Metal Separator Dot-Primed Rubber Bonding for Blister Control
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Solution Overview
Problem
In fuel cells, the primer coating on metal separators can be lost during production, leading to potential leakage and corrosion issues due to electric potential differences, and vaporized coolant can form blisters that obstruct fluid flow.
Innovation Solution
A metal separator design with rubber extension parts adhered to the metal plate using dot primers, creating channels that connect fluid passages and flow fields, allowing for efficient water discharge and preventing blister formation and corrosion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If a primer is coated uniformly on the metal plate to form rubber, then adhesion between the metal plate and rubber member is improved, but the primer may be lost locally due to die closing, leading to pitting corrosion
Solution Approach 1:
The primer coating is segmented into multiple discrete dots rather than a continuous uniform layer. This segmentation allows the rubber member to be adhered at multiple discrete points, ensuring sufficient adhesion strength while preventing complete primer loss that would lead to pitting corrosion. The dotted pattern distributes the adhesion function across multiple locations.
Solution Approach 2:
The primer is applied with different properties at different locations: dots are placed specifically at positions requiring adhesion (e.g., around coolant passages and at the periphery), while other areas remain primer-free. This local differentiation ensures adhesion where needed while preventing corrosion in areas where primer loss would be problematic.
2Reliability
If the rubber member is adhered firmly to the metal plate, then leakage prevention is improved, but water vapor condensation forms blisters between the metal plate and rubber member, obstructing fluid flow
Solution Approach 1:
The adhesion between the rubber member and metal plate is segmented into discrete dotted regions rather than a continuous bond. This segmentation maintains leakage prevention at the dotted adhesion points while creating non-adhered spaces that allow water vapor to escape, preventing blister formation that would obstruct fluid flow.
Solution Approach 2:
The dotted primer pattern acts as an intermediary structure that partially adheres the rubber member to the metal plate. This partial adhesion maintains sealing function while allowing vapor transmission paths to exist in the non-adhered regions, preventing blister formation.
3Strength
If the primer is coated on the entire metal plate surface, then adhesion coverage is maximized, but manufacturing complexity and material consumption increase
Solution Approach 1:
The primer coating is segmented into discrete dots positioned at specific locations rather than a continuous full-surface coating. This segmentation reduces the total amount of primer material needed and simplifies the coating process, as the primer can be applied selectively at key adhesion points using simpler application methods.
Solution Approach 2:
Instead of applying primer to the entire metal plate surface (excessive action), primer is applied only at the necessary discrete locations for adhesion (partial action). This partial application achieves sufficient adhesion coverage while reducing manufacturing complexity and material consumption.
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 effectively prevents blister formation and corrosion by ensuring water is discharged from the interface between the metal plate and rubber member, maintaining fluid flow and reducing the risk of pitting corrosion.
Implementation Method 1
The plurality of rubber extension parts are adhered to the metal plate through a plurality of dot primers between the metal plate and the rubber extension parts
Implementation Method 2
water which has been vaporized, etc. (coolant) may enter the portion between the metal plate and the rubber member, and the water vapor may be condensed to form blisters (water swelling) between the metal plate and the rubber member
Data Source
AI summary
A metal separator is stacked on each of both surfaces of a membrane electrode assembly to form a fuel cell. A method of producing the metal separator includes a metal plate processing step of producing a metal plate including a fluid passage and a fluid flow field, and a rubber adding step of adhering a plurality of rubber extension parts extending from the fluid passage toward the fluid flow field, to the metal plate. In the rubber adding step, a primer is coated on the metal plate in an island pattern, and the metal plate and the rubber extension parts are adhered together through the primer in a dot pattern.