When is flexible packaging considered recyclable?

I think it depends a lot on where you're from and the laws and regulations etc there. But....

Are we talking plastic? Things are changing at the moment with new thresholds and working towards a circular economy but to put it as simply as possible - it depends on the primary material and the secondary materials of the plastic. For example, if the plastic is primarily made of PE, then to be recyclable, the PE would need to make up at least 80% of the total composition, but the secondary materials matter too. Like if PVDC is one of the secondary materials, this makes the plastic not recyclable at all, even though it's 80% PE. If the secondary materials are things like Nylon and EVOH, you can have a layer of Nylon that makes up 10% of the composition, and a layer of EVOH that also makes up 10%.

I think you should google CEFLEX, I might be bad at explaining.

Agree with the above.  Actually most plastic films are actually recyclable, the problem is many communities do not have the capability to recycle the film.  

depends.. depending of material construction. The lesser the layer more recyclable.

hope this would help