Solution needed for sieving of small but long plastic material

[01Mercy]

Hello,

I'm in search of a solution for a sieving problem I have.
In our process we sieve our material to be <12mm after grinding.
The material is a plastic bottle (with cap).

The as we all know just under the cap of a plastic bottle is a strip to secure the cap when the bottle is not used yet.
The problem lies with these strips. When they go to our grinding process they will pass a 12mm sieve because they are very small, eventhough they are longer than 12mm.

This is a problem for our customer because they need material to be <12mm but we can't sieve those strip pieces in a good way.
I figure this is a problem which probably isn't experienced only in our process but in other processes also where they try to sieve and have problems with long small materials.

Does anyone know of a solution to this problem?

Thanks in advance!

 

[CoryPad]

Water flotation - PET has specific gravity higher than water, PP is lower.

 

[01Mercy]

Yes that is used allso but after the grinding. PET and HDPE are grinded together. We need a way to sieve off everything smaller than 12,5mm (those long pieces not included) before it goes in the floatation tanks.

 

[berkshire]

Try Googling matchstick sifters. They have a corrugated screen with slots in the bottom, the match sticks orient one way on the screen, the slots remove the short sticks. A different set of slots remove the long sticks.
B.E.

You are judged not by what you know, but by what you can do.

 

[limey1]

http://www.kason.com/Circular-Vibratory-Screeners-Separators/index.php

I was thinking maybe a vibratory seperator, see link.

 

[01Mercy]

Thanks for the input, most helpful!