17th IMACS World Congress
Scientific Computation, Applied Mathematics and Simulation
Paris, France July 11 - 15, 2005
Innovative Optical Device for Gloss
Evaluation of Worn Garments
J.M. Lucas, R.A.L. Miguel, P.T. Fiadeiro, M.J.S. Silva, M.L.A.G. Carvalho
jlucas@ubi.pt
University of Beira Interior
R&D Unit of Textile and Paper Materials – Dep. of Textiles
Covilhã - PORTUGAL
Innovative Optical Device for Gloss Evaluation of Worn Garments
Introduction
The abrasion resistance is one of the most important
properties of garment fabrics.
During wear, clothes are permanently subjected to friction,
either between them or against common objects.
Abrasion usually causes:
loss of weight
yarn breakage
change of colour
pilling formation
gloss
J. M. Lucas
University of Beira Interior - PORTUGAL
Introduction
Innovative Optical Device for Gloss Evaluation of Worn Garments
One of the main reasons to reject a worsted fabric is due
to the level of gloss caused by wear, this being possible
without having a significant weight loss.
Rejection point of a
garment:
Excessive surface gloss
Small physical fibre
degradation
J. M. Lucas
University of Beira Interior - PORTUGAL
Introduction
Innovative Optical Device for Gloss Evaluation of Worn Garments
Given the multiplicity of parameters that influence the abrasion
procedure and the difficulty to quantify the fabric abrasion
resistance, no analytic method is yet available which is accepted
without constrains by the different textile organisations.
The classical methods to evaluate abrasion resistance
do not include the assessment of gloss.
J. M. Lucas
University of Beira Interior - PORTUGAL
Introduction
Innovative Optical Device for Gloss Evaluation of Worn Garments
Testing methods based on the Martindale Wear & Abrasion
Tester simulate abrasion undergone by fabrics during wear, the
test being carried out up to the breakage of two yarns in the
specimens subjected to friction.
This is an objective method that does not translate the
useful life of fabrics, since well before the physical
degradation takes place, fabrics may already have lost
wear properties due to the change of their surface
appearance.
J. M. Lucas
University of Beira Interior - PORTUGAL
Introduction
Innovative Optical Device for Gloss Evaluation of Worn Garments
The testing methodology simulates the abrasion of fabrics against
frequent contact materials which enable gloss formation.
The Martindale abrasion procedure was changed, the standard
abrasion fabric being substituted by a common material that
easily allows an increase of gloss.
All fabrics tested were subjected to a given set of abrasion
stages.
J. M. Lucas
University of Beira Interior - PORTUGAL
Introduction
Innovative Optical Device for Gloss Evaluation of Worn Garments
Optimistic results have been achieved using three different
techniques:
Measurement of colour parameters using spectrophotometer,
the evaluation of gloss being made using luminance and total
colour difference;
Assessment of lightness of abraded samples using an image
analysis system;
Measurement of gloss using an optical set up using a collimated
laser beam.
J. M. Lucas
University of Beira Interior - PORTUGAL
Objectives
Introduction
Innovative Optical Device for Gloss Evaluation of Worn Garments
Establishment of a gloss measuring quality control
method to evaluate loss of appearance of fabrics
subjected to abrasion.
Establishment of a scientific and technological
basis to develop an apparatus for the evaluation of
gloss on worn garments.
J. M. Lucas
University of Beira Interior - PORTUGAL
Materials and Methods
Innovative Optical Device for Gloss Evaluation of Worn Garments
10 fabrics
100% wool
10 fabrics
polyester/wool
Abrasion Stages
1000
Gloss formation
of fabrics
Useful life Limit
Woolmark Company
IWS TM112 test
method
20000 abrasion
cycles
5000
100
10000
200
15000
400
20000
600
1000
1500
2000
3000
5000
10000
15000
20000
J. M. Lucas
University of Beira Interior - PORTUGAL
Innovative Optical Device for Gloss Evaluation of Worn Garments
Laser Setup
100
Materials and Methods
200
Image Analysis
System
400
600
1000
1000
1500
5000
2000
10000
3000
15000
5000
20000
10000
15000
20000
All fabrics
2 WO
2 PES/WO
fabrics
J. M. Lucas
Panel of Users:
Wear Limit
University of Beira Interior - PORTUGAL
In the most recent works, the
Differential Gloss Gradient
(DGG) at 20000 cycles was
evaluated for each fabric.
Recent work
Results and Discussion
Innovative Optical Device for Gloss Evaluation of Worn Garments
On the basis of a 0 to 10
scale, the user’s panel
classified fabrics concerning
the amount of gloss formed.
