Again fermentation
Dear Philippe,
I had a deeper look into my own archives for fermentation dyes. It is like you said: for small tests or amounts,
done in the home kitchen, it is a nice alternative. How good it will be depends mainly on the experience that will
build up within years. For the carpet industry and for those who want to apply sustainable, ecologically optimized
methods for the textile industry the fermentation dyeing process is useless.
It depends on the amount of water-soluble primary substances in the plant that develop to be water-insoluble dye
stuff substances during the process. This substance then forms dye lakes
in the fiber. Therefore all dye substances that are already in this form in the plant (their amount is quite high
in old madder roots or in black Rhamnus petiolaris, Cehri) will not be effective in this process - and are lost.
Ecologically to put that high amounts of valuable dye stuff to the waste is no good idea. For this reason we work
with fermentation-type processes
, enhanced by enzymes, not in the dyeing process but one step before: the aim is to optimize the release of useful
dye stuff when the plant later, in a different step, is extracted. The second benefit is that unwelcome side products,
which makes the dye lakes more matt or
"dirty", decay to a high amount during these processes. To make a good extract one needs not only high
amounts of dye stuffs in the final product but also a high dye stuff : "dirt" proportion. - As for the
industrial application of natural dyes the low dye stuff content of most plants is the reason for high prices any
optimization of this aspect is important. But principally this low temperature system is a nice thing.
Regards
Michael
Dear Michael,
Probably, as you say, the low temperature is a good thing. Probably too , I guess, is a good thing to have not
at all ( for me ) or almost not ( if you consider there is some, naturally, in plants) metallic mordant, or in
a not significant proportion ( in weight ).
I read on you, if I remember or understand right, that you prefer indigo , when you make it with a fermenting vat,
than with the sulphuric way..
About the weight of the goods, necessary to die, I have no idea of what be seen in the industry.
But, with plants, I seemed to me that the weight of the dried plant ( sometimes, it is better with freshly picked
ones : weld for ex) was very often in a vague proportion with the weight of the wool : I call " in proportion"
when it is possible to compare easily - the weight of the two. ( perhaps 10 to 100 % ). Indeed, it means nothing,
it is only a rough idea.
It is not the same with cochineals, for exemple.
In every case, it is expensive: it is a real work to find in the ground 5 or 6 Kg of madder to make a large rug
( 10 Kg ? )...And, you have not to be in a hurry, to make the colour..
Perhaps you have an idea about the real proportion of pigments, everywhere. And, is it possible to have an idea,
in the industry of which quantity goes on the wool, or is lost ?
To have very good ( saturated ) colours, it is necessary to make the process of fermentation dyeing several times.
I think it is odd, but, it is, very often. It is the case also for indigo, and I do not understand well the reason.
The kind of the wools are also very important. I remember me making dyeing by the means of onions ( not a good
dye ) with an australian wool of the trade, and with an almost raw wool found in France : the first was yellow,
the second, orange, in the same bath...It is similar with madder.
Regards
Philippe
Dear Philippe,
to start with the end: your experiment has shown that the French raw wool absorbed the dye better than the Australien
wool, as the real aluminium dye lake from onion is pure Quercetin ( with a dark orange-yellow hue). There seems
to be something wrong with the Australian wool.
"Probably too , I guess, is a good thing to have not at all ( for me ) or almost not ( if you consider there
is some, naturally, in plants) metallic mordant, or in a not significant proportion ( in weight )." - That
is not up to you or me: you need a certain balance between the amount of dye stuff molecules and the amount of
metallic mordants to have a certain amount of dye lake formed. If you use more dye stuff than mordant this amount
will leave the fiber with the time, rendering your dye not fast against light. Too much mordant keeps the wool
to absorb a lot of different substances from the environment ( look at the bleeding problem with certain Turcoman
reds) and this lowers the fastness as well.
"I read on you, if I remember or understand right, that you prefer indigo , when you make it with a fermenting
vat, than with the sulphuric way.. " - Of course, but the point is not the fermenting vat but not to use the
extreme harsh hydro sulphite / caustic soda process without any redox buffer capacity which kills all the minor
components in any natural Indigo material.
"Perhaps you have an idea about the real proportion of pigments, everywhere. And, is it possible to have an
idea, in the industry of which quantity goes on the wool, or is lost ?" - No quick answer is possible as the
amount of dye stuff released from a certain plant depends on the extraction method. In order to be able to compare
things we calculated only in terms of
plant dry matter, never with fresh plants.
For fermentation dyeing with madder, which depends on the water soluble fraction of the dye stuffs in the root,
I guess that one needs several kg of madder per kg wool for a really saturated dye. But this depends on the specific
quality of your madder.
I guess that for safe fermentation dyeing one should always collect the own dye material with the own hands. Only
then one can be sure that the processes can be reproduced strict enough
- and it needs some decades of experience as well: experimenting, learning from own mistakes .... As it may take
years to test the light fastness without the expensive standard methods this know how grows, but in a slow manner.
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