Abstract A web of material is predisposed to folding by being passed through a pair of cooperatively mounted mating rolls; i.e., a male and female roll, which roll along what become the lines of fold of the web, prior to its being manipulated into its folded position. The rolls tend to loosen bonds in the web transverse of the ultimate lines of fold, thereby facilitating folding. Because the mating rolls manipulate the web only slightly, in distinction to the action of conventional folding devices, the web maintains its alignment while passing through the mating rolls relatively well, resulting in accurately located lines along which the web is predisposed to fold. Since the lines of predisposition to folding are accurately located, the ultimate folded structure is more dimensionally consistent than heretofore possible. In the preferred embodiments, the rolls press against the web with constant pressure, rather than being fixedly mounted, thereby providing a built-in adjustment for variations in web thickness.
An apparatus for predisposing a moving web of disposable diaper material or the like having an initial thickness, prior to compression, of from about 0.100 to about 0.250 inches to fold along at least one predetermined fold line, said apparatus comprising: a. a male roll having an arcuate convex raised periphery, said arcuate convex raised periphery having a minimum width approximately 1.7 times greater than the thickness of said web prior to compression; b. a mating female roll having an arcuate concave peripheral groove, said groove having a minimum width approximately equal to the sum of the width of said arcuate convex raised periphery plus twice the thickness of said web prior to compression; c. means for engaging said web between said mating rolls so that the axis of rotation of each of said rolls is perpendicularly aligned to the direction of movement of said web; and d. means for urging said mating rolls together against said web to compress said web to a minimum thickness of between about 0.004 inches and about 0.008 inches while said web is engaged between said rolls, thereby flexing and pressing said web in the area of said web between said rolls.
Claim 2
Independent Claim
198 words
An apparatus for predisposing a moving web of disposable diaper material or the like having an initial thickness, prior to compression, of from about 0.100 to about 0.250 inches to fold along at least one predetermined fold line, said apparatus comprising: a. a male roll having an arcuate convex raised periphery, said arcuate convex raised periphery having a minimum width approximately 1.7 times greater than the thickness of said web prior to compression; b. a mating female roll having an arcuate concave peripheral groove, said groove having a minimum width approximately equal to the sum of the width of said arcuate convex raised periphery plus twice the thickness of said web prior to compression; c. means for engaging said web between said mating rolls so that the axis of rotation of each of said rolls is perpendicularly aligned to the direction of movement of said web; and d. means for urging said mating rolls together against said web to compress said web to a minimum thickness of between about 0.004 inches and about 0.008 inches while said web is engaged between said rolls, thereby flexing and pressing said web in the area of said web between said rolls.
Claim 3
Dependent Claim
25 words
The apparatus of claim 1, wherein said means for urging said mating rolls together against said web is comprised of a constant force generating mechanism.
Claim 4
Dependent Claim
64 words
The apparatus of claim 1, wherein said means for urging said mating rolls together against said web is comprised of a fixed gap spacing between said rolls, said fixed gap spacing being between about 0.004 inches and about 0.008 inches, as measured between said mating rolls at the highest point on said raised convex periphery and the lowest point on said concave peripheral groove.