Mold apparatus and method for injection molding

A mold apparatus, comprising:

• a first mold core defining a through hole, a first cavity, a second cavity, a first sub-runner connected to the first cavity, and a second sub-runner connected to the second cavity;
• a second mold core defining a third cavity, a fourth cavity, a third sub-runner connected to the third cavity, and a fourth sub-runner connected to the fourth cavity;
• a first insert having a protruded end portion;
• a second insert having a recessed end portion;
• a sprue bushing received in the through hole, the sprue bushing having:
• a sprue extending through the sprue bushing;
• a first guiding groove connecting the sprue with the first sub-runner;
• a second guiding groove connecting the sprue with the second sub-runner;
• a first recess configured for receiving a first insert or a second insert, the first recess is defined in the first guiding groove;
• and
• a second recess configured for receiving a first insert or a second insert, the second recess is defined in the second guiding groove;
• wherein the first cavity and the third cavity form a first molding chamber;
• the second cavity and the fourth cavity form a second molding chamber;
• the first sub-runner, the first guiding groove and the third sub-runner cooperatively form a first runner;
• the second sub-runner, the second guiding groove and the fourth sub-runner cooperatively form a second runner;
• the protruded end portion of the first insert is configured to protrude into the first recess or second recess, thereby preventing the sprue from communicating with the first molding chamber or the second molding chamber, respectively;
• the recessed end portion of the second insert is configured to compensate the first recess or second recess and to communicate the first molding chamber or the second molding chamber with the sprue.