Effect of finishing on Knit Fabrics

Southeast University
School of Science and Engineering, Department of Textile Engineering
Effect of finishing on Knit Fabrics
Effect of finishing on Knit Fabrics 1

Introduction
 Textile finishing is a term commonly applied to different
processes that the textile materials undergo after
pretreatments, dyeing or printing for final embellishments to
enhance their attractiveness and sale apparels well as for
comfort and usefulness.
 Finishing process improves the physical properties of fabric
like feel, softness, tensile strength, elongation, G.S.M, dia,
shrinkage, spirality, twisting, and insulation properties.
Dhaka,15.05.2011 Effect of finishing on Knit Fabrics 2

The techniques of finishing depend
on the following:
• Nature of the fabric, i.e. chemical composition, state, weave,
etc. This determines the appearance, i.e. transparences,
luster, fullness, weight, whiteness, etc.
• The physical properties of the fabric, i.e. feel, softness,
stiffness, tensile strength, elongation, shrinkage property,
insulation etc.
• The end-use of the material i.e. non-shrinking, non-creasing,
stiffening etc.
• Receptivity of the fabric to various finishing operations, i.e.
water-proofing, flame-proofing, rot-proofing etc.
• Susceptibility to chemical modifications.

Finishing treatments are basically
meant to give the textile material
certain desirable properties like:
 Softness
 Lusture
 Pleasant handle
 Drape
 Dimensional stability
 Crease recovery
 Antistatic
 Non-slip
 Soil release

Definition of Finishing
Finishing is a term usually employed for process
other than scouring, bleaching, dyeing or printing, to
which the fabric are subjected to improve their
appearance, properties & serviceability.

Classification of Finishes
 The most common classifications are:
• Aesthetic finishes:
• Functional finishes
 Textile finishes are also categorized as:
• Mechanical finishes (Dry finishes)
• Chemical finishes (Wet finishes)

Classification of Finishes
Finishes can also be classified by their degree of
performance as follows:
• Permanent finishes
• Durable finishes
• Semi-durable finishes
• Temporary finishes

Controling parameter of finishing
• Dia of the fabric
• GSM of the fabric
• Shrinkage of the fabric
• Weight loss or gain
• Tension control
• Temparature of different stage
• Spirality control etc.
• Color fastness of the fabric etc.

Finishing process
Process of finishing for Open fabric
Dhaka,15.05.2011 Effect of finishing on Knit Fabrics
.
9
Unload fabric from Dyeing
Hydro extracting
Dryer/Stentering
Open compacting

Finishing process
Process of finishing for Tube fabric
Tube form fabric
Dewatering
Dryer for drying
Tube compacting
Slitting
Stentering
Open compacting

Finishing terms
GSM:
GSM means fabric weight in grams per square
meter’s .
 
 

Fabric Weight In Grams
2
length In m
GSM

Finishing terms
Shrinkage:
The amount of shrinkage for any given knit fabric is
primarily dependent upon the
product specifications and the knitting parameters used to
meet those specifications.
Formula of shrinkage % measurement:
Before Wash Length After Wash Length
Length Wise Shrinkage % 100
Before Wash Width After Wash Width
Width Wise Shrinkage % 100
.

 
Before Wash Length

 
Before Wash Width

Finishing terms
Spairality:
“Spirality” arises from twist stress in the
constituent’s yarns of plain fabric, causing all loops
to distort and throwing the fabric wales and
courses into an angular relationship
Dhaka,15.05.2011 Color fastness of dye goods. 13

Finishing terms
Color fastness:
The stability of color or its fastness is one of the
most important requirements of valuable
customers. Colour fastness of dyed goods means
the resistance power of dyed goods against any
hazards.
The color textiles show different resistance power
to different agencies such as light, wash, rubbing,
perspiration, water, bleach, acid, alkali etc.
.
.
14

Effect of Hydro and Dewatering
 If water remove from fabric is very much percentage than
fabric surface show crease mark, this fault can’t be
remove.
 If length wise run the fabric then 20% shrinkage occurs.
 If breakdown occur of de-twister than puckering occurs.
 If twist problem occur than it effect on knit garments.
 If do not take proper ballooning than folding mark occurs.
.
.
15

Effect of Hydro and Dewatering
 If squeeze roller/padder pressure is high than fabric surface
show pressure mark.
 If over feed dia of delivery side is not perfect than length
wise shrinkage occurs.
 If dia increase than become poor shrinkage properties.
 Dia increase in this stage because it helps to better work for
dryer & slitting.
 Dia mark also occurs in this stage.
.
16

