Calendering Roller Pattern to Prevent Dark Points in Textured Nonwovens
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Solution Overview
Problem
Existing calendering rollers for manufacturing cloth-like textured nonwoven fabrics with papermaking fibers tend to gather fibers, resulting in 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 accumulation and maintaining cleanliness during high compression, while producing a fabric with a cloth-like visual texture.
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 cloth-like visual texture, but the roller surface gathers papermaking fibers during compression, resulting in 'dark points' and low product quality
Solution Approach 1:
The patent inverts the traditional negative pattern (cavities and channels) to a positive pattern where the calendering roller surface features raised elements instead of recessed ones. This inversion prevents fiber accumulation in recessed areas while still transferring the desired texture pattern to the nonwoven fabric surface, thereby eliminating 'dark points' and improving product quality while maintaining the cloth-like visual appearance.
2Shape
If the calendering roller pattern density is increased to enhance texture definition, then the visual texture becomes more pronounced, but fiber aggregation in the pattern cavities increases, leading to more 'dark points'
Solution Approach 1:
By inverting the pattern from negative to positive, the design eliminates the cavities that trap fibers during compression. The raised positive elements transfer texture without creating recessed spaces where fiber aggregation occurs, thus allowing higher pattern density for better texture definition without increasing harmful fiber aggregation.
3Manufacturing precision
If high compression pressure is applied during calendering to improve fabric density and texture, then the cloth-like appearance is enhanced, but the roller surface becomes fouled with fiber aggregates more rapidly
Solution Approach 1:
The positive pattern design with raised elements instead of recessed cavities prevents fiber accumulation during high compression. Since there are no depressions to collect and hold fiber aggregates, the roller surface remains cleaner for longer periods even under high compression pressure, reducing maintenance frequency while maintaining enhanced fabric density and texture.
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 that meets consumer standards.
Implementation Method 1
the calendering process
Data Source
AI summary
A calendering roller used to manufacture textured nonwoven fabric including papermaking fibers is disclosed. The calendering roller includes a positive pattern that includes a basic element having a ring shape and a repetition of said basic element along multiple rows and columns substantially overall a peripheral surface of the calendaring roller. The ring defines an apex relatively to a center portion of the ring defining a cavity and a grinded surrounding zone. The ring includes at least one radial channel putting in communication the cavity and the grinded surrounding zone so as to define a discontinuous calendering surface. The repetition is regular except for multiple substantially longitudinally and transversally oriented regions. The regions are of limited size with respect to a calendering roller size and randomly distributed so as to define multiple random longitudinal and transverse lines in the textured nonwoven fabric including papermaking fibers, generating a cloth-like visual texture.