0
1
2
3
4
5
6
7
8
9
10
Same appearance as
original fabric
Highest amount of
gloss
J. M. Lucas
University of Beira Interior - PORTUGAL
The correlation between the objective evaluation (image
analysis system) and the subjective one (user’s panel) has
regression coefficient R2 of 73%.
Recent work
Results and Discussion
Innovative Optical Device for Gloss Evaluation of Worn Garments
From this value it may be considered quite promising to
consider a valid objective method, considering the
experience of the user’s panel.
J. M. Lucas
University of Beira Interior - PORTUGAL
Innovative Optical Device for Gloss Evaluation of Worn Garments
Wool Fabrics
Recent work
Results and Discussion
CORRELATION BETWEEN OBJECTIVE AND SUBJECTIVE GLOSS
EVALUATION FOR WOOL AND POLYESTER/WOOL FABRICS
Polyester/Wool Fabrics
Fabric
DGG
(20000 cycles)
User´s Panel
Evaluation
Fabric
DGG
(20000 cycles)
User´s Panel
Evaluation
LAL1
35
4
PLL1
3,6
3
LAL2
53,8
1
PLL2
37,7
7
LAL3
98,5
7
PLL3
17,4
8
LAL4
70,3
8
PLL4
58,5
10
LAL5
14,4
1
PLL5
8,5
1
LAL6
33,4
5
PLL6
24,2
7
LAL7
4,6
1
PLL7
43,7
7
LAL8
159,6
10
PLL8
13,8
5
LAL9
57,5
5
PLL9
3,5
1
LAL10
29,3
3
PLL10
42,3
8
Regression Coeficien
R2 = 73%
J. M. Lucas
Regression Coeficien
R2 = 71%
University of Beira Interior - PORTUGAL
Innovative Optical Device for Gloss Evaluation of Worn Garments
Conclusions
The low correlation values (1) have been achieved for fabrics
which present at least one of the following characteristics:
- Polyester fibres in its composition;
- Blend effects with a marked contrast;
- Yarn unevenness when warp and weft have different colours.
For fabrics having these characteristics, the followed method is
not the most suitable to evaluate gloss formation.
J. M. Lucas
University of Beira Interior - PORTUGAL
Conclusions
Innovative Optical Device for Gloss Evaluation of Worn Garments
Comparing the obtained results by both methods to evaluate
the gloss formation in fabrics, it can be said that the R2 values
for regressions between DGG and the abrasion stages are of
the same order for 100% wool fabrics.
In polyester/wool fabrics the R2 values between the abrasion
stages and DGG obtained using the optical laser set up seem
to be much better than those used the other measuring
technique.
J. M. Lucas
University of Beira Interior - PORTUGAL
Innovative Optical Device for Gloss Evaluation of Worn Garments
Conclusions
Based on the experience, the user’s panel may define, as a
function of the fabric end use, a limit value on the subjective
scale.
This value represents the point from which the fabric is no
longer suitable for use, due to the high amount of gloss.
Through the regression curve, the limit DGG can be found.
J. M. Lucas
University of Beira Interior - PORTUGAL
Conclusions
Innovative Optical Device for Gloss Evaluation of Worn Garments
Thus, conditions are met to establish a new objective method of
quality control concerning the tendency of fabrics to form gloss
and, thus, to evaluate the useful life respecting to this
characteristic.
For this, it is enough to submit the fabric to the abrasion
process in the Martindale apparatus, using a proper abrasion
surface during 20000 cycles.
After, the amount of gloss should be measured in both fabric
samples, before and after abrasion using the image analysis
system, and then calculate the DGG of fabric and compare it
with limit DGG defined by the user’s panel.
