Dead Wool
Hi John,
Ill take the wool subject.
Dead sheep wool has a
reputation for being dry, brittle and lacking of luster.
I dont know if it
is the same for American wild white goats.
It seems, though, that even if
that wool was dead it had no consequence on the durability of the
textiles.
How old are the earliest Chilkat Dancing Blankets still
surviving?
Best regards,
Filiberto
Hi Filiberto -
I actually thought that the "dead wool" issue would be
a real "lightning rod" for some folks here, since it is so denigrated among rug
collectors. I need to dig out some descriptions, but it is clear that the
literature sees "dead wool" as the lowest of the low.
I think, though,
that the root of this objection may in fact be in the methods used to remove the
wool from the hide. Apparently it is these that damage the wool severely. It
would be nice to have some one with a knowledge of chemistry speak to the likely
sources of wool damage during removal. The Chilkat method is detailed in the
salon essay, but the character of the substance used is not specifically
indicated.
But to your question. The oldest Chilkat weavings were
apparently collected during the three voyages to that area by Cook. These
occurred in the late 1700s. The transitional piece below (also shown in the
salon essay) was collected by Cook during his third voyage.
Regards,
R. John
Howe
Hi Guys
I wonder how much substance there really is to the "dead wool"
belief that is widely accepted among collectors. Once the wool is off the
animal, as nearly as I can tell, it's pretty stable stuff. That is, you can
stick it in a bag and use it at a much later date and everything is just fine.
That being the case, why should it matter if it is still on the skin of a dead
animal for a long time before being shorn and used? That is, what do we suppose
happens to it as a result of being attached to a dead animal that doesn't happen
to it when it is not attached to any animal at all? I can't think of any
sensible answer to this (but that doesn't mean that there isn't one, of
course).
Regards,
Steve Price
Steve -
That's why I mentioned the method of removal.
Here's
what Eiland and Eiland say"
"Another concern is the method by which the
wool is removed from the sheep. Several processes other than the usual shearing
have been developed in which the wool is removed chemically from dead animal
skins. This 'skin' wool, is scraped from hides after then have been immersed in
caustic solutions, and it is usually significantly weakened in the process. Such
wool is cheaper than shorn wool and is readily available in some markets. Not
only have the natural oils been removed, making the wool more brittle and less
lustrous, but the wool may also be more difficult to dye because the hair
remains intact, with a hard surface not only along the shaft but at both ends.
Thus the dye does not penetrate so easily into the interior of the fiber. When
wool is cut, dye enters more easily though the break in the surface of the fiber
than it does through an intact membrane. Rugs made from skin wool ofen have a
flat, lusterless tone. However, the difference is subtle; so it may be difficult
to detect the presence of skin wool on a rug."
I wonder whether the
chemicals used in removing the wool from the goat skins by the Chilkats are less
damaging to the wool in the process. There is no hint in the descriptions of the
resulting wool that suggests that it is brittle at
all.
Regards,
R. John Howe
Dear folks -
Steve Price's indication above, reminded me that I too
have often been skeptical of seeming distinction in the literature between shorn
wool and that taken from a dead animal. This skepticism is based first on some
commonsensical personal experience that seems analgous.
Notice that human
hair above the skin can be cut without its owner experiencing pain. Must mean
that there are no nerves implicated in hair above the skin line. And there is no
resulting blood either. Would seem to suggest that human hair above the skin
line is dead in some sense. Still something is happening below the skin, since
it continues to grow. And there is real pain when someone pulls on one's hair,
indicating that there is nerve engagement further down.
So I looked
around on the internet for some more technically grounded information about
human hair.
Here is what one site said:
"...Each hair on your body
grows from a hair follicle, a tiny, saclike hole in your skin. At the bottom of
each follicle is a cluster of special cells that reproduce to make new hair
cells. The new cells that are produced are added on at the root of the hair,
causing the hair to grow longer.
"The living tissue that makes your hair
grow is
hidden inside the hair follicle. The shaft, the part of a hair that
you see, is made of cells that aren't living anymore."
They provide this
image:
A
micrograph of a hair shaft. Note the layered cuticle on the shaft and the bulb
at the bottom.
--Micrograph courtesy of Paula Sicurello/U.C. Berkeley
Electron Microscope Laboratory.
Next I looked around for some indication
about wool itself. Here is what another site indicated:
"...The woolen
fiber has two parts, the root, which is living right
below the surface of the
skins, and the shaft which is the dead fur-like part of the fiber that we,
humans, see."
They also provided this graphic, the labeling on which I
cannot sharpen:
It may be that the title of this thread caters, inadvertently,
to the distinction in the literature between shorn wool and wool on/from a dead
animal. All wool above the skin line is dead. Any distinction about the quality
of shorn wool and wool on/from a dead animal must have another basis.
Now
it may seem that I have gone on a bit here about something that is pretty
obvious. But the strength and persistence of the distinction between shorn wool
(the richness of the lanolin and all that) and wool on/from dead animals is such
that a detailed factual confrontation is needed.
