Speedpack inline "H-Style" automatic case sealer integrates a flap-folding case sealer, a corner-and-edge case sealer, a cross-shaped rotating unit, and a side-pushing mechanism. The system automatically folds the top flaps of the carton, and dual-side motor-driven belts align and convey the carton smoothly and steadily. It first applies a horizontal ("I"-type) tape seal on both the top and bottom of the carton. Immediately afterward, the carton is transferred via the cross-rotating and side-pushing mechanisms into the corner-and-edge sealing station for complete four-corner edge sealing. When changing carton sizes, manual adjustment is required but takes only about one minute. The working height, as well as carton width and height settings, are easily adjustable—simple and practical. With an elegant and robust design, the machine also features a blade guard to prevent accidental cuts during operation.