Stretch Laminate Hook Registration for Uniform Incontinent Fastening
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Solution Overview
Problem
The production of stretch laminates with integral fastening hooks for absorbent articles faces challenges such as inadequate bonding strength, abrasive edges, non-uniform roll formation, and increased material waste due to separate processing of components like stretch laminates, hooks, and adhesive, which complicates assembly and unwinding processes.
Innovation Solution
A stretch laminate with a stretch zone and a dead zone, integrated with a hook layer, where the hook layer is registered within the dead zone, ensuring adequate bonding strength and uniform thickness, reducing processing steps and material waste.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hooks are laminated to the stretch laminate, then assembly efficiency is improved by reducing processing steps, but bonding strength may be inadequate when subjected to strong peel or shear force
Solution Approach 1:
The hook layer is pre-bonded to the stretch laminate during manufacturing to create an integrated structure with integral fastening hooks. This preliminary bonding action ensures that the hooks are already attached before the diaper assembly process, eliminating the need for separate hook attachment steps and improving assembly efficiency while maintaining adequate bonding strength through controlled lamination conditions
Solution Approach 2:
The patent controls lamination parameters including adhesive application patterns (continuous, intermittent, dotted), adhesive thickness (0.02-0.08 inches), and bonding pressure/temperature conditions to optimize both bonding strength and roll uniformity. By adjusting these parameters, the patent achieves sufficient bonding strength to withstand peel and shear forces during use while maintaining production efficiency
2Ease of manufacture
If hooks are laminated to the stretch laminate, then integral fastening is achieved, but roll formation becomes non-uniform due to increased thickness in lamination zones
Solution Approach 1:
The patent applies adhesive in specific patterns (continuous, intermittent, or dotted) rather than uniformly across the entire surface. This localized adhesive application ensures bonding strength is concentrated where needed while minimizing overall thickness increase, thereby maintaining roll uniformity for proper winding and unwinding during manufacturing and use
Solution Approach 2:
The patent uses controlled adhesive thickness (0.02-0.08 inches) and selective adhesive placement to achieve sufficient bonding without excessive material application. This partial action approach provides adequate bonding strength while preventing excessive thickness buildup that would compromise roll uniformity
3Device complexity
If hooks are integrated into the laminate, then the number of processing stations is reduced, but material waste increases due to scrap from splicing
Solution Approach 1:
The patent combines the hook layer and stretch laminate into a single integrated structure with integral fastening hooks. This merging of components eliminates the need for separate hook attachment processing stations and reduces the number of incoming raw materials that require splicing, thereby reducing material waste from splicing operations while simplifying the overall manufacturing process
4Ease of manufacture
If hooks are laminated to the stretch laminate, then fastening function is integrated, but unwinding becomes difficult when hooks engage in the opposite layer
Solution Approach 1:
The patent positions the hook layer specifically within the dead zone of the stretch laminate, creating a localized functional structure. This positioning ensures hooks are available for fastening where needed while the stretch zones remain free of hooks, allowing the laminate to stretch and unwind properly without hook engagement in the opposite layer
Data Source
AI summary
An element for an incontinent device includes: a stretch laminate having a stretch zone having an elongation with a set of less than about 20%, at a tensile load of 10 N/inch, a dead zone having an elongation of at least about 20% lower than the elongation of the stretch zone, and a hook layer registered in the dead zone of the stretch laminate, and where: H1+H2≥H3, when the hook layer having a height H1, the stretch zone having a height H2, and the dead zone where the hook layer is registered having a height H3.