Regards,
R. John
Howe
wool quality ...
Hallo everybody, dear R. John Howe,
first a big Bravo for Your
nice presentation !
Now to the question of how to prepare the wool. To use
dry ( specially
dehydrated clay ) is a common thing not only for the Indians.
As this clay is
highly absorptive both for water and (!) fatty materials one
can use it for a
kind of "dry wash" of hairs. I remember that I used this
sometimes when I was
young. Whether this material is still commercially
available here I do not know.
"To remove the wool from the hide, the
skin side was
wetted and the hide sidethen rolled and left to set for several
days. The roots
of the fibers wouldloosen during this time so that the
fleece would readily
release from the hide."
You put the question
whether this process would affect the wool quality.
ofcourse can be
the only answer. But to which extent - and what happens ?
At that point
within the hair where no living tissue remains the wet conditions
leads to a
kind of fouling and the hair then can be removed
from
the skin.
A constant inner red line of our ( Memduh Kürtül and me)
contributions
here is to stress that and how industrial processes aim
at reducing the
amount of human labour on the expense of
quality. This is an
excellent example:
- instead of a several days
consuming soft process one may substitute it
by using strong alkali
plus strong reducing agents ( like sodium sulfid ) at it
is done in the
leather industry. One may remove the wool now in a short time -
but the
damage to the wool's integrity and its lustre is much stronger.
- in case one
uses a bit softer alkali and a bit less strong reducing agents one
has the
process that is applied to 99.9 % of modern carpets: the
chemical washing process.
Therefore these new items are
dead ...
There is, according to the best of our knowledge, no
reason to assume that there
is a kind of metaphysical "hidden life" in the
wool hair. To cut the wool with a
sharp knife some minutes after having
killed the sheep would most likely not
affect the wool integrity. But this is
an academic question only. Skins are
collected for the leather industry - and
this alone is comparable to the process
of wet fermentation that you
discribed here. And if then later the strong
active material is applied =>
good bye to wool quality !
Yours sincerely
Michael Bischof
HI Michael,
Thanks for checking in.
I know some sheep are first
led through the mud before shearing. Think this helps the hair to become more
soft and less sticky.
Do you think hair gets dyed inside, after it is
cut? Isn't hair dyed because molecules attach?
And what about
death-stress?
All kind of chemical reactions the body sets in motion, the
moment death is at the doorstep?
Because if dyes DO get inside, cut "dead"
hair, it seems logic that the same can happen if the hair is attached to the
skin?
Best regards,
Vincent
Hi Vincent
I believe indigo only coats the surface of fibers, while
most other dyes penetrate. My guess is that the outer surface usually gets a
heavier load of dye than the innermost part. Michael can speak to this with
authority.
As for "death stress", nothing that happens in the animal will
happen in the hair or wool except at the very small living zone at the base of
the hair (or wool). The rest is dead, with neither nerves nor a blood supply, so
there is no route of communication or transfer of material (chemicals) between
it and the animal. If chemicals get inside cut hair and wool (and I'm pretty
sure most dyes do), it's because the hair or wool is immersed in those chemicals
when it is being dyed.
Regards,
Steve Price
Like Modulation, Except Completely Different
Hi All,
The term you're all grasping for (you didn't know you were
grasping, did you..
) is
MEDULLATION, which is: the degree to which a wool fiber is medullated.
Medullation is why shorn wool takes up dye better than plucked wool. Medullar
fibers have linear voids internal to the fiber which, in combination with
capillary imbibation along internal cells and underneath exterior scales,
provides a pathway for dyes to penetrate beneathe the exterior of a wool
fiber.
As you might expect, the Aussies have studied wool to death, and
have a great page on BREEDING CARPET WOOL FLOCKS here:
http://www.agric.nsw.gov.au/reader/wool/a312.htm
A
concise discussion of medullation, and nice images, can be found at:
http://www.sgs.com.au/services/wtsServices/pdfFiles/Info-bulletin5.4.pdf
Regards,
Chuck
__________________
Chuck
Wagner
medullation - dead wool ...
Hallo everybody, hallo Chuck,
thanks a lot for these nice additional
informations !
Yes, this is what I meant: there is no reason to assume
any effect to non-living parts of the wool fiber - but in case it is separated
from the skin using harsh methods the fiber is damaged.
Damage makes dyes
penetrate easier...
Another thing with sheep wool is
kemp.
Thick white hairs that do not take up dye as easy as wool fibers
do. To dye them to a sufficiently saturated level so that the yarn that contains
kemp does not look "poor" from having a visible amount of undyed thick
white
fibers in it is a real headache. The Civit dye house in Konya masters
it but in frank words: to burn the ready carpet a bit stronger and then run a
higher amount of chemical washing ingredients over it is the cheaper solution
for todays chuckle...
Unfortunately in the Orient there is not much
grading of wool shorn from different sheep left and no longer a systematic
optimization in breeding against kemp - as the wool prices are that low.
