Figure 10- 1 Weaving

Warp Cross Section

10-2 Woven Fabrics

Basic Functions Of A loom Or Weaving Machine

I

Warp and Filling

W~~mFabr lcs 10-5

Flow Of Yarn On A Loom

Warp Beam

Back Rest (Breast Beam)

Drop Wires

Harness and Heddles

Reed

ClothFell

FabricRoll

W I

104 Woven Fa-

/- warp

Figure 10-2 Shedding Formation

W ~ ~ m F a b r l c s 10-5

n

Shedding Motion

Definition Shedding is a function of weaving involving the lifting of harnesses containing warp ends in order to provide a shed opening for filling insertion and to control design.

Types O f Shedding Cam Shedding - Employs circular profiled cams to lift the harnesses - Usually 6 - 8 hamesses

- High loom speeds - Lifting plan relatively easy to change

. - Plain, simple twill and satin weaves

Dobby Shedding - Employs a chain of wooden bars with pegs inserted or plastic

- Usually 8 - 24 harnesses - More complex twill and satin weaves - Small geometric figures and spot weaves - Pattern stripes - Slower loom speeds than cam shedding - Lifting plan more dimcult to change

paper with holes inserted or computer controls

10-6 Woven Fabrlcs

Jacquard Shedding - Employs cardboard cards with holes inserted, plastic paper with

holes, or computer controls - Individual warp ends or groups of warp ends are lifted without the

use of harnesses - Design capability is virtually unlimited - Can produce very large design repeats - Slowest loom speeds - More expensive fabrics

W O V ~ Fabrtcs 10-7

i;-J Water

Projectile

Rapier

Other

$ 2 P

Lp ;, '\ I

Filling Insertion Rate '*,

10-8 Woven Fabrlcs

Woven Fabric Production

Running Time Efficiency (Em = Running Time + Down Time

Pick Densitv The number of picks required per unit length of fabric. PicWinch (ppi)

Loom Speed ?;he number of picks inserted into the fabric per unit time. PicWminute (ppm)

minuteshour x EFF inchedyard X pickdminute

picwinch Fabric Production =

_-

= linear yards of fabrichour

W O V W I F ~ ~ W 10-9

I

Figure 10-3 Rapier Systems

Head

single RUM Rapier

Giver Taker

Double Flex Rapiers

10-1 0 WOVWI F a b h

Figure 10-4 Rapier Filling Insertion System

Woven Fabrlcs 10-1 1

Figure 10-5 Projectile Filling Insertion System

_-

10-12 woven Fabrlcs

--

Figure 10-6 Air-Jet Filling Insertion Systems

WovenFaklcs 10-13

Figure 10-7 Air-Jet Filling Insertion: Schematic Representation of the Pick Insertion Sequence

10-14 Woven Fabrlcs

3

Beat-Up Motion

Functions of the reed - Keep ends parallel and in the same position - Beat the filling yarn into the fabric - Provide some control for filling insertion

Enddinch Endddent Note: Reed No. =

Implications of increased beat-up - Filling density - Warp tension - Noise and vibration - Fabric structure and properties

Woven Faklcs 10-15

Figure 10-8 Beat - Up

10-16 W O V ~ FabtlCS

Wo

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Fab

rlc~ 10-17

P

B

I

Warp Control

Let-off - Controls rate of yarn removal from the warp beam - Controls tension of warp ends

Take-up - Controls pick spacing and rate the fabric is delivered from

- Must be synchronized with the Let-Off for proper yam tension the loom

control during weaving

10-18 Woven Fabrlcs

Woven Fabric Design

I. Fabric Constntction Factors The following factors show the detailed information that is necessary in producing a woven fabric for a specified end use.

k TypeofFiber 1. Natural 2. Man-made

B. Type ofyarn 1. count 2. Structure 3. Twist 4. Color

C. Fabric Set (Construction) 1. Fabric count 2. Yarn count (warp and filling) 3. Cover 4. Fabricwidth 5. Fabric weight

D. Yarn Arrangement in Fabric 1. Denting: regular or irregular 2. Type of yam: same or different for warp and filling 3. Warp beams: one or more with same or Merent tensions

