This research primarily focuses on increasing the physical strength and surface texture of the ABS prototype. The material used is a Scrylonitrile Butadiene Styrene (ABS), and is fed into the extrusion head and heated to a semi-liquid state. A primary modeling nozzle is used to produce the model geometry and a secondary nozzle, or release aterial nozzle, is used to create the support structure for the model being built. The physical and quality (surface texture) of a prototype is a fuction of various process parameters, some of which the operator can control while other cannot be controlled. Critical controllable factors are the Nozzle geometry, air gap, hatch pattern, layer thickness, road width, flow rate, envelope temperature, and extrusio or model liquefier temperature. The prototype strength depends on the bulk polymer strength, the mesostructure and the fiber-to-fiber bond strenth. The presence of voids in the FDM-ABS material decreases the amount of load carrying material in the case of tensile loading. Here, most importantly the extrusion profile of the nozzle, a hardware parameter of the FDM machine, is altered and comparison study is done on the basis of the minimum void density in the inter-lamellar layers of the prototype resulting from the modified nozzle to the regular profile cylindrical nozzle. Optimum settings leads to the minimum void density of the prototype and hence the higher tensile strength. Higher tensile strength improves the stability of the material and can be used in fit, form and fuction applications with greater efficency. Replacement models for limbs and joints in the bio-medical fields are tougher and are better wear and tear resistant.
|Original language||English (US)|
|State||Published - Mar 9 2004|