Seat elastomeric stopper / closure onto filled vial

Immediately after dosing, each open filled vial must receive a rubber stopper that is pressed into the vial neck to form the primary sterile seal (with a crimp cap applied downstream). The task requires placing a small compliant elastomeric stopper concentrically over the vial opening and pressing it home with controlled force so the seal is complete but the glass is not over-stressed and the stopper is not deformed or cocked. It is a terminal sterility-defining step inside the isolator. It is hard for a robot because seating quality cannot be confirmed visually with certainty — an under-seated or tilted stopper compromises container-closure integrity, and excessive press force on glass risks cracking. Stopper and glass geometry both vary within ISO tolerances, so a fixed-position press is unreliable. We identified this through our own research; we have not confirmed the specifics with the customer directly. This page is our researched read — a starting point for that conversation.