Posted by Filiberto Boncompagni on 10-07-2003 06:09 AM:

Dead Wool

Hi John,

I’ll take the wool subject.

Dead sheep wool has a reputation for being dry, brittle and lacking of luster.
I don’t 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


Posted by R. John Howe on 10-07-2003 08:48 AM:

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


Posted by Steve Price on 10-07-2003 08:50 AM:

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


Posted by R. John Howe on 10-07-2003 09:21 AM:

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


Posted by R. John Howe on 10-09-2003 08:22 AM:

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


Posted by Michael Bischof on 10-11-2003 08:09 AM:

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


Posted by Vincent Keers on 10-11-2003 10:23 AM:

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


Posted by Steve Price on 10-11-2003 11:15 AM:

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


Posted by Chuck Wagner on 10-11-2003 01:09 PM:

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


Posted by Michael Bischof on 10-11-2003 03:21 PM:

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


Posted by R. John Howe on 10-11-2003 03:48 PM:

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


Posted by Chuck Wagner on 10-11-2003 10:55 PM:

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


Posted by Sue Zimmerman on 10-11-2003 11:33 PM:

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


Posted by Steve Price on 10-12-2003 07:12 AM:

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


Posted by R. John Howe on 10-12-2003 08:17 AM:

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


Posted by Chuck Wagner on 10-12-2003 10:57 AM:

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


Posted by Michael Bischof on 10-12-2003 01:10 PM:

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


Posted by R. John Howe on 10-12-2003 02:21 PM:

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


Posted by Michael Bischof on 10-12-2003 03:12 PM:

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


Posted by Chuck Wagner on 10-12-2003 04:29 PM:

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


Posted by R. John Howe on 10-12-2003 09:01 PM:

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


Posted by Sue Zimmrman on 10-12-2003 09:31 PM:

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


Posted by Michael Bischof on 10-12-2003 11:29 PM:

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


Posted by R. John Howe on 10-13-2003 12:29 AM:

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


Posted by R. John Howe on 10-13-2003 07:21 AM:

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


Posted by Steve Price on 10-13-2003 08:08 AM:

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


Posted by Chuck Wagner on 10-13-2003 12:00 PM:

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


Posted by R. John Howe on 10-13-2003 03:20 PM:

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


Posted by Sue Zimmerman on 10-13-2003 08:06 PM:

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


Posted by Michael Bischof on 10-19-2003 03:10 AM:

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


Posted by R. John Howe on 10-19-2003 05:12 AM:

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