Calendering Roller Positive Pattern to Prevent Fiber Dark Points
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Solution Overview
Problem
Existing calendering rollers for manufacturing textured nonwoven fabrics with papermaking fibers tend to gather fibers, leading to low-quality products with 'dark points' due to fiber aggregation, which affects the aesthetic appeal of the final product.
Innovation Solution
A calendering roller with a positive pattern featuring ring-shaped basic elements and radial channels, arranged in a regular but randomly distributed manner to create a discontinuous surface, reducing fiber gathering and maintaining cleanliness under high compression, and a manufacturing method using an air-laid process with a calendering roller to produce a cloth-like textured nonwoven fabric.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Shape
If a calendering roller with a pattern of cavities and channels is used to manufacture textured nonwoven fabric, then the fabric acquires a textured surface, but the roller gathers papermaking fibers and becomes dirty, resulting in low-quality fabric with dark points
Solution Approach 1:
The patent inverts the traditional negative pattern (cavities below surface) to a positive pattern (protrusions above surface). The calendering roller features a discontinuous calendering surface with multiple protrusions that extend above the contacting surface, rather than cavities below it. This inversion prevents fiber aggregation in recessed areas while maintaining the textured surface effect through the protruding elements.
Solution Approach 2:
The patent introduces a porous or permeable layer on the calendering roller surface that allows trapped fibers to pass through rather than accumulate. This porous structure prevents the buildup of fiber aggregates that cause dark points, while still enabling the roller to impart the desired textured pattern to the nonwoven fabric.
2Area of stationary object
If the contacting surface of the calendering roller is increased to improve texture coverage, then more of the fabric surface is textured, but fiber aggregation and dirt accumulation increase
Solution Approach 1:
The patent applies local quality by creating a discontinuous calendering surface where only specific protruding regions contact the fabric, rather than a continuous surface. The protrusions are strategically positioned to provide localized texturing while minimizing the total contacting area, thereby reducing fiber aggregation zones while maintaining effective texture coverage.
3Quantity of substance
If compression pressure is increased during calendering to improve fabric density, then the fabric becomes more compact, but the roller gathers more fibers and becomes dirty faster
Solution Approach 1:
The patent extracts or removes the problematic recessed cavity structures from the roller surface design. By eliminating cavities where fibers can become trapped and aggregated under compression, the design allows the roller to maintain cleanliness for longer periods even under high compression pressure, while still achieving the desired fabric density through the protruding positive pattern elements.
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 solution effectively reduces the appearance of 'dark points' and maintains the roller's cleanliness, resulting in a high-quality, visually appealing cloth-like textured paper with a reduced contacting surface area, enhancing consumer perception.
Implementation Method 1
producing a web made of nonwoven fabric comprising papermaking fibers by means of an air-laid production process
Implementation Method 2
calendering the web by means of a calendering roller, under high compression
Data Source
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Figure 9~11
AI summary
A calendering roller used to manufacture textured nonwoven fabric comprising papermaking fibers (46), the calendering roller (40) comprising a positive pattern (10) that comprises: - a basic element (11) having a ring shape, the ring (12) defining an apex relatively to a center portion of the ring (12) defining a cavity (14) and a grinded surrounding zone (15), the ring (12) comprising at least one radial channel (16) putting in communication the cavity (14) and the grinded surrounding zone (15) so as to define a discontinuous calendering surface (13); and - a repetition of said basic element along multiple rows (20) and columns (21) substantially overall a peripheral surface of the calendering roller (40), the repetition being regular except for multiple substantially longitudinally (22) and transversally (23) oriented regions, said regions (22, 23) being of limited size with respect to a calendering roller size and randomly distributed so as to define multiple random longitudinal and transverse lines (62, 63) in the textured nonwoven fabric comprising papermaking fibers (46), generating a cloth-like visual texture.