卷帘门 is composed of the characters 卷 meaning 'to roll,' 帘 meaning 'curtain,' and 门 meaning 'door.' The combination directly denotes a type of door that operates by rolling up like a curtain, hence a rolling shutter door.
Word Definition - 卷帘门
juǎn lián ménvariant of 捲簾門|卷帘门[juǎnliánmén]; roll-up door; roller shutter door