| 摘要 |
<p>A method for the manufacture of wide sheets of water impermeable coating material useful in hydraulic engineering which comprises passing carrier sheet having a width in excess of 4 meters through a molten petroleum bitumen coating composition, coating said carrier sheet on both sides with said coating composition and placing the resultant coated sheet as soon as possible onto a conveyor belt while inserting between said coated sheet and said conveyor belt a surfacing material comprising one or more paper strips and a strip of plastic film easily removed from the coated carrier sheet after cooling in a manner such that the strip of plastic film forms a lateral boundary of the surfacing material.</p> |
