Stretch Laminate Hot Melt Adhesive Composition
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional stretch laminates in disposable absorbent diapers face issues with high strain rates and strain percentages during mechanical activation, leading to defects, increased adhesive usage, and higher costs, along with adhesive bleed-through and reduced cost-effectiveness.
Innovation Solution
A stretch laminate hot melt adhesive composition comprising 35 to 70 weight percent of a polypropylene (co)polymer with a heat of fusion less than 15J/g and a propylene content greater than 50%, 2 to 15 weight percent of a wax with a heat of fusion greater than 50 J/g and a melting peak greater than 100°C, and a tackifier, which provides improved adhesion, reduced bleed-through, and enhanced aged performance.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional stretch laminates are mechanically activated with high strain rates and high percentages of strain, then extensibility is improved, but defects increase and adhesive bleed-through occurs
Solution Approach 1:
The patent changes the chemical composition parameters of the adhesive by incorporating specific polyethylene terephthalate (PET) polymers with controlled molecular weights and compositions, along with reactive diluents and catalysts. This chemical parameter modification allows the adhesive to maintain flexibility and adhesion under high strain conditions without bleeding through or creating defects, thus resolving the contradiction between extensibility and reliability.
2Reliability
If higher amounts of adhesives are used to prevent defects, then reliability is improved, but adhesive bleed-through increases and cost increases
Solution Approach 1:
The patent modifies the adhesive composition by using PET polymers with specific molecular weight ranges and incorporating reactive diluents that reduce viscosity and improve flow characteristics. This allows the adhesive to spread evenly and bond effectively at lower application rates, preventing defects without causing bleed-through, thus resolving the contradiction between reliability and harmful effects.
Solution Approach 2:
The patent creates a composite adhesive system combining PET polymers with specific molecular weights, reactive diluents, and catalysts. This composite formulation synergistically improves adhesion strength and flexibility while controlling bleed-through behavior, allowing effective defect prevention at optimized adhesive quantities.
3Ease of manufacture
If conventional adhesives are used in stretch laminates, then manufacturing is simplified, but aged performance deteriorates
Solution Approach 1:
The patent changes the chemical parameters of the adhesive by incorporating PET polymers with controlled molecular weights and adding reactive diluents with specific functional groups. These compositional changes enhance the adhesive's resistance to aging while maintaining compatibility with standard manufacturing processes, thus resolving the contradiction between ease of manufacture and aged performance.
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
The adhesive composition enhances the extensibility and bond strength of stretch laminates while minimizing substrate bleed-through and maintaining high peel strength even after aging, thus improving the overall performance and cost-effectiveness of the laminates.
Implementation Method 1
the two nonwoven materials are attached to the elastic film via an adhesive
Implementation Method 2
a wax having (i) a heat of fusion greater than 50 J/g measured at 10°C/min heating and cooling rate
Implementation Method 3
a hot melt adhesive composition comprising 35 to 70 weight percent of a polypropylene (co)polymer
Data Source
Figure 1
Figure 2a)~2b)
Figure 3
AI summary
Stretch laminate hot melt adhesives and stretch laminates are described. The stretch laminate hot melt adhesives are suitable for adhering elastic materials with inelastic substrates, and allow permanent deformation of the inelastic substrate and extensions and retractions of the elastic materials. The stretch laminate hot melt adhesive is particularly suitable for back ear lamination for disposable absorbent articles.