SUMMARY
The paper presents investigations results of geometric surface structure (SGP) and kinetic friction coefficient μ_k of yarn at these surfaces
and micro-hardness of yarn guides made of sintered materials. The analysis was made for guides produced of sintered carbide G10 (94% of wolfram carbide + 6% of cobalt), porcelain covered with glaze and ceramal - Al₂O₃, as well as yarn guides made of 45 steel with ceramic Al₂O₃ coating obtained by plasma spraying. Authors determined the value of correlation coefficient for each parameter taken to SGP estimation in function of yarn friction coefficient μ_k. On this basis to SGP estimation of yarn guides these parameters were proposed, for which the R coefficient reached the greatest value, i.e. R_t, R_pm, S_m, Δq and r. The best proprieties of surface layer were obtained in the case of yarn guides produced from porcelain coated with hard glaze and yarn guides made of Al₂O₃ ceramal.

Key words
Yarn guides, surface layer, coating, friction coefficient of yarn.

¹ Akademia Techniczno-Humanistyczna, Bielsko-Biała