Study On Influence Of Processing Parameters On Weld Line Tensile Performance Of Injection Molded Nylon 6/Montmorillonite Nanocomposites

The polymer/montmorillonite nanocomposites have received significant attention, due to their distinctive structures lead that they have better properties in mechanical, thermal and gas/liquid barrier resistance when compared with the pure polymer and conventional composites. Today polymer/montmorillonite nanocomposites have showed their important significance and comprehensive applied future.As the development of this field is not long enough and the research is rather plain both in extension and in depth no matter in home and abroad. The published paper are mainly focused on the preparation of materials, the character of the microstructure and the mechanical properties. But systematic studies on the application of injection molded nanocomposites with weld line lacked for investigation.The main work of this paper include following parts:1. The effects of each process factor on the tensile strength of specimens with weld line and without weld line are investigated using the specimens that are injected by two different nylon 6 materials, one is pure nylon 6 and the other is the nylon 6/ montmorillonite nanocomposites with 5wt% nano-montmorillonite. It is found that with addition of montmorillonite particles the weld line strength becomes significantly weakens as compare to those pure nylon 6 parts.2. An L9 experimental matrix design based on the orthogonal test designs are conducted to optimize the injection molded parts of nylon 6/montmorillonite nanocomposites tensile strength with and without weld line. Four factors including mold temperature, melt temperature, injection speed and packing pressure are selected in the experiment. The optimum tensile strength and processing conditions are predicted.3. Based on the orthogonal test designs, twenty-five-group quantitative data are gained. Neural network is trained by the data, thus the neural model is developed. Mold temperature, melt temperature, injection speed and packing pressure are four important processing conditions, which affect the tensile strength of specimen on weld line. The neural network model mapped the relationship between these injection parameters and the tensile strength of nylon 6/montmorillonite nanocomposites injection molded specimen.