Elastomeric Film Adhesion Stability in Stretch Laminates
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Solution Overview
Problem
Conventional elastic films used in disposable absorbent articles face issues with mechanical failure due to decreased adhesion strength over time, especially in thinner films, leading to potential bodily exudate leakage and separation from the wearer, and require improvements in failure resistance while maintaining cost-effectiveness.
Innovation Solution
A structure comprising an elastomeric film layer with a SEEPS block copolymer, a thermoplastic polymer additive, a tackifier greater than 7% by weight, and a plasticizer, along with an adhesive containing a block copolymer, tackifier, and plasticizer, which provides enhanced Slow Peel Resistance and Peel Force.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional adhesive is used to attach elastic material to nonwovens, then initial adhesion is achieved, but adhesion strength decreases over time during distribution and storage
Solution Approach 1:
The patent modifies the adhesive composition by incorporating specific additives including hindered phenol antioxidants, phosphite antioxidants, and amine light stabilizers. These chemical parameter changes prevent degradation of the adhesive-elastomer bond over time, maintaining adhesion strength throughout storage and distribution periods.
Solution Approach 2:
The patent introduces intermediary substances (antioxidants and light stabilizers) that mediate between the adhesive and elastomer to prevent harmful chemical interactions. These intermediaries protect the bond from degradation caused by oxidation and UV exposure during storage, preventing adhesion strength loss.
2Quantity of substance
If thinner films are used to reduce material costs, then material cost decreases, but tear resistance and mechanical integrity deteriorate
Solution Approach 1:
The patent creates a composite laminate structure combining the elastomeric film with adhesive layers containing stabilizers. This composite approach allows thinner films to achieve adequate mechanical integrity through the synergistic combination of materials, where the adhesive composite provides reinforcement and protection against tear propagation.
Solution Approach 2:
The patent incorporates antioxidants and light stabilizers into the adhesive composition before bonding occurs. These protective agents act as preemptive measures against degradation, cushioning the thinner film structure from environmental damage and maintaining its mechanical integrity throughout the product lifecycle.
3Ease of manufacture
If adhesive bonding is used to attach elastic laminate, then mechanical assembly is facilitated, but chemical interactions cause adhesion degradation over time
Solution Approach 1:
The patent introduces antioxidant and light stabilizer intermediaries into the adhesive system to mediate and prevent harmful chemical interactions between the adhesive and elastomer. These intermediaries block degradation reactions while allowing the adhesive to maintain its bonding function throughout storage and use.
Solution Approach 2:
The patent chemically modifies the adhesive composition by adding specific concentrations of hindered phenols, phosphites, and amine stabilizers. These parameter changes alter the chemical behavior of the adhesive to prevent degradation reactions, maintaining reliable adhesion strength while preserving the ease of manufacturing benefits.
Data Source
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AI summary
A structure comprising an elastic film layer and an adhesive in contact therewith is disclosed. The elastomeric film layer may include a plasticizer and greater than 7 percent by weight of a tackifier. The elastomeric film formulation provides reduced loss of adhesion strength with the adhesive over time, providing for improvement in mechanical performance of the stretch laminate over time.