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What's the thickest material that you can shred?

This topic contains 5 replies, has 5 voices, and was last updated by  Halim Widya Kusuma 2 years ago.

Marcus Rosenthal marcusinnovate

What's the thickest material that you can shred?

21/02/2018 at 13:57

We at Precious Plastic Los Angeles have built a shredder. It works well for cups, coffee lids and other thin plastics, but whenever we seem to put something thicker in, it stalls out. We are curious to know how thick of materials people have successfully cut with their shredders. Have you needed to sharpen the blades? From our observation there are only 0.5mm gaps for plastic to go through, so if there would be plastic thicker than that, then we were expecting it to get stalled because it would jam as it is being pushed through. I’d appreciate to see videos of others and get the specs on the motor and gearbox you used and any other tuning you did to the shredder parts.

We used a 60:1 gear reducer with a 1.5HP motor and are running it at about 45-60RPM. We used a chain drive due to orientation of the motor, but with tightening the shredder box and the mounting to our frame, that did not seem to be the issue. We don’t have the best video yet of our shredder, but here is one: https://www.instagram.com/p/BfU2o-6hqvf/?taken-by=preciousplasticla

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21/02/2018 at 22:43

Change the chain ring to speed down till 30 rpm and the torque will be double…

21/02/2018 at 22:46

Or you can change the blade orientation so they take only small pieces of plastic por time and it will be easier crush ticker plastic.

27/02/2018 at 05:50

Hello @marcusinnovate
1.5HP at 60RPM will give you 178.01N.m of Torque minus your gear box efficiency loss, and the minimum recommended for shredding plastic is 300N.m so that explains why your machine stalls.

Since you already made the investment in that motor, I would use
@fabirihotmail-com‘s suggestion and speed down the motor to 30RPM using chains, that would give you 356.03N.m which is more than enough for shredding without problems.


31/05/2018 at 21:00

Hello every one,

I’m curently building the shredder, to recycle 3dprint parts made of ABS and nylon. Those plastics or far more resistant than PET and the parts I have could be realy thick. I put you a example of part I want to shred and that I think it could be complicated. It’s like 3x4x4 cm.
I plan to have a motor of 2HP with a 40:1 reduction… It will gave me 300Nm more or less.

What do you think ? I think I may have to redesign the blades to have smaller teeth and take less pastic at a time. Someone already shred thick plastic ? I only have seen videos of plastic bottle been shred..

Thanks for your help!

17/01/2019 at 05:20

here’s prototype for “over thick” plastic shredding

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