Yours sincerely,
Michael Bischof
Hi Chuck -
I'm going to go very slowly here because I want to
understand this.
I looked up "medula" and it seems refer to the "inner
core" as in the marrow of a bone. There is a related term "medulary sheath" that
is also denoted by "myelin" and which refers to "a white fatty material encasing
some nerve tissues." So there seem usages of medula based terms that refer to
the core and some that refer to something that surrounds the core.
Eiland
and Eiland in the passage quoted above seem to accentuate the importance of
getting dye through the cut ends into the core of the wool fiber. They say
regarding "skin" wool:
"...the wool may also be more difficult to dye
because the hair remains intact, with a hard surface not only along the shaft
but at both ends."
This suggests to me that they see the advantage of
shorn wool to be that it has openings "at the ends" (cutting the wool will not I
think affect the shaft) that permit the dye to enter the core of the wool.
Apparently, "skin" wool has both ends of each strand still closed in some
sense.
If I am reading it correctly, your own definition seems to allow
for wool (that has medulation) to absorb dyes not only through the cut ends but
perhaps (and I am not sure about this) also under the "scales" along the shaft
of the wool fiber.
Here is the relevant passage:
"...Medullar
fibers have linear voids internal to the fiber which, in combination with
capillary imbibation along internal cells and underneath exterior scales,
provides a pathway for dyes to penetrate beneathe the exterior of a wool
fiber."
This latter species of medulation would seem unrelated to whether
or not wool has been shorn. Wool has or does not have medulation in some degree
regardless of whether it was taken from a live animal or from a dead one. The
fact that medulated wool has a core that might be made accessible by cutting,
would be relevant, but any species of medulation that might make entry of dyes
possible at the sides of the shaft of the wool fiber, would not, since this
would not be affected by cutting.
We might want Michael Bischof, if he is
willing, to sort us out a bit regarding his understanding of whether dyes are
taken into wool fibers only at the cut ends or through the sides or
both.
Regards,
R. John Howe
Hi John,
Your confusion is due to a lack of clarity on my part.
Medullation is a term dealing strictly with phenomenon occuring in the interior
of the wool fiber having to do with long void spaces between
cells.
Capillary imbibition has to do with surface tension effects on
fluids, and is very much dependant on the fluid type and the size of the gap
between the surfaces being penetrated by the fluid.
It may well be the
primary means by which dyes penetrate the fiber, whether through a medullar void
or along surfaces of long cells that have been disturbed by shearing or wool
processing.
Any capillary imbibition of dyestuffs between overlapping
scale cells is an exterior phenomenon and is unrelated to medullation.
I'm
not stating for certain that this occurs, but it makes sense from a surface
electrostatics point of view. If it does occur, one might expect that flexing of
the wool fiber might cause abrasive wear on any dye material between overlapping
scales
And, Michael, that lack of attention to wool details is why the
Afghanis and Pakistanis use "Bel-jee-kee" (Belgian) and Australian wools on the
Khal Mohammadi rugs instead of local wools.
Regards,
Chuck
__________________
Chuck
Wagner
Medullation
From my understanding of Chuck's links medullation is a nice way of saying
kemp. Or is the word "kemp" just a garbage-can catchall term which includes
medullation?
If the carpet industry wants, as the Australian government
site says it does, lackluster wool with a minimum of 20% medullation, aren't
they just looking for wool more durable so their chemicals won't destroy
anything worth destroying, that is, wool which has already been destroyed? It
appears to me, from the pictures in Chuck's second link, that the rug industry
coveted gene for medullated fiber is defective, a genetic FLAW producer.
Michael, am I wrong?
Lest we forget -- hairs which have not been immersed
in chemicals post-mortem retain chemicals it's growers, sheep, have been exposed
to while living, too. There is a whole pharmacopoeia, the Australian government
site urges use of, prepared for the peripheral consequences of destructive
animal husbandry practices. Thank you Chuck and Michael, for providing
enlightenment on the circle jerk. Sue
Hi Sue
My understanding of the link Chuck gave on medullation is quite
different than yours. If I read it correctly, there is an optimum degree of
medullation for carpets that gives high resistance to abrasion and high
resilience. I didn't see anything in there about resistance to chemicals used in
dying, and I don't think they are generally destructive to wool (except for some
corrosive dyes that have been pretty much abandoned for about 100 years now).
I doubt that there's much in the way of low molecular weight compounds
in wool that wouldn't be washed out in the dying process whether the wool was
exposed to things to make it easier to get off the animal's skin or not. The
destructive effects of some washes are almost certainly on the water-insoluble
protein that makes up the bulk of the fiber. (How do we know it's
water-insoluble? Easy. If it was water soluble, the pastures would be full of
naked sheep after every rain.
)
As for the genetic selections being for flaws, of course they are.
Modern sheep are the result of centuries of selection for wool of specific
qualities, and the animals in the flocks of shepherds 2000 years ago wouldn't
have lasted long in the wild.
