其特别之处在于采用灵活的预压杆机构对产品超厚部分进行二级保压，解决了矿灯凸透镜部分容易产生收缩和真空泡等问题。
It specially uses flexible pre-pressing pole mechanism to do second packing to the extra thick wall , so as to solve the miner 's lamp convex problems including shrinking and vacuum bubble .
收缩泡