This is the full transcript of episode 4 of my podcast Conscious Communication Design:
What is paper?
Paper is a material manufactured in thin sheets from the pulp of wood or other fibres, and used for writing, drawing, or printing on, or as wrapping material.
Although many of you will have designed packagings also, paper used for packaging has other requirements than Graphic paper, especially if used for packaging foods, there usually needs to be a barrier, which is created as a bond or coating on the paper. This is to protect both the food and the paper from one another, especially when grease or liquids are involved.
The categorisation of paper products is diverse, depending on who you ask. We can differentiate between Graphic Papers, which includes Newsprint, printing and writing paper, Packaging paper and board, which also includes corrugated paper like for boxes, hygienic paper, which are mainly tissue paper, and Industrial and special papers, for example for money, cigarette paper, tickets, etc.
Paper accounts for 2.5% of industrial production 2.0% of world trade.
Paper consumption is related to population and to wealth, so the richer a nation gets, the more paper they consume.
The production of one kilogram of paper emits about 1.15 kg of CO2.
Around 80% of all products sold in the United States and the European Union are packaged in cardboard.
Paper use increases year on year and has quadrupled over the past 50 years. In 2014, global paper production hit 400 million tonnes per year for the first time2 (ironically the same year that atmospheric CO2 levels exceeded 400 parts per million). More than half of this paper is consumed in China (106 million tonnes), the USA (71 million tonnes), and Japan (27 million tonnes), with a further quarter in Europe (92 million tonnes). The entire continent of Africa accounts for just 2% of global paper use, consuming a mere 8 million tonnes per year. Oceania and Latin America between them account for around 8%.
Let’s have a look at the per capita consumption: The global average is 55 kg per person per year. North American consumption is four times that (215 kg) while the African average is just 7 kg. China’s average per capita consumption is just higher than the global average at 76 kg. Eastern European levels are similar to China’s (77 kg) with the Western European average being almost double that (147 kg). Seven of the ten countries with the largest per capita consumption are in Europe.
1 ton of uncoated virgin (non-recycled) printing and office paper uses 24 trees. A “pallet” of copier paper (20-lb. sheet weight) contains 40 cartons and weighs 1 ton.
Paper waste accounts for up to 40% of total waste produced in the United States each year, which adds up to 71.6 million tons of paper waste per year in the United States alone. The average office worker in the US prints 31 pages every day. Americans also use an average of 16 billion paper cups per year.
Conventional bleaching of wood pulp produces and releases large amounts of chlorinated organic compounds into the environment.
This includes chlorinated dioxins, which are a persistent environmental pollutant, regulated internationally by the Stockholm Convention on Persistent Organic Pollutants. Dioxins are highly toxic and can lead to reproductive, developmental, immune and hormonal problems in humans. And they are carcinogenic. We are exposed to these dioxins mostly through the consumption of meat, dairy and fish because dioxins accumulate in the fatty tissue of animals and that’s how they enter the food chain. If you didn’t have enough reasons yet to reduce your meat&dairy consumption – there ya go!
But that is conventional bleaching, there are other methods, we’ll talk about those in a bit.
The paper pulp and print industries together make up about 1% of the world’s Greenhouse-gas emissions. The industry has substantial climate change and environmental impacts, from its raw material sourcing in forests, through production, to the end of life of its products. So there are great opportunities for reducing greenhouse gas emissions through better land management and fibre choices. Wood fibres aren’t the most economical when we consider the time trees need to grow and the space they need. But while new technologies and developments in utilising speciality fibres are always hyped, I think we should always, always consider what grows best locally, and also the environmental impact of growing that crop, apart from just GHG emissions and land use, we need to consider biodiversity as well.
Looking at the recycled content in paper, that is relatively high and estimated at about 50% newsprint and packaging, but printing and writing paper has a global average of only 8% recycled content. So there is still much room for improvement. By more effectively controlling contamination and implementing more robust recycling systems in developing countries, the amount of recycled fibre that could be used could still be nearly doubled before it reaches the upper limit of technical potential.
Because one thing we need to keep in mind is that fibres always shorten when they are being recycled. So in order to use fibres from Post Consumer Waste, they need to be mixed with virgin fibres. The longer the fibres, the stronger the paper. Recycling shortens the average length of fibres. At some stage they’ve reached their end of life, at the last stage, they can become toilet rolls, as in the carton bit in the middle on which the tissue paper is rolled around. That’s why these shouldn’t normally go into the recycling bin, as these can’t be recycled anymore. But you’re best to check with your local recycling company to confirm this.
What is pulp and what is paper?
Tree trunks = wood
Wood = Fibers + Lignin (glue)
Pulp = Loose fibers in water
Paper = dried pulp in sheet form
A tree consists of about 25% branches and bark 75% trunk wood → logs
On an acre, you can grow approximately 16-20 mature trees.
A wood log contains about 27% lignin (glue) 73% fiber (what goes into paper)
Every tree requires 130 gallons (490 L) of water for growth
50 gallons (189 L) of water for processing into paper
The first step in paper making is pulping. It can be done chemically or mechanically. In chemical pulping, the so called “kraft pulping” process is mostly used. It has the advantage that there’s a chemical reaction happening with the chemicals added and the lignin, and that produces heat. So this heat can be used to run generators, and is often used to power the other machines involved, like the paper machine. The process also recovers and reuses all inorganic chemical reagents. But what happens here is basically that they add a cooking liquor into the pulp, that dissolves the lignin and than all that is washed out.
