摘要 |
A single facer has corrugating rolls of which the cross-sectional tip and root curves are elliptical (as broadly defined) to form a medium compression zone 38 beyond which, on each side of the tip center line, the root extends to define a clearance gap greater than the thickness of the medium; the root curve may (FIGS. 2 and 3) continue as an ellipse which also defines the flute flank, or alternatively the flute flank may be defined by a straight line 76 (FIG. 4) with a transition curve 58 between the straight line and the root curve 52. According to a different aspect of this invention, flank clearance is provided by the use of differently shaped flutes on the two corrugating rolls; for example (FIG. 5) the second roll 71 which carries the medium after corrugating may have straight flanks 76, and the other roll may have concave flanks 78. |