ICAR Technical Series no. 7 - Nitra Proc.

Influence of ageing on linersThe results will be evaluated by methods of variety analysis,calculation of correlative relationships and regressive analysis.2. Condition of inner side of liner tested on raster scan scope.Results anddiscusionThe measured results of physical and mechanical properties of linersproduced by differend producers after different function times are showedin table 1 and 2.Following the achieved results the hardness of liners, expressed in Sh A,increased during the operating time till 300 hours, later decreased (besidessample number 1, new rubber, by which the hardness changed onlyminimally after 600 operating hours). The hardness increased achievedthe significant differences between the variats of individual rubber samples.Following the statistical evaluation, the hardness of sample number1 decreased opposite the all other operating times statistically significantlyafter 600 hours.Table 1. Physical-mechanical characteristics of liners (sample n. 1).OperationThickness,mmResistance,MPa Tensibility, % Hardness, Sh Atime, hours x s x s x s x sNew 2.00 0.11 10.9 1.32 448 22.8 54.9 0.71300 h 2.18 0.12 9.8 1.21 428 59.3 54.5 0.41600 h 1.74 0.11 12.1 1.75 416 41.0 53.9 1.56900 h 2.14 0.14 9.3 0.62 432 17.9 45.9 1.181 200 h 2.18 0.12 10.4 1.34 480 28.3 49.7 2.36Table 2. Physical-mechanical characteristics of liners (sample n. 2).OperationThickness,mmResistance,MPa Tensibility, % Hardness, Sh Atime, hours x s x s x s x sNew 2.18 0.06 12.3 1.67 456 8.9 47.7 1.63300 h 1.98 0.12 15.0 1.15 408 11.0 54.8 1.01600 h 2.49 0.08 11.7 0.26 448 11.0 44.9 1.82900 h 2.12 0.09 13.7 0.56 420 24.7 43.1 1.571 200 h 2.49 0.08 12.3 0.87 476 21.9 45.1 0.86208Conference on "Physiological and technicalaspects of machine milking"