
Making paper
We’ve come a long way from the papyrus reeds of the ancient Egyptians to the galaxy of paper products we use today. But, then again, not as far as you might think. The essence of papermaking is an elegantly simple process…
Gore. Heart of Country and Western music. Land of the rolled “r”. Navel of Southland. Gore is where I have my first look at the Mataura River, which flows through here from its source in the Remarkables, down past my destination, the Mataura Paper Mill, a few kilometres away, and on to the southern coast at Fortrose.
It’s a troublesome river to all who live on its banks, but it’s also the reason for many of them living here at all. Today, swollen by melting snow, it is a dirty brown torrent. In a couple of days the people down in Mataura will no doubt wake up and remind each other of the heartache of 12 years ago. For it was 12 years ago this day that the river had its big flood, sending two feet of water and stinking silt through their homes.
“Everything is wet, everything is dirty. You throw away your furniture, you throw away your photos, you throw away your books. You throw away part of your life, and it’s not recoverable,” says Sylvia Gilder, personnel officer at the mill, when I arrive there half an hour later.
We’re standing on the mill’s pier. Here the river narrows and enters a gorge, its water forced between and over several rocky outcrops. Its power is clearly visible today, its voice in the background of every conversation I’m to have with the people of this mill, the southernmost paper mill in the world and the oldest in New Zealand.
Sylvia Gilder points at the 2.7-metre concrete wall which shields the mill from the river. “We’ve raised the height of that three times. We should be right, now.”
The third addition was made after the ’78 flood swept through the factory, taking machinery and and a one and a half tonne roll of paper and depositing them on roads miles away. In its wake it left gorse and scrub piled on top of the papermaking machines and silt through every moving part of the machinery. It took the mill workers six weeks to strip everything and to get the mill working again.
“But the water is why the mill is here,” Sylvia Gilder says.
Without rivers such as this one, the papermaking industry in New Zealand, or, for that matter, in the world, would not exist. papermaking depends upon access to vast quantities of clean water to mix with the raw ingredients. For every tonne of paper made, 99 tonnes of water is needed to make it. Eventually, this water is spat back out into the waterways somewhat the worse for use.
Exactly how much worse has become an issue of debate between paper manufacturers and their environmental watchdogs.
It’s hard to imagine life without paper. There would be no newspapers, no toilet paper, no writing paper, no cartons, few books, no libraries. Without paper, our knowledge of history would be limited to information passed down to us by word of mouth. Government, educational systems and industry simply would not function.
In New Zealand we are big users of paper. According to the statistics, we each use 182.4 kilograms each year. That’s less than consumers in the United States, who need 297 kilograms each year, but it’s higher than France’s 130 kilograms, and we streak away from the Indians with their 2.7 kilograms per person per year.
On the production side, we turn out 1,523,000 tonnes each year; by 1991 the estimate is 1,625,000 tonnes. Compared with the USA’s output of 52,000,000 tonnes, Canada’s 24,000,000 tonnes, or even France’s smallish two and a bit million tonnes, we’re really small fry. However, there are aspects of papermaking in which we lead the international field. Our radiata fluff pulp, which goes into disposable nappies and sanitary products, is widely regarded as the best in the world, and some of our packaging grades are unmatched for tensile strength.
New Zealand has eight mills. Two of these — NZFP Pulp & Paper’s mills at Whakatane and Te Papapa — produce only paper. Two more — Winstone’s pulp mill in Karioi, near Ohakune, and Carter Oji Kokusaku Pan Pacific, in Napier — produce only pulp. NZFP’s other two mills, Mataura and the flagship, Kinleith, at Tokoroa, are integrated pulp and paper mills. Caxton, manufacturer of the country’s toilet paper, tissues and other health products, has its mill in Kawerau, next door to Tasman, New Zealand’s only newsprint mill.
Mataura holds a special place in the history of papermaking in New Zealand. It wasn’t the first New Zealand mill to produce paper — it was beaten to that claim by a month in 1876 by a Dunedin mill. But, while other mills have come and gone, Mataura, in spite of floods and economic changes, has survived.
