A 3D Scanning System for Fabric Fuzziness and Pilling Evaluations Bugao Xu and Ming Yao The University of Texas at Austin January 2005

3D Laser Scanning System Goal to acquire the surface profile of a fabric and to characterize the surface roughness. Setup Profile sensor: 10um 2-axis stage: 0.5 um/step A/D board: 12 bits

Hardware Dimension: 8 x 8 x 6 inches

Software

Samples Five knitted fabric (interlock, dark blue) were washed and dried different cycles. F5: no fuzz F4: low F3: medium F2: high (a few pills) F1: severe ( a lot pills)

Procedures Scan the sample Level the surface Set the central plane Select the offset plane Calculate surface parameters

Scanning Profiles, 1x1 in2 Surface, 200 DPI Surface, 400 DPI

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

Leveling Scanned Surface B-spline Fit Plane Leveled Surface

Offset Plane Central Plane u=0 um Offset Plane u=0.25um

Surface Roughness (ANSI/ASME B46.1-1985) Roughness Average Ra Root-Mean-Square Roughness Rq Skewness Rs Central Line yi

Skewness

Surface Roughness (ANSI/ASME B46.1-1985) Ten-point Height Rz:

Surface Roughness (ANSI/ASME B46.1-1985) Bearing Length Ratio tp: Mean Spacing Rsm:

Surface Roughness Peak Count Np: Peak Size Average Sa: Peak Height Average Ha:

F5

F4

F3

F2

F1

Pilling

Results

Results

Results F1 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

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.