Non-woven laminate and method for producing same
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing nonwoven laminates with elastic properties are complex, costly, and result in unsatisfactory compromises between extensibility, elastic recovery forces, and softness, often leading to undesirable creases and material damage.
Innovation Solution
A method involving the production of nonwoven laminates with at least two spunbond layers, where the second layer consists of polypropylene-based elastomer filaments, and optionally crimped bicomponent filaments, combined with crimped filaments in the first and third layers, to create a laminate with high-loft cover layers and an elastic core, allowing for optimal elastic behavior without additional stretching.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If Lycra threads are embedded within the nonwoven fabric structure to achieve elasticity, then elastic properties are improved, but process complexity increases and visible threads create aesthetic defects
Solution Approach 1:
The patent applies local quality by incorporating elastomer fibers specifically in the core layer of the nonwoven laminate, while the outer cover layers use different fibers. This localized placement of elastic properties where needed most achieves the desired elasticity without requiring Lycra threads throughout the entire fabric structure, thereby reducing process complexity and avoiding visible thread defects.
Solution Approach 2:
The patent uses composite materials by creating a three-layer laminate structure with different fiber compositions in each layer. The core layer contains elastomer fibers for elasticity, while the outer layers provide structural integrity and softness. This composite approach achieves elastic properties through material composition rather than through embedded Lycra threads, simplifying the process and avoiding aesthetic defects.
2Reliability
If TPU fibers are used to achieve elasticity in nonwoven fabric, then elastic properties are improved, but production cost increases and recycling difficulty worsens
Solution Approach 1:
The patent applies local quality by concentrating elastomer fibers specifically in the core layer rather than using expensive TPU throughout the entire nonwoven structure. This localized approach provides the necessary elastic properties in the core region while using more cost-effective fibers in the outer layers, thereby reducing overall production cost while maintaining elastic functionality.
Solution Approach 2:
The patent employs cheaper alternative fibers in the outer cover layers instead of expensive TPU, using materials that are more cost-effective and easier to recycle. The expensive elastomer is restricted to the core layer where it is most needed for elastic recovery, while the outer layers use affordable fibers that fulfill their structural and comfort functions without requiring elastic properties.
3Ease of operation
If nonwoven web is stretched to allow Lycra thread expansion, then elastic extensibility is improved, but creases and aesthetic defects occur when threads return to original state
Solution Approach 1:
The patent applies preliminary action by pre-distributing elastomer fibers uniformly within the core layer during the nonwoven formation process, before any stretching occurs. This preliminary distribution of elastic elements ensures that when stretching happens, the elasticity is already built into the structure through the elastomer fibers rather than relying on Lycra threads that need to be stretched and then return, thereby avoiding creases and surface defects.
4Manufacturing precision
If polypropylene fibers are added to prevent TPU fiber adhesion, then fiber placement quality is improved, but elastic properties deteriorate due to lack of stretchability
Solution Approach 1:
The patent applies segmentation by dividing the nonwoven structure into distinct functional layers: outer cover layers for structural integrity and fiber placement quality, and a core layer dedicated to elastic properties. This segmentation allows polypropylene fibers to be used in the outer layers where they provide good fiber placement and prevent adhesion issues, while elastomer fibers are concentrated in the core layer where elastic properties are most needed, thus maintaining both manufacturing precision and elastic reliability.
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 achieves high elastic elongation up to 70%, combining softness and stretchability with elastic recovery forces, suitable for hygiene products like diapers, while avoiding complex processes and material damage.
Implementation Method 1
continuous filaments are spun using at least one spinnerette to produce each spunbond nonwoven layer
Implementation Method 2
then cooled, subsequently drawn, and finally laid down
Implementation Method 3
subsequently drawn
Implementation Method 4
laminating a stretched, elastic plastic film onto a nonwoven web
Implementation Method 5
The nonwoven laminate is characterized in that it is sufficiently soft and also exhibits excellent elastic properties. On the one hand, the nonwoven laminate is stretchable, and on the other hand, it possesses sufficient elastic recovery forces.
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A method for producing a nonwoven laminate with at least two layers, wherein both layers are produced as spunbond nonwovens. To produce each layer, continuous filaments are spun using at least one spinnerette, then cooled, subsequently drawn, and finally laid down into a web on a lay-up device. At least one first spunbond nonwoven is produced from crimped multi-component filaments, and at least one second spunbond nonwoven is produced from mono-component filaments. The mono-component filaments of the second spunbond have a polypropylene-based elastomer.