Hot runner mould has different kinds of gate, such as direct gate, point gate, valve gate. Now let's learn something about the valve gate hot runner mould.

According to the injection principle, there are two types valve gate system: cylinder and spring. Now most hot runner supplier use cylinder type; it means air cylinder control the opening and closing of the needle, this system have complex structure, but the design is simple. As to the spring type, FISA is the only one supplier who use the spring control the needle.

Working valve gate hot runner mould need air compressor, because the needle inside of the system is driven by compressed air. Following is one kind of valve gate hot runner design: