Glass fibre preforms

Claim 1

THE PROCESS WHICH COMPRISES FORMING A RANDOM GLASS FIBRE MAT PARTIALLY IMPREGNATED WITH A COMPOSITION COMPRISING AN EMULSION OF THE OIL-IN-WATER TYPE CONTAINING FROM 20 TO 50 PARTS OF A DIALLYL PHTHALATE PREPOLYMER CONSISTING OF HOMOPOLYMERIZED DIALLYL PHTHALATE WHICH IS ESSENTIALLY A CURABLE NON-CROSS-LINKED LINEAR POLYMER HAVING ALLYLIC UNSATURATION, CORRESPONDINGLY FROM 70 TO 40 PARTS OF DIALLYL PHTHALATE MONOMER, AND FROM 5 TO 10 PARTS OF A NONIONIC EMULSIFYING AGENT, IN ADMIXTURE WITH A CATALYST AND WATER, HEATING THE RESULTING MAT TO CURE THE RESINOUS BINDER AND REMOVE EXCESS WATER, THE AMOUNT OF SAID COMPOSITION BEING SUCH THAT THE RESULTING MAT CONTAINS 5-15% BINDER AND IS OPEN AND RECEPTIVE TO IMPREGNATION, SUBSEQUENTLY IMPREGNATING THE RESULTING MAT WITH A STRENGTH-IMPARTING CURABLE POLYESTER-CROSS-LINKER RESIN OF DIFFERENT CHARACTER THAN THE BINDER CONTAINED THEREIN, THE CROSS-LINKER IN SAID POLYESTER-CROSS-LINKER RESIN BEING SELECTED FROM THE GROUP CONSISTING OF STYRENE, VINYLTOLUENE, ALPHA-METHYLSTYRENE, DIALLYL PHTHALATE, TRIALLYL CYANURATE, THE DIALLYL ESTER OF CARBIC ANHYDRIDE, METHYL METHACRYLATE, AND MIXTURES OF THESE MONOMERS, AND CURING SAID LAST-NAMED RESIN.