Plastic hot runner mould gate types
- The needle tip method is the most common type of injecting method. It determines the quality of injection molded parts by several factors such as gate size, gate cooling, and tip temperature. It is applicable to almost all known plastics. The tip mouth will leave a small gate mark on the surface of the product, the size of which is determined by the size of the gate and by the different plastics.
- For the needle valve, its valve needle is controlled by mechanical pneumatic or hydraulic pressure. The valve needle closes the gate at the end of the pressure-keeping period. That is to say, when the product is not yet completely condensed, the gluing system is closed. This can also shorten the valve. Forming cycle. Needle valve nozzle can be made without gate marks, leaving only a circle or even no marks on the surface of the product. This is the best solution for surface application. It can provide a gate size large enough to reduce shear heat and pressure loss, which in turn reduces filling stress and provides a very generous molding environment. It is also effective for extremely difficult-to-shape plastics or extremely sensitive filling materials. At the same time, the feed gate can also be controlled in sequence. By extension, all plastics can also achieve better product performance, expand the injection volume, and increase the injection speed. For extremely “thin” plastics, “raw wire” is also avoided.
- A real open mouthpiece with a mouthpiece on the surface of the injection molded product will leave a small section of cold head, which can provide a large gate size and achieve excellent pressure holding effect to reduce product stress. Applied to the gate marks is not high or shunt channel into the way. In simple terms, the mouth can be called the extension of the injection nozzle and enter the position closest to the cavity, replacing the traditional hot mouth to achieve the purpose of saving the rubber and reducing the pressure loss (environmental protection and energy saving).