The outer frame is constructed from moisture-proof and moisture-resistant cardboard, ensuring it does not deform, break, or twist under normal operating conditions. The diagonal support design at the front and rear of the outer frame securely fixes the filter material. The pleated filter screen provides the maximum open filtering area, enhancing dust collection efficiency through optimal airflow. This robust structure ensures stable filtering performance and extends service life. The filter material is tightly bonded to the outer frame to prevent any air leakage.

The outer casing is made of moisture-resistant cardboard, which will not deform, crack, or warp under normal operating conditions. It is designed
Diagonal support on both the front and rear to securely hold the filter material. The pleated design provides maximum open filtering area for convenient airflow, enhancing dust capture efficiency. It has a strong structure and stable filtering performance, extending its service life. The filter material and outer frame are tightly bonded to prevent air leakage.