Regards,
Steve Price
Dear folks -
Although I am convinced that many of the activities of
industry are dysfunctional for a number of aspects of human life, that is not
what I'd like to get clear about here. Let's leave the ideology aside for the
moment.
I would still like to hear from Michael Bischof about whether dye
is absorbed only through the ends of wool fibers or also "under the scales" so
to speak along the sides (shafts) of the wool fibers.
And if I am reading
some parts of the posts above some are suggesting that the processing of some
wools before dyeing (I am not sure whether these include the methods used to
remove "skin" wool) actually affects the sides of the fibers so that they more
readily take in dyes. I'm clear that "kemp" fibers are per se more difficult to
dye, but leaving those aside also for the moment (and I'm also clear that wool
sorting is not much indulged in anymore), if the processing of wool prior to
dyeing sometimes works to increase its ability to absorb dye, then it seems hard
to see why the resulting colors are often described as flat and
dull.
Michael?
Regards,
R. John Howe
Hi All,
First, what is probably more than you want to know about wool
in general, when medullation becomes objectionable, and the transition from
medullated fiber to kemp fiber, see the following:
http://www.awta.com.au/Publications/Research_Papers/Wool_Contamination/Fibre_Medullation.pdf
And if that's not enough detail, knock yourself out:
http://www.ofda.com/technical/Papers/b14.pdf
To
summarize, kemp is the result of an excessively broad medullar void that results
in brittle and opaque fiber walls. That's unfortunate if you use the wool for
rugs, but great if you need it for insulation.
And Sue, yes, you are
wrong. They didn't discuss flaws, they discussed dominance. If you were right,
it would be like saying the Santa Gerturdis cattle breed is flawed because it's
the result of crossbreeding animals that can survive under rotten living
conditions. It's not flawed, it's the result of selective breeding, which is the
extent of they do down in Oz. Not exactly Frankensteinian.
If you're
really interested though, start here:
http://www.awta.com.au/Publications/Research_Papers/Sheep_Breeding/ASGS_Summary.pdf
But I'm with John at this point; let's get back to the impact on those
rugs we all love....
Regards,
Chuck
__________________
Chuck
Wagner
dead wool
Hallo everybody,
uff, quite some material come to the surface
now.
First the most urgent question: how does the wool fiber take up dyes
?
According to my experience ( ! - I did or could not do lengthy research
using
electron microscopes , lack of funding ... ) dyes penetrate the surface
and or
not wandering into the fiber through a kind of capillaric
effect from the
point where it has been cut off the animal.
In this case (
theoretical assumption) a kemp hair should "pick up" dyes better
than normal
wool - but the opposite is the case. A brillant natural dye on wool requires a
"healthy" fiber with high lustre for building up shiny lacquers.
Low
quality wool ( for carpets ) has a lot of kemp, high quality nearly
nothing.
Australian and European wool for carpets is an old experience
for Turkish carpet
producers, nothing new. But it is not well suited
for carpets or kilims.
You must keep in mind that , as we have shown in the
"carpets and wine" salon
( => Archived Salons ) , carpet producing on a
firm's level is not an old, uninterrupted tradition. The weavers ( all close to
the wool - people ) have this know how. But not the cottage industry firm owners
who select and decide on wool - these are all new,late entrances. I remember
that 10-12 years ago
Turkish carpet producers even published expensive
advertisements in HALI claiming that they use Australian Merino wool for their
pieces - a shockingly amateurish wrong decision as this is the wool type which
is not suitable.
Though I do not personally know the owner of the Khal
Mohammadi rugs I guess it is similar. In Turkey it is still like that: the
Australian wool is used for the cheap commercial carpets becauseone can have it
easily in whatever amount one wants it and it comes in a kind of standard form,
easy to process it. The matt appearance of such weaves ( though the damaged
fiber picks up more dye) has another reason: natural dyes are ( except Indigoids
) dye lakes (
lacquers ) whose appearance depends on intact wool and whose
integrity is later attacked by the usual chemical washing processes.
The
best Turkish wool type comes from the
Karaman sheep ( not the place Karaman,
but the sheep race "Karaman"). It is much
better suited for carpets and
kilims, combines high lustre with long-term stability , whereas the daglic type
( a race from Western Anatolia ) supplies finer wool which has less lustre and
tends to get matt when used. Nevertheless
sometimes one sees magnificent
antique weaves ( I have in mind a certain
yüncü kilim witht a wool that
shines really silky ).
Have a lookat a very finelittle silk
minder where you may hardly see the single yellow wool warp : hair-thin but
it would cut into your finger in case you want to tear it. This is possible
through painstakingly careful preparation of the wool ( shaking all kemp, dirty,
broken fibers out via a special "combing" process using the "jay" , 7-10 days to
prepare 1 kg of raw wool after having had it washed in the river without any
soap or even agressive chemicals like lauryl-ether-sulphate or so ... ) .
So
the trick is to prepare the wool for dyeing in a lengthy process with
soft auxilliaries - whereas the strong ones which are used in the leather
industry ( Calcium hydroxide, sodium sulfide ) are attacking the
integrity of
all fibers, kemp and wool.
