Method and apparatus for ultrasonic sealing and cutting, and tabs produced thereby

Claim 2

A tab for a sanitary napkin belt comprising three layers of which the outer layers are of flexible ultrasonically sealable fabric and the intermediate layer is of flexible ultrasonically sealable padding material to constitute padding for the tab, the three layers being sealed together along each of their side edges and at each end thereof by a series of discrete thermoplastic stitches, and at least one score transverse to the length of the tab, the score being spaced from but adjacent to one end of the tab.

Claim 3

A tab as set forth in claim 1 wherein the outer layers are of polyester fabric.

Claim 4

A tab as set forth in claim 2 wherein the intermediate layer is also of polyester fabric but of heavier loft than the outer layers.

Claim 5

A tab as set forth in claim 3 wherein the intermediate layer is of a nonwoven polyester fabric.

Claim 6

A tab as set forth in claim 4 wherein the outer layers are also of a nonwoven polyester fabric.

Claim 7

A tab as set forth in claim 5 wherein the outer surfaces of the outer layers are relatively harder than the intermediate layer for abrasion resistance.

Claim 8

A sanitary napkin belt comprising an elastic waistband of ultrasonically sealable material and tabs as set forth in claim 6 secured to said waistband by discrete thermoplastic stitches.

Claim 11

The method of claim 8 wherein the composite strip is made by combining three strips each of flexible polyester material one upon another with the intermediate strip being of heavier loft.

Claim 14

The method of claim 10 wherein the composite strip is scored on a line extending transversely of the composite strip adjacent the straight-line seal on the side of the straight-line seal opposite the arcuate seal.

Claim 15

The method of claim 10 wherein the strips are ultrasonically stitched together along their side edges, and along said arcuate and straight lines of seal by discrete ultrasonically fused stitches.

Claim 18

The method of claim 13 wherein one end seal is straight and the other is curved, and the cutting edge cuts out the material between said seals.

Claim 19

The method of claim 14 wherein the cut-out material is blown away.

Claim 20

Apparatus for ultrasonically sealing and cutting an ultrasonically sealable workpiece in the form of a continuous strip comprising an anvil having a raised pattern corresponding to the seal to be made and an ultrasonic horn relatively movable toward and away from one another, the raised pattern on the anvil comprising two lines of projections on the anvil, said lines being spaced lengthwise relative to the strip, said anvil having an opening between said lines, one of said lines of projections being an arcuate line for sealing the strip from one side thereof to the other and the other of said lines of projections being a straight line of projections for sealing the strip from one side thereof to the other spaced from but adjacent the arcuate line of projections on the convex side of the arcuate line of projections, the horn being adapted to clamp a workpiece against the raised pattern on the anvil when the horn and anvil are moved relatively to one another, means for ultrasonically powering the horn for ultrasonically sealing the workpiece where it is clamped against said raised pattern by the horn, means for intermittently feeding the strip forward a predetermined distance with a dwell between successive feed cycles, the strip being clamped between the anvil and the horn during each dwell, and a cutter associated with the anvil and operable in the opening thereof having an arcuate cutting edge adjacent the arcuate line of projections and a straight cutting edge adjacent the straight line of projections, said cutter being movable relative to the anvil to press its cutting edge into the workpiece from the anvil side of the workpiece to cut through the workpiece while it is ultrasonically activated adjacent the ultrasonic seal made by the raised pattern.

Claim 21

Apparatus for ultrasonically sealing and cutting an ultrasonically sealable workpiece in the form of a continuous strip comprising an anvil having a raised pattern corresponding to the seal to be made and an ultrasonic horn relatively movable toward and away from one another, the raised pattern on the anvil comprising two lines of projections on the anvil, said lines being spaced lengthwise relative to the strip, said anvil having an opening between said lines, one of said lines of projections being an arcuate line for sealing the strip from one side thereof to the other and the other of said lines of projections being a straight line of projections for sealing the strip from one side thereof to the other spaced from but adjacent the arcuate line of projections on the convex side of the arcuate line of projections, the horn being adapted to clamp a workpiece against the raised pattern on the anvil when the horn and anvil are moved relatively to one another, means for ultrasonically powering the horn for ultrasonically sealing the workpiece where it is clamped against said raised pattern by the horn, means for intermittently feeding the strip forward a predetermined distance with a dwell between successive feed cycles, the strip being clamped between the anvil and the horn during each dwell, and a cutter associated with the anvil and operable in the opening thereof having an arcuate cutting edge adjacent the arcuate line of projections and a straight cutting edge adjacent the straight line of projections, said cutter being movable relative to the anvil to press its cutting edge into the workpiece from the anvil side of the workpiece to cut through the workpiece while it is ultrasonically activated adjacent the ultrasonic seal made by the raised pattern.

Claim 22

Apparatus as set forth in claim 16 wherein the cutter has a straight blade having said straight cutting edge, and a curved blade having said arcuate cutting edge spaced from the straight blade, and means for blowing material cut from the workpiece out from between said blades.