Das Plastik soll recycelt werden, damit es nicht im Restmüll landet.

The plastic should be recycled so that it does not end up in the residual waste.

Breakdown of Das Plastik soll recycelt werden, damit es nicht im Restmüll landet.

• nicht: not
• es: it
• sollen: should
• damit: so that

Questions & Answers about Das Plastik soll recycelt werden, damit es nicht im Restmüll landet.

Why is it das Plastik and not der/die Plastik?

Plastik can have different genders depending on meaning. In this sentence it means plastic as a material, which is commonly neuter: das Plastik.
If you mean a plastic object / plastic (as an item), people sometimes use other genders in certain contexts, but das Plastik is the standard for the material.

What does soll mean here—does it mean “should,” “is supposed to,” or “will”?

Here soll expresses a recommendation / expectation / instruction: it’s supposed to be recycled or it should be recycled.
It does not primarily mean future like English “will.” For a neutral future you’d typically use the present tense (often without any special marker) or werden as a future auxiliary in other structures.

Why is soll recycelt werden in this order, and why are there two verbs at the end?

This is modal verb + passive.

• soll is the modal (finite verb in position 2 in a main clause)
• recycelt werden is the passive infinitive (non-finite verbs go to the end)

So the structure is: Das Plastik soll … recycelt werden.
In German, when you stack verbs, the non-finite parts typically cluster at the end.