Stuck or Derailed System-Window Sash

Symptom: after some time, an aluminium sliding window sash may become stiff to slide, derail or even fall. Solutions: use a flexible connection in the gap between frame and wall to prevent the frame from being squeezed and deformed; choose aluminium profiles of the specified thickness to prevent deformation from thin sections; and use quality rollers matched to the sash, ensuring they are installed on the same straight line.