This application claims the full Paris Convention Priority from, and is a U.S. National Stage entry of PCT/GB2010/002052 filed Nov. 9, 2010; which is based upon GB 0920100.5, filed Nov. 17, 2009, the contents of which are incorporated by reference, each as if fully set forth herein in its entirety.
The invention relates to processing metallic plates, for example, for use in manufacturing fuel cell electrode plates.
Electrode or separator plates for fuel cells, i.e. in the form of anode or cathode plates, need to meet stringent requirements to avoid or remove any contamination, and typically require a series of different processing steps to be applied before the plates can be assembled into a fuel cell stack. Various types of coatings and other surface treatments may be required, which may need to be carried out in an enclosed chamber, for example in a vapour or ion deposition process. To prevent the risk of non-adherence of coatings, the surfaces of the plates to be coated must first be free of organic contaminants such as grease or oil. The preceding stamping operations used for applying surface features to the plates cannot however be generally assumed to be clean processes, which results in a significant risk of cross-contamination. The raw material, which may be in the form of a sheet metal roll, also cannot be assumed to be clean. Given that volume production of fuel cell parts requires a large number of such plates to be handled in rapid succession, a solution that enables continuous feeding of metallic plates through a batch type process is ideally required.
Current known processes for applying surface treatments to electrode plates include handling of individual plates and applying various surface treatments to the plates individually, as for example disclosed in US 2005/0241732, in which pressed plates are treated with a passivating solution followed by rinsing and drying steps.
A problem with existing processes is that automated handling of individual plates involves complex machinery.
A further problem, in particular in relation to fuel cell electrode or separator plates, is that such plates are thin and may be prone to damage by being handled individually.
A further problem is, on a mass-production scale where hundreds of thousands of plates are to be processed, how to handle batches of plates between processes, some of which may require a break in a production line.
A further problem is how to minimise on use of resources such as solutions for surface treatment and to reduce energy usage for applying other treatments such as surface deposited layers.
A further problem is how to minimise the space required for surface treatment apparatus configured to handle many thousands of plates in rapid succession.
It is an object of the invention to address one or more of the above mentioned problems.
In accordance with the invention there is provided a method of processing a linked series of metallic plates, in which each plate is connected to an adjacent plate along adjoining edges, the method comprising: providing the series of plates as a first fan-folded stack of plates; drawing the plates in sequence from the stack; applying a surface treatment to one or more of the plates; and, stacking the plates in reverse order to form a second fan-folded stack of plates.
By processing the metallic plates as a fan-folded stack, problems relating to handling of individual plates are substantially reduced, since the plates only need to be handled in the form of readily transported batches of plates. Such batches would be provided in the form of cartridges containing large numbers of plates in a highly compact form.
In preferred embodiments, a plurality of the metallic plates in at least the second fan-fold stack comprise one or more fuel cell electrode plates. As applied to the production of fuel cell electrode plates, the invention has substantial advantages over existing techniques, not least because the problems associated with applying the various different surface processing treatments required for such types of plates are substantially reduced.
In order to increase the efficiency of the process further, each plate may comprise a regular array of fuel cell electrode plates.
The surface treatment applied to the plates may comprise one or more of a cleaning, stamping, spraying, moulding and heat treatment process.
In an exemplary cleaning process, the first fan-folded stack of plates may be at least partially immersed in a cleaning solvent. The amount of solvent used during the process is minimised by immersing the stack, rather than each individual plate, in the cleaning solvent.
Each plate may be connected to an adjacent plate along a line of weakened material joining the plates. Such a join, typically referred to as a ‘living hinge’ can be designed to withstand repeated folding and unfolding steps, sufficient to subject a stack of plates to a series of processing steps, before separating each plate in a final step before assembly of the plates into a fuel cell stack.
The line of weakened material may be provided by a series of perforations. This type of fold can be applied, for example, during a stamping process as the stack of plates is prepared from a raw sheet metal reel.
Alternatively, each plate may be connected to an adjacent plate by a hinge, which may be in the form of a temporary joining piece that is removed once the processing steps are completed. The hinge may comprise one or more corresponding tab and slot connections joining adjacent plates together. This type of join may be suitable where individual plates are stamped from a starting material, for example a larger sheet of metal, followed by a process that joins the plates together to form a stack.
According to a second aspect of the invention there is provided a cartridge of metallic plates for a surface treatment process, the cartridge comprising a linked series of metallic plates, in which each plate is connected to an adjacent plate along adjoining edges forming a fan-folded stack.
According to a third aspect of the invention there is provided an apparatus for applying a surface treatment to a series of metallic plates, the apparatus comprising: a first cradle configured to receive a first fan-folded stack of metallic plates; a first rotatable transfer spool assembly configured to draw the metallic plates from cradle in sequence; and a second cradle configured to receive in reverse order a second fan-folded stack of the plates drawn by the first transfer spool from the first fan-folded stack.
