Nonwoven Fabric Laminate Adhesive Bleed-Through Barrier
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional nonwoven fabric laminates used in sanitary products face issues with softness, water resistance, and bleed-through of hot melt adhesive when laminated with a moisture-permeable film, leading to inadequate performance in preventing adhesive penetration and maintaining comfort.
Innovation Solution
A nonwoven fabric laminate structure is developed, where the basis weight and thickness of the first spunbonded nonwoven fabric are increased relative to the second spunbonded nonwoven fabric, with a decreased basis weight of the melt blown nonwoven fabric, to absorb and block the hot melt adhesive, preventing bleed-through and enhancing softness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the basis weight of the MB nonwoven fabric is increased to improve water resistance, then water resistance is improved, but softness deteriorates and the structure becomes bulky
Solution Approach 1:
The patent applies different basis weights to different SB nonwoven fabric layers: the first SB nonwoven fabric (contacting hot melt adhesive) has a higher basis weight (1.6-3.0 times the second layer) to prevent adhesive penetration, while the second SB nonwoven fabric has a lower basis weight to maintain softness. This local differentiation resolves the contradiction between water resistance and softness.
Solution Approach 2:
The patent divides the SB nonwoven fabric into two distinct layers with different functions: the first layer primarily serves as an adhesive barrier, while the second layer provides softness and comfort. This segmentation allows each layer to be optimized independently for its specific function.
2Strength
If hot melt adhesive is used to laminate nonwoven fabric to moisture-permeable film, then bonding strength is improved, but adhesive bleed-through occurs
Solution Approach 1:
The first SB nonwoven fabric acts as an intermediary layer between the hot melt adhesive and the MB nonwoven fabric. Its higher basis weight and specific structure serve as a mediator that absorbs and contains the adhesive, preventing it from penetrating through to the opposite side while still allowing effective bonding.
3Reliability
If the SMS nonwoven fabric structure is used to improve water resistance, then water resistance is improved, but softness deteriorates
Solution Approach 1:
The patent differentiates the basis weight of SB nonwoven fabric layers: the first layer (adhesive contact side) has higher basis weight (1.6-3.0 times the second layer) to prevent adhesive penetration and provide water resistance, while the second layer maintains lower basis weight for softness and comfort.
Solution Approach 2:
The patent segments the nonwoven fabric structure into two functional SB layers with distinct roles: the first layer provides adhesive barrier and water resistance functions, while the second layer provides softness and comfort functions, allowing independent optimization of each property.
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 laminate effectively prevents hot melt adhesive bleed-through while maintaining high softness and water resistance, providing improved performance in sanitary products by diffusing the adhesive into the first spunbonded nonwoven fabric and shielding it with the melt blown nonwoven fabric.
Implementation Method 1
the first spunbonded nonwoven fabric, the melt-blown nonwoven fabric and the second spun-bonded nonwoven fabric are laminated in this order; the nonwoven fabric laminate having overall basis weight of not more than 30 g/m2
Implementation Method 2
diffusing the adhesive into the first spunbonded nonwoven fabric
Implementation Method 3
shielding it with the melt blown nonwoven fabric
Implementation Method 4
a moisture-permeable film, a waterproof film or the like is sometimes bonded (laminated) thereto in order to further give a function, and as a means for the lamination, a hot melt adhesive has been used
Data Source
AI summary
There is provided by the present invention a nonwoven fabric laminate which comprises a first spunbonded nonwoven fabric comprising a propylene-based polymer (first SB nonwoven fabric), a melt blown nonwoven fabric comprising a propylene-based polymer and laminated on the first spunbonded nonwoven fabric, and a second spunbonded nonwaven fabric (second SB nonwoven fabric) comprising a propylene-based polymer and laminated on the melt blown nonwoven fabric, and which has overall basis weight of not more than 30 g/m2, wherein the basis weight of the first SB nonwoven fabric is in the range of 3 to 25 g/m2, the basis weight of the second SB nonwoven fabric is in the range of 1 to 11 g/m2, the ratio of the basis weight of the first SB nonwoven fabric to the basis weight of the second SB nonwoven fabric is not less than 1.6, the ratio of a thickness of the first SB nonwoven fabric to a thickness of the second SB nonwoven fabric is not less than 1.4, the basis weight of the melt blown nonwoven fabric is less than 3 g/m2, and the compression bond area ratio is in the range of 6 to 25%.