| 摘要 |
PROBLEM TO BE SOLVED: To judge the blister-resistant suitability of an actual press which is close to that of an offset rotary press by a method wherein a pressurization treatment and a heating treatment are executed to one pair of heating rolls and pressurization rolls at uniform speed or by setting a circumferential speed difference. SOLUTION: A top roll 1 can be heated and pressurized, and a bottom roll 2 can be heated and pressurized as required. The surface roughness value Rmax of the metal rolls 1, 2 is at 0.05 to 2.0μm, a roll circumferential speed is at 0.5 to 500m/min, a circumferential speed difference of 0 to±10% can be set for the roll circumferential speed, and a pressurization force which is applied to the rolls 1, 2 is at 1 to 6000kg/cm<2> . While a sheet of paper is being passed through an apparatus, a heating treatment and a pressurization treatment are executed to the sheet of paper. Then, moisture in the sheet of paper is evaporated, vapor which is generated is passed through the gap between coating layers so as to escape from the sheet of paper. At this time, when the amount of steam is much so as to be more than its passable amount, a large pressure is generated at the inside. A temperature which generates a blister when a paper layer is destroyted due to an increase in the inside pressure is evaluated as a blister generation temperature.
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