| 摘要 |
PROBLEM TO BE SOLVED: To ensure a stabilized print image quality by setting the rubber hardness of a single urethane rubber layer formed on a roller core metal such that the single urethane rubber layer has a specified hardness when the surface temperature thereof has a specified level thereby preventing generation of paper powder streak or blanc contamination (white ground contamination). SOLUTION: Since an inking roller 2 is provided by forming a single urethane rubber layer 12 on a roller core metal 11 with the rubber hardness of the single urethane rubber layer 12 being set at 40-45 deg. when the surface temperature thereof is 25 deg.C, generation of paper powder streak (white streak) due to missing of ink can be prevented effectively. The rubber hardness is based on JIS spring type hardness test type A. The inking roller is especially suitable for an inking unit having a doctor blade in a waterless offset printer, it may be employed in other waterless printers or a doctor blade type inking unit for water offset printer employing a PS plate, etc. |
