A modified form of sprue gate is also used on underfeed moulds and runnerless moulds.

口形式的模具或无流道模具中也用到另一种形式流道。

The grooved head of the sprue puller creates an effective undercut which is used to pull the sprue, or secondary sprues in underfeed designs.

流道料杆头部的凹槽形成了一个有效的底切，可以用来流道或者是下进料设计中的二级流道。