a 3d scanning system for fabric fuzziness and pilling evaluations

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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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LevelingScannedSurface

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

R 1

21iq y

NR

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1i

qs y

NRR

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Skewness

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

Ten-point Height Rz:

5)()( 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

00.20.40.60.8

11.21.4

1 2 3 4 5

RaRqRz

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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 0.092Rq 0.365 0.181 0.158 0.127 0.110 0.140Rz 1.257 0.613 0.573 0.383 0.334 0.690Rs 0.518 0.455 0.237 0.005 -0.001 2.270tp 0.259 0.061 0.056 0.017 0.008 0.019Np 0.446 0.481 0.535 0.277 0.184 0.047Sa 0.507 0.154 0.109 0.089 0.067 0.248Ha 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.