Textiles Exam 2 pt 1

Fabric

flat surface structure pliable enough to be made into 3D products

Fabrication

process of forming fabric from starting materials

What are the different methods of fabrication?

weaving, knitting, nonwovens

What’s the minimum set of yarns for weaving?

2 sets

What’s special about weaving?

• it’s the most widely used method of fabrication

• different combinations/great amount of variation

Characteristics about weaving:

• interlaced at right angle

• different interlacing patterns

• fabrics ravel, fray, and have grain

• low elasticity

Interlacing

yarn changes position from one side to another

Warp yarn characteristics

• run vertically to loom/parallel to the selvage

• stronger

• more uniform

• higher density

• usually simple/spun yarns, rarely novelty of crepe

• less stretch

Filling/Weft/Picks yarns: 

• Run horizontal, perpendicular to selvage

• More stretch

• Maybe fancy or special function

• Less uniform, lower twist

Selvage

edge of the fabric where the filling yarn returns back across the fabric or where filling yarns end

Why do you need selvage?

• So fabric doesn’t start falling apart 

• If you have a loose weave, need a dense selvage to hold in place

What are the 4 types of selvage?

regular, leno, french, tuffing

Warp Beam

holds the warp yarns in place with tension

Shuttle

holds the weft/filling yarn

Heddles

 then vertical wires with an eyelet that each warp will go through

Harnesses

 frames that go up and down, they control the heddles

Reed/batten

tighten fabric and aligns with the rest of the fabric

Shed

where the shuttle goes through, created by raised and lowered warp yarns

What are examples of ways to create tension for a loom?

• Use warp-weighted loom

• Backstrap loom

Why use a shuttleless loom?

• Quicker and quieter than the shuttle loom

• Industrialized → more inexpensive fabrics

What are the types of shuttleless looms

• Projectile loom

• Rapier loom

• Jet loom

  • Air Jet loom

  • Water jet loom 

• Multiphased

What are the loom advancements mentioned in class?

• Pattern capabilities -  see in interior designs, upholstery

• Computers and electronic monitors - design on computers and softwares

• Loom efficiency 

What are the steps for preparing for weaving?

• Winding

• Creeling

• Warping/dressing the loom

What is Winding?

prep for weaving, repacking yarn for loom: may increase twist or ply yarns

What is Creeling?

 prep for weaving, yarn packers on creel for winding on warp beam

What is Warping/dressing the loom

prep for weaving, yarns threaded through the heddles in specific harnesses (Done by tech, controls structure)

What are the steps for weaving?

• Shedding

• Picking

• Beating/Battening Up

• Take Up

• Letting Off

What is shedding?

1st step in weaving, rolling/lowering harnesses in sequence to separate warp yarns and create a shed

what is picking?

2nd step in weaving, Insert filling yarns through the shed

What is Beating/battening up?

3rd step in weaving, pushing filling yarn next to the previous filling yarn with reed

what is take up?

4th step in weaving, Winding up woven fabric on the cloth beam 

What is letting off?

5th step in weaving, securing the finished stitches and removing the knitted piece from the loom, ensuring it doesn't unravel

Float

yarn crosses over more than 1 yarn at a time

Count

number of warp and filling yarn per unit measure (per square inch), indicator of fabric quality

What number is first in a count for a fabric?

warp

Grain vs. Off Grain

Grain: position of warp to filling yarn at perfect right angle

Off Grain: 

• Skew: filling not at a right angle as warp

• Bow: filling yarns dip into curve across warp

What does skew mean?

type of off grain, filling not at a right angle as warp

what does bow mean?

type of  filling yarns dip into curve across warp

Balanced vs Unbalanced

Balanced: same amount of warp (ends) and weft (picks) (ex. Percale) 

Unbalanced: more warp or weft (ex. broadcloth)

Example of balanced fabric?

Percale

Example of unbalanced fabric?

