二. Corrugated Board Bridge -Draped in an overlapping wave pattern to the double-backer station Purpose-Isolating the two ends of the corrugating machine; balance; slow down The double-backer section of corrugating machine where a second linerboard is applied to the single-faced material coming from the single-facer unit二. Corrugated Board Bridge -Draped in an overlapping wave pattern to the double-backer station Purpose-Isolating the two ends of the corrugating machine; balance; slow down The double-backer section of corrugating machine where a second linerboard is applied to the single-faced material coming from the single-facer unit