Therefore (!) this particular type of "wool" is
called "dead" , with reason. But that does not mean that there are metaphysical
effects to be taken into account, like getting the wool from the "living
animal". It is done like that, yes, but for different reasons.
All this
has nothing to do with ideology but a lot with "backyard details" - I guess a
good product is that one where one can admit to move close to itsproduction
steps without loosing theappetite ...
Yours sincerely
Michael
Bischof
Dear folks -
I want to summarize my understanding to this point if for
no other reason than to provide a target for correction.
1. There appears
agreement that it is the character of the methods used to obtain the wool from
the hide that is of the most concern in the "live wool-dead wool" debate. I
think we are agreed that there is no intrinsic difference between shorn wool and
wool on a dead animal immediatedly after death.
2. There appear to be
"softer" method for removing wool from the pelt of a dead animal and those that
are "harsher." It may be that the Chilkat Indians employed a species of the
"softer" wool removal methods that affect the quality of the wool but not
greatly and that those employed by the leather industry are harsher and do
affect the quality of the wool greatly.
3. We seem agreed that dye is
taken into wool fibers through its ends and in that case, a cut end seems to
provide a more easy absorption passage than does the "sealed" end of a fiber
taken from "skin" wool which has been loosened chemically from the hide but not
cut.
4. We are not sure whether dye is also taken into wool fibers under
the "scales" along the shaft. The shaft seem unlikely to be affected in shorn
wool, but could have its integrity intruded upon in some "skin" wool removal
methods.
5. The "medullation" of the wool has been offered as one
explanation for variations in the degree of ready absorbtion of dyes. Since the
medulla is the core of particular wool fibers its relative size and
accessibility seem to provide a basis for understanding why dyes might be
absorbed more or less readily. That is, wool fibers with medullas or larger
medullas and which are cut on the ends might seem to be the best candidates for
better dye absorption. In fact, it is the "kemp" hairs that are the mostly highy
"medullated" and these fibers are famous for their resistance to
dyeing.
6. So it would seem than an alternative explanation is needed of
why the rug fibers most desirious for dyeing and weaving, the "wool," both seem
to have less medullation AND a greater ability to absorb
dyes.
Regards,
R. John Howe
dead wool ...
Hallo everybody, hallo R. John Howe, hallo Vincent Keers,
this point
"3." is where I would not agree.
"3. We seem agreed that dye is taken
into wool fibers through its ends and in
that case, a cut end seems to
provide a more easy absorption passage than does
the "sealed" end of a fiber
taken from "skin" wool which has been loosened
chemically from the hide but
not cut."
It does not seem to function like this. The dye stuff material
and all the
auxilliaries apparently move through the more or less integer
skin - and
damaging this "skin" too much results in lacklustre dye
lacquers.
Heavy contradiction within (5.) therefore
...
"6. So it would seem than an alternative explanation is
needed of why the rug
fibers most desirious for dyeing and weaving, the
"wool," both seem to have less
medullation AND a greater ability to absorb
dyes."
Damaged wool takes even more dyes - but then the "dye lacquer"
quality is lower.
Here my cooperation will necessarily end as KOEK, the
firm for which I work,
is not at liberty to release the details necessary to
shed light on dissolving
this contradiction - but anyway this discussion
leads to the real focus of the
matter.
I find very interesting the
note of Vincent that in fact the habit to treat
sheeps a short time before
shearing them with clay corresponds with the clay
treatment in the make of
Chilkat blankets. There are very effective soft "soap
analoga" in the wool so
clay plus cool water after the clay treatment would give
the best preparation
for shearing. For this reason in the mountains southwest of
Konya people had
constructed big pools where in ancient time this treatment was
done. In the
summer they are all empty as the climate is too dry then.
People who
announce their visit to Konya in time , preferably under the
guidance of Samy
Rabinovic, might see it ...
This habit is no longer executed as the
real business with wool is done counting in truck
loads. Grading the wool
does not make sense for the people any more - the same for taking care of kemp
in breeding sheep. It is possible to get fascinating qualities today - but as
with any anti-mainstream business the expenses of such a task are high and lead
to niche
products.
Yours sincerely,
Michael Bischof
OK, we'll do it the hard way...
John et all,
I'm no expert in this field, but I'm getting there, with
the help of other people who are. So, here it is:
There are two types of
corticular cells within a wool fiber: the ortho- and para- cortex cells, which
have distinctly different reactions to exposure to reagents in wet chemistry
experiments. In addition, they have slightly different helical molecular
structures that cause them to react differently to stretching deformation, e.g.
one kinks more easily that the other.
They are constrained within the
body of the fiber by the scale cells, and are relatively short compared to the
total length of the fiber. Medullar voids often develop between these corticular
cells, generally toward the central axis of the fiber. The wider the fiber, the
easier it is for a medullar void to develop. But any single medullar void may
not run the length of the fiber because it's size is related to the length of
the corticular cells, and the voids may not be interconnected.
