The semi automatic corner sealing machine GPG-50 which is suitable for all types of cartons, after being sealed in the first half(upper cover), the carton is pushed by the L-shaped corner to seal the four corners. It need to manually adjust the size of the carton when the carton size changes. The carton is driven by the upper and lower belts. It is fast and stable when sealing, and has no folds at the four corners. It is suitable for those customers who have high requirements on the outer packaging of products, or those who require strict protection for internal products.