Cause
When the folded paper is transported to the fold crease unit, the leading edge (creased edge) enters the fold nip prepared level for the press guide [B], and then is pressed by the on the paper transport guide. The press guide is provided with three press rollers [A]. The friction between the press guide and press guide plate as the paper is fed can scratch or mark the matte finish of the paper.
The surface of the guide plate is rough and can cause marks on the surface of the paper. The surface of the plate becomes smoother after about 2,000 sheets have feed through the folding unit and these marks disappear.
The surface of gloss coated paper is much smoother, so these marks do not appear on glossy paper.
The surface of Normal paper is untreated, so these marks do not appear with Normal paper.
