Usually it’s the weather’s fault when a metal door sticks. If the sun shines, its outer side expands. If it’s cold outside, however, the door bulges inwards. Ensinger now has a new solution to this well-known problem encountered with thermally separated metal doors, the bi-temperature effect (also known as the bi-metal effect): The shear-free insulating profile. It minimises this linear expansion and keeps the door in perfect shape even in the event of extreme differences between the external and internal temperature.