Chopped strand non-woven mat production

In the manufacture of a wide variety of products, especially molded products, chopped fiber (e.g. glass fiber) mats are used in the molding operation and typically saturated with resin. These mats have conventionally been produced by air laid techniques, at a production rate that is normally between about 20-30 m/min., and must be relatively thick/dense otherwise they have too many holes and discontinuities to be fully effective in molding on other subsequent processing operations. These mats are typically made of fiber bundles having five or more fibers per bundle, typically about 10-450 fibers/bundle. A non-woven mat useful for a wide variety of purposes, including forming reinforced resin products, is produced in a manner having different specific uses of, and advantages over, conventional chopped strand mats and conventional glass tissue. The mat is preferably made by the foam process (but may be made by the liquid process), and at speeds well in excess of 60 m./min., and has a substantially uniform construction even when low density (e.g. 100 g/mor less). At least 20% (preferably at least 85%) of the fibers are in fiber bundles with between 5-450 fibers/bundle. The fibers (typically at least 85%) have a length between 5-100 mm, preferably 7-50 mm, substantially the same as the length of the fiber bundle they are in. The fibers are preferably held in the bundles by substantially non-water soluble sizing, such as epoxy resin or PVOH. The fibers in the bundles typically have diameters of approximately 7-500 microns, preferably about 7-35 microns. The bundles may comprise at least 10% reinforcing fibers, such as glass, aramid or acrylic.