Roll-Formed Bipolar Plates With Independent Two-Sided Channels
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Solution Overview
Problem
Existing methods for structuring sheet metal bipolar plates in electrochemical cells, such as electrolysis or fuel cells, are limited by local material redistribution, high labor and tooling costs, complexity, and hazardous waste production, and lack independent structuring of both sides.
Innovation Solution
A bulk forming process using rollers with profiled and unprofiled segments to create independent fluid structures on both sides of sheet metal, allowing continuous and simultaneous processing with minimal material flow and deformation, enabling high throughput and efficient production of bipolar plates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If traditional sheet metal forming methods are used to structure bipolar plates, then local material redistribution can create some channel structures, but independent structuring of both front and back sides is not possible and material flow is limited to local areas only
Solution Approach 1:
The patent divides the structuring process into two independent roller pairs: one roller pair structures the front side while the other roller pair structures the back side. This segmentation allows each side to be structured independently with different channel patterns, depths, and geometries without interfering with each other, resolving the limitation of traditional single-sided structuring methods
Solution Approach 2:
The patent transitions from traditional 2D surface structuring to 3D bulk forming by using counter-rotating rollers that create volumetric channel structures extending through the sheet thickness. This dimensional change enables independent control of front and back side structures while achieving through-thickness fluid flow paths
2Manufacturing precision
If machining processes like milling are used to incorporate structures into sheet metal, then detailed shapes can be created, but significant labor and tooling costs are incurred and each sheet must be processed separately
Solution Approach 1:
The patent implements continuous processing by feeding sheet metal or coils through the roller structuring system without interruption. Multiple sheets can be processed sequentially or simultaneously through the same roller gap, eliminating the need for separate machining operations on each sheet and dramatically increasing production throughput while maintaining precise channel geometries
Solution Approach 2:
The patent replaces traditional mechanical machining processes (milling, drilling) with a roller-based bulk forming mechanism. The profiled rollers impart channel structures directly onto the sheet metal through controlled material flow, eliminating the need for complex machining tools, tooling changes, and manual operations while maintaining high structural precision
3Manufacturing precision
If electrochemical etching (ECM) is used to create highly detailed shapes on sheet metal surfaces, then complex structures can be achieved, but the process becomes very complex and expensive to implement and produces hazardous waste products
Solution Approach 1:
The patent replaces complex electrochemical etching processes with a purely mechanical roller-based bulk forming system. The profiled rollers directly create channel structures through controlled plastic deformation and material flow, eliminating the need for electrochemical baths, power supplies, and waste treatment systems while achieving comparable or superior structural precision
Solution Approach 2:
The patent converts the potentially harmful electrochemical etching process into a beneficial mechanical forming process that produces no hazardous waste. The roller-based system uses controlled material flow and plastic deformation to create precise channel structures without generating toxic byproducts, thereby eliminating waste disposal requirements
4Productivity
If bulk forming with rollers is used to structure sheet metal, then continuous processing and high throughput are enabled, but the sheet must have sufficient thickness and strength to prevent warping during rolling
Solution Approach 1:
The patent uses a pair of counter-rotating rollers where the bottom roller provides support and counteracts the warping forces generated by the top roller's forming action. This counterbalancing mechanism distributes stresses evenly through the sheet thickness, preventing warping and maintaining flatness even during high-speed continuous processing of thinner sheets
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
Enables high-speed, cost-effective production of bipolar plates with independent structuring on both sides, reducing material waste and tooling costs, and facilitating large-scale production without additional post-processing steps.
Implementation Method 1
the front of two rollers, by bulk forming, imprints initial structures into the front side of the sheet metal
Implementation Method 2
Material flow, in the form of a redistribution of material, only occurs locally in areas with a high degree of deformation
Data Source
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AI summary
The present invention relates to a method for bulk forming of sheet metal (1) with a sheet thickness of at least 0.3 mm, wherein the sheet metal (1) is moved through a gap between two rolls (2, 3) in a first rolling step, wherein a front roll (2) embosses first channels (4) into the sheet metal (1) by means of bulk forming, wherein the back side (13) of the sheet metal (1) is not structured and remains flat due to the embossing by means of the front roll (2). The invention further relates to a bipolar plate (10) separated from the sheet metal (1).