Glass Fiber Manufacturing Process Development.

A program is undertaken to select forming equipment and operating conditions to give optimum fiber properties with X-2285 glass, a composition in the SiO2 -Al2O3 -MgO -BeO FIELD. Target values are tensile strength of 800,000 psi minimum; modulus of elasticity of 16 x 106 psi minimum; density of 2.49 g/ cc maximum; and a pull of twelve pounds per hour. Nineteen bushing trials are made, involving four sizes of melters, three variations in bushing designs, five types of tips and five hole sizes. Excellent operation is achieved at desired pull rates. Highest strength achieved is 700,000 psi and highest modulus is 14 x 106 psi, which are below the targets. However, density is 2.421 g/cc, which is significantly under the desired maximum. On a specific basis, strength is 90.0% of the target and modulus is 89.7% of the target. A planned program of evaluating the material in reinforced plastics is dropped because of the failure to attain the target properties. However, a few tests are performed which indicate that the strength and modulus of the fibers manifest themselves in reinforced plastic composites. (Author-PL)