1. The document describes a study on developing a natural convection solar dryer for drying plastic materials like Nylon-6. 2. A mathematical model was developed to simulate the solar collector and optimize design parameters like absorber plate temperature. Experimental results matched the model with less than 5% variation. 3. Drying experiments were conducted with Nylon-6 pellets in the solar dryer. Temperatures up to 70°C were achieved with air velocities up to 2m/s. Effective moisture diffusivity of Nylon-6 was calculated to be 4-6.5x10-9 cm2/s from drying kinetics data.