Tham khảo tài liệu 'optoelectronics materials and techniques part 11', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Optoelectronic Techniques for Surface Characterization of Fabrics 289 of abrasive particles of the emery paper. P80 corresponds to a density of 80 particles per mm2 with an average 201 pm in diameter and P800 correspond to a density of 800 particles per mm2 with an average pm in diameter. Notation Elem weav ent e ary Surface state Material Number of elements cm S1 NE E-P80 E-P800 100 cotton 28 warp yarns cm 17 weft yarns cm diagonals cm S2 NE E 96 polyester 4 elasthanne 44 warp yarns cm 37 weft yarns cm 21 diagonals cm S3 NE E 100 cotton 29 warp yarns cm 19 weft yarns cm 11 diagonals cm plain woven fabric B E NE 100 cotton warp yarns cm weft yarns cm Table 1. Characteristics of the woven fabrics used in our tests. a b Fig. 2. SEM images of twill woven fabric a non-emerized S2 and b emerized S2. 290 Optoelectronics - Materials and Techniques Spunbonded nonwovens for medical use are also studied. Two samples are available one was defined by the manufacturer as not compliant noted NT4-NC in terms of softness in comparison with the second one NT4-C Figure 3 . The cohesion of this filament web was obtained by thermobonding. Compliant Not Compliant Di . II r. D2 di d2 points I cm Di D2 points I cm Thermobonding point Fig. 3. Our test samples of spunbonded nonwovens. 3. Profilometry State of the art Two elements have to be considered for characterizing textile surfaces the structure and the hairiness. In order to scan surfaces for constructing a profile of the sample several methods have to be cited. Based on a point by point scanning of a surface different technologies of optical profilometers exist. The laser triangulation technique is used by Ramgulam et al. 1993 . Seifert et al. 1995 compare this method with a classical contact method using a stylus probe. At each scanned point of the surface the laser beam is reflected on an optical sensor. Hence the vertical coordinate of the point is recorded. From several points it is possible to .
