Windows must be tight in their frames to ensure the energy efficiency of a building. To achieve this, wooden sash windows are usually fitted with a number of seals, each with a different function, including two circumferential seals for casement rebate and overlap sealing. 
The D3630 profile was developed as an all-in-one rebate and overlap seal that makes the use of two different sealing profiles unnecessary. The seal is designed to simplify stocking and fitment for construction firms, ultimately helping lower overall build costs. 

Michael Cramer, Trelleborg Industrial Solutions, Design Engineer for sealing profiles, says: “Today, waterproofing in wooden windows must meet a variety of requirements. This includes protection against moisture and driving rain, as well as, prevention of ingress of dirt and the reduction of noise. Of particular importance, is the windows energy efficiency, which is dependent on the window and its seal matching perfectly, with the gasket fitting exactly into the window groove. One millimeter can determine whether the window and window seal fit together. It is only when the seal fits precisely into the specially designed groove that a reliable level of air-tightness and water-tightness can be ensured.”