#4 Research Initiatives -Susie Kirsh

Research Initiatives

Weaves and Knits

a.    Weaving

²  Millions of miles of fabric are needed every year to meet consumer demand – the industrial loom makes it possible

²  Basic materials needed for weaving are two sets of threads where first set is weft, and second set is the warp

²  Warps are threaded through eyes

²  The read then pushes the threads together

²  Pedals provide control on the machine

²  Shaft raises so the pedals go up and the thread is moved with them

²  A few hundred pedals and two shafts moving up and down together are required to create simple patterns

²  Speed of the machine comes from the loom and its need to move the weft through the warp as fast as possible

²  Two challenges of the modern loom, how to weave thread quickly without a shuttle and how to minimize thread removing

²  Two rapiers that “exchange” thread as they meet in the middle

²  Patterns are created through the set-up of thread on the track with a weft presenter to select different colors as the machine works; each strand has its own control system; a jacquard loom helps with more colors for a more complicated pattern (holds more strands of thread)

²  Threading of a jacquard loom is so time-consuming that it is done just once

b.    Twill Weaving

²  twill fabric is characterized by diagonal lines on the face of the cloth, formed by the rising or floating of warp yarn over the filling yarns

²  twill line determines the direction of the diagonal (right hand twill = z-twill; eft hand twill = s-twill)

²  twill lines can be anywhere from 15-75 degrees

²  45 degrees is normal, anything higher is a steep twill

²  Counter of a twill designates the order of weaving of the first hand of the repeat

²  1 by 2 = warp faced twill; 2 by 1 = filling faced twill

c.    Jacquard

²  Plain weave

²  Patterned weave

²  Before 1800, patterns were picked out by hand until 1801 when joseph jacquard invented a revolutionary new loom attachment that automated how patterns were woven

²  Automation enabled through the loom made complex designs cheaper to produce, so intricate patterns became available to more people

d.    Knits – Weft and Warp Knitting

²  Weft knitting is done when loops are formed in a horizontal manner by adjacent needles

²  Warp knitting is accomplished by forming loops in a vertical direction; intermeshed vertically with two whales

e.    Fire Identification by Burning

²  Cotton (natural cellulosic fiber) – burns, doesn’t melt; smells like burning paper or wood; residue is gray ash

²  Flax (natural cellulosic fiber) – burns, doesn’t melt; smells like burning paper or wood; residue is fine gray ash

²  Wool (natural protein fiber) – burns, doesn’t melt; strongly smells of burning hair or feathers; stops burning when removed from fire; residue is black hollow bead that can be crushed to black powder

²  Silk (natural protein fiber) – burns, doesn’t melt; smells of burning hair or feathers (odor is not as strong as wool, silk doesn’t contain sulphur); stops burning when removed from fire; residue is black hollow bead that can be crushed to black powder

²  Rayon (artificial cellulosic fiber) – burns, doesn’t melt; smells like burning paper or wood; residue is fine gray ash

²  Polyester (artificial fiber) – shrinks from heat, melts, burns, can drip; smells chemical, sweet; residue is hard cream or black colored bead that cannot be crushed

²  Nylon (artificial fiber) – shrinks from heat, melts, can burn; smells a bit like celery; residue is hard cream or black colored bead that cannot be crushed

²  Acrylic (artificial fiber) – shrinks from heat, melts, and burns; sputters when burning; acrid smell; residue is hard black bead that can be partially crushed

²  Acetate (artificial fiber) – shrinks from heat, melts, and burns; smells like burning cellulosic fibers (of burned wood, paper) with a bit of vinegar; residue is hard black bead that cam be partially crushed

f.      Testing

²  Tensile strength test – determines the strength and the elongation of a strip of fabric; when the fabric breaks, the test is stopped; force is measured in kilograms and extension/stretch is measured in millimeters