The Study on Tensile Strength of High Density Polyethylene at Various Cross Head Speed

Abstract

This paper was the study whether ultimate tensile strength of high density polyethylene (HDPE) in different cross head speeds had affected to tensile strength in statistical significance. In this experiment, the specimens were prepared as the size of the standard ASTM D 638 Type-I and brought to testing to find the value of tensile strength with Tensile Testing Machine. The specimens were divided into 4 groups in order to be tested with cross head speed of 10, 20, 30 and 40 mm/s and each group were repeated for three times. The result shown that, group A with the cross head speed at 10 mm/s had average of tensile strength as 21.50 N/mm², group B with the cross head speed at 20 mm/s had average of tensile strength 22.47 N/mm², group C with the cross head speed at 30 mm/s had average of tensile strength 23.20 N/mm² and group D with the cross head speed at 40 mm/s had average of tensile strength 23.76 N/mm². Though, the Analysis of variance or ANOVA on the difference in cross head speed found that tensile strength value was increasing according to cross head speed. That means the use of higher cross head speed resulted to higher tensile strength and in the use of ANOVA helped in analysing of statistical result found the calculated value was at critical region, that was Reject, H0 and Accept H1 , showed that the difference of cross head speed had effect to the change of tensile strenght value.