At the processing of materials such as municipal waste, there is a chance that this material will solidify the openings in the press cylinder. These openings are used by the needles to wrap the thread around the bale.
To improve the process of these materials, the ram can be fitted with a REFU. The REFU is an inner ram moved by an inner cylinder. The inner ram closes the openings in the head of the ram when material is compressed. When the needles are to be lowered, the inner ram opens the openings in the ram.