J. M. Lucas
University of Beira Interior - PORTUGAL
Innovative Optical Device for Gloss Evaluation of Worn
Garments
J.M. Lucas, R.A.L. Miguel, P.T. Fiadeiro, M.J.S. Silva, M.L.A.G. Carvalho
jlucas@ubi.pt
University of Beira Interior
R&D Unit of Textile and Paper Materials – Dep. of Textiles
Covilhã - PORTUGAL
Innovative Optical Device for Gloss Evaluation of Worn Garments
Characteristics of fabrics studied
100% wool fabrics
polyester/ wool fabrics
Fabric
Weight
(gr/m2)
Weave
Kind of
Finish
Colour Effect
Fabric
LAL1
174
Plain
Clear
Single colour
LAL2
184
Plain
Clear
LAL3
146
Plain
LAL4
174
LAL5
Weight
(gr/m2)
Weave
Kind of
Finish
Colour Effect
PLL1
243
Twill 3
Clear
Single colour
Blend
PLL2
188
Fantasy
Clear
Single colour
Clear
Blend
PLL3
161
Plain
Clear
Single colour
Plain
Clear
Single colour
PLL4
177
Fantasy
Clear
203
Twill 3
Soft Milled
Blend
Different colours
of warp and weft
PLL5
177
Plain
Clear
Blend
LAL6
147
Plain
Clear
Different colours
of warp and weft
PLL6
218
Twill 2/2
Clear
Single colour
LAL7
181
Twill 3
Soft Milled
Blend
PLL7
176
Plain
Clear
Single colour
LAL8
174
Twill 3
Clear
Single colour
PLL8
196
Fantasy
Clear
Single colour
LAL9
161
Twill 2/2
Clear
Blend
PLL9
184
Plain
Clear
Blend
LAL10
225
Fantasy
Clear
Single colour
PLL10
224
Plain
Clear
Single colour
J. M. Lucas
University of Beira Interior - PORTUGAL
Differential Gloss Gradient values for each abrasion
stage of 100% wool fabrics, using the image analysis
system
Differential Gloss Gradient (%)
180,0
Previous work
Results and Discussion
Innovative Optical Device for Gloss Evaluation of Worn Garments
160,0
140,0
120,0
100,0
80,0
60,0
40,0
20,0
0,0
1000
5000
10000
15000
20000
Abrasion Stage (cycles)
LAL1
LAL2
LAL3
J. M. Lucas
LAL4
LAL5
LAL6
LAL7
LAL8
LAL9
LAL10
University of Beira Interior - PORTUGAL
Differential Gloss Gradient values for each abrasion
stage of polyester/wool fabrics, using the image
analysis system
Differential Gloss Gradient (%)
70,0
Previous work
Results and Discussion
Innovative Optical Device for Gloss Evaluation of Worn Garments
60,0
50,0
40,0
30,0
20,0
10,0
0,0
1000
5000
10000
15000
20000
Abrasion Stage (cycles)
PLL1
PLL2
PLL3
J. M. Lucas
PLL4
PLL5
PLL6
PLL7
PLL8
PLL9
University of Beira Interior - PORTUGAL
PLL10
Innovative Optical Device for Gloss Evaluation of Worn Garments
Number of limit abrasion cycles for a limit DGG
(wool fabrics).
Fabric
Previous work
Results and Discussion
Relationship between differential gloss
gradient and number of abrasion cycles
Image Analysis System
Number of limit abrasion cycles for a limit DGG
(polyester/wool fabrics).
Fabric
Image Analysis System
R2 (%)
Number of limit cycles
PLL1
11.84
(1)
17713
PLL2
89.88
20239
98.97
13046
PLL3
96.80
(2)
LAL4
99.25
12324
PLL4
97.66
12270
LAL5
94.27
(3)
PLL5
98.44
102390
LAL6
78.74
(1)
PLL6
60.16
(1)
LAL7
93.72
78543
PLL7
99.82
16713
LAL8
98.41
8448
PLL8
73.70
(1)
LAL9
98.94
15001
PLL9
5.07
(1)
LAL10
95.71
26449
PLL10
99.91
18402
R2 (%)
Number of limit cycles
LAL1
91.26
67784
LAL2
91.40
LAL3
(1) Low correlation values
(2) Light colour fabric
(3) Surface pile fabric
J. M. Lucas
University of Beira Interior - PORTUGAL
Differential Gloss Gradient values for each abrasion
stage of 100% wool and polyester/wool fabrics,
using the optical laser set up
300
Differential Gloss Gradient (%)
250
Previous work
Results and Discussion
Innovative Optical Device for Gloss Evaluation of Worn Garments
200
150
100
50
0
100
200
400
600
1000
1500
2000
3000
5000 10000 15000 20000
-50
Abrasion Stage (cycles)
LAL1
J. M. Lucas
LAL4
LAL8
LAL9
University of Beira Interior - PORTUGAL
Innovative Optical Device for Gloss Evaluation of Worn Garments
J. M. Lucas
University of Beira Interior - PORTUGAL
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
17th IMACS WORLD CONGRESS SCIENTIFIC
COMPUTATION, APPLIED MATHEMATICS AND
SIMULATION
Paris, France July 11-15, 2005
A NEW EQUIPMENT FOR PILLING EVALUATION ON
WOOL FABRICS BASED ON OPTICAL ANALYSIS
M.L.Carvalho, R.A.L.Miguel, J.M.Lucas, P.T.Fiadeiro, M.J.S. Silva
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
Pilling formation
 Is the result of abrasion fabric that
mostly affects its surface appearance.
