Comparative study of friction coefficient in nonwovens usin frictorq, fabric friction tester

Abstract

Nonwovens single-use surgical gowns are used ad frequently touched by thr human skin. Interaction with human sense is therefore an important performance property. When touched by the human hand, friction is one of the the first feeling and therefore friction coeficiente is an important parameter. Recently, a patented laboratory instrument was investigated and designed at the University of Minho based on an innovative method of accessing friction coefficient of 2D surfaces (fabrics, nonwovens, soft papers). Unlikely othrer methods, frictorq is based on rotary movement and therefore on the measurement of a friction reaction torque. On the more recent version the contact between the 2D sample and the instrument contact sensors is restricted to 3 small special elements radially disposed at 120º. Providing during the test a relative displacement of approximately 90º, it is assures that a new portion of the sample is always moved under the sensors. In the model, friction coefficient is worked out from the friction reaction torque measured by means of a high sensitive torque sensors, the normal load created by the contact sensors and geometrical parameter. Contact pressure on the fabric samples was set to 3.5KPa and the linear velocity in the geometric centre of each contact element was approximately 1,5 mm/s. In the paer, a description of the instrument is given as well as it fundamentals and working principle followed by a study, where a comparison between thre different materials for manufacturing medical gows was performed under controlled atmosphere. The tested materials were materials were two spunlace nonwoven and one SMS. the results of the experimental work are analysed using various tools, including spss14.0 statistical package and discussed on the light of the importance of friction to the performance of surgical gowns. Differences in friction coefficient were detected associated to the manufacturing process, composition of the nonwoven materials and outer or inner-facees.