For production scrap, if material is in rolls, a pre-cut is indispensable and a guillotine will serve the purpose.

For post consume material, heavy contamination will make the cutting system to be maintained pretty often.  

The only approach in this case will be the single shaft shredder, because it is, specially for high production rates, the less expensive machine in terms of "currency" per Kg.

The material is shredded, using a grid of about 50 mm in order not to  create lots of fines during washing and drying.