Kemp
fibers are less well structured than a wool fiber, have opaque fiber walls, and
have a large medullar volume compared to a normal wool fiber.
In both
cases the basal end of the fiber terminates in what is called the papilla, which
is where blood interacts with the live portion of the fiber.
The basal
end of plucked wool is often not fully separated from the papilla and any
medullar void at the basal end of the fiber may not be available for fluid
transport. Clearly, this is not the case for a fiber that has been
cut.
The interscalar gap may play an important part in allowing dyes into
the distal portions of the fiber, and provide a conduit for dyes to move into
any medullar voids further out in the body of the fiber.
So, what does
that all mean ?
1) Kemp fibers are generally opaque, so internal dye
uptake would be of low value. And, their reflectivity would be low compared to
layered transparent or translucent scales on the surface of a normal wool fiber.
A large medullar void, and its contents, would not be visible from outside the
fiber.
Not everyone hates kemp though; Harris-tweed-type-materials
contain dark and light kemp to add some linear contrast to the yarns.
2)
There are multiple pathways for dye liquids to penetrate a wool fiber, and
migrate within the fiber.
3) Chemical treatments can attack the kinkiness
of the corticular fibers, and change the way fluids can migrate within the
fiber.
4) Nothing else. So I'm going to bed.
See the following for
a not bad drawing:
http://www.higginsinsulation.com.au/images/woollge.jpg
Regards,
Chuck
__________________
Chuck
Wagner
Michael -
Thank you for your further patient explanation.
I
would not dream of asking you to reveal the trade secrets of your firm but
thought that the question of whether dyes are absorbed only through the cut ends
of wool fibers or perhaps also along the sides of the fiber, would be a question
that would permit an answer that would not require that kind of
specificity.
And Chuck Wagner's further post seems to indicate that this
is the case.
Chuck, I found especially useful the phrase:
"...There are multiple pathways for dye liquids to penetrate a wool
fiber, and migrate within the fiber."
Maybe most others have been clear
on this point, but that is what I have been asking about.
It does appear
that "medullation" is not directly correlated with ability to absorb dye. Else
kemp would be easier to dye.
(I should mention for those who might want
to read what is in the detailed links that Chuck has provided, that some of them
appear very small on my screen but print off in nicely readable form. So if you
want to read them, I'd encourage you to print them off.)
Thanks, again to
you both,
Regards,
R. John Howe
WOOL DYE ABSORBTION
I think I am starting to understand. If I am right the answers to dye
absorbtion lie in the matrix. The high-sulfer high-tyr proteins are highly
"electrically" attractive to metal salts. Those good old SULFUR BONDS! The
mordant bath metal salts, like bulls in a china shop, stampede through every
available fiber entryway, reaming them microscopically and allowing for more and
faster access to a greater surface area for the coming dye lacquers which might
otherwise be curtailed by the size of the passageways wherein they could fall
victim to surface tension and denied the pathways of capillary imbibition.
I suspect that the medulated fibers have less sulfur content. For these
fibers the internal surface area may be greater but the bonds between
fiber/mordant/dye would be more mechanical and artificially "sandblasted" into
existance than those naturally and freely provided, the
biostatic-electro-chemical ones, or whatever they are called. I could say more
on this but I don't want to verge on any of Michael's trade secrets. He has been
so helpful.
I don't know if this is applicable or not but I did a little
experiment with available hairs. The large diameter white ones, when burned, had
much less of a sulfur smell than the less coarse brown ones! Sue
Sue's experiment ...
Hallo everybody, hallo Sue,
thanks a lot for your interesting
experiment ! I had to smile: this is exactly the way we work ... I studied
biology but never had access to big enough funds to do proper research. So
everything depended on easy enough experiments and good enough viewing and
"digesting" it. Of course one needs a suitable theoretical model to interprete
the results ...
What I still cannot understand is why they just did not
cut the wool from the skin of the fresh hunt with a suitable knife and applied
this long "fouling off" method ... may be there is the risk to hurt the skin and
endanger the quality of the later leather product derived from this skin
?
Regards,
Michael
Dear folks -
Since Michael is still musing about the "why" of the
Chilkat Indians' use of a clay compound to loosen the wool from mountain goat
pelts, let me give you one other sentence that occurs in the Dockstader book,
that I have mentioned in the thread about "dog hair."
The Salish, living
south of the Chilkats, wove "nobility blankets" too, as I have shown in that
thread, but also two other kinds that were mostly white with little decoration.
Here is what Dockstader reports, apparently about these latter two kinds of
Salish weavings:
"...After the textile was completed, the white blankets
were whitened with clay and beaten to clean them, and also to give them a
stiffened, fresh appearance. This beating was accomplished by a carved wooden
instrument resembling a sabre..."
Could it be that the Chilkats used a
clay-based wool removal process in part to achieve similar whitening
effects?
Regards,
R. John Howe
Dear folks -
I should have acknowledged Sue Zimmerman's post in my
previous one.
