2. What is spider silk ?
• Spider silk is protein fiber spun by spiders.
Spiders use their silk to make webs or other
structures, which function as nets to catch other
animals, or as nests or sosoons for protection
for their offspring . They can also suspend
themselves using their silk.
• The silk is secreted from glands inside the
spiders spinnerets, located on the back of a
spiders abdomen.
3.
4. Spider silk is renounced for being stronger than steal by
mass and is surprisingly elastic and has generated
interest for an array of applications.
6. Properties
Each spider and each type of silk has a set of
mechanical properties optimised for their biological
function.
They exhibit a unique
combination of high tensile
strength and extensibility. This
enables a silk fiber to absorb
a lot of energy before breaking (toughness, the area
under a stress-strain curve).
Silk is stronger than steel , but not as strong as kevlar.
silk is ,however ,tougher than kevlar
7. Strength
• In detail a spider silk’s tensile strength is
comparable to that of high-grade
alloy steel (450 - 1970 MPa),and about
half as strong as aramid filaments, such
Kevlar (3000 MPa).
8. Toughness
• The combination of strength and ductility
gives dragline silks a very high
toughness (or work to fracture), which
"equals that of commercial
polyaramid (aromatic nylon) filaments,
which themselves are benchmarks of
modern polymer fiber technology".
9. Density
• Consisting of mainly protein , silks are about a
sixth of the density is steel (1.31 g/cm3). As a
result , a strand long enough to circle the earth
eould weigh less than 500 grams(18 oz).
