Post on 05-Aug-2018
Figure 10- 1 Weaving
Warp Cross Section
10-2 Woven Fabrics
Basic Functions Of A loom Or Weaving Machine
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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
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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
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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 =
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= linear yards of fabrichour
W O V W I F ~ ~ W 10-9
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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
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10-12 woven Fabrlcs
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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
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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
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Fab
rlc~ 10-17
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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
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10-20 woven Fabrics
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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
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1 1 I I
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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
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WovenFabrlcs 10-23
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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
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Fa
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10-27
Figure 10- 13 Warp Satin And Filling Satin (Sateen)
10-28 W O V ~ FabrfCS
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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
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0
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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.