Effects of filler contents and processing parameters on the weldline strength of compression molded natural rubber

Abstract

The presence of weldlines in rubber products is regarded as a one of the most undesirable phenomena, since it results in poor mechanical properties. Compression molding of large or complicated products are prepared by multiple charges, which produces weldlines once the melt fronts are joined by the impingement flow. In this work, the effects of curing systems, processing parameters, filler types, and contents on weldline strength of compression molded natural rubber (NR) were investigated. Furthermore, the effects of curing systems on the aging properties of NR vulcanizates were studied in details. The results show that an increased amount of calcium carbonate does not affect the weldline strength. However, the difference in tensile strength between weldline and nonweldline specimens becomes larger with the high loading of silica and carbon black. In addition, for the factors selected in the experiments, clamping pressure, and curing system were found to be the principal factors affecting the weldline property of vulcanizates. POLYM. ENG. SCI., 2011. © 2011 Society of Plastics Engineers

Development of Hyperelastic Model for Natural Rubber Containing Weldlines

“…Generally, one of the assumptions used for the calculation is the homogeneous matrix without any defects such as voids and weldlines. However, it is well known that these defects significantly affect the mechanical strength of materials [12][13][14] . In this work, NN model was employed to capture the strain-energy-density function with the wide range of uniaxial tensile deformation for natural rubber containing a weldline.…”

“…Figure 1. (a) compression mold for the preparation of the test piece, (b) vulcanized rubber sheet with weldline,and (c) tensile specimens13 …”

Development of Hyperelastic Model for Weldlines Containing Natural Rubber Molded Part

“…Generally, one of the assumptions used for the calculation is the homogeneous matrix without any defects such as voids and weldlines. However, it is well known that these defects significantly affect the mechanical strength of materials [12][13][14]. In this work, NN model was employed to capture the strain-energy-density function with the wide range of uniaxial tensile deformation for weldline containing rubber part.…”