摘要 |
The method and apparatus for making a preform which is a rigid shaped item formed of glass fibers rigidly joined to each other where adjacent fibers touch. The interstices between the fibers are unfilled for the use of matrix resin to subsequently form a molded article. The preform is formed by shaping fibers into the preform shape, applying a binder to the fibers so that they are coated at the locations where they touch. The binder is sensitive or responds to the application of electromagnetic energy. In completing the preform after the application of the binder, the preform is subjected to electromagnetic energy so that the binder hardens to form a rigid preform. In one species form, the electromagnetic energy is applied in the form of microwave energy. The application of electromagnetic energy causes a reaction in the binder without requiring heating of the glass fibers so that the preforms can be rigidified rapidly and efficiently. |