Suppose that, before you throw an empty plastic bag into the blue bag, you think: ‘I'll just fill that bag with PMD and once that bag is full, I'll button it up and throw it into the blue bag’. Seems like a no-brainer, and certainly handy if you don't have room in the kitchen to store a full blue bag. But if you seal that bag and throw it in the blue bag like that, that bag and the packaging inside it have no chance of being recognised in the sorting facilities. The same with a plastic container that you fill with PMD and seal. Result: although you do sort PMD in the blue bag, by doing so your PMD will not be recycled but incinerated.
Of course, you may collect your PMD in a smaller bag first, but once that bag is full, tip the collected PMD in that bag into the blue bag first, followed by the bag itself. This way, you will have put all your PMD loose in the blue bag and everything will be able to be further processed at the sorting facilities and afterwards at the recycling companies.
