One of the biggest problems recycling plants face is very dirty plastic waste, - pre-shredded agricultural films or post-consumer bottles. These material cause heavy wear and often lead to more frequent machinery breakdowns due to the excessive contamination and prevent plants from running at maximum capacity.
This problem is easily remedied with the installation of a Herbold pre-wash drum. The pre-wash drum works by passing material through a rotating cylinder where it gets wet to wash off surface dirt. The cylinder is either partly or completely sieved to let the dirty water run off. It is fitted with baffles which help turn the waste as it is washed.
The pre-washing drum is suitable for nearly all plastic waste containing coarse pieces, large pieces of film must be pre-cut. The use of a guillotine is preferred because it does not generate fines that would be lost in the screen drum. Even larger containers or bottles filled with sand should be pre-shred with a single- or multiple shaft shredder.
Our pre-wash drum is able to average approximately 8 t/h, suitable for pre-treatment at the entrance of the plastic washing facility. The subsequent steps of removing contamination, wet shredding, washing, separation, and drying are improved by removing contamination up front.