The invention relates to a productive technology for producing wood-gum
flange, in particular to a technology and device for one time injection molding of
chlorinated polyvinyl chloride lap joint flanges. The technology comprises industrial processes of burdening,
drying, injection molding, pressure maintaining and model opening, wherein in the
injection molding process, the heating portion of a charging
barrel of an injection
machine is divided into seven segments, the temperature ranges of the segments are respectively 150-155 DEG C, 168-173 DEG C, 162-167 DEG C, 160-165 DEG C, 155-160 DEG C, 150-155 DEG C, and 145-150 DEG C, the temperature of a die is controlled between 60 and 70 DEG C, the
injection pressure when injection molding is divided into three segments which are respectively56 MPa, 59MPa and 76MPa. The
pitch of a screw of the injection
machine used in the method is equal to the
diameter of the screw, the delivery segment occupies 25 percent of the whole length, the compressing segment occupies 50 percent of the whole length, and the homogenizing segment occupies 25 percent of the whole length. The invention realizes one time injection molding of DN400 large-scale
lap joint flanges via improving the technology and the device.