What is H-pattern (H-type) case sealing?

The image above illustrates H-pattern automatic case sealing. In terms of sealing appearance, the result produced by an H-pattern case sealer resembles the Chinese character “工” (gōng), which visually matches the letter “H”—hence why some users refer to it as “H-type” sealing. Therefore, “H-type sealing” and “Gongzi sealing” describe the same sealing configuration.
H-pattern sealing is a common packaging method in which tape is applied both along the top/bottom center seam (“I-seal”) and around all four vertical edges of the carton, forming an “H” or “工” shape when viewed from above. Technically, an H-pattern case sealer is not a single machine but a combined system—typically consisting of a straight-line (I-seal) case sealer paired with a corner-edge sealer, along with a right-angle transfer or 90° turntable mechanism to reorient the box between sealing stages.
There are various types of straight-line sealers, differentiated by drive configuration—such as left/right driven, top/bottom driven, or hybrid systems. The most common setup uses an automatic flap-folding case sealer combined with a corner-edge sealer to achieve the H-pattern. For fully automated production lines, a fully automatic flap-folding sealer integrated with a fully automatic corner-edge sealer forms a complete fully automatic H-pattern case sealing system.