Two Scots share the honour of starting the papermaking industry: Edward McGlashan in Dunedin and James Bain, founder of the Southland News and later proprietor of the Southland Times, in Invercargill. Both saw the potential for a mill at Mataura, and it was Bain who won the race to establish one there.
It looked a likely spot. First, Bain noted, there was the river. But as well, Mataura sat in an area with a virtually unlimited supply of raw papermaking materials: tussock grass and flax.
Traditionally, paper had been made from rags and waste paper—neither of which were abundant in the small settlements of the new colony. Then, on a journey to his homeland, Bain saw something that made his Scots eye gleam: paper-makers were successfully combining tussock and rags. He came back thinking that he was sitting on a potential goldmine in his new home country.
By the end of June, 1876, the Mataura Mill was reeling out a heavy, crude wrapping paper. It wasn’t highly regarded. When Bain sent some to the government it was suggested that some of the thinner paper could be used for placards by the Railways Department.
Dogged by poor management, a flood, competition from imports and low prices, the mill failed in 1884 and was taken over by new owners.
By this stage the raw ingredients included “sacking, rope, flax, and rags of all descriptions, from a baby’s sock to a lady’s improver, from the white shirt of a master to the blue smock of a Chinaman.” And a lot of waste paper. “Immense heaps of account books, the pages of which were once eagerly scanned by anxious and perhaps despairing eyes are now destined to oblivion and the cruel knives of the rag engine,” one report said.
Papermaking, whether it’s a small handmade craft operation or a giant mill the size of Tasman, is a surprisingly simple process. Ingredients change, the scale of operation ranges from a household blender to huge, multimillion dollar digesters, but the basic method has remained virtually unchanged since it was first discovered centuries ago.
Paper is made up of a number of layers of the dried microscopic fibres of vegetable matter — nowadays usually from wood, but occasionally, especially with handmade papers, from such things as straw, flax, corn husks, even dahlia stalks, carrots and banana palms (“Ginger plants are superb,” says one local papermaker). Anything that will break down to cellulose will make paper.
These ingredients are treated either chemically, thermally or mechanically (or a combination of these ways) to break them down to their basic fibres and remove the fleshy parts. The fibres are mixed with water, and sometimes various fillers, beaten to roughen them — so they will hold together better — and the pulp is spread over a wire mesh. The water is drained off, and a layer of pulp remains. The rest of the water is then squeezed away, the pulp is dried and… we have paper.
[Chapter Break]
Pespiration Beads Davie Donaldson’s forehead as we stand beside the Number 2 paper-making machine in the Mataura Mill. The temperature and the humidity are about the same as midday in Bali. “It’s the heat from the drying cylinders,” he shouts over the thunder of the machine. “It’s good in winter,” he adds. Beside us a highway of white paper two metres wide is pouring off the machine onto one and a half tonne rolls — rolls which are higher than we are.
A genial Scot, Donaldson is the company’s production superintendent, and came out to the mill in 1964. He’s probably as close as the New Zealand papermaking industry gets to a craftsman in the old tradition: someone who could tell paper quality by sight and feel. These days computers do all that, but Donaldson still loves paper and his face comes alive as he talks about it — its “rattle”, its texture, its surface sheen the sorts of things which designers agonise over in their search for stocks which look and feel right for their purposes.
“Each of these rolls takes about 40 minutes to make,” he tells me. “This machine turns out 2.7 tonnes per hour — that’s 232 metres each minute.”
Donaldson has just shown me through the mill. First to the floor where two huge vats, rumbling like some Neanderthal digestive process. churn the raw materials with water. One is filled with brown recycled waste, the other with a white mixture which looks rather like semolina, but turns out to be fresh pulp.
Then to the blend floor with its bags of starch, size, chemical brighteners and clays. “A sheet of paper is like a woven mesh,” Donaldson explains. “The clay is used to fill the weave. It improves opacity and gives a good finish to the paper — and it’s cheaper than wood pulp.” Starch is used to strengthen the surface and improve printability, sizing agents give the paper water resistance, and brighteners make it whiter.
Later, in the refining room, the pulp is ground to its final slurry before going to the papermaking machine. Now, when I feel the mixture, it is slimy — a sign, Donaldson tells me, that the raw pulp has been broken down into its individual fibres, ready to be made into paper.
