What is a needle valve hot runner system? What is the working principle of a needle valve hot runner system?
Publisher: Administrator Date: 2023-11-02
The opening and closing of the valve needle is controlled by the injection signal of the injection molding machine. Gate opening - The injection signal is transmitted to the electromagnetic valve of the nozzle, which controls the intake channel of the cylinder, causing the piston of the cylinder to drive the valve needle upward, thus opening the gate. Plastic melt is injected into the mold cavity through the main flow channel and nozzle body flow channel from the injection machine nozzle. When the gate is closed and the injection is completed, the injection signal disappears, the solenoid valve is powered off, and the cylinder changes the intake channel, causing the piston to drive the valve needle to move downwards, thus closing the gate. The melt in the channel remains in a molten state without overflow, flowing, and other phenomena. The melt in the mold cavity gradually cools and solidifies, ultimately obtaining the required product. The air pressure for controlling the upward and downward movement of the valve needle should not be less than 6bar, otherwise it is recommended to use an air compressor. If the air source is oil-free compressed air, additional lubricating oil needs to be added inside the cylinder.