of perception, which can always be changed for the better.
We hope this information section has been useful to you as paper users and would always welcome comments and alterations from any customers or readers. Please read our ‘About Us’ page for more information on the issues concerning green and ethical businesses:
http://www.greenstat.co.uk/storefront/evolution_ContentPage.html?Content=1
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