When you think of silk, besides thinking about the luxurious feel, its softness and cool touch to the skin, you might also think about the silkworm that is generally associated with its production. However that beautiful silk scarf you like to wear may one day soon actually be made from spider silk instead. This method of producing silk fiber is being seriously researched these days.
The charm of the silk fabric has allured mankind for thousands for years. The dazzle, broad range of colors and the excellent texture has made this fabric the most loved of all. Silk fabric is manufactured both naturally and artificially.
There are four types of natural silk available, namely tasar, mulberry, muga and eri. However, the higher demand for natural silk led pressure to find out other options to make silk. The four natural silk sources seem incapable of catering for the increasing demands. Now here a significant question arises – Is there any other source available to get natural silk? The answer is “YES”, it’s a “Spider Silk”. It is true that such an irritating and ignored insect can produce good silk fibre.
Spider silk is a fibre, which is extracted from spiders. It is strong fibre, even its tensile strength is compared to steel. The tensile strength for one type of steel is at 1.65 Gpa, whereas spider silk is nearly at 1.3 Gpa. But, the density of spider silk is much less than steel and its tensile strength to density is about five times more than steel, such as DuPont’s Kelvar, aromatic filaments
Spider silk’s Structure
Within a distinctive fibre, there are crystalline sectors with amorphous linkages. These crystal sectors are beta-sheets, which are put together. Spider silk is very flexible, and can be stretched up to 40 percent of its original length with no breakage problems. This results in a high ductility. Liquid crystalline spinning of spider silk is similar to aromatic nylon.
Spider silk is made of complex molecules of protein. Spider can’t be farmed such as silkworms, as they are cannibals. Due to this nature they even eat each other. The silk extracted is very fine, thus to make one square yard cloth 400 spiders are required. The fibre gets hardened when it is exposed to open air that creates a problem to work with. Because of the repetitive symptoms of the DNA encoding it is difficult to recognize its sequence. Only from 14 species the protein has been decoded.
Although various protein sequences are found in different spiders, a common one in spider silk structure is a sequence of amino acids, which self-assemble into a beta sheet group. The Ala rich blocks are distinguished by segments of amino acids with heavier side groups. The beta sheets gathers to make crystals, on the other side, other segments makes amorphous domains. The interaction between the crystalline segments and elastic amorphous regions results in exclusive spider silk properties.
Spider Silk Origin
The silk gland releases the fibre. Different spider species have different glands for their own reason like web-creation, housing, capturing the prey and defense. The visible part of the gland is called as the spinneret. The initial part of the gland is full of thiol and tyrosine, the key ingredients in silk fibre. After the making of fibres, the ampulla plays the role of a storage box.
Here, the spinning duct sweeps-off water from the fiber and small channels also help in this process. Liquid separation is conducted at the verge of the distal limb of the duct, and further passes to the valve. The valve is anticipated to help in fixing broken fibers again, playing more in the way of a helical pump.
Artificial spider silk
It is not usually possible to utilize spiders to produce spider silk in enormous quantity to cater to industrial demands, because it is hard to manage huge number of spiders. Steps have been taken in extracting the spider silk gene and using other options to manufacture the needed quantity of spider silk. In the year 2000, a Canadian biotechnology company, Nexia was successful in making spider silk protein in goats.
These goats hold the spider silk protein gene, and the milk produced contains considerable amounts of the protein. However, the trials were unsuccessful at spinning the protein into a fibre equivalent to the natural spider silk.
The spider’s spinneret is able in turn the silk proteins into strong domains. Particularly, the spinneret makes an incline of protein concentration, pH and pressure that leads the protein blend through liquid crystalline transitions, resulting creation the required silk structure. Imitating this process in laboratory has been witnessed very tough. Nexia tried to imitate this process by pressing the solution of protein via fine holes; however, this was an insufficient trial to manage the fibres appropriately.
Spider Silk Applications
Recent research on spider silk includes its potential utilization as an extremely strong and versatile thing. The interest in producing the spider silk is mostly due to a blend, both its mechanical properties and the non-polluting option. The manufacturing of latest man-made fibres like Dupont’s Kevlar, are made from petrochemical processing that results massive pollution. On the other hand, the manufacturing of spider silk is entirely environment-friendly, as it is produced by spiders at normal temperature, pressure and water, without any pollution. Additionally, spider silk is fully biodegradable. If the production of spider silk increases, it may replace Kevlar and can be used for a range of products like bullet-proof clothing, wear-resistant lightweight clothing, topes, nets, seat belts, parachutes, rust-free panels on motor vehicles or boats, bio-degradable bottles and medical items.
Conclusion
The spider silk has raised an open challenge to scientist, engineer, spinner and weavers to manage its development and to get acquainted with inherent skills of spider in making the silk thread.
The spider is equipped with eight eyes, two of which are extremely large and face forward giving the spider highly clear and magnified vision. The spider’s back legs are extremely strong and when the spider hunts, it does so covertly and then leaps on its … Spider silk is five time stronger than steel and twice as strong as bullet proof kevlar. This is in pound for pound studies. Spider silk is also capable of stretching about 30 per…
Big in Japan: Socks warm the toes and sooth the soul
The problem with harvesting spider silk is that it’s difficult to near impossible to mass-produce due to the limited amount that spiders can make. This of course is why the work of Dr. Nakagaki is so groundbreaking.
The Quality Stocks Newsletter For Smallcap Companies
Researchers around the world are working hard to untangle one of nature’s greatest mysteries: exactly how do spiders make silk and can it be produced on a commercial scale by man. … But it does nobody any good if it can’t be produced in the volumes necessary, and therein rests the biggest problem. There is currently no proven large scale way to produce spider silk. It turns out that you can’t just corral a bunch of spiders to spin their magic.
Reference
http://en.wikipedia.org/ http://www.amonline.net/ htpp://www.chm.bris.ac.uk/
Fibre2fashion.com – Leading B2B Portal and Marketplace of Global Textile, Apparel and Fashion Industry offers F.ree Articles
To read more articles on Textile, Fashion, Apparel, Technology, Retail and General please visit http://www.fibre2fashion.com/industry-article
Article Source: http://EzineArticles.com/?expert=Gaurav_Doshi
