Recyling plastics using a paper shredder

Since a lot of bottles and pots are made of thermoplastics, could you use a shredder to make extrudable strips? My ancient shredder just about managed to turn a white plastic milk bottle into lots of 5mmx1mm (approx) strips, with the only work necessary cutting off the curved top and bottom, then making a slit lengthways across the tube of the bottle. If some way of joining the strips to make a long one could be devised, i think a different extruder could use it quite well. Any thoughts on the feasibility of this idea?

Also, I wonder how one could recycle the plastic in all the botched prototype-prints,
so that they don't accumulate in one's workshop or the nearest land-fill.

And indeed, it would be nice in the long run, if one could use recycled
standard thermoplastics. (Maybe by using a separate machine, that
makes from the recycled plastic shreds appropriate fiber, good for
feeding into RepRap.)

Being a newbie
(just introduced myself at [forums.reprap.org] )
I don't know if this is a FAQ, but has anybody done any work on that line,
and which of the plastics mentioned e.g. in
[en.wikipedia.org]
and [en.wikipedia.org]
would be the most suitable for RepRap?
(And which ones are definitely no-no.)

I wrote:

>And indeed, it would be nice in the long run, if one could use recycled
>standard thermoplastics. (Maybe by using a separate machine, that
>makes from the recycled plastic shreds appropriate fiber, good for
>feeding into RepRap.)

And just a couple of threads towards the bottom of page, found this one:
[forums.reprap.org]

Sorry.