What is the standard of injection mold exhaust slot opening?

What is the standard of injection mold exhaust slot opening?

The standard of injection mold exhaust tank is very important to ensure product quality and production efficiency. The main function of the exhaust tank is to remove the air in the mold and the gas generated during the injection molding process to prevent the occurrence of undesirable phenomena such as bubbles, depressions, burning, etc. The following is the standard for injection mold exhaust tank opening:

(1) Location selection:
The exhaust groove should be opened in the last fill area of the mold cavity, usually away from the injection molding machine nozzle or gate. This ensures that during the injection molding process, air and gas can be expelled as the plastic flows.

(2) Size design:
The width and depth of the exhaust groove should be determined according to the type of plastic, mold size and the pressure of the injection molding machine. Generally, the width of the exhaust tank is between 0.01 and 0.05 inches (about 0.25 to 1.25 mm), and the depth is usually slightly greater than the width.

(3) Shape and layout:
The shape of the exhaust groove can be straight, curved or circular, and the specific shape should be determined according to the structure of the mold and the flow characteristics of the plastic. In terms of layout, the exhaust groove should be evenly distributed on the surface of the mold cavity to ensure that the gas can be smoothly discharged.

(4) Quantity and size:
The number and size of the exhaust tank should be determined according to the size and complexity of the mold. Too few exhaust slots may lead to poor gas emission, while too many exhaust slots may increase the difficulty and cost of mold manufacturing.

(5) Prevent leakage:
Exhaust tanks should be designed to avoid plastic leakage. For this purpose, a small baffle or labyrinth structure can be set up at the outlet of the exhaust tank to block the flow of plastic.

(6) Cleaning and maintenance:
The exhaust tank should be kept clean to avoid clogging. During the production process, the exhaust tank should be checked and cleaned regularly to ensure that it is unimpeded.

(7) Simulation and test:
During the mold design phase, injection molding simulation software can be used to predict the flow of plastics and gas emissions, thereby optimizing the design of the exhaust tank. In actual production, the effect of the exhaust tank should also be verified through mold testing and testing, and adjusted according to needs.

In summary, the opening standards of injection mold exhaust slots involve location selection, size design, shape and layout, quantity and size, leakage prevention, cleaning and maintenance, as well as simulation and testing. By following these standards, the normal operation of the mold and the stability of the product quality can be ensured.