Heated shredder

What if we heat up the shredder ? From what I know about plastics, their characteristics are strongly linked to the temperature: higher temperature = lower mechanical characteristics. By heating up the shredder, we would need less torque so we would need a less powerful motor. I think, we should not go higher than 60°C for safety reasons.
What do you think of this idea? As anyone tried it already?

i think the sturdiness of the plastic is key in shredding it, if it gets soft, it will no longer “break into pieces” but in stead just deform, and not turn into flakes.

also, the power “won” on the motor might be lost on the heating again

@dan3008, @saluc42,

Hey guys! Have you tried freezing plastic before shredding it yet?

I’ve stumbled upon a problem of PP(5) being soft and somewhat stretchy, so that it is stuck between the blade plates. I was thinking of making it a bit more brittle so that it shredds properly.

I think all options are worth experimenting with. try it and see what happens.

When our shredder, here in Lyon, will be ready (before September), I’ll be free to test all this! I’ll come back to you to give our feedback.

Ok, I have no idea how you made the reply like that… so i’m just going to reply like this

I meant to put the plastic in the freezer first, and then take it out and shred. Of course, doing this you’d only be able to do small batches at a time.

although, having looked up the properties of some plastics, it looks like it would only be useful for HDPE, LDPE and PP, which have glass transition temp’s below room tempriture

PC (Polycabornate) glass transition temperature: 145°C, it means it is already under its glass transition temperature when at room temperature if I’m correct 🙂
Making it more brittle would help for sure, but maybe only with PP (glass transition temperature 0°C or -20°C). It would be also difficult to cool the system (how? impact on bearings?)

In some home appliances, it’s quite common to have plastics reaching 50°C or slightly more and it remains stiff enough (for example: coffee machines). I should check how much it affects the mechanical properties.
Finding a smaller motor is easier and using a simple hair dryer would be fine I suppose but it may require more power in total, you’re right.

You would probably do better to freeze the plastic to below its “glass transition” temp when it becomes brittle