Effect of slitting
 If dia is less than basket dia than fabrics do not cut
and if dia is greater than basket than GSM problem
occurs.
 Cut the fabric break wales line wise.
 Basket dia must be less then fabric dia.
.
17

Effect of Stentering
 Over feed tension is very important for this stage.
 If over feed decrease than length increase.
 More over feed give in white fabric.
 If need light shade of the fabric than increase padder
pressure.
 If need dark shade of the fabric than temperature increase
20˚C.
 For Lycra heat setting temperature need (190-200) ˚C.
 If half feeder Lycra fabric than increase speed and decrease
temp.
 If full feeder Lycra fabric temp need 200˚C.
 Heat setting takes for width fixed of Lycra fabric.
.
18

Effect of Compacting
Many textile manufacturers have, and still do, rely on
compaction as a means of shrinkage control. Compaction is a
method whereby the course loops are compressed upon
themselves. Different machines incorporate a variety of
techniques to accomplish this. There are basically two
classifications of compaction: heated rolls and shoe units or belt
shrinking units. Both methods rely on speed differential and
their patented compaction zones to accomplish the compaction.
Tubular and open-width systems are available. The fabric is
steamed to add moisture and then introduced to the compacting
zone. The compaction mechanism, along with heat and
moisture, forces the length stitches (courses) to be compacted.
.
19

Results and discussion
.
20
For finding the effect of finishing on knit fabric
some experiment are done on different types of
knit fabric.

Compare the GSM change for Single jersey
and single jersey lycra fabric
200
195
190
185
180
175
170
165
160
136
134
132
130
128
126
124
122
120
118
.
.
21
Grey Dyeing Slitting Stentering Compacting
155
GSM
GSM variation Stages
GSM
Grey Heat setting Dyeing Slitting Stentering Compacting
116
GSM

Compare the Variation of GSM for 1×1 rib
fabric and Interlock fabric
210
205
200
195
190
185
230
220
210
200
190
180
.
22
180
GSM
170
GSMChange

Compare the variation of GSM for fleece
fabric and Pique
235
230
225
220
215
210
205
220
210
200
190
180
.
23
Grey Dyeing Slitting Stentering Compacting Brushing
200
GSM
170
GSM

Compare the shrinkage % change for Single
jersey and single jersey lycra fabric
3
2
1
0
-1
-2
-3
-4
1
0
-1
-2
-3
-4
.
24
Dyeing Slitting Stentering Compacting
-5
Shrinkage%
width%
length%
-5
Width%
Length%

Compare the Variation Shrinkage % for 1×1
rib fabric and Interlock fabric
1.0
0.5
0.0
-0.5
-1.0
-1.5
-2.0
1
0
-1
-2
.
25
-2.5
length%
width%
-3
Length%
Width%

Compare the shrinkage % of fleece
fabric and Pique
1.0
0.5
0.0
-0.5
-1.0
3
2
1
0
-1
-2
-3
.
26
-1.5
Length%
Width%
-4
length%
width%

Spirality % change for Single jersey and
single jersey lycra fabric
3.0
2.5
2.0
1.5
1.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
.
27
0.5
Spirality%
0.0
Spirality%

Spirality % change for 1×1 rib fabric
and Interlock fabric
2.5
2.0
1.5
1.0
0.5
2.6
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
.
28
0.0
Spirality%
0.8
Spirality%

Spirality % of fleece fabric and Pique
Spirality%
3.0
2.5
2.0
1.5
1.0
spirality%
3.2
3.0
2.8
2.6
2.4
2.2
2.0
1.8
1.6
1.4

Discussion

References
• http://www.thesmarttime.com
• Books of Finishing ,By-Petro Bellini,Ferruccio Bonetti.
• Lecture sheet of Dr. Zulhash Uddin
• Experimental data from Paddma poly cotton knit fabrics
Ltd.

Acknowledgement
We would like to express many thanks to our
honorable teacher Md. Fazley Elahi for giving us a
very good opportunity for presenting ourselves. We
also thanks our parents who encouraged us every
step of our life. Lastly thanks all of you who are
give kind attention for this presentation ceremony

33
Thank you ALL for your Attention

Effect of finishing on Knit Fabrics

More Related Content

What's hot

Viewers also liked

Similar to Effect of finishing on Knit Fabrics

More from Mazadul Hasan Shishir

Recently uploaded

Effect of finishing on Knit Fabrics