Visual Machine Development And Process Study On Rotational Molding

Rotational molding is a new polymer processing. It is introduced relatively comprehensively about the general situation in rotation molding, such as the principle, the advantages and disadvantages, the application, the materials, the machines and the process performance of plastics and the development in past time and now days in home and abroad.. It is noticeable that with the development of rotational molding technology it has been an important force in polymer processing.To comprehend more about the rotational molding process, a new visual rotational molding machine was designed in this subject. It could be heated by far-infrared or micro-wave. And it was vacant that the process was combined with visualization, far-infrared heating or microwave heating. Some new way was supplied in the process study in rotational molding such as applying visualization, heating by far-infrared or microwave. And at the same time, the new machine could be a strong guarantee for the process study.The rotational molding has been developed perfectly abroad, but rarely in China. Many experiments has been done by using the home-made rotational foaming molding machine. LLDPE and AC blowing agent was set into the home-made machine respectively according to a certain weight in advance. Then the polymer would be foamed when the mould was heated up to a certain temperature. After the polymer was foamed completely, cool the mould and take out the part. The operation conditions of rotational foam molding was exposed in the experiments. It showed that the heating and cooling temperature and rate was the factor effecting the process except for the blowing agent variety and the loading weigh. And the demoulding agent should be also noticed in the rotational foam molding.The base theory would be found though the study of plastic heated by microwave for the succedent rotational micro-wave heating molding. The sensitizing agent such as N₂₃₄,HG-1P,Al₂O₃, was set into the HDPE or LLDPE respectively according to a certain weight in advance. After the mixture was melt, compounded and prilled by twin screw extruder, the blender was dispersed uniformly and heated in the micro-wave area. The heating-up curve was drawed after the experiment. It showed that the variety of plastic and sensitizing agent and the vary of the weigh had a serious effect on the plastication in the rotational micro-wave heating molding. The mixture radio of plastic and sensitizing agent also played an important role in the plastication. The heating and cooling temperature and time were important in the rotational micro-wave heating molding.