Papermachine Fabric Weave Pattern for Marking Reduction
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Solution Overview
Problem
High-speed paper machines face challenges in maintaining uniformity and reducing marking tendencies, water trails, and operational noise due to the limitations of existing paper machine fabrics, which affect dewatering efficiency and paper quality.
Innovation Solution
A paper machine fabric design with a specific weave pattern that incorporates two transverse threads per longitudinal thread on the running side, reducing crossing points and allowing for thinner transverse threads, which enhances fiber support, stability, and drainage performance while minimizing marking and water retention.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If the number of crossing points for longitudinal threads is increased, then fiber support is improved, but marking tendency in the paper increases
Solution Approach 1:
The patent applies local quality by differentiating the function and structure of transverse threads at different locations. Transverse threads of the first type (on the paper side) have larger diameters and provide fiber support, while transverse threads of the second type (on the machine side) have smaller diameters and reduce marking. This localized differentiation allows each region to optimize its function without compromising the other.
Solution Approach 2:
The patent segments the transverse threads into two distinct types based on their location and function. Type 1 threads are positioned on the paper side and type 2 threads on the machine side, with each type having different diameter characteristics. This segmentation allows the fabric to simultaneously achieve good fiber support and low marking tendency through differentiated thread designs.
2Strength
If transverse thread diameter is increased, then fiber support is improved, but water trail formation increases
Solution Approach 1:
The patent implements local quality by assigning different diameter characteristics to transverse threads based on their location. Threads on the paper side have larger diameters for fiber support, while threads on the machine side have smaller diameters to prevent water accumulation and water trail formation during high-speed operation.
Solution Approach 2:
The patent segments transverse threads into two categories: type 1 threads with larger diameters for fiber support function, and type 2 threads with smaller diameters for drainage and water trail prevention. This segmentation enables the fabric to simultaneously achieve both fiber support and effective water removal.
3Productivity
If the number of transverse threads is increased, then dewatering performance is improved, but fabric uniformity and marking tendency worsen
Solution Approach 1:
The patent applies local quality by positioning different types of transverse threads in different regions of the fabric structure. The paper-side threads (type 1) provide uniform appearance and fiber support, while the machine-side threads (type 2) enhance dewatering capability. This spatial differentiation allows the fabric to achieve both uniformity and high dewatering performance.
Solution Approach 2:
The patent segments the transverse thread system into functional groups: type 1 threads optimized for fabric uniformity and fiber support, and type 2 threads optimized for dewatering and drainage. By distributing these segmented thread types throughout the fabric structure, the patent achieves enhanced dewatering performance while maintaining fabric uniformity.
4Productivity
If fabric openness is increased, then dewatering speed is improved, but fiber support is reduced
Solution Approach 1:
The patent implements local quality by creating regions of different openness within the fabric structure. The paper-side weave provides sufficient openness for fiber support and uniform appearance, while the machine-side weave provides enhanced openness for rapid dewatering. This localized differentiation allows simultaneous optimization of both fiber support and dewatering speed.
Solution Approach 2:
The patent segments the fabric structure into functional zones with different weave characteristics. The upper fabric layer maintains tighter weave for fiber support, while the lower fabric layer provides more open structure for rapid water drainage. This segmentation enables the fabric to simultaneously achieve good fiber support and high dewatering speed.
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 improves fabric uniformity, reduces marking and water trails, and enhances dewatering performance, making it suitable for high-speed paper machines, particularly in the graphic sector, by maintaining high manufacturing quality and preventing operational issues like noise and wear.
Implementation Method 1
A fibrous suspension is a mixture of wood or cellulose fibers, fillers, chemical additives and mostly water. This filtration process, which is often also called sheet formation, takes place in the sheet formation section of the wet end of the paper machine.
Implementation Method 2
the wire cannot be emptied or cannot be emptied sufficiently by the dewatering elements after leaving the sheet-forming zone and the residual water is thrown out of the fabric by the resulting centrifugal forces on a deflection roller of the paper machine
Data Source
Figure 1~2
Figure 3a~3h
Figure 4
AI summary
The invention relates to a papermachine fabric, in particular for the sheet forming zone, having a paper side and a running side, inter alia comprising a first type of transverse threads of the paper side and a second type of transverse threads (25 to 40) of the running side which are interwoven with at least one type of longitudinal threads (41 to 56). The result of the fact that the longitudinal threads (41 to 56) intersect in each case two transverse threads of the second type (25, 28; 31, 34; 37, 40) on the running side within a running-side weave repeat is an improved distribution of the change points or crossing points for the longitudinal threads, with the result that markings in the paper which is to be produced are avoided as far as possible.