Michael Bischof, a chemist, does not seem to question her
explanation.
My own chemistry was not only taken in 1955, but from one
V.V. Alderman, who taught General Chemistry in a mode understandable to "chem
majors" only. He flunked about 60% of his class that year (and was not invited
by the college to repeat this performance in the next one). I took my
"gentleman's C" and escaped gratefully. So I don't know much about "good old
sulphur bonds" or about how mordants might ream fiber passages making way for
the subsequent dye stuffs.
But if Sue is right about the functions of the
various chemical reactions in dyeing, that is a useful
advance.
Regards,
R. John Howe
Hi John
Here's the nickel lecture on what's probably relevant about
sulfur bonds in proteins: Proteins are very long molecules, chains of hundreds
or thousands of amino acids (there are about 20 different amino acids). There
are three amino acids with sulfur in their structure, and in one of them the
sulfur is in a form in which it can connect with the sulfur in the same kind of
amino acid somewhere else along the length of the chain, or even with one in
another chain. This "crosslinking" gives the proteins certain physical
characteristics. Changing the extent of crosslinking changes those
characteristics. In the case of wool or hair, the important effect is a change
in the tendency to form tight curls, which is a factor in the resilience of
wool.
I think Sue is confused about mordants. They don't create or
enlarge passages. They form (or promote the formation of) links between the
protein of the fibers and the molecules of the dye, making it possible for the
dye to stick tightly to the protein. A more familiar analogy is the primer coat
for paint.
Regards,
Steve Price
The Bad Penny Returns
Hi All,
First, because I haven't mentioned this yet, congratulations
to John on a really interesting salon. I'm struck by the similar geometries and
now would like to pursue information on historical weavings of the what is now
the Russian Far East. I'm curious about cross-strait cultural
linkages.
Regarding Michaels musings on why the goat hair was not clipped
off, I would suggest:
A) Smell a goat. Because clay particles have a
huge surface area compared to their thickness, they are great electrostatic
precipitators, flocculators, and adsorbers of large organic molecules. As such,
not only oils present in the hair follicles but fatty materials from the skin,
liquids from sweat glands, and probably most important: musk and other heavy
glandular secretions, would be "dry cleaned" from the pelt. And moisture would
be withdrawn from the hide, shrink the skin, and loosen the hairs.
If the
fleece were clipped from a fresh hide, a serious washing process would have to
be in place, complete with water and heat sources. Much more trouble and
temporaly constrained: it all has to happen in a well organized and synchronous
procedure so that the water and heat sources aren't wasted. Doing one hide at a
time, randomly, would be problematic.
B) Note that goat hair is a lot
more delicate than most wools because the cuticle scales are much thinner. But,
because the scales are there it still felts up nicely. And there are a lot of
short fine fibers that would be missed in a clip that would be taken up by
felting.
Now, a dead goat will hold still for you a lot longer than a
live one will, so if the fibers have become loose as a result of dessicating the
hide with dry clay, then just rolling the fibers off the hide in a nicely felted
heap is as simple as it gets. And no tools are required.
Last, I'll make
a couple more points on the kemp dye uptake issue:
First, I think kemp
DOES take up the dye fluids but because the cuticle is generally opaque it
doesn't matter because you can't see the dyes.
Second, because there's a
single large central medullar void, if the hair is broken or split then what dye
IS inside is easily exposed to washing liquids and/or the effects of abrasion.
Contrast this with the multiple elongate voids and intercellular surfaces
available for binding dye liquids in a modestly medullated wool
fiber.
Regards,
Chuck Wagner
__________________
Chuck
Wagner
Dear folks -
Chuck Wagner points out that one disadvantage of clipping
the wool off the hide of a dead goat is that there would be a large "dry
cleaning job" that is avoided by using the clay balls method.
Here again
for convenience is the passage from Samuel quoted in Part 2 of the initial salon
essay that describes this wool removal.
"...When it came time to remove
the fleece, the woman would first spread the skin before her and sprinkle it
with a soft, white powdered clay. This clay was obtained from deposits in the
ground, molded into rounded balls twelve to sixteen centimeters in diameter, and
baked in a fire until dry. The balls were then powdered and beaten into the
fleece with a long flat stick until much of the dirt and oils had been removed
and the wool looked snowy white. To remove the wool from the hide, the skin
side was wetted and the hide side then rolled and left to set for several days.
The roots of the fibers would loosen during this time so that the fleece would
readily release from the hide. Sitting on the ground, the woman would take the
skin across her knees and push the fleece from her, rolling it off the hide in
large patches. These she would set aside in low, flat baskets, repeating the
process until the entire fleece was free..."
The italics here are mine.
Note that the white powdered clay has a specific "cleaning" function and that it
explicitly included removing some of the oils from the wool in addition to the
dirt.
So I think Chuck may be right.
I was thinking about this
thread during my exercise walk this morning (it is a beautiful Fall day here in
Washington, D.C.) and another association clicked for me.
