2 10 3 10 4 md cd cracking resistance 98 100 99 99not crackedmit fold count 55 38 39 43______________________________________ the bleached kraft board in example 1 was sized with corn starch pick up was 2 8 lb 3000 ft 2 one portion of the sized board was conventionally dried 110 u00b0 c for 9 seconds 34 c 34 in the table a second portion was heat treated at 410 u00b0 f 210 u00b0 c for 28 8 seconds without intermediate drying 34 ht 34 a third portion of the sized board was heat treated for 14 3 seconds under identical conditions rewetted by a water spray on both sides to contain 15 moisture by weight and heat treated again for 14 3 seconds 34 ht rw 34 the board was conditioned for 48 hours under standard conditions resultant board properties are listed in table ii notably conventional drying did not improve the wet tensile of the sized board vs the unsized one however both the wet tensile and stiffness of the heat treated sized board is higher than that of the unsized board table ii______________________________________ control heat twice board treated rewettedproperties c ht ht rw ______________________________________basis weight 140 5 144 6 141 8 lb 3000 ft sup 2 caliper mils 15 8 15 9 16 0taber stiffness 122 71 136 71 134 66 gm cm stiffness improvement 11 0 10 7dry tensile lb in 68 0 43 7 70 4 41 6 70 3 43 2 md cd wet tensile lb.