A Rapid Determination of the Graphite Fiber Content of Plastic Composites
Abstract
The recent advent of graphite fiber as a practical reinforcing agent for plastic composites has greatly increased the need for a rapid, accurate method for determining the exact amount of this fiber present in composite specimens. The traditional method of determining fiber content by ignition loss in glass fiber reinforced composites (often used in boron fiber composites, as well) is not practical for graphite fiber systems because of oxidative- sensitivity of the graphite. The host of laboratory procedures based on solvent extraction of dissolved resin tends to be too slow and cumbersome to be effective or economical for routine quality control applications, particularly when the resin is a thermoset. The more recent acid digestion methods are definite improvements, but also tend to be slow and usually require a high level of operator training to prevent handling losses. One of the better of these, a method developed by Kuhbander calls for three two-hour treatments with concentrated nitric acid followed by a distilled water rinse, drying the remaining material for two hours and final weighing. In addition to the error caused by carbon losses during the long acid treatment, the physical handling of the graphite in the four filtration steps and during weighing offers opportunity for additional error. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1970
- Accession Number
- AD0865304
Entities
People
- T. L. Tolbert
- W. M. Haynes
Organizations
- Monsanto