Production of waterproof corrugated paperboard

In a process for the production of waterproof corrugated board wherein a waterproofing resin is added to a conventional Stein-Hall high performance starch based composite adhesive containing cooked and uncooked starch employed to produce the corrugated board from a paper stock so as to render the corrugated board waterproof, the improvement which comprises employing an amount of resin, from about 225-600 lbs. of the resin per 1,000 gallons of adhesive, which imparts extremely poor stability to the adhesive;

• adding the resin the adhesive simultaneously with or immediately prior to the application of the adhesive to the paper stock;
• and applying the resin-containing adhesive to the paper stock at the rate of about 3.5-5 lbs/1,000 sq. ft. of board.