Posted: 16/08/2017 at 14:03
Impact shredders cope much better with soft green material than 'quiet' shredders which use a screw-type blade and/or crush the material. Go for a design with a straight-through path which helps to avoid blockages. I bought an Al-ko about 20 years ago and it's still going strong. A pair of replacement blades are about £20 - I'm on my 3rd set. The blades can be removed and sharpened on a flat oilstone.
However, shredding technique (which is something you will soon learn!) is as important as design. I keep 2 piles - one soft green stuff and one branches and dried material such as perennial stems and put some green stuff in followed by a branch or some dry stuff. As well as minimising blockages, doing this also keep the shredded material mixed properly in order to minimise the time needed for the composted material to decompose.
This is what I mean about the "straight-through" design:
'Industrial' chippers are another matter and can cope with just about anything but cost is upwards of £1500.