SHEET MOLDING COMPOUND AND MATERIALS THEREOF

摘要

The specification describes a process for making a sheet molding compound wherein a layer of resin-filler paste that includes a thickening agent and a hardening catalyst is put down upon a first layer of sheet material; a layer of glass fibers that are sized with a material which induces wet out is placed thereon; following which another layer of the resin-filler paste containing the catalyst is placed thereon and covered by a second layer of sheet material. The sandwich thus formed is fed into the bite of rollers which squeeze out air and compress the resin-filler paste around the sized fibers, following which the composite is placed under further compaction that includes a perforating means which forces needle-like members through at least one layer of the sheet material, through the resin-filled paste, and into the layer of fibers for the removal of remaining entrapped air. The glass fibers which are used are sized with a material that includes both a hardening resin, and a nonhardening resin. Specifically, the fibers are coated with an unsaturated polyester resin and a saturated polyester resin which are preferably deposited on the glass fibers as emulsified particles.