Papermaking Felt Base Fabric Warp-Weft Double Woven Structure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing papermaking felts fail to simultaneously achieve lightweight design, excellent water squeezing properties, prevention of the icicle phenomenon, and avoidance of seam marks, which are critical for efficient paper production.
Innovation Solution
A base fabric with a warp-weft double woven structure, featuring specific weave repeats and yarn configurations, including twisted CD yarns and alternating contact patterns between MD and CD yarns, to ensure lightweight construction, effective water squeezing, and uniform thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of moving object
If the basis weight of the base fabric is reduced to make the papermaking felt lighter, then the product price decreases and hanging load is reduced, but the strength and dimensional stability of the felt deteriorate
Solution Approach 1:
The patent uses a composite base fabric structure combining a first fabric layer and a second fabric layer with different yarn configurations and weave patterns. The first layer uses high-strength yarns in the MD direction to maintain seam strength, while the second layer uses lower density yarns to reduce overall weight. This composite structure allows the felt to achieve lightweight design while maintaining adequate strength through the synergistic combination of different fabric layers.
Solution Approach 2:
The patent applies different fabric structures to different regions and directions: the MD direction uses tighter weaving and higher strength yarns to maintain seam strength, while the CD direction uses more open structure to reduce weight. The seam region specifically benefits from enhanced MD direction strength, while non-seam areas can be lighter, achieving local optimization of both weight and strength requirements.
2Productivity
If the void volume of the papermaking felt is increased to improve water squeezing properties, then water removal efficiency increases, but the structural stability and resistance to deformation decrease
Solution Approach 1:
The patent creates different fabric structures for different functional regions: the press surface area has a structure optimized for water squeezing with appropriate void volume, while the edge and seam regions maintain tighter construction for structural stability. The first and second fabric layers have different void volumes and yarn densities in different directions, allowing local optimization of water removal efficiency while maintaining overall structural integrity.
Solution Approach 2:
The composite base fabric combines two fabric layers with different void volume characteristics. The first layer provides structural stability with lower void volume, while the second layer enhances water squeezing properties with higher void volume in specific directions. This composite structure allows the felt to achieve good water removal efficiency while maintaining structural stability through the complementary functions of the two layers.
3Reliability
If a double woven structure is used to prevent the icicle phenomenon, then yarn stability improves, but the manufacturing complexity and production time increase
Solution Approach 1:
The patent divides the base fabric into two separate fabric layers, each with specific weave patterns and yarn configurations. The first fabric layer uses a plain weave pattern that effectively prevents the icicle phenomenon in the MD direction, while the second layer provides complementary stability. By segmenting the fabric into two functional layers rather than using a single complex weave, the patent achieves reliable icicle prevention while keeping each layer's manufacturing relatively simple.
Solution Approach 2:
The patent uses a composite base fabric with two fabric layers having different weave patterns and yarn properties. The first layer is designed specifically to prevent the icicle phenomenon through its MD direction yarn configuration and weave structure, while the second layer provides additional stability. This composite approach achieves reliable icicle phenomenon prevention by distributing the functional requirements across two simpler layers rather than one complex layer.
4Strength
If the basis weight of the base fabric is increased to improve seam strength, then the strength of the seam region increases, but the product price increases and the felt becomes heavier
Solution Approach 1:
The patent concentrates strength enhancement in the MD direction where seam strength is critical, while keeping the CD direction and overall fabric weight lower. The first fabric layer uses higher strength yarns and tighter weaving specifically in the MD direction to strengthen the seam region, while the second layer provides lighter construction. This local quality approach allows the patent to improve seam strength without proportionally increasing the overall basis weight and price.
Solution Approach 2:
The composite base fabric structure allows differential weighting: the first layer with higher strength characteristics provides seam strength, while the second layer with lower density provides lightness. This composite construction achieves adequate seam strength through the combined effect of the two layers rather than uniformly increasing the basis weight of a single layer, thereby reducing overall weight and price while maintaining required strength.
5Productivity
If the contact area between the papermaking felt and the roll is increased to improve water squeezing properties, then water removal efficiency increases, but the basis weight must be increased which raises the product price
Solution Approach 1:
The patent optimizes the fabric structure specifically at the press surface contact area with the roll. The first fabric layer has a structure that enhances contact area and water squeezing efficiency at the press interface, while the overall fabric weight is controlled through the second lighter layer. This local quality approach allows improved water removal efficiency at the critical contact zone without proportionally increasing the overall basis weight and price.
Solution Approach 2:
The composite base fabric enables improved water squeezing efficiency through the first layer's press-optimized structure while the second layer maintains lower weight. The combination allows the felt to achieve good contact area and water removal performance at the roll interface without requiring a uniform increase in basis weight across the entire fabric, thereby controlling product price while improving productivity.
Data Source
AI summary
A base fabric forms a warp-weft double woven structure. In the base fabric, the base fabric is made of an MD yarn in a MD direction and a CD yarn in a CD direction, and the base fabric includes a weave repeat. In the weave repeat, the CD yarn includes an upper CD yarn and a lower CD yarn, the MD yarn is woven into both of the upper CD yarn and the lower CD yarn, the MD yarn includes at least one combination of a first MD yarn and a second MD yarn adjacent to the first MD yarn in the CD direction, the weave repeat includes first to fourth structural units, and the weave repeat includes a location at which the first and the second structural units are formed in pairs on both surfaces of the base fabric.