Nonwoven Fabric with Elementary Segments for Low Porosity
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Solution Overview
Problem
Existing nonwoven fabrics lack the mechanical properties and low porosity required for applications needing high flexural rigidity and low air permeability, such as packaging and insulation, while maintaining the advantages of traditional nonwovens.
Innovation Solution
A method producing nonwoven fabrics with multi-component fibers, where a first polymer with a higher melting point is distributed as elementary segments in a matrix of a second polymer with a lower melting point, achieving a dense structure and low porosity through controlled temperature and pressure application without hydroentanglement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If nonwoven fabrics are produced using traditional methods (carding, meltblown, air laying), then the manufacturing process is simple and well-established, but the resulting fabrics have high porosity and lack the mechanical properties needed for applications requiring high flexural rigidity and low air permeability
Solution Approach 1:
The patent applies parameter changes by controlling temperature and pressure during the bonding process to achieve full-surface bonding. Specifically, the bonding process uses temperatures of 100-300°C and pressures of 40-150 N/mm, which melt the thermoplastic fibers and enable them to form bonds across the entire surface area, transforming the physical state of the material to achieve dense structure and low porosity
Solution Approach 2:
The patent uses composite materials by combining different fiber types with distinct properties. It employs a mixture of thermoplastic fibers (for bonding capability) and non-thermoplastic fibers (for structural integrity), creating a composite nonwoven fabric that achieves both low porosity through full-surface bonding and maintained mechanical properties through the complementary characteristics of different fiber components
2Strength
If the nonwoven fabric is fully bonded to achieve low porosity, then the flexural rigidity and density improve, but the air permeability decreases too much for certain applications
Solution Approach 1:
The patent applies local quality by creating different bonding characteristics in different regions of the nonwoven fabric. The full-surface bonding process ensures that bonding occurs wherever thermoplastic fibers are present, but the actual bond density and strength vary locally based on the distribution and concentration of thermoplastic fibers, allowing the fabric to achieve high flexural rigidity in bonded regions while maintaining some air permeability in regions with fewer bonds
3Strength
If thermoplastic fibers are used for bonding, then the bonding strength and flexural rigidity improve, but the static friction increases making processing and handling more difficult
Solution Approach 1:
The patent applies parameter changes by carefully controlling the bonding temperature and pressure parameters. By using temperatures of 100-300°C and pressures of 40-150 N/mm, the process achieves adequate bonding strength while avoiding excessive bonding that would create high friction. The parameters are optimized to melt sufficient thermoplastic fibers for bonding without creating an overly dense or sticky surface
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 resulting nonwoven fabric exhibits high flexural rigidity, low static friction, and low porosity, enabling applications like packaging and insulation with improved processing and handling characteristics.
Implementation Method 1
The nonwoven material can be used in particular as an insulating material
Implementation Method 2
The nonwoven material can be used in particular as an insulating material against heat and/or sound
Data Source
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AI summary
The invention relates to a method for producing a nonwoven fabric containing at least one first polymer component, which is distributed in the form of elementary segments in a matrix made of at least one second polymer component, said method comprising the following steps: a) provision of multicomponent fibers comprising a first polymer component and a second polymer component, wherein - the first polymer component is arranged in a first zone and the second polymer component in a second zone over the cross-section of the multicomponent fibers, wherein - the two polymer components extend in the longitudinal direction of the multicomponent fibers, wherein - the first polymer component has a melting point above the melting point of the second polymer component and wherein - the first zone comprises the first polymer component in the form of at least two separable elementary segments; b) connection of the multicomponent fibers in sheet form by application of pressure and temperature in such a manner that elementary segments made from the first polymer component are distributed in a matrix made from the second polymer component. The method according to the invention makes it possible to produce nonwoven fabrics with a high rigidity, smoothness, a dense structure and low porosity.