Down in the papermaking area, another machine is producing Sandow (rhymes with cow). It’s brown paper, made totally from recycled cartons which arrive at the Mataura Station by rail from all over New Zealand. Demand for Sandow, originally made as a wrapping paper, has more than trebled over the past year with the new search for recycled products by consumers. Now customers are seeking it for printing purposes. It’s a good sign for the mill.
This afternoon the mill is making both the Sandow and bond — writing paper. Yes, Donaldson agrees, it’s a bit like making two different types of cake. He explains that the white papers are made with a mix of long-fibred pulp (from Pin us radiata) and short-fibred pulp (from hard‑ wood trees such as eucalypts). The pine pulp is sent down from Kinleith and arrives in bales of white sheets which look like blotting paper. Hardwood fibre is imported.
On the morning of my visit the mill had been making a different white paper — one suitable for photocopying machines.
“That’s a lighter sheet than this one,” he explains. “So this morning they were using 60 per cent long fibre, 40 per cent short. Now they’ve adjusted the batch to make a heavier sheet — and that means they need more short-fibred pulp.”
As in the other mills around the country, the range of products coming out of Mataura has narrowed dramatically over the years. In the name of competitiveness, they’ve cut their range back to copier paper, higher grade offset printing papers, bond paper, cheque paper and ledger paper. They also make what they call ticket board, which goes into lotto and TAB tickets, wallpaper base and, of course, their old faithful Sandow, which has been made here since 1926.
“We’ve had a crack at a lot of different papers over the years,” mill manager Jeff Rankin says. “We’ve made linoleum base, the blue paper they used for fireworks, toilet paper, waxed paper which people used to wrap their lunches, matchbox covers…”
Mataura also used to turn out the black paper used for photo albums.
Rankin shudders at the memory. “You can’t get a true black. We had to load the machines with ink and the guys would look like the Black and White Minstrel show at the end of the shift. Heaven help us if that ever comes in again!”
Onte, the mill produced custom-made’ papers for manufacturers. South Islanders may remember “Arthur Ellis Red”, used to wrap mattresses, or the Arthur Barnett grey paper used as wrapping by the store. All long gone now, but replaced by another method for individualising paper: the watermark. (See example following page 64)
[Chapter Break]
This morning I expected a cheque in the mail. As usual, there was no cheque. As usual, there was a handful of junk mail for me to sift through. This morning I was exhorted to buy a traditional Japanese yukata (whatever that is), an oak filing cabinet, a mobile computer workstation, three pairs of men’s underpants, or an oil drain dish (with plastic funnel) for just $10. If I used such-and-such a credit card just five times during December I could be in to win a Christmas bonus. I could buy at crazy prices if I went to the opening day of a new shopping mall.
Junk mail, says a report held by Greenpeace, will account for up to 40 per cent of the increase in paper production in the next 10 years.
The last decade has been one of the strongest growth periods in the history of paper, and there are no signs of it abating. World paper consumption has gone from 167 million tonnes in 1982 to almost 233 million tonnes in 1989. Compare this with the 1955 total of just 57 million tonnes.
Ironically, the advent of the computer has been one of the main reasons for this increase — instead of the paperless society that computers promised, their proliferation has meant millions of kilometres of computer printouts. Copying machines have burgeoned too; so have disposable goods.
In New Zealand we now use 50 million disposable nappies — paper pulp products — each year. And who among us ever uses a handkerchief now? Paper products account for about 40 per cent of all rubbish dumped each year.
It is a hot windy day when I visit Rory Gordon, manager of the NZFP recycling plant at Te Papapa, Auckland. Bank statements, envelopes, and loose sheets of newspapers swirl aimlessly, and a school committee report attaches itself firmly to my leg. Seeing me reading it, Gordon says that some suppliers, such as the army, bring in their paper and take it straight to the pulping vats to make sure no one sees what’s written on it.
We walk past a mountain of newspapers, telephone books and bound bundles of comics; in all, about half the size of a football field and four metres high.
“That’s about 3000 tonnes — two weeks’ worth of paper collection,” he tells me. Soon these discarded items will be converted into the fluting that goes in the middle of corrugated cardboard.
