POLYESTER PREMIX FOR INJECTION MOLDING

摘要

PURPOSE:To easily take a balance between a good surface state and good mechanical strength by mixing a predetermined amount of a glass fiber with a compound like polyester premix containing a specific amount of a resin solid and a filler powder to prepare an injection molding material. CONSTITUTION:A compound like polyester premix wherein a compound viscosity index obtained by dividing the sum of the amount of a resin solid and that of a filler powder by the total amount of a styrene monomer is 5.5-7.0 is prepared and a predetermined amount of a glass fiber is mixed with said premix to obtain an injection molding material. When a case of electric machinery is prepared by injection molding using the obtained molding material, a conventional problem wherein the glass fiber compounded with the polyester premix is damaged by the screw of an injection molding machine is reduced to a large extent.