Chemically pulped paper is also called wood-free, which I find particularly confusing. But it really just means that the lignin is removed.
Because in mechanical pulping, the lignin stays in the paper. There is two different processes in mechanical pulping, the logs are is either chipped and then refined, or they go directly into a massive grinder. Mechanical pulping has a much higher yield, over 95% actually, but the downside is that the fibres are much shorter, which means the paper isn’t going to be as strong, and the lignin in it means that the paper is going to go brown, so it doesn’t age well.
Now that we have the pulp, we can add stuff. There’s a long history of adding stuff to pulp. Traditionally those are starches, chalks or china clay, but also chemicals. These additives are either put directly into the pulp, so before the sheets are formed, or are added later, as surface sizing or coatings.
The pulp goes on a mesh and the water is squeezed out. And then the whole thing is dried with a steam dryer. This all happens in the so-called paper machine, which produces very, very large rolls of continuous paper which can later be cut into sheets.
Once we have that dried paper, there may be a layer of sizing added, or the paper is coated. Both has the intention to make the paper useable for printing and drawing on. So it changes the way the ink reacts with the surface of the paper.
In my research that I briefly mentioned in the first episode where I introduced myself, I did a comparison study between two different sizing ingredients. I obviously didn’t know much about paper, or science for that matter. But I wanted to get a better understanding for both. And I was very interested in paper finishings, so the sizing and coating, what kinds of chemicals go into it and how that affects the recyclability of the paper as well.
So I’m going to explain the study I did to give you an idea of the complexity of analysing print paper products for their environmental impact.
I’ll explain this in layman terms though, as there’s no need for fancy academic jargon at this stage.
I did an Environmental Sciences Masters, a one year programme in Trinity College Dublin. Why would they let someone like me into a science programme, you may ask? It was designed in a way that they would allow for a percentage of students from a non-natural sciences background, so there were a few other blow-ins like myself. It was obviously tough, as I literally suck so bad at chemistry and physics that I don’t even know the basics. But I somehow managed. And after countless jampacked weeks of learning how to measure the health of soil and water and climate changes and things like that, we got to write a thesis. In a kind of last-minute thing I applied to do a project with the Papiertechnische Stiftung in Dresden.
That translates as Foundation for Paper Technology. They are an institute that does research on paper! It’s partially state-funded and partially funded by industry. So they can do lab tests on the specific properties of papers, or analyse their printability or recyclability, and loads more.
For me, this was heaven! Obviously, the people there are academics or lab technicians with an advanced background in chemistry, so it certainly wasn’t easy for them to deal with someone like me!
But they helped me set up this comparison study, where we came up with a conventional sizing recipe, which includes polyDADMAC, which is a high charge cationic polymer. But that stuff is derived from non-renewable resources and we also suspected that it would negatively impact the deinking process. That’s the stage within paper recycling where they put in other chemicals with the pulp which separates the ink from the printed pulp in order to wash it out.
My study couldn’t prove that the latter was the case, the deinking worked fine. But anywho, this bad bad polyDADMAC stuff is used in paper sizing because of its cationisation. That’s something you need in order to print on it.
It’s a bit anticlimactic in real life, as it’s just a clear liquid. And not visible once applied on the paper. But in order to test this, we created a second recipe that just included a cationic starch. So that would be better for the environment, – all natural.
So we had these two liquids, one conventional, one eco-variation. We applied those onto a test substrate. That’s all done in the lab and by hand. Those papers were then measured and compared with another.
The application for these sized papers would be in inkjet printing. You need different papers, and different coatings for different print processes.
The way the printability was tested was through a range of lab tests. Those included Code verification, ink and calcium chloride penetration depth measurements, Mottling,- Bleeding and Wicking calculations, print density and colour analysis.
I won’t bore you with the details, although I have to say for me this was some of the most fascinating stuff I ever got to experience! But there’s a whole range of stuff that can be measured, there are test patterns that you can print and then look at the patterns under the microscope, but we also looked at the sizes substrates – always in comparison to base paper, which has nothing on it, even under the Electron Microscope, where you can see the actual particles clinging onto the fibres.
Overall, my eco-recipe didn’t do the job, in some tests it performed ok, especially in how the ink looked, so the sizing created a good barrier, which means that the ink stays on the surface, where we want it to be. But my eco-recipe took too long to dry! On average 1394.7ms. So that’s one and a half seconds. Ish. And that means that in an industrial printer, it would smudge.
Also good news was that both papers did ok in the deinking test, so they recycled ok.
To summarise: we probably need all this stuff in and on our paper, as we want to be able to print on it. But there needs to be more research done on the environmental effects of these chemicals. How they are being produced, and how the wastewater is treated in recycling mills.
There’s a shit tonne we should know about paper, so this is just the start!
What are your thoughts on paper? How relevant do you think LCA of paper products are to your work?
Help me spread the word about this podcast, so that we can have a discourse, and this doesn’t remain a one sided communication. You can get in touch with me through twitter or instagram, the handle is @ccdbylisa in both.
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I’ll talk to you next week, where I’ll continue with the introduction to paper, and go into the history and tree fibre alternatives.
Until then, thank you for listening and take care!