NZFP are the main recyclers of paper in New Zealand. This plant uses 70,000 tonnes of newspapers, cartons, telephone books and printers’ trimmings each year. It is capable of taking all the waste Auckland can produce and turning it into 200 tonnes of corrugated cardboard a day. About a quarter of the mill’s output is exported.
Not far from this mill is another NZFP operation, Fibre Products, which turns newspapers into egg cartons, egg and apple trays, and unexpected items like hospital bedpans. Last year NZFP used 86,000 tonnes of the 90,000 tonnes of waste paper which was recycled in New Zealand. Next year this figure should be closer to 140,000 tonnes.
Newsprint is the biggest source of paper waste in New Zealand. We manufacture more than 300,000 tonnes of newsprint each year, all of it at Tasman’s pulp and paper mill in Kawerau. Sixty per cent of this paper mountain is exported, a significant quantity finding its way into Australia. About a tenth of the newsprint output ends up in telephone and other directories; the rest is turned into newspapers and magazines.
Each day Tasman turns out enough newsprint to run a 6.8 metre wide strip (the width of the paper reel) from North Cape to Bluff, all the way back again, and a considerable distance down country yet again. That’s 4000 kilometres each day, or 1.4 million kilometres each year — enough newsprint to circle the earth 36 times.
Of the newsprint we use, around half is collected, and a third of this amount is exported. As yet, none finds its way back into fresh newsprint. Before this can happen a de-inking plant would have to be installed, and, according to Tasman, the current volumes of economically collectable paper are not great enough to make such a plant viable.
To re-use newsprint for anything other than products where the colour doesn’t matter is difficult. Over the past decade or so the market has developed a fetish for white paper and not just white, but dazzling, pristine white. It’s this single demand for whiteness that is at the root of almost all the environmental concern over the papermaking industry.
As a raw material for making paper, wood has a particular problem. The cellulose in trees is reinforced by a tough resinous adhesive called lignin. Lignin strengthens the individual cells of the trunk and stems, thereby giving the tree its rigidity. It comprises 25 to 30 per cent of the wood of trees. To make paper, the wood must be reduced to fibres which can then be formed into sheets. This can be done chemically, by cooking wood chips in a solution of chemicals which dissolve away the lignin, or mechanically, by grinding the chips into a pulp.
Chemical pulping leaves very little lignin or other residues, and because it’s the lignin in paper which makes it turn yellow when exposed to light, papers pulped in this way don’t have the discolouration problem. But the pulp is brown — and to use it for white papers it then has to be bleached.
To date, the bleaching process has almost universally involved the use of a chlorine. Unfortunately, chlorine has the habit of combining with some of the organic compounds it’s working on to produce a range of substances called organochlorines — a group which includes the dioxins. While many organochlorines are relatively harmless, some are carcinogens, and others are known to cause chromosomal damage. Inevitably, some of these chemicals end up in the water used by mills where bleaching is carried out, and thus get into our waterways. It’s an issue which concerns the mills, and one which worries environmental watchdog groups such as Greenpeace.
Gordon Jackman is Greenpeace’s pulp and paper campaigner. He’s been employed on this campaign for most of this year, and has collected vast amounts of information from around the world. “So much paper,” he sighs, shuffling through hundreds of reports.
I ask him what solutions he can see.
“Well, you have to understand why the mills feel the need to bleach to this degree,” he says. “Over the past 20 years the markets have been demanding whiter and whiter paper — and the usual way to get papers white is to use chlorine bleaches. Now, we see no justifiable reason for this — there are no products which have to be that dazzling white, but the big players ‘ in the international markets haven’t switched to accepting lower whiteness — or brightness as the industry calls it.”
Jackman shows me some papers made without chlorine bleaching.
“Look at this,” he says, showing me an elegant paper which has a creamy tint. “This one came from a Swedish manufacturer. It’s about 80 per cent of the whiteness of bright white papers. There are overseas companies producing to perfectly acceptable standards without using the chlorine process.”
New Zealand mills are already moving away from the use of free chlorine. Chlorine dioxide has been used for a number of years, and other nonchlorinated reagents are being tested and introduced. NZFP Pulp & Paper scientists have recently developed a technique which will eliminate the use of chlorine from their bleaching processes and result in dioxin-free pulps.
