| 摘要 |
An offset printing apparatus has a fluid-cooled nip roll which, in use, presses a hot, rapidly moving, endless printed and dried web into intimate contact with the first downstream chill roll while avoiding damage to the web, nip roll, or chill roll, and while avoiding ink picking by the web surface contacted by the nip roll. Employing the nip roll in the system also permits the use of a substantially shorter dryer and fewer chill rolls as compared to a conventional system operating at the same web speed. A coolant circuit for the nip roll preferably includes a warmup loop which temporarily circulates warm fluid through the nip roll when the system is first taken off-line, thereby preventing condensate formation or frost formation on the nip roll.
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