Method and apparatus for preventing warp in corrugated cardboard

A method for treating corrugated board comprising:

• (a) moving an upper liner, a lower liner, and an intermediate corrugated sheet toward a cutting zone;
• (b) securing said upper liner, said intermediate liner and said lower liner together with said intermediate sheet sandwiched between said upper and lower liners to form a corrugated board prior to movement through said cutting zone;
• (c) cutting said corrugated board into sections in said cutting zone;
• (d) imparting forcibly different curvature to said board on alternate lengths corresponding to prescribed number of said cut sections during movement of said board prior to said cutting step;
• (e) stacking in order successive cut sections of corrugated board on preceding cut sections of corrguated board;
• and
• (f) said imparting step being controlled for imparting curvature on said board to permit the weight of said stack to correct said formed different curvature and render said cut sections substantially flat.