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A 3D Scanning System for Fabric Fuzziness and Pilling Evaluations

Bugao Xu and Ming Yao

The University of Texas at AustinJanuary 2005

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3D Laser Scanning System

Goalto acquire the surface profile of a fabric

and to characterize the surface roughness.

SetupProfile sensor: 10um 2-axis stage: 0.5 um/stepA/D board: 12 bits

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HardwareDimension: 8 x 8 x 6 inches

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Software

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Samples

Five knitted fabric (interlock, dark blue) were washed and dried different cycles.

F5: no fuzzF4: lowF3: mediumF2: high (a few pills)F1: severe ( a lot pills)

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Procedures

• Scan the sample

• Level the surface

• Set the central plane

• Select the offset plane

• Calculate surface parameters

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Scanning

Profiles, 1x1 in2

Surface, 200 DPI

Surface, 400 DPI

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Leveling (B-spline Approximation)

u and v: two parameters

Ni,q(v) and Nj,p: basis functions

p and q: degrees

{Pi,j|0<i<m, 0<j<n}: control points

m

i

n

jjipjqi PuNvNvuS

0 0,,, )()(),(

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Leveling

ScannedSurface

B-spline Fit Plane Leveled Surface

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Offset Plane

Central Planeu=0 um

Offset Planeu=0.25um

Offset Planeu=0.3um

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Surface Roughness(ANSI/ASME B46.1-1985)

Roughness Average Ra

Root-Mean-Square Roughness Rq

Skewness Rs

Central Lineyi

ia yN

R1

21iq y

NR

33

1i

qs y

NRR

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Skewness

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Surface Roughness(ANSI/ASME B46.1-1985)

Ten-point Height Rz:

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)()( 10864297531 RRRRRRRRRRRz

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Surface Roughness(ANSI/ASME B46.1-1985)

Bearing Length Ratio tp:

Mean Spacing Rsm:

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Surface Roughness

Peak Count Np:

Peak Size Average Sa:

Peak Height Average Ha:

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F5

17

F4

18

F3

19

F2

20

F1

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Pilling

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Results

0

0.2

0.4

0.6

0.8

1

1.2

1.4

1 2 3 4 5

Ra

Rq

Rz

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Results

-0.1

0

0.1

0.2

0.3

0.4

0.5

0.6

1 2 3 4 5

Skew

tpc

Peak count

Peak size

Peak height

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ResultsF1 F2 F3 F4 F5 F6

Ra 0.287 0.139 0.123 0.101 0.086 0.092

Rq 0.365 0.181 0.158 0.127 0.110 0.140

Rz 1.257 0.613 0.573 0.383 0.334 0.690

Rs 0.518 0.455 0.237 0.005 -0.001 2.270

tp 0.259 0.061 0.056 0.017 0.008 0.019

Np 0.446 0.481 0.535 0.277 0.184 0.047

Sa 0.507 0.154 0.109 0.089 0.067 0.248

Ha 0.511 0.368 0.335 0.304 0.296 0.714

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Conclusions

• The selected surface parameters can effectively differentiate the level of fabric fuzziness/pilling.

• It provides the characteristic information about fuzz and pills.

• It is independent of fabric structure, color and orientation.

• The scanning is a slow process.