Re: [papercreters] Re: Insulation Value

Two issues with this. First is the amount of soap one needs to use to get good foam. Then the settling/draining issue of the slurry. The foam tends to follow the water. I tried increasing the foaming using glycerin. I did not have much luck with it and increased the cost of the material. You may get a 5 gallon bucket of material to do what you want, but when you up-size it it goes to pot. The aerators you are thinking about are foam generators. They are commonly used to foam AFFF fire fighting foam.  Hope you had better luck with it than I did and who knows, you may find the trick.

mountainfair <yahooposting@dreamthefuture.org> wrote:

Speaking of insulation value, has anyone here tried foaming their
papercrete?

I have read about using mixers that aerate the mix as well as adding
dish soap to the mix to foam it in order to achieve higher R values.

One site mentioned using an additive to speed the setting time of the
concrete so that it would set before the bubbles settled out.

Anyone experimenting with this?

-Eli

--- In papercreters@yahoogroups.com, "slurryguy" <slurryguy@...> wrote:
>
> It's time to talk about papercrete's counter-intuitiveness again.
>
> I've tested relative R-Value with a homemade calorimeter.
> I described the apparatus and testing method in this previous post:
> http://groups.yahoo.com/group/papercreters/message/45
>
> My results indicated that compressing the slurry into the form
> INCREASED the insulating properties. The more a sample was
> compressed, the higher the R-Value. My most compressed sample was
> compressed by driving a front tire of pickup truck wheel on top of
> the form. I estimate it was greater than 400 PSI compression.
>
> While I think it may be possible to compress wet uncured papercrete
> so much that it will start to lose R-Value, I don't think it is
> PRACTIAL to overcompress it in a DIY environment. My wild
> undocumented guess is that one would need to compress the wet slurry
> to thousands of PSI to crush the paper fibers enough to start
> decreasing insulation properties.
>
> My sample size in these tests is small and I certainly haven't tested
> every possible combination. It takes time and attention to detail to
> run a calorimeter test and get good data. Calorimeters are fiddly to
> use in the best circumstances.
>
> My theory to explain this phenomenon is that the best insulation is
> achieved by trapping air INSIDE the paper fibers. Loosly hindering
> air flow BETWEEN fibers is only moderately effective. I think
> compressing the slurry tends to push the fibers closer together which
> significantly reduces the permeability of the final product to air
> infiltration. I also theorize that micro convection currents are
> greatly diminished by the denser fibers.
>
> Keep in mind that almost all papercrete with significant paper
> content will have higher insulation value than fiberglass batts.
> Also remember that cellulose insulation manufacturers list "packed"
> cellulose insulation to have a higher R-Value than "loose"
> cellulose.
>
> Another point to remember is that the higher the mineral content of
> papercrete the lower the insulating value will be. A balance between
> strength, weight, and insulation is appropriate. Different recipes
> of papercrete for different applications make sense.
>
> The idea that compressing insulation hinders performance applies
> primarily to fiberglass batts. Fiberglass fibers are solid glass
> rods. Compressing the batts pushes out all the air. Compressing
> cellulose only pushes out the loose air. The trapped air inside the
> paper fibers remains.
>
> I estimate that a mix ratio of 1:2:1 paper, portand, sand, can reach
> R4 with very tight slurry compression. I haven't run any calibrated
> tests to determine if this is correct. I'm very confident that a mix
> ratio of 1:1:1, paper, portland, sand will go well above R4 with
> slurry compression. Perhaps as high as R5. Again, I haven't done
> any calibrated tests to prove it.
>
> --- In papercreters@yahoogroups.com, "mdumiller" <mdmiller1@>
> wrote:
> >
> > I haven't tested this theory, but I think the amount of water
> > reabsorption of cured papercrete is related to the amount of
> original
> > water in the mix as poured/used. As the water evaporates from
> curing
> > PC, creating airspace voids in the pC, rewetting will tend to
> permit
> > water back into these itsy spaces. The fibers are probably encased
> > in portland and don't absorb much, which is why a block that is
> > rewetted dries so quickly.
> >
> > I'm guessing that if you took two identical just-poured pc blocks
> and
> > squeezed all the water out of one of them and let them both dry,
> the
> > one with the water squeezed out is smaller and of higher density
> and
> > probably won't absorb as much water. It contains less air space,
> > even though they both contain the same amount of paper and other
> > material.
> >
> > On the other hand, if you don't put in enough portland to coat the
> > fiber, then the paper fibers themselves will saturate and become
> part
> > of the equation, and in this case, I think you're right.
> >
> > In situations where you expect to have PC exposed to a lot of
> > moisture, based on this theory, it would be wise to compress the
> > blocks while wet to eliminate water. Obviously this could impact
> the
> > insulative properties of the finished product. And this is just a
> > theory, so don't do anything based on this untested crazy idea.
> >
>

---

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