Monday, May 20, 2013

Paper 1

I have only a couple days before I leave on my trip, and I wanted to get something else done before I left, so a quick attempt at paper seemed reasonable. This may seem more craft than chemistry, but filter paper is important later on, so I'm including it here.

Raw materials: Dry grass, Potash, Water
Tools: A boiling pot, heat, a screen 

So here's the dry grass. It's really dry. It's been sitting in a box for weeks or longer, waiting for a project to come along. Originally it was going to be compost carbon, then weaving material, but finally it has become paper pulp fiber.
1 meter stalks of dry California grass

Step 1: Remove the nodes

I am not really sure why this is necessary, but all the small-scale references insist on it. I expect that if you're doing large-scale crushing or boiling the nodes break down by themselves, but on this scale it's worth doing the pruning.

Break the grass up into lengths with no "inter-segment nodes". That basically means break off the little hard parts where branches or leaves come out. Here is a piece of grass with two nodes circled
Grass with nodes circled
And break out the nodes completely, leaving just the stem bit
Grass stems

I am very slow, so after 50 minutes, I had a single thick handful, which I deemed a half liter or so.
A handful (~500ml) of straight grass stems

Step 2: Prep the Alkali

50ml Potash
WARNING: Do not use aluminum containers when working with alkali. Hot alkali, under the right conditions, can burn right through aluminum. When combined with boiling water, flames, and caustic solutions, this can be bad. Use glass, ceramic, or stainless steel containers.

I made a solution of 50ml of loose potash in 1 gal of water.

Step 3: Boil

The handful above contains more than a little woody stem (not wanted) as well as dirt, dust, and other detritus we want to get rid of. Boiling in alkali will separate all of these things for us as well as preparing the fibers themselves. If we were going to bleach the paper, this is the point where we'd do it. I didn't have the materials, so I skipped that step and just did the boiling.

I had the stems in the alkali while it came to a boil. After about 30 minutes of boiling, the scent of the steam changed from grassy to distinctly sweet. I held it at a boil for 60 minutes total, replacing the water as it boiled away. After that hour I took it off the fire, poured off the alkali and replaced it with fresh water.

Step 4: Rinse and Crush

This is pretty straightforward. I'm trying to separate the fibers from the rest of the stuff without making them too short.  I used a round wood stick against a flat wood surface, and the stems split and mashed immediately. Even though the stems were still rigid, the fibers themselves were extremely pliable and soft. The integrity of the stems as a whole was entirely an artifact of their geometry as a tube. During the rolling, some individual fibers got caught on the rolling stick and wound themselves up along it providing a very nice yarn which could be removed with a fingernail. The average fiber length at this point was quite long: over 8 cm.

Step 4a: The plan changes

The length of the fibers and the fact that they weren't crosslinking (they were staying parallel) gave me pause. I took the stems out and they bent and flattened easily, but the individual fibers stayed attached to their bretheren on the stem until something else snagged them.

I decided to alter the experiment mid course: I cut maybe half of the fibers to a length of about 3 cm using a knife and reboiled them in plain water, hoping that this would separate them and let them entangle/mat/felt more.
Shorter fibers boiling

Still not convinced

I took handfuls of the fibers and crushed them between two rocks, hoping to see something that looked like paper. Either this is going to take much longer than I expected (multiple hours) or the fibers are way too long. Perhaps more research is in order.