Laminated Seamable Press Fabric for Caliper and Moiré Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current press fabrics in papermaking processes suffer from caliper variation, Moiré Effect, and production inefficiencies due to discontinuities and imperfect seam formation, which affect surface smoothness, pressure distribution, and production speed.
Innovation Solution
A flat woven full-width base fabric with demarcated regions and Circumflex yarns is used, woven in multiple patterns and densities, then laminated and seamed into an endless loop to minimize caliper variation and Moiré Effect, and improve seam quality and production speed.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional woven base fabrics are used with standard seam formation, then production speed can be maintained, but caliper variation and Moiré Effect occur affecting surface smoothness
Solution Approach 1:
The fabric is divided into multiple woven layers with different yarn densities and patterns, where each layer serves a specific function. The base fabric includes a first layer with higher yarn density and a second layer with lower yarn density, creating a segmented structure that reduces Moiré Effect while maintaining production efficiency
Solution Approach 2:
Different regions of the fabric have different yarn densities and weave patterns optimized for their specific locations. The edge portions have different characteristics than the center portions, with circumflex yarns positioned at edges to reduce caliper variation and improve seam quality without compromising overall production speed
2Manufacturing precision
If fabric width is increased to reduce seams, then surface uniformity improves, but manufacturing complexity increases
Solution Approach 1:
The fabric structure is made asymmetric with circumflex yarns positioned only at edge portions rather than uniformly throughout. This asymmetric arrangement reduces caliper variation at critical seam areas without requiring complete redesign of the entire fabric structure, thereby managing manufacturing complexity
Solution Approach 2:
The invention introduces circumflex yarns that extend in the cross-machine direction at fabric edges, adding a dimensional element to the traditionally two-directional weave. This third dimension of yarn arrangement reduces surface irregularities and caliper variation without significantly increasing overall manufacturing complexity
3Reliability
If seam formation is improved to eliminate discontinuities, then fabric reliability increases, but production time increases
Solution Approach 1:
Circumflex yarns are incorporated into the fabric structure during the initial weaving process, preparing the edge portions for seam formation in advance. This preliminary action ensures that when seams are formed, the circumflex yarns are already positioned to create smooth, continuous transitions, reducing the time needed for seam processing while improving seam quality
Solution Approach 2:
The yarn density and arrangement parameters are changed at fabric edges through the incorporation of circumflex yarns. This parameter change creates a transition zone that facilitates easier and faster seam formation with fewer discontinuities, improving reliability without significantly increasing production time
Data Source
Figure 1~3A
Figure 3(B)
AI summary
A laminated on-machine-seamable industrial fabric made from a flat woven full width base fabric layer wherein the base fabric layer is folded inwardly and flattened to produce a fabric with seaming loops disposed at the two widthwise edges.