Why not make paper from leaves?

I guess the subject says it all. Paper is basically crushed and pulped cellulose fiber; many tree leaves are fibrous; and tree leaves are a much more renewable resource than whole trees.

And this way (wait for it) paper really can grow on trees (ha ha).

:smack: Okay, for the purposes of this question, we can pretend I didn’t say that.

The fiber has to be strong enough to survive being cooked, among other things. My papermaking teacher one said that there’s a fine line between preparing fiber for making paper and making soup. Also, the fibers have to be long enough to tangle and weave in and out of each other.

Historically, paper wasn’t made from wood, at least in the West. It was made of linen, hemp, cotton, etc. Basically, the same plants clothing is made of. Making paper from chemically processed wood pulp is a pretty modern invention.

Japanese paper, like kozo (“rice paper”), is made from mulberry tree bark, not the actual wood of the tree.

Wikipedia say otherwise: <http://en.wikipedia.org/wiki/Rice_paper>
“In fact, it consists of the pith of a small tree, Tetrapanax papyrifer, the rice paper plant.”

I forgot to add that my favorite fiber, abaca, is made from the leaves of the banana plant. So it is done, but in hand papermaking, not commerical papermaking.

In this case, whoever wrote that article has no idea what they’re talking about. The paper that people usually call “rice paper” is made of mulberry bark. It is possible to make paper from rice straw, which I suppose could be considered rice paper, but that’s not what people mean when they say “rice paper.”

The process that article describes is not papermaking. Papermaking involves suspending prepared fibers in water, and then forming it into sheets. I would say that the process described in that article is more along the lines of making papyrus.

Oddly enough, the best kozo paper is now made in Iowa City, at the university of Iowa Center for the Book. They grow their own kozo, then harvest and prepare it. They use completely traditional techniques that aren’t even used in Japan anymore.

I’ve prepared kozo (albeit in a slightly less traditional manner, but still all by hand) from mulberry bark myself. I should edit that Wikipedia article.

It also helps to have long fiber to make a sheet strong enough to get through a paper machine. Much of the paper we use is a combination of long cellulose fibers (good strength - usually from something like pine) and short fibers (for good printablity - from various hardwoods).

That said, someone could probably make paper out of leaves. The process would have to be modified to make it work (expensive). Then the trick would be to get enough leaves of the right type to make the project viable year round. This is a problem with some seasonal plant sources. Leaves are light and bulky so transportation might be expensive.

Some companies chip up wood for making paper in the forest (field chipping) and then ship it to the companies by truck. Some time back someone said, “let’s try chipping whole trees” - wood, bark, limbs, leaves. It isn’t done much anymore because it introduced another variable into the process - some people brought in pure wood chips on one day and on other days whole tree chips would come in. Didn’t work very well. Short, weak fibers are often lost in the process. To keep them retained in the sheet takes advanced chemistry. Bark and other non-white items also have to be bleached so there is added cost for that process and the chemicals it takes. The whiter the fiber, the fewer chemicals required to get that nice, white paper people demand. A lot of wood fiber is very light in color.

So it gets down to economics - it’s easy to go bankrupt in the paper industry using the best and most efficient processes available. And it is a very capital intensive enterprise.

I’m not sure about handmade paper but it probably would not be a problem depending on how you liked the color and strength of the product.

Also IIRC leaves are a importaint composting material to regenerate the soil, removing them will either degrade the soil or require other fertilizer.

So will removing any other biomass to make paper out of it; what you’re describing is the nature of agriculture in general.

Wow, lots of replies, thanks! :slight_smile:

I was thinking about banana leaves, actually, as well as palm leaves. Plenty o’ fiber in them, and since they’re tropical plants, they can be harvested pretty much year round.

Another possibility I was thinking of is corn (maize) husks and stalks. The US generates a huge amount of corn each year; I would imagine that there is a lot of waste from the parts of the plant that don’t end up in the bag of chips.

Other people have already mentioned the unsuitability of the fibers found in leaves for papermaking purposes. Corn husks and stalks, called corn stover, does have some possibilities for papermaking uses, as does sugar cane waste, and some other annual plants, commonly called bagasse.

I’ve done some chemical analysis of some annual fibers. What you want for good paper is a lot cellulose, a glucose polymer. Hemicelluloses, formed of arabinose, galactose, xylose, and mannose, are less desirable, and most of them are lost in conventional pulping processes. Annual plants are pretty high in hemicelluloses for good yields, but as wood prices increase, do start to look more feasible.

The big issue is year round availability. Building a large greenfield pulp and paper mill would cost in excess of a billion dollars, and no one is building small paper mills these days. It takes the nearly the same labor cost to run a 3,000 ton per day mill as a 1,000 ton per day one, so the economy of scale makes 1,000,000 ton per year mills more attractive.

With wood, approximately 50% of the weight of the wood coming in is water, and 50% of the weight of what’s left is lignin, which you’ve got to get rid of, so you’ve got to bring 4,000,000 tons of wood in per year to make 1,000,000 tons of paper. Bagasse has a lower yield and higher water content than wood, so assume 6,000,000 tons of bagasse per year.

Okay, say for instance you’ve got 6,000,000 tons of bagasse. That’s the corn stover production of Wisconsin. But corn stover is only available at harvest, in the fall. You’ve got to be able to store the supply for the entire year, and store it in a way that won’t allow the cellulose that is present to degrade.

I don’t have bulk density numbers on hand for corn stover, but I doubt that it’s denser than wood chips, which average around 11 pounds dry weight/cubic foot. At that density you’re talking about cube of plant waste over 1,000 feet on a side. At it’s angle of repose it’s going to have a much bigger footprint, I don’t know exactly how much bigger, but it’s going to be big.

Add to this that the per dry ton harvesting, baling, and delivery costs for corn stover approach that of wood, and corn is not a reasonable supply of fiber.

The same goes for hemp, by the way. Put down that hacky-sack and pay attention, you damn hippies.

Paper can be made from *any *fibrous substance. “Rice paper” originated in China and was indeed made from rice but the name was also applied to the paper made in Japan. which the Japanese call washi. Washi is made usually of kozo-paper mulberry, mitsumata or gampi. Washi can and is made also from other plants including rice but these tend to be in a mixture with kozo.

The article in WIKI should be revised.

You guys made me think while I was on the throne. Could toilet paper be made from leaves? Doesn’t need to be as strong, various colors acceptable…
And, of course, once it was…