Mixing of glass fibers with nylon 6,6

Nylon 6,6 is one of the toughest of the engineering thermoplastic resins. It is resistant to corrosion and chemicals, but has a limited capability due to low rigidity, strength and moisture adsorption. Glass fibers are very strong and rigid but susceptible to environmental attack. Proper mixing of these two materials would form a fiber composite with high strength, toughness, rigidity and stability at elevated temperatures. The main purpose of this work was to study the effect of properties of a fiber composite containing 20% loading of glass fibers in Nylon 6,6. Two different types of twin screw extruders, one a co-rotating and the other a counter-rotating, were used. Two different screw designs, a high-shear and a low-shear design, were used on each of these extruders. A statistical process study was developed using ECHIP. RPM of the screw and the output rate of the extruder were the identified variables in the process. Molded samples were evaluated for tensile, flexural, impact and heat deflection characteristics. Scanning Electron Microscopy study was also performed to evaluate the fiber distribution, length and wetting characteristics. The results were analyzed for all of the above properties and it was concluded that there was a great improvement in the properties of the reinforced material. Also, it was found that low RPM and output rates on the co-rotating twin-screw extruder would result in the best properties.