Abstract: An improved method and apparatus for incrementally stretching "zero strain" stretch laminate webs to impart elasticity thereto in the direction of initial stretching, at least up to the point of initial stretching. The "zero strain" stretch laminate material is formed of at least two plies of material which are either intermittently or substantially continuously secured to one another along at least a portion of their coextensive surfaces while in a substantially untensioned ("zero strain") condition. One of the plies is stretchable and elastomeric, while the second ply is elongatable, but not necessarily elastomeric. The second ply will, upon stretching of the laminate, be at least to a degree permanently elongated so that, upon release of the applied tensile forces, it will not return to its original undistorted configuration.

Abstract: A "zero strain" stretch laminate web exhibiting a non-uniform degree of elasticity, as measured in the direction of elasticization at various points along an axis oriented substantially perpendicular to the direction of elasticization. Improved method and apparatus for non-uniformly stretching "zero strain" stretch laminate webs to impart elasticity thereto in the direction of stretching, at least up to the point of initial stretching are also disclosed. The "zero strain" stretch laminate material is formed of at least two plies of material which are either intermittently or substantially continuously secured to one another along at least a portion of their coextensive surfaces while in a substantially untensioned ("zero strain") condition. One of the plies is stretchable and elastomeric, while the second ply is elongatable, but not necessarily elastomeric.

Abstract: An improved method and apparatus for incrementally stretching "zero strain" stretch laminate webs to impart elasticity thereto in the direction of stretching, at least up to the point of initial stretching. The "zero strain" stretch laminate material is formed of at least two plies of material which are either intermittently or substantially continuously secured to one another along at least a portion of their coextensive surfaces while in a substantially untensioned ("zero strain") condition. One of the plies is stretchable and elastomeric, while the second ply is elongatable, but not necessarily elastomeric. The second ply will, upon stretching of the laminate, be at least to a degree permanently elongated so that, upon release of the applied tensile forces, it will not return to its original undistorted configuration.

Abstract: Method and apparatus for ultrasonically bonding continuously moving webs to one another using a stationary vibrating horn and a relatively slick, non-thermally softenable moving slip layer interposed between the webs to be bonded and the horn to prevent web damage. Interposing the slip layer between the webs to be bonded and the ultrasonic horn improves both the quality and efficiency of web bonding. It reduces friction between the travelling webs and the substantially stationary ultrasonic horn not only due to its relatively slick surface, but also due to the compressive force which the slip layer exerts upon the webs to be bonded. This in turn minimizes jamming and hangups in the very limited clearance existing between the rotating anvil roll and the substantially stationary vibrating ultrasonic horn. In addition, the slip layer maximizes retention of heat either generated in the laminate web by the ultrasonic horn or transferred to the laminate web structure by preheating one or more of the webs.

Abstract: Method and apparatus for ultrasonically bonding continuously moving webs to one another using a stationary vibrating horn and a relatively slick, non-thermally softenable moving slip layer interposed between the webs to be bonded and the horn to prevent web damage. Interposing the slip layer between the webs to be bonded and the ultrasonic horn improves both the quality and efficiency of web bonding. It reduces friction between the travelling webs and the substantially stationary ultrasonic horn not only due to its relatively slick surface, but also due to the compressive force which the slip layer exerts upon the webs to be bonded. This in turn minimizes jamming and hangups in the very limited clearance existing between the rotating anvil roll and the substantially stationary vibrating ultrasonic horn. In addition, the slip layer maximizes retention of heat either generated in the laminate web by the ultrasonic horn or transferred to the laminate web structure by preheating one or more of the webs.

Abstract: An apparatus for unwinding a roll of web material which is prone to blocking: for example, an elastomeric film which, while rolled, is prone to having the convolutions of the roll stick together. The apparatus induces a sufficiently high rate of strain in a short span adjacent the roll to effect continuously peeling the outermost convolution from the roll. Additionally, the apparatus is of such a geometry that, in the event blocking precipitates circumferential shifting of the point of web separation from the roll, the stripping angle is increased. This, in turn, increases the effectiveness of the rate of strain induced peeling force on the web whereby more positive peeling occurs.

Abstract: An interconnected web of disposable diapers containing a pair of continuous, stretched strands of elastic aligned generally parallel to the direction of web travel, is folded along its length from a substantially flat condition to produce a C-shaped, transverse cross-section by means of a conventional board and guide folder. The C-folded web is maintained under tension during the longitudinal folding operation to keep the continuous elastic strands in a stretched condition, and the web is cut transverse to the direction of web travel without releasing the tension in either the individual diapers cut from the web or in the advancing web. Means are provided for transversely folding the individual diapers cut from the web about their midpoints while maintaining the elastic strands associated therewith in a stretched condition and the diaper under positive control.