Silk fibers spinning

Research on silk fiber spinning continues, even intensifying on several bases ... 

Microdenier nylon and polyester were a significant spinning breakthrough when demonstrated in 1985. The finer-than-silk fibers added a new dimension to fabric aesthetics, comfort, and performance. Microdenier nylons are used in weaving, warp knits, and weft knits for sports-, leisure-, and... 

The feeling of a spider web may be unsettling, but a similar natural material has been used for centuries to make silk fabric that is prized for its smooth texture. Silkworms produce the silk fibers used to make clothing. They feast on mulberry leaves and convert the molecules from these leaves into silk, from which they spin cocoons. 

Synthetic Spider Silk Fibers Natural i/s Artificial Spinning Strategies... 

Synthetic Spider Silk Fibers Natural vs Artificial Spinning Strategies 174... 

Silk is an animal fiber valued for its texture, strength, and luster. First prepared in ancient China, silk fabric was expensive, luxurious, and soft its popularity led to the development of a trade route known as the Silk Road leading from Asia to Europe. Early American entrepreneurs such as Benjamin Franklin promoted the silk industry in the colonies. Silkworms spin cocoons that are collected, steamed, and unwound to obtain the silk fiber by a process known as reeling. A number of fibers are twisted together to form a thread of raw silk. Threads are combined, cleaned, stretched, dyed, and woven into fine fabrics. Silk fibers have great tensile strength and are sometimes used in cordage. 

Ha, S.W., Tonelli, A.E., and Hudson, S.M. "Structural studies of Bombyx mori silk fibroin during regeneration from solutions and wet fiber spinning". Biomacromolecules 6(3), 1722-1731 (2005). 

Work, R.W. "Dimensions, birefringences, and force-elongation behavior of major and minor ampullate silk fibers from Orb-Web-Spinning Spiders - Effects of wetting on these properties". Text. Res. ]. 47(10), 650-662 (1977). 

Yao, J.M., Masuda, H., Zhao, C.H., and Asakura, T. "Artificial spinning and characterization of silk fiber from Bombyx mori silk fibroin in hexafluoroacetone hydrate". Macromolecules 35(1), 6-9 (2002). 

The silkworms can produce strong and stiff fibers at room temperature and from an aqueous solution (1). Therefore, it is important to know the structure of the silk fibroin in silkworm in order to understand the mechanisrn of fiber formation at the molecular level. Two crystalline forms, silk I and silk n, have been reported as the dimorphs of silk fibroin from B. mori based on several spectroscopic investigations (2). The silk II structure (tiie structure of silk fiber after spinning) was first proposed by Marsh et al. (3) to be an anti-parallel p-sheet, which was subsequently supported by other researchers (1). However, flie deterniination of the silk I stmcture was difficult because any attaupts to induce (sientation of the silk fibroin or the model polypeptides with silk I form for studio by X-ray and electron difl action, causes the silk I form to readify convert to the more... 

Other types of spider webs include tangle webs and sheet webs sptm by different species. Many other insects spin silk fibers for cocoons, shelter, egg sacs, egg stalks, and tunnels. For example, tarantulas use silk to spin tunnel-shaped shelters, and spin fibers from their feet as support lines. Caddisfiy larvae spin underwater tubes and nets, and the aquatic midge spins underwater silk tubes. Honeybee larvae spin silk to inCTease the mechanical strength and thermal stability of the beehive. These silks are subject to inaeasing amounts of research, as reviewed in Reference 11. 

Silkworms spin composites of two silk fibers out of two converging silk glands. These fibers are surrounded by a glue-like seridn protein coating that holds the fibers and thus the cocoons together. The individual silkworm silk fibers (brin) are 10-12 xm in diameter with a triangular cross section. 

The properties of artifidally spun silk fibers are extremely dependent on processing conditions. Most work to create fibers from silk utilizes a wet spinning process, whereby the concentrated silk dope is extruded through an orifice on the order of 100 pm in diameter into a coagulation bath. A subsequent post-spin draw is performed, whereby the fiber is constrained in a stretched state and allowed to dry or further coagulate. 

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