High flute density, printable, corrugated paperboard

A method of manufacturing a corrugated paperboard, said corrugated paperboard having an approximate caliper thickness of about 0.040 inches or less, said method comprising the following steps:

• selecting a first roll of paper stock for use as a first liner, said first roll of paper stock having a caliper thickness of about 0.0085 to 0.010 inches and having a porosity, based on a lactic acid drop test, of less than about 450 seconds;
• selecting a second roll of paper stock for use as a corrugated medium, said second roll of paper stock having a caliper thickness of about 0.005 to 0.008 inches and having a porosity, based on the lactic acid drop test, of less than about 450 seconds;
• selecting a third roll of paper stock for use as a second liner, said third roll of paper stock having a caliper thickness of about 0.0065 to 0.010 inches and having a printable surface;
• mixing an adhesive, said adhesive having a solid content of about 28 to 30 percent, and a Steinhall viscosity of about 20 to 25 seconds;
• corrugating said second roll of paper stock by forming in it a regular pattern of flutes, said flutes having a cordal flute height not exceeding about 0.021 inches and the distance between any two adjacent flutes not exceeding about 0.070 inches;
• applying a thin film of adhesive about 0.002 to 0.003 inches thick onto a first set of flute crests on one said of the corrugated medium;
• bonding the first liner to said one side of said corrugated medium by bringing said first liner into contact with said first set of flute crests and by applying pressure onto said first liner over an area covering a plurality of flute crests;
• applying a thin film of adhesive about 0.004 to about 0.005 inches thick onto a second set of flute crests on the other side of the corrugated medium;
• bringing said second liner into contact with said second set of flute crests on the other side of the corrugated medium, thereby forming said corrugated paperboard;
• and progressively heating said corrugated paperboard to evaporate moisture in the adhesive out through the porous first liner and corrugated medium.