Development of a Dislodging Prevention Design for Sliding Window Screens

If a sliding window screen falls off due to strong winds, for example, it can cause major damage. The screens installed in ordinary double-sliding windows for single-family houses are equipped as standard with a stopper at the top to prevent them from becoming dislodged. However, this must be set manually after the screen door is installed, a step that could be forgotten when the screen is re-installed, such as after maintenance.
To reduce these risks and further enhance safety, YKK AP has developed a "dislodging prevention design" for sliding window screens.

In the past, the "overlap allowance," which refers to the overlap between the bottom of the screen frame and the screen rail, was 4 mm, and a problem was that the screen could easily come off if the stopper at the top did not perform its function.
To address this, we reviewed the design and increased the overlap allowance to 7mm. This way, even if an unexpected force is applied and the screen is lifted up, it is less likely to be dislodged from the window frame.

Furthermore, for cases where the screen is lifted up over the rail, we have developed and manufactured our own screen rollers with an anti-dislodging mechanism.
When an upward lifting force is applied to the screen, the screen rollers pop out from the bottom to prevent dislodging. This means that even if the screen is lifted over the lower frame, the anti-dislodging mechanism catches on the rail to keep the screen in place. This makes the screen even more difficult to dislodge than previous products.
To confirm safety, verification testing is conducted under various scenarios, such as an unexpected force being applied or the screen being operated in a way it was not designed to

Rather than just employing a standard stopper, YKK AP has developed a "dislodging prevention design" for even greater safety. The key to preventing dislodging is to increase the overlap allowance, but if the allowance is increased too much, the screen cannot be hung. To address this, we developed a screen roller with an anti-dislodging mechanism to further enhance safety.
As the scale of damage caused by large typhoons and torrential rains with strong winds continues to grow, the risk of accidents caused by sliding window screens becoming dislodged is increasing. As such, we at YKK AP will continue to pursue further safety improvements.