When my wife
bred and showed collies, I often got involved around the edges of the show
grooming. The American Kennel Club has rules that forbid any alteration in the
texture or color of the coat of a dog brought to the ring for judging. This rule
is noteworthy, mostly, for being largely uncomplied with, and largely
unenforced. But attempts to preserve niceties have led to the development of
certain euphemisms to permit one to talk in polite company about doing the
forbidden.
The rough-coated version of the collie (think "Lassie") is
double-coated with a long rough outer coat and a soft undercoat. One of the most
widespread preparations of this collie variety for the ring was to sprinkle on
the coat a kind of white powder (a mixture of powdered blackboard chalk and corn
starch) and then to brush it both "into" the coat and the excess out of it. This
was called "chalking" the dog and was described as a species of coat "cleaning."
("Cleaning" is the euphemism here.)
But the true effect being sought was
not so much a drycleaning, although there was undoubtedly some of that, but
rather, first, to give the coat a healthy feeling of "fullness" when handled,
and secondly and most important, to make the individual coat hairs stand out
separately from one another. This enhanced "definition" of the individual coat
hairs was visibly attractive, especially when the dog went "on alert."
My
analgous thought while walking was to wonder if another function of the addition
of the white clay powder and then the beating of it might not have been not just
to clean the wool for the Chilkat dancing blankets, but also to provide an order
of fiber definition that the very soft goat wool (and in the case of the Salish,
dog hair) needed to keep it from matting. Certainly, the fibers in the Salish
weavings on the "dog hair" thread have considerable definition.
So it may
be that the white clay powder, helped loosen the wool from the hide with minimal
damage, cleaned it somewhat and provided it with needed fiber
definition.
Regards,
R. John Howe
Your welcome, Michael. Thanks for the dye links. Especially the silk one,
which I found encouraging.
Good question about the "fouling off" method.
Who taught them that? "Keestadores"? They don't seem the type. The fur trade
used diatomaceous earth for cleaning which would have had the added benefit of
helping with parasite problems but no need to calcine that.
I think the
clay used was Palygoskite. I think their teachers moved on with the most
important ingredient of a recipe for Maya Blue. Not to say Mayans had the only
one,
http://www.chemsoc.org/chembytes/ezine/2001/butler_apr01.htm,
http://pippo.ingentaselect.com/vl=32890494/cl=42/nw=1/rpsv/cgi-bin/linker?ini=cms&reqidx=/cw/cms/00098604/v51n3/s4/p279,
etc.
I think the "fouling off" originally had to do with vat bacteria, dyeing in the
wool, fantastic leather goods probably burnished to a nice coppery over-glow.
Stuff like that.
You know what to do. Sue
after digestion ...
Hi everybody, hallo Chuck Wagner,
thanks a lot for having submitted a lot
of interesting URL's for studying wool
qualities. Sorry for the delay -
communicating here is not the only thing I can
do. Now I have "digested" it -
and my view is clear:
Manufacturer's specifications for specialty
carpet wool
Staple length: More than 100 mm
Fibre diameter:
36-45 microns
Medullated fibre: As high as possible, 20%
minimum
Kemp: Nil
Bulk: Helical crimp
Colour:
White
Lustre: None
Fibre strength: Sound
Vegetable matter:
Nil
Open fleece (no cots): Yes
That means in clear words: this
type of carpet wool is most likely
suitable for machine-made
carpets but it is impossible to use it with
hand-madeOriental carpets
!
In Germany we discriminate "Teppich" (carpet) from the inferior
"Teppichboden"
( the industrial construct) - and within carpets there is the
distinction
between "machine-knotted" and "hand-made".
No lustre (
chalk white ) and a high amount of medullation is the
opposite of what
one needs for making excellent carpets and kilims.
The use of Belgian and
such Australian wool in Pakistan enhances our view of
uprooted carpetoids
done there - but, as a matter of fact, the big commercial
producers of
carpets in Turkey and Iran use this material as well. The smaller firms who
select their stuff from the (Australian and New Zealand) vleeceschoose wool
qualities with total different properties. But the "real thing",
specially
selected English long-wools, is not imported to Turkey ( this quality could come
theoretically from New Zealand: but their wool is not suitable for first class
carpets anyway as it alwalys contains pesticides ).
Sorry, R. John Howe -
this topic went a bit too far and hopefully it does not steal attraction from
your main salon which is on Chilkats.
Regards,
Michael Bischof
Michael -
Thanks for this additional comment.
I do not feel at
all that this discussion has been unrelated since what triggered it was the
Chilkat use of wool taken from dead goats.
It seemed to me that this put
some potential pressure on the horror that most writers and collectors have for
"skin" wool and on the distinction between "skin" wool and "shorn" wool.
I fully expected a rather vigorous discussion in this area and it seems
to me that we have explored usefully the likely actual character of what in fact
causes wool damage as well what goes on during mordanting. In the process Chuck
Wagner introduced us usefully to a new wool analysis term,
"medullation."
It all seems to me quite appropriate and potentially
useful.
Regards,
R. John Howe