Broadcloth

Identifying particular fabric names

• Fabric names can come from:

  •  structure, balance, weight

  • Yarn type, twist, finish (ex crepe fabric made with crepe yarns) 

• Diagrams

What are the 3 basic weaves?

 plain, twill, satin

How do you create different weaves?

Raise and lower harnesses to create different types of weaves

What is a plain weave?

• Yarns at the right angle pass over and under each other

• Requires a 2-harness loom, raising every other warp to interlace weft

What’s special about plain weaves?

• Simplest and easiest of the 3

• Cheapest to produce because it is simple

• Most popular

• Can be balanced and unbalanced (rib or rep)

What does plain weave surface look like?

• No technical face or back (looks the same on both sides)

• Plain surface, interesting effects with fancy yarn

Other characteristics of plain weave performance:

• Maximum interlacing

• Yarn type and finish influence performance 

• Less absorbent bc so tightly woven, liquids slide off

What are the characteristics of unbalanced plain weave (rib/rep)

• more warp or weft

• Ribs or ridges will be seen or felt on the fabric surface

• slippage may occur with filament yarns

• Yarn size often differs between warp and weft/filling

Slippage

• when yarns slip from each other, seen on the seam and create holes in the fabric may occur with filament yarns

What are the characteristics of a basket weave?

• Type of plain weave

• Can be balanced (full)  or unbalanced (half basket)

• 2 or more yarns in warp or filling, acting as 1 yarn

• Flexible 

• Wrinkle resistant 

• Snags easily 

What is the most important characteristic of twill weave?

• wales! Each warp/filling yarn floats across 2 or more filling/warp yarns with a progression of interlacing by 1 to the left or right to form a distinct line or wale (diagonals)

• Less apparent soiling (why we use it for pants)

Other characteristics for twill weave

• 2nd basic weave

• 2 up and 2 down, and, 2 up and 1 down most common

• If you see more of the warp its warped faced and vice versa

• May have a technical face or back, interesting surface

What are the different directions for twill weaves?

• Right-handed twill: diagonals run upward to the right

• Left-handed twill: diagonals run upward to the left

• Broken Twill: changes directions 

  • Ex herringbone (broken V), Chevron (continous V)

What are the characteristics of even-sided twill?

• No face or back, so it's reversible

• Exposes the same amount of warp and weft

• 2 up and 2 down

What are the characteristics of Uneven-sided twill?

• Exposes more warp/weft 

• Not reversible 

• Stronger and more abrasion resistant

• 2 up and 1 down or 3 up and 2 down

What are the characteristics of a satin weave?

• Long floats, progressions of 2

  • The most common 4 up and 1 down

• Smooth hand and definite face and back (normally warp faced)

• 1 set of yarn on the face, and 1 set of yarn on the back

• Requires loom of 5-12 harnesses

• Satin made with filament yarns are prone to slippage

Satin Performance:

• Performance depends on the count

• The highest quality satin is silk satin

• Use for wedding dresses

What is the difference between Satin and Sateen Fabric?

• Satin fabric: warp-faced, filament

• Sateen fabric: weft-faced, staple

Fabric Weight

describes how much a fabric weighs for a given area or length of fabric.

What systems are used for fabric weight?

yards per pound, meters per kilogram, ounces per square yard or grams per square meter

What are the categories for fabric weight?

• Lightweight or top-weight fabrics are those that weigh less than 4.0 oz/yd2

  • are softer and more comfortable next to the skin and have better drape.

• Medium-weight fabrics weigh from 4.0 to 6.0 oz/yd2 (135.0 to 200.0 gsm).

  • Used for heavier and stiffer apparel, etc.

• Heavyweight fabrics They weigh more than 6.0 oz/yd(more than 200 gsm)

  • also are described as bottom-weight or suiting-weight goods because they are used for apparel bottoms such as pants, skirts and for suiting. They are durable, stiff fabrics used for outerwear, work apparel, upholstery, draperies, bedspreads, and technical products.

 How does the # of harnesses in a loom relate to the floats in a fabric?

The more harnesses the longer the float/ directly relates to the complexity and type of floats