 Is the consequence of abrasion of
garments, either between them, or against
common objects of day life.
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
Pilling is the formation of fuzzy balls on the
surface of a fabric.
Pilling occurs when loose fibres in the
fabric are worked to the surface after the
fabric is subjected to abrasion.
Pilling phenomenon is highly revealed on
fabrics made of synthetics fibres.
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
Evaluation of fabric ability for pilling formation:
Comparison of fabric appearance with
photographic standards;
Counting or weighting the neps on a given
surface area of the fabric;
Image analysis techniques;
Laser triangulation techniques.
The accuracy of the results not always
is the best one
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
EVALUATION
The comparison of the abraded fabric
appearance with photographic standards is the
most current evaluation method for pilling
formation, but this method is highly subjective,
and the photographic standard cannot
represent all the kind of fabrics.
For this reason, it becomes important the
definition of an objective method to evaluate
pilling formation.
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
EVALUATION
 In this study, we propose a method for pilling
evaluation, objective, based on the optical profile
analysis, using a collimated light beam. The
optical profiles are measured using a CCD
detector along fabric sample, the untreated one
and those subjected to pilling.
The pilling simulation was made using
Martindale Wear & Abrasion Tester, according to
Woolmark TM 196 (2000) Test method.
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
Optical profile analysis
The proposed method is based on the shade
generated by the pilling developed along the
sample optical profile.
Original sample
Sample with pilling
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
Experimental mounting
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
It is possible to quantify the variation of the
illuminated area L
L = Lp – La
Lp- illuminated area of original sample
La- illuminated area of the sample subjected to abrasion
Pilling Index IP:
IP = (L / Lp)x100
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
RESULTS AND DISCUSSION
The variation of the illuminates area L increases
with the amount of pilling formed.
Pilling
Degree PD
Standard
illuminated area
Lp
Sample illuminated
area after abrasion
La
Difference of
illuminated area
L
Pilling
Index IP
1
1-2
2
2-3
3
3-5
4
4-5
5
98.624
97.997
97.951
98.887
99.071
99.048
99.077
99.049
99.326
94.644
94.756
95.049
97.129
97.758
97.657
98.616
98.445
99.300
3.977
3.241
2.902
1.758
1.313
1.391
0.461
0.634
0.026
4.033
3.308
2.963
1.778
1.32 5
1.404
0.465
0.640
0.026
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
5
Pilling Index IP
4
3
2
1
0
-1
1
1.5
2
2.5
3
3.5
4
4.5
5
Pilling Degree PD
1,5 corresponds to 1-2 degree
3,5 corresponds to 3-4 degree
2,5 corresponds to 2-3 degree
4,5 corresponds to 4-5 degree
Relationship between the conventional degree of
pilling PD and the pilling index IP (average values)
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
1,5 corresponds to 1-2 degree
3,5 corresponds to 3-4 degree
2,5 corresponds to 2-3 degree
4,5 corresponds to 4-5 degree
Relationship between the conventional degree of pilling
DP and the pilling index IP
(measured values)
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
RESULTS AND DISCUSSION
The correlation between objective evaluation of
pilling formation, given by IP (Pilling Index) and the
subjective evaluation of the same property based
on photographic scale of standard PD (Pilling
Degree) is given by the following mathematics
equation:
IP = 4.75 – 0.96 PD
This equation has an interesting correlation
coefficient R2 of 89.8%
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
CONCLUSIONS
The existing methods to evaluate pilling formation
are visual and thus subjective.
The proposed method allows
evaluation of this characteristic.
an
objective
It is based on the relationship between the
illuminated area of the optical profiles of fabric with
pilling and of original sample (standard). The
variation of illuminated area relates directly to the
pilling index IP.
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
CONCLUSIONS
The next steps will comprise the definition of an
equation that better correlates the pilling index IP
and the degree of pilling determined by the
subjective evaluation.
Using a properly designed computer application,
the optical system for pilling formation evaluation
may convert the optical reading to pilling degree
well known in the textile area.
UNIVERSITY OF BEIRA INTERIOR
R&D Unit of Textile and Paper Materials –
Textile Department
CONCLUSIONS
The correlation found has an R2 of 89.9%, this
value being quite hopeful to keep increasing the
number of tests, in order to achieve a more accurate
tendency of the relationship between objective and
subjective evaluations.