Study On Yacht And Optimization Of Part Design For Rotational Molding

Rotational molding is a manufacturing process for producing hollowplastic parts. In this process, molds carrying the plastic powder aremounted on the arm of the machine, which rotates about a central axis.The mold, in turn, rotates about its own (perpendicular) axis, whichresults in a biaxial rotational system. While in the uniformly heatedfurnace, the plastic melts and sticks to the inner surface of the mold cavity.The yacht for the rotational molding was studied in this thesis.AUTOCAD was utilized to design and manufacture of wobblingrotational molding machine, single axis rotational molding device andbiaxial rotational molding machine.UG and FREESHIP were adopted to design and optimize the yacht on the basis of rotational molding machine. Optimizing parameters of yacht based on fiber reinforced plastic boat and hydraulics was applied to launch the yacht's modeling and achieved the most optimized 3-D modeling.According to the mold design criterion of rotational molding, the mold for yacht was built. And many details of devising needed to be solved very carefully during the design such as parting faces, fixtures and vent hole.Based on the single axis rotational molding device, the processing of rotational molding was studied and predigested. Especially the heat transfer during rotational molding was analyzed and a detailed mathematic model was presented. The heating time of mold and the heating time of resin material was resolved. It was also brought forward that the solution of analyzing the function of time, radius and distribution about melting process. These groups satisfied the boundary conditions and the dimensional analysis, so could be applied in the manufacture with care.A hypothesis based on the six experiments during trial run of the single axis rotational molding machine was proposed to explain the cause of scrap.An innovation and breakthrough in theoretical research of rotational molding were achieved in the study. The research must contribute to the development of yacht for rotational molding in theory and experiment.