Bast Fiber Nonwoven Composition for Soft Flushable Wipes
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing methods for producing nonwoven fabrics from bast fibers do not adequately address the need for biodegradability and suitability for dry and wet wipes, particularly in terms of softness and dispersibility for flushable applications.
Innovation Solution
A method involving carding bast fibers with man-made cellulose fibers, hydroentangling using varying energy levels in multiple units, and drying at specific temperatures to create a nonwoven fabric with enhanced biodegradability and improved softness and dispersibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If bast fibres are used to produce nonwoven fabric, then biodegradability is improved, but softness and suitability for wipes deteriorates
Solution Approach 1:
The patent combines bast fibres with man-made cellulose fibres to create a composite nonwoven fabric that achieves both biodegradability and softness. The mixture of natural bast fibres (providing biodegradability) and processed cellulose fibres (providing softness and wipe suitability) resolves the contradiction between these two properties.
Solution Approach 2:
The patent applies specific parameter changes including fibre length (10-60 mm), crimp angle (at least 20°), and multi-stage hydroentangling with varying energy levels to optimize both biodegradability and softness. These parameter adjustments allow the bast fibre composite to achieve desired softness while maintaining biodegradable characteristics.
2Reliability
If bast fibres are processed for wipe manufacturing, then biodegradability is improved, but dispersibility for flushable applications deteriorates
Solution Approach 1:
The composite structure of bast fibres combined with man-made cellulose fibres provides both biodegradability and improved dispersibility. The cellulose component enhances water solubility and dispersal in aqueous environments while the bast fibre portion maintains biodegradable properties, enabling flushable wipe applications.
Solution Approach 2:
Different regions of the nonwoven fabric have different properties - the bast fibre regions provide biodegradability while the cellulose regions provide dispersibility. This local differentiation of material properties within the composite structure resolves the contradiction between biodegradability and dispersibility.
3Device complexity
If single-stage hydroentangling is used, then production simplicity is maintained, but fibre entanglement and fabric strength deteriorates
Solution Approach 1:
The hydroentangling process is segmented into multiple stages with different energy levels. The first hydroentangling unit applies lower energy to initially bind fibres, while the second unit applies higher energy to strengthen entanglement. This segmentation improves fabric strength while maintaining reasonable process complexity.
Solution Approach 2:
The hydroentangling process uses dynamic energy adjustment between stages. The varying energy levels applied in different stages allow optimisation of both fibre entanglement quality and process efficiency, resolving the contradiction between simplicity and strength.
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 significantly higher dry softness and lower wet softness compared to viscose fabrics, with improved dispersibility, making it suitable for flushable wipes and various hygiene products.
Implementation Method 1
hydroentangling the formed web by using at least a first and a second hydroentangling unit, wherein a hydroentanglement energy in the first hydroentangling unit is lower than the hydroentanglement energy in the second hydroentangling unit
Implementation Method 2
drying the dewatered web at a temperature of 105-125 °C
Data Source
Figure 1
Figure 2A~2B
AI summary
According to an aspect of the present invention, there is provided a method for producing a nonwoven fabric, the method comprising the steps of providing fibres comprising 10-100 wt-% of bast fibres, the bast fibres having at least one angle of at least 20°, and the bast fibres having an average fibre length of 10-60 mm; carding the fibres and forming a web of fibres on a wire support; hydroentangling the formed web by using at least a first and a second hydroentangling unit, wherein a hydroentanglement energy in the first hydroentangling unit is lower than the hydroentanglement energy in the second hydroentangling unit; dewatering the hydroentangled web; and drying the dewatered web at a temperature of 105-125 °C.