Paper machine clothing and method of producing the same
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Solution Overview
Problem
Existing paper machine clothing technologies face challenges in achieving uniform dewatering of nascent paper webs, leading to markings and suboptimal fiber web quality due to uneven permeability and fiber retention issues.
Innovation Solution
The development of a paper machine clothing with a 'pin-like-structure' where neighboring through-channels have upper rims with a common local maximum, forming an intersecting line with convex, concave, and convex portions, enhancing fiber support and uniform dewatering, and anisotropic properties through varying cross-sectional areas and channel arrangements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional laser drilling is used to create through-channels in the substrate, then the substrate can be perforated to enable dewatering, but the dewatering is uneven and causes markings on the paper web
Solution Approach 1:
The patent applies local quality by creating pin-like structures at specific locations where through-channels intersect. These pin-like structures are formed by overlapping circular paths during laser drilling, creating localized raised features that protrude into the fiber web. This local structural modification ensures uniform contact between the clothing and fiber web, preventing markings while maintaining effective dewatering across the entire surface.
Solution Approach 2:
The patent utilizes spheroidality by creating pin-like structures with curved, rounded tops through the laser drilling process. These pin-like structures have a convex curvature that allows them to protrude uniformly into the fiber web, ensuring consistent contact and pressure distribution. The curved geometry of the pin-like structures prevents localized stress concentrations that would cause markings on the paper web.
2Quantity of substance
If through-channels are created to enable dewatering, then permeability is improved, but fiber support and retention become suboptimal
Solution Approach 1:
The patent applies local quality by creating pin-like structures at specific locations where through-channels intersect. These pin-like structures are formed by overlapping circular paths during laser drilling, creating localized raised features that protrude into the fiber web. This local structural modification ensures uniform contact between the clothing and fiber web, preventing markings while maintaining effective dewatering across the entire surface.
Solution Approach 2:
The patent utilizes spheroidality by creating pin-like structures with curved, rounded tops through the laser drilling process. These pin-like structures have a convex curvature that allows them to protrude uniformly into the fiber web, ensuring consistent contact and pressure distribution. The curved geometry of the pin-like structures prevents localized stress concentrations that would cause markings on the paper web.
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
This design ensures substantial equal dewatering over the complete surface of the nascent paper web, reducing markings and improving fiber web quality by providing effective fiber support and enhanced permeability.
Implementation Method 1
The substrate is perforated using a laser beam LB from a laser that is connected to a controller so as to drill a plurality of discrete through-channels 30 into the substrate
Data Source
Figure 1~3c
Figure 4~7
Figure 8~14
AI summary
The present invention concerns a paper machine clothing comprising a substrate (20) with an upper side (22), a lower side, two lateral edges and an usable region between the two lateral edges, wherein the usable region comprises a plurality of through-channels extending through the substrate (20) and connecting the upper side (22) with the lower side, wherein the through-channels are non-cylindrical with a cross sectional area becoming smaller when going in a thickness direction of the substrate (20) from the upper side (22) to a middle region of the substrate between the upper side and the lower side, wherein an upper rim of at least one of the plurality of through-channels directly contacts an upper rim of at least one other neighboring through-channel of the plurality of through-channels, wherein the upper rims of both neighboring through-channels have at least one common local maximum (42), wherein a sectional plane being parallel to the thickness direction of the substrate (20), comprising the at least one common local maximum (42) and comprising or intersecting the central axis of at least one of the two neighboring through-channels defines an intersecting line with a sidewall of the at least one of the two neighboring through-channels, and wherein the intersecting line comprises a first portion (44) that is convexly shaped, a second portion (46) that is concavely shaped and a third portion (48) that is again convexly shaped when going in the thickness direction of the substrate (20) from the at least one common local maximum (42) toward the middle region of the substrate (20). Furthermore, the present invention refers to a method of producing such a paper machine clothing.