E. Weaving _ _ 1. Design

a. Weave b. DraRplan c. Camplan

Woven Fabrics 10- 19

2. Type of loom 3. Special loom requirements

F. Surface Alteration (Finishing) 1. Printing 2. Chemical treatment 3. Mechanical treatment 4. Coating

II, Basic Weaves

A. Plain Weave and Its Derivatives 1. Warp rib weave 2. Filling rib weave 3. Basket weave

B. Twill

C. Satin

I& Weave Variations are Produced B y

A. Different ply, count or texture of yarns

B. Equal or unequal size and count for warp nd filling

C. Equal or unequal yam count for warp and filling

D. Equal yam size and unequal or dented spacing

E. Equal yam count for warp and filling and unequal yam size

F. Interlacing different patterns and weave effects

G. Interlacing different colored yarns

- .

10-20 woven Fabrics

t

i

1

i EZenents of the Weave

A Risers and sinkers

B. Binding points

C. Floats

D. Intersections

- V. Use of Design Paper A Graphically shows the interlacing of warp and filling yarns

1. Vertical row of squares represents a warp end. 2. Horizontal row of squares represents a pick.

B. Interpretation of design on paper 1. End over pick 2. Pick over end

C. Repeat of a weave

woven Fabrlcz, 10-21

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Figure 10-9 Fabric Weaves

1 1 1 1 1 1 I I I I I I

I

1 1 I I

~

1 I I I I I

I I 1 1 - I I I I

I I I , - I I I I 1 1 1 I I 1 1 1 I I 1 I I ,

10-a WovenFabrlcs

U U

WovenFabrlcs 10-23

L

Figure 1040 Twill Weaves

10-24 W O V ~ FabrlCS

Figure 10- 1 1 Basket Weave and Twill Weaves

Woven FaMa 10-25

Figure 10-12 Twill Weaves

3/1 RH.MI 41 R.H.MiQ

10-26 W O V ~ FabIkS

Wo

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Fa

btk

S

10-27

Figure 10- 13 Warp Satin And Filling Satin (Sateen)

10-28 W O V ~ FabrfCS

I

Fabric Grading

Pumose ClassLfy fabric according to quality, first quality, second quality, etc.

Supply information to management as to the qualities being produced.

Fabric Qual it?

Physical Properties - Specification

Material Defects

WovenFabrlcs 10-29

I

L-

o

0

0

0

0

Physical Properties

Weight

Construction

Strength - tensile and tear

Abrasion resistance and pilling

Dimensional stability (heat, washing, dry cleaning)

Appearance &r washing

Fastness (wash, light, gas)

Stiffness and drape (handle)

Sewability (seam strength and resistance to slippage)

10-30 WOV- FabkS

Fabric Defects

Warn Imnerfections Filling Imnerfections Broken or Missing End Broken Pick Coarse End Missing Pick Slubs Coarse Pick Streaks Slubs

Uneven Yam Uneven Weaving Reed Marks Misdraw Slack End Others

Streaks Mixed Filling, Barr6 Bar (start up, thick, thin) Jerk - Ins (slough-off) Kinky Filling Bias, Bowed, Skewed Filling Others

W O V ~ Fabtic~ 10-31

Fabric Structure vs. Fabric Expectations

Types of fibers or yarns, method of fabric construction and finishes applied interrelate in the production of a fabric. When one of these components is changed, the fabric will change and will affect the fabrics.

0 Weight

Hand

0 Drapability

Performance Expectations

0 Appearance

Covering Power

SurfaceTexture

Thickness

Luster

Strength

m Flexibility

Resiliency

Warmth

0 Affbity to Dyestuff

EndUse

cost

These are basic inherent properties to be found in a given fiber, yam, finish, and fabric construction. One or more of these properties may be modified or altered to achieve the desired results for a fabric applicable to a particular end use or design.