Gate, also called tunnel gate, is composed of a pin point gate evolved, it can not only overcome the shortcoming of complex mould with pin point gate, it maintains the advantage of pin point gate. Submarine gate can be located in the dynamic side, also can be arranged on the fixed mould side. It can be placed in the plastic parts of the inner surface or the side cover, can also be placed in the plastic parts of the bar, column, can also be placed in the parting plane. The mold ejector rod method to set the gate is a kind of simple and easy. Submarine gate is generally conical shape, and the cavity with a certain angle, often 20 degrees -45 degrees, the gate size can be selected according to the gate size.
  1.Advantages of  type gate. The feeding gate are generally in the plastic parts of the inner surface or the side surface of the shelter, does not affect the appearance of product. Product formation, in the top will automatically snap and plastic parts. Therefore, easy to realize the automation of production. The submarine gate can be set in the surface invisible bar, column, forming not WIP surface leaving because the jet spray mark and bring lines.
  2.The submarine gate into the sub surface below, along the diagonal into the cavity, so the processing is difficult. Because the gate is in the shape of a cone, as the top is easy to cut, so the diameter should be smaller, but for thin-walled products, due to a loss of pressure is too big and easy to condensate, so do not apply. 
  3.plication of submarine gate. Submarine gate is especially suitable for feeding from the side of the plastic parts, generally applicable to the two plate mold. Because of the impact force, strong for the plastic parts in the ejection so, for too tough plastic such as PA, it is difficult to cut off; and for the brittle plastic, such as PS, have to break and blocking gate.