How do you grind plastic items for injection molding?

[s-paine]

I have been collecting plastic bottles, containers, etc and sorting them by type. I would like to know if anyone can recommend an easy way to grind up plastic bottles and similar itmes for use as injecting material. So far I have been cutting them up by hand and it is getting very old.

Any recomendations or information would be appriciated.

Thanks!

[307startup]

Unless you have a wood chipper or want to build a chipper box, like the recycling facilities use, I'd say you're stuck cutting them up by hand. You could try cutting the tops and bottoms off the bottles and slitting them lengthwise to run through a paper-shredder...
A chipper box is simply a chute w/a few revolving drums that have teeth or fingers that intermesh.

[DJPLAST]

Get a plastic granulator. Here's one on e-bay.
http://cgi.ebay.com/Machine-builder-...QQcmdZViewItem

[s-paine]

Wow, now I just need a mini version of one of those! On the right track though... Anyone have ideas on making a small one?

[High Seas]

Even a small one takes up space in the shop. How about renting a wood chipper once every few months.
CHEERS - JIM

[harryn]

Freeze it, then smash with a hammer. If a normal freezer is not cold enough, usually dry ice will do it. Of course, Liquid Nitrogen always works, but is a bit more spendy. The plastic will shatter like glass when cold enough. BTW, this is commonly used with rubber, and only a small number of plastics will resisit this method.

Protect your eyes when doing this.

[ImanCarrot]

And don't do it in an enclosed space- you will suffocate without even noticing

http://en.wikipedia.org/wiki/Nitrogen_asphyxiation

[svenakela]

Wouldn't a standard wood chipper from any shopping mall take care of plastics?

[mxtras]

What about using a food processor?

[s-paine]

I was actually wondering if a food processor would work too. Or how about a coffee grinder?

[mxtras]

A coffee grinder turns stuff into powder. I think a chopping blade would be better. Not really sure, but it seems feasible!

Scott

[Scooby]

So was this progressed any further?