Another area in which New Zealand scientists are making a contribution is in fibre research. Wood fibre is at the heart of the papermaking process, and research into new products and markets invariably starts with a close look at the behaviour of the fibres.
Two important considerations are how the fibres conform, or bed down into the paper sheet, and how they bond together. The first characteristic affects the structure of the paper; the second, its strength.
Mechanically pulped fibres give good opacity and printability, but the process tends to damage many of the fibres, causing them to form only weak bonds in the final sheet. This is why newsprint (which is mostly mechanical pulp) tears easily, especially when wet.
Chemical pulping processes are kinder to the fibres, leaving them strong, whole and undamaged, but the yield is much lower: less than 50 per cent of the original wood, compared with up to 95 per cent for mechanical fibre. On the other hand, the final sheet is stronger. There are two main methods for chemical pulping. One uses alkaline chemistry to break down the wood structure (the kraft or sulphate process); the other is mildly acidic (the sulphite process). Of the two, kraft pulping predominates in New Zealand and overseas because it is able to cope with most wood types, produces stronger pulps and incorporates an effective chemical recovery process. Sulphite pulps, on the other hand, are lower in strength, but lighter in colour and easier to bleach.
Many factors influence the types of pulp used to produce different paper products. Mechanical papers do not have the strength and rigidity necessary for making, say, apple boxes. The papermaker would choose a kraft linerboard for this purpose. Conversely, newspapers, which are usually read once and disposed of, are best printed on low cost, low strength paper made mainly from mechanical pulp.
The nature of the timber is also important. In New Zealand the main commercial forest crop is radiata pine — a softwood species which produces long, strong, thick-walled fibres. When pulped using the kraft process these fibres are ideally suited for packaging papers and excellent for fluff pulp (the sort of pulp that goes into disposable nappies and the like). They are satisfactory for printing and writing papers, but not as good for this application as hardwood (short fibre) chemical pulps.
Because we have so much pine, the challenge before New Zealand producers has been to develop grades of pulp and paper which can make best use of its fibre characteristics. At PAPRO, New Zealand’s Pulp and Paper Research Organisation, jointly funded by government and the paper industry, scientists have been addressing this challenge over the last decade, and have come up with an interesting solution. Paul Kibblewhite, leader of PAPRO’s Fibre and Paper Group, explains:
“In New Zealand we grow radiata pine in a variety of geographical locations, all with slightly different growing conditions. Some trees grow quickly; others grow slowly, and this affects the shape and size of the fibres. The fibres also vary according to how old the tree is when harvested, and the part of the tree where the fibres come from. So within any pile of wood chips waiting to be pulped there will be a wide range of fibre types. We reasoned that if we could segregate the fibres into coarse, medium and fine grades, then we could target specific end-uses with specific fibres. Instead of throwing a mishmash of fibres into everything, we could separate out the shorter, finer fibres for higher quality grades, and keep the long, thick, absorbent fibres for the packaging grades, fluff pulp and fibre cement products used in the building industry.”
The strategy has worked. It has been adopted by all the pulp mills, and has been successful in opening up new products and markets for radiata pulp. Now PAPRO is looking at ways to reduce the energy levels required to refine radiata wood chips, and thus achieve a cost advantage compared with overseas pulps.
Says PAPRO director Terry Fullerton, “Even a saving of one per cent in energy utilisation can make a huge difference when you consider the amount of timber being pulped.”
Increasing the yield of chemical pulps is another project PAPRO scientists are working on. By introducing catalysts at key stages in the oxidation reaction that removes lignin from the fibres it may be possible to save more of the precious cellulose which at the moment gets washed away with the chemical reagents.
“The significance of this work will really start to be felt at the turn of the century, when radiata planted in the 1960s comes on stream,” says Fullerton. “New Zealand’s timber harvest will double, and there will be enough timber residues to supply at least five new mechanical mills around the country.”
That’s a lot of pulp. But as long as we continue blowing our noses on it, packing our goods in it and reading our news off it, New Zealand paper and its allies look set for a bright, though perhaps not dazzling white, future.