Injection mold cooling water leakage is a frequent occurrence, for many reasons, mainly in the following aspects:
1. The most occurs at the joint of the mold cooling water pipe. If water leakage is found, the sealing tape should be wound around the thread of the pipe joint and then tightened.
2. Due to long-term molding conditions, the waterproof ring inside the mold will be damaged, and the O-shaped waterproof rubber ring will easily harden and crack, resulting in water leakage. Some poorly installed waterproof rings can also cause seal failure. It is generally necessary to periodically check the installation position and sealing performance of the seal.
3. The hole wall of the cooling water hole is broken. This often happens when a new mold is tried. The wall thickness of the design is sufficient, but the hole wall is broken due to machining errors or post-processing. In most cases, leaking water holes can no longer be used.
4. Inspection of the cooling water hole. It is easy to form scale in the cooling water hole, which hinders heat transfer. In severe cases, the water path is blocked and needs regular maintenance. For straight water holes, an iron bar smaller than the diameter of the cooling water hole can be inserted and tapped with a hammer to remove scale and rust. For the cooling water pipe buried in the mold, the mold should be decomposed to remove rust.
After the inspection, the water leakage test shall be carried out. The water pressure is filled into the water hole by the hand pressure pump, and kept at a pressure of 2 MPa for 5 minutes. It is judged whether the water hole leaks by observing whether the water pressure is lowered. The water leakage can be blocked by mechanical fastening methods using elastic materials such as rubber and cork, and the room temperature curing type silica gel can be tried as a sealing material.
5. Regularly overhaul the heating and decompression pumps and use them. The heating tube is an effective heat transfer element and is very effective for core cooling of deep and deep structures. In the area where the cooling water is easy to pass, a one-way heating pipe is provided to reduce water leakage. In addition, the use of a vacuum pump to pump cooling water is also a method of preventing leakage of cooling water.