Three-way filter housing injection molding

Here are the injection molding difficult points: uneven cooling due to the asymmetrical structure, tight tolerances on threads and sealing surfaces, and controlling the fit clearance with the union nuts. Here are the mold design and process points to ensure sealing precision:

The main body is Y-shaped, so you have to use split sliders (lifters) to form the side outlets. The sliders need wear plates and angle pins to make sure they open and close smoothly.

The big threads on the union nuts are usually unscrewed automatically using a hydraulic motor-driven unscrewing mechanism. For small quantities, we can use threaded inserts and manually unscrew them to save on tooling costs. But for high-volume production, make sure the unscrewing speed stays perfectly synced with the mold opening to avoid scratching up the threads.

The three-way geometry has uneven wall thickness—thick at the joints and thin on the pipe walls. so reasonable cooling system design is needed.

The union nut areas are pretty thick, so they're prone to sink marks.

Materials like PP are temperature-sensitive. We need to set up zone-by-zone barrel temperatures to avoid overheating and degradation.

Set up a test fixture, put the nuts and seals in place, and then perform the pressure test to check the leak rate. This will catch any out-of-tolerance parts before they ship.