Papermaking Felt Base Fabric Seam Loop Formation
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Solution Overview
Problem
The existing methods for forming seam loops in papermaking felts often damage the MD yarns, leading to reduced seam loop strength and a shorter service life due to scratches or dissolution during the removal of CD yarns.
Innovation Solution
The approach involves removing CD yarns from a specific 'CD yarn no-removal part' and moving them from this area to the part where they were originally removed, thereby forming seam loops without damaging the MD yarns, thus maintaining their strength.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If CD yarns are removed from the seam loop region to form seam loops, then seam loops can be formed for joining ends, but MD yarns are damaged leading to reduced seam loop strength
Solution Approach 1:
The seam loop region is divided into multiple zones along the MD direction: a first region where CD yarns are removed to form seam loops, a second region where CD yarns are retained to protect MD yarns, and a third region where CD yarns are removed again. This segmentation allows seam loop formation while preserving MD yarn strength in the protected second region.
Solution Approach 2:
Different regions of the seam loop area are given different qualities: the first and third regions have CD yarns removed to enable seam loop formation, while the second region maintains CD yarns to provide protection. This local differentiation allows the fabric to have both seam loop formability and MD yarn protection in appropriate locations.
2Ease of manufacture
If CD yarns are removed from the seam loop region, then seam loops can be formed, but MD yarns suffer scratches or dissolution during removal
Solution Approach 1:
CD yarns are retained in the second region beforehand to act as a protective cushion for MD yarns during the removal process in adjacent regions. This pre-positioned protection prevents scratches and dissolution of MD yarns that would otherwise occur during CD yarn removal.
Solution Approach 2:
The CD yarns in the second region serve as an intermediary protective layer between the removal process in the first/third regions and the MD yarns. They absorb the harmful effects of the removal process and prevent direct damage to MD yarns.
3Ease of manufacture
If seam loops are formed by traditional methods, then ends can be joined, but service life of the felt is reduced due to MD yarn damage
Solution Approach 1:
The seam loop region is segmented into protected and unprotected zones, allowing seam loops to be formed for end joining while MD yarns in the protected second region maintain their strength and integrity throughout the felt's service life.
Solution Approach 2:
The fabric structure varies locally within the seam loop region, with strengthened zones (second region) that protect MD yarns and extend service life, and formation zones (first and third regions) that enable seam loop creation for end joining.
Data Source
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AI summary
The object is to provide a base fabric for a papermaking felt wherein there is no damage to the MD yarns of the seam loops and a method of producing the same. This is achieved by a base fabric for a papermaking felt wherein seam loops are formed by MD yarns, which is made from MD yarns of the felt running direction (MD) and CD yarns of the felt cross-direction (CD); wherein the seam loops are obtained by removing CD yarns from a part other than the CD yarn no-removal part of a woven fabric comprising a seam loop region having the CD yarn no-removal part, and by moving CD yarns of the CD yarn no-removal part and CD yarns from between the CD yarn no-removal part and the part in which the CD yarns have been removed in the direction of the part in which the CD yarns have been removed, and wherein the strength of the MD yarns of the part in which the CD yarns have been removed is lower than the strength of the MD yarns of the CD yarn no-removal part.