Embossing Protrusion Height Variation for Non-Uniform Stretch Substrates
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Solution Overview
Problem
Deep-nested embossing processes struggle to achieve uniform embossment quality on web materials with non-uniform stretch characteristics, leading to inconsistent emboss patterns due to varying heights and rigidity of embossments across different regions.
Innovation Solution
The process involves delivering web materials with differential stretch directions through an embossing apparatus with coordinated embossing cylinders having protrusions in a non-random pattern, where the height of protrusions in regions with higher stretch directions is greater than those in regions with lower stretch directions, ensuring consistent embossment across the web.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If uniform embossing protrusions are used across all regions, then the embossing process is simple, but the embossment height becomes non-uniform on substrates with non-uniform stretch characteristics
Solution Approach 1:
The patent applies local quality by varying the height of embossing protrusions based on the specific stretch characteristics of different substrate regions. Regions with higher stretch characteristics receive taller protrusions, while regions with lower stretch characteristics receive shorter protrusions. This localized adaptation ensures uniform embossment height across the entire substrate despite non-uniform material properties.
Solution Approach 2:
The patent implements dynamics by making the embossing apparatus adjustable, allowing the height of protrusions to be modified according to the substrate's stretch characteristics. This dynamic adjustment capability enables the same apparatus to handle different substrate types and regions by changing the protrusion configuration, rather than requiring fixed geometry.
2Manufacturing precision
If protrusion height is increased in high stretch regions, then uniform embossment quality is achieved, but the complexity of coordinating multiple cylinder patterns increases
Solution Approach 1:
The patent applies segmentation by dividing the embossing system into multiple coordinated cylinders, each responsible for specific regions of the substrate. The first and second embossing cylinders work in sequence, with each cylinder's protrusions strategically positioned and sized for its designated region. This segmentation allows complex height variations to be managed through modular, region-specific configurations.
Solution Approach 2:
The patent implements asymmetry by using non-uniform protrusion heights and non-symmetrical positioning of embossing elements across different cylinders and regions. The protrusions are deliberately designed with asymmetric characteristics to match the asymmetric stretch properties of the substrate, rather than applying symmetric patterns uniformly across all areas.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach results in a uniformly embossed product with consistent embossment height and quality, maintaining the structural integrity of the web material while enhancing its aesthetic and functional properties.
Implementation Method 1
Embossing protrusions on the rolls compress and/or deform the web
Implementation Method 2
the patterns are meshed together. Nested embossing aligns the knob crests on the male embossing roll with the low areas on the female embossing roll
Data Source
AI summary
The present invention provides a process for producing a deep-nested embossed paper product comprising the steps of delivering one or more plies of paper to an embossing apparatus and embossing the one or more plies of the paper between two opposed embossing cylinders. The one or more plies of paper have a first direction and a second direction that is perpendicular to the first direction where both the first and second directions are in the plane of the paper and the one or more plies of paper have a stretch characteristic in the first direction that is higher than the stretch characteristic in the second direction. Each of the embossing cylinders having a plurality of protrusions, each of which have a height, where the embossing protrusions are disposed in an overall non-random pattern where the respective overall non-random patterns on the cylinders are coordinated to each other and the two embossing cylinders are aligned such that the respective coordinated overall non-random patterns of embossing protrusions nest together such that the protrusions engage each other to a depth of greater than about 1.016 mm. The overall non-random pattern of protrusions comprises a plurality of emboss regions where each of the emboss regions comprising a fraction of the total number of protrusions in the overall non-random pattern. All of the protrusions within an embossing region have about the same height and the pattern of protrusions within an emboss region creates a localized primary line of stress on the paper as the plies of paper are embossed where the line of stress has a component in the first direction and a component in the second direction. The height of the protrusions within an embossing region having a higher line of stress component in the first direction is greater than the height of the protrusions in an embossing region having a lower line of stress component in the first direction.