Drafts do not affect luggage. The baggage is scanned with an X-ray machine. Leaded rubber curtain to reduce parasitic radiation. Remember that when visiting an X-ray room, you can see a doctor in a rubber apron, or you are covered with such an apron.
As I understand it, you are talking about the tape curtain. This "simplified version of the door" is installed where something is constantly moving. Reduces heat loss, etc. (drafts, radiation, etc.).