| I've been making paper adobe and paper blocks out of cardboard mixed in the usual papercrete manner with a tow mixer doing the pulping. I make the paper blocks using my forms I use for the paper adobe, 12"X16"X6". I find that the paper blocks shrink more than the ones with clay in the mix but not that much as I squish the mix into the forms and when some of the water has drained away top them off with more mix and level the tops. I lhave a large sheet of heavy plastic tarp nailed to the ground and I place the forms on this which enables the water to run off rather quickly and doesn't create a big mud hole. I pull as much of the plastic off the cardboard as is feasible when I stack it but there is always quite a bit left to deal with. I leave this plastic tape in the blocks as I feel this material will help bind the blocks together. I try to put it in the middle of the blocks and work it in the mix and away from the edges but on occasion some will find it's way to the edges but is easily trimmed away. I use this method with the larger pieces of cardboard as well as there is always some that hangs up on the front of the blade and stays in bigger chunks. The paper adobe blocks made in the forms described above shrink to approximately 5"X11"X15" while the paper only blocks shrink perhaps 1/4 to 1/2" more on all sides. Soaking the cardboard is almost a must as it is quite tough and resists the pulping operation much more so than newsprint, especially large multi layer boxes. The blocks made in this manner do take a long time to dry, but once dry they are as strong as the paper adobe blocks I make using clay as a binder and they are lighter. I live in a very hot dry climate (SW Arizona) so this works in my favor. I also have a lot of room to spread out the blocks while they are drying. I bought some boric acid online and I am going to spray this on the surface of the blocks for fire retardancy. I will have to experiment with this and may have to add it to the mix. The blocks themselves will burn but I believe in a wall where the air can't get around the entire block it would be like a slow smolder. Even out in the open the burn is still a smolder so I think the fire issue can be resolved. I will try and post some pictures of my operation.
--- On Sat, 6/4/11, Wayne <huon@intas.net.au> wrote:
From: Wayne <huon@intas.net.au>
Subject: [papercreters] PPB's
To: papercreters@yahoogroups.com
Date: Saturday, June 4, 2011, 11:28 PM
PPB's or Pure Paper Blocks are the most lightweight building product I
have come across. In simple form you just mix paper to a pulp with water,
pour into moulds and let dry. Sounds easy but as with many things the
devil is in the detail, so prctice and experimatation is the key.
1. The Pulp.
I use a horizontal style cement mixer and a thin soupy mix. This allolws
the wood fibers to be teased apart gently. Toss any paper/cardboard whole
into the water, but cardboard will benefit the most from pre soaking. I
piock out the stickytape/plastic from the mix after it has separated.
Once the pulp has no chunks of paper left visible it can be poured into an
old bath or similar vessel for thickening. Thickening is simply a matter
of letting the pulp settle and the excess water run off. A large bucket
works well for smaller amounts. As each batch settles the next one can
gently be poured in to push the excess water out.
2. The Mould.
This is where it gets a little bit harder. A simple brick muold can be
made by building a square from timber and sitting this on a mesh base.
Line the mould with a piece of cloth. More complex designs require more
complex moulds, but the main thing to remember are that you have to allow
water to escape and you have to allow alot of settling room. For example
I use a 4" thick flat mould to make a 1" thick flat panel. A 10" tall
mould will make about a 4" tall brick but it does depend on the thickness
of your pulp.
3. Drying.
Allow the poured mould to drain (over the thicknesser if you want to
recycle the water) for 24hrs. Then set it aside out of the rain to dry.
This can take months for a larger pour, or can be sat near the wood heater
over winter to speed up smaller pours to a few days drying time. As the
block dries it will shrink away from the mould. Once dry to a firm touch
the cloth liner can be peeled off for use in the next mould.
4. Imagination.
This is the key ingredient. As an example of product I have a square
timber mould 24" x 24" x 4". I sit this on a piece of galvanized mesh
with 4" squares. Lay a piece of old bed sheet over the whole thing and
pouir in the pulp. When dry I peel of the cloth to reveal a smooth panel
with a soft squared pattern that makes an intersting wall board panel with
fantastic insulating qualities. It can be nailed, screwed or glued. It
will hold a plaster screw better than plaster. It can be screwed or glued
to a beam made from pulp. It can be sawn (the sawdust from this is a
light fluffy cotton wool like product that is a great fill insulation).
It has good soundproof ability. If you add borax powder it can be made
insect proof, rodent proof and FIRE PROOF!!!!
This may be a little of topic but this is the closest group I have been
able to find for learning and building with pulp.
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