There are three basic types of automatic glass doors, swinging, folding, and sliding.
Swinging doors consist of a single door that can swing towards or away from the person walking through. They can also consist of double doors that function in the same manner.
Folding doors consist of at least two panels, and when activated they fold up into a “V” shape, much like the portable, manually operated room dividers in conference rooms and banquet halls.
Sliding doors are flat panels that horizontally slide out of the way. These are very common in places such as grocery stores and many shopping malls.
No matter what type of sliding door it is most are constructed of an aluminum, fiberglass, or steel frame and the glass is safety coated. Clear and dark bronze are most often used for the finish and cladding materials may include brass and aluminum.
Low traffic doors weigh less than 125 pounds per panel and are intended for traffic of 1 person every five minutes.
Medium traffic automatic doors also weigh less than 125 pounds per panel and are intended for traffic of 1 person every minute.
High Traffic doors are a better made and more sturdy at 150 pounds per panel and their traffic rating is 2 persons per minute. These are the types of doors you see at grocery stores and other high traffic locations.