Exterior stable doors
Interior Doors and their classification of way of opening : Exterior Stable Doors
Quote from Article entitled Interior Doors and their classification of way of opening:
Folding doors consist of panels which fold at the opening. Construction includes an upper (sometimes lower) guide roll, a pulley and panels connected with hinges.Opening and closing are silently and effortlessly because of bearings in a pulley. Package also includes stoppers which fix the door in the same position.Panels can be both solid and glazed. Folding doors are suitable for small apartments, they save space. Among disadvantages we can note weak thermal and acoustic insulation and fragility because of a large number of small moving elements.
The full version of the article can be found here.