| 摘要 |
PURPOSE:To distribute a release agent uniformly over the entire surface of a heating roll and to prevent the generation of offset by forming the heat-resistant coating layer of the surface of said roll porous. CONSTITUTION:When the surface tension of the heat resistant coating layer (tetrafluoroethylene resin layer) 4 of a heating roll 1 is smaller slightly than the surface tension of a release agent (silicone oil) 7, the wetting of the oil to the roll surface is not sufficient and this produces the areas where no oil films exist partially, which can lead to offset. If the layer 4 is formed porous, the apparent surface area of the heating roll increases and the wetting to the release agent is improved. In addition, the release agent percolates into the pores and as a result, the release agent distributes uniformly over the entire surface of the heating roll thereby generating virtually no offset on the surface of the heating roll. |