The first rotatable transfer spool assembly preferably comprises a series of arms equally spaced around the assembly, the spacing corresponding with the width of the plates in the stack.
The apparatus may comprise a second rotatable transfer spool configured to receive plates drawn from the first cradle by the first transfer spool and to transfer the plates into the second cradle.
The invention will now be described by way of example, and with reference to the enclosed drawings in which:
Processing of fan-folded stacks of paper is a well-known method for printing, in particular for printing large quantities of computer-generated forms. One example is that disclosed in U.S. Pat. No. 3,683,756, in which a first fan-folded stack of paper is fed into an address printer, which outputs the paper to create a second fan-folded stack of paper having address details printed on each sheet. Such a method would not, however, be suitable for processing metallic plates as shown in
The assembly 10 shown in
The plates in the first stack 1 may be interconnected in various ways, for example via tabs connecting adjacent plates, the tabs being configured to yield when the plates are being stacked and re-stacked. Adjacent plates may alternatively be connected by tabs engaging with corresponding slots or by the use of additional temporary hinge components. Examples of different types of hinges are illustrated in
A combination of the second type of hinge with the first type of hinge is possible, for example using the second type for initial cleaning operations on the plates followed by the use of the first type of hinge for subsequent operations. This may in some circumstances be necessary, for example if the cleaning operations involve high temperatures that the hinge component 23 (
A typical fan-folded stack of plates 1 may for example comprise flat rectangular plates that each contain a regular array of components. A 12×12 array of components in each plate, with an series of such plates formed into a stack containing 100 such plates, results in one stack containing 14400 individual components. The process thereby provides an efficient way of handling large numbers of components.
The process of de-stacking to re-stacking is space efficient and could be totally contained within an environment that may be dictated by the process, for example in a sealed vacuum chamber of a PVD (Physical Vapour Deposition) magnetron.
In processes where the surface treatment is a cleaning process, the first (or dispensing) stack could be partially or fully immersed in a cleaning solution, with the transfer spool indexing the plates across an air stripper.
The fan-folded stack can provide a common format suitable for many types of processing that may be required during the manufacture of fuel cell electrode plates. One type of processing that would be particularly suitable for the invention is that of multi-cavity injection moulding, in which components are moulded on to the plates as they are indexed through a moulding tool. The invention is therefore particularly suited for automated handling, both within the processing stage and between different processes.
An exemplary embodiment of an assembly for processing a stack of fan-folded plates in accordance with the invention is illustrated in
The plates 9 are passed through the press 51 sequentially by means of a stepper motor 53 linked to one or more teeth that engage with corresponding tractor holes provided along one or more edges of the plates 9. The stepper motor 53 and press 51 are configured to be operated such that the plates are moved while the platens 52 are separated and maintained stationary while the press 51 operates. The press 51 is operated by actuating a hydraulic ram 54. The press 51 could alternatively be configured to operate as a stamping press for embossing or punching features on to the plates 9.
Other embodiments are intentionally within the scope of the invention as defined by the appended claims.
Number | Date | Country | Kind |
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0920100.5 | Nov 2009 | GB | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/GB2010/002052 | 11/9/2010 | WO | 00 | 6/27/2012 |
Publishing Document | Publishing Date | Country | Kind |
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WO2011/061472 | 5/26/2011 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
2362884 | Clark | Nov 1944 | A |
2845019 | Stiefel | Jul 1958 | A |
3683756 | Wilson | Aug 1972 | A |
4842573 | Peter et al. | Jun 1989 | A |
5147273 | Rottmann et al. | Sep 1992 | A |
5300008 | Lee et al. | Apr 1994 | A |
6595089 | Stojanowski | Jul 2003 | B1 |
6832571 | Eagles | Dec 2004 | B2 |
7024736 | Ragland et al. | Apr 2006 | B2 |
7049024 | Leban | May 2006 | B2 |
8870977 | Lee | Oct 2014 | B2 |
20050019652 | Fauteux | Jan 2005 | A1 |
20050129917 | Ragland | Jun 2005 | A1 |
20050241732 | Ishigami et al. | Nov 2005 | A1 |
20070113614 | Durney et al. | May 2007 | A1 |
Number | Date | Country |
---|---|---|
1406159 | Mar 2003 | CN |
3 431 509 | Jan 1986 | DE |
1 414 796 | Nov 1975 | GB |
2 073 716 | Oct 1981 | GB |
2 374 306 | Oct 2002 | GB |
2 387 343 | Oct 2003 | GB |
WO 2007088551 | Aug 2007 | WO |
Entry |
---|
Hungary Patent Application No. 201203485-6; Written Opinion; dated Jun. 13, 2013; 6 pages. |
Hungary Patent Application No. 201203485-6; Written Opinion; dated Apr. 22, 2014; 8 pages. |
Number | Date | Country | |
---|---|---|---|
20120264038 A1 | Oct 2012 | US |