Spider Silk
On the outside of the patio door to my office is a huge
spider web. I would say about 18 inches
in diameter and tethered to various
hanging baskets. The spider responsible
is an enormous orange garden spider who appears occasionally in the center of
the web, otherwise I don’t know where it resides, which, I admit makes me
nervous when I’m outside. I don’t like
spiders at all, but “Goldie” is living outside and her web is so delicate and
intricate that I find myself looking at it often.
fabric swatch American, cotton, c 1930
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Many years ago I was writing an introductory course on
Textile History (Textiles 101, if you
will) and prepared a lecture on little-known animal fibers. Several animals produce silk filaments, of
course Bombyx mori is the most notable, but certain mollusks, insects, as well
as my “unfriends” the arachnids.
According to the Roman poet, Ovid, Arachne was widely noted
for her weaving skills and challenged the goddess Athena to a contest, which,
apparently she won hands-down. Now
Athena was never known to be a gracious loser and in a rage of envy destroyed
Arachne’s beautiful tapestry. In
despair, Arachne tried to hang herself , but was transformed by Athena into a
spider.
As silk producers, arachnids ( nearly 300 million years ago)
far preceded the silk “worm”.
The physical properties are very impressive. Different species produce silk of varying
characteristics. Spider attachment
discs are made of a strong glue to secure the draglines and framelines. Certain species produce a dragline silk that
is stronger by weight to steel, surpassing Kevlar. This excellent tensile strength has been suggested that a pencil
thick strand of silk could stop a 747 in flight., and its elasticity is
superior to Nylon. Some silks are good
insulators, while some absorb water, and some are water resistant. The reason insects, when in contact with a
web, cannot escape their demise is as special silken thread called “cribellate” which forms a fine sticky mat combed atop the more substantial silk tract.
Historically, several cultures have used spider silk
medicinally , as well as for fishing nets
There have been attempts to use the silk for textiles in the early
1700’s but the care of the living spiders proved too difficult. Speaking of difficult, in the 1800’s spider
silk was reeled directly from harnessed spiders. The military has long investigated spider silk for strong
lightweight materials.
DuPont’s advertisement in the Scientific American of July
1996 tells that they were studying these biopolymer structures of spider webs
by using recombinant DNA technology. I
had not heard more about this research until several years ago while attending
a Textile Society conference, I met a retired chemist who had worked for
DuPont. She told me a fellow chemist
had resurrected these studies. So
maybe, we shall see spider filament for use in textiles.
For me, a spider silk
sweater, NO WAY!!!!
