• process-production

Getting your product into the production process quickly

Terrella is developing high volume roll embossing equipment that is based on a continous line flow process which provides maximum through put using minimal resources and materials. The process is highly optimized for flexible graphite materials, which is becoming a leading material of choice in todays energy and thermal management markets. This process can take your design to production in short order without the tedious cost and time delay for tooling, setup and and implementation. We have the equipment ready for servicing your parts.

Starting with your CAD geometry and basic requirements, we will convert your plate configuration to a roll pattern that is applied to a roll die. This roll die will be used to compress and create graphite components at a high volume. We have the technique and skills to convert your flow field plate geometry into embossing dies for either flat or roll embossing, depending on your special requirements. Bring us your CAD design in most popular formats. Our tooling and fabrication centers are closely coupled to allow real-time scenarios for determining CAD to machine code conversions. This ensures fast turnaround and quick assessments of die compliance with your original design.

One of our key value propositions is the ability to apply your prototype design to an embossed configuration that can validate your component early in your design cycle. We provide material modeling tools to ensure formed parts meet the critical features that you desire for your component. This includes evaluating material properties such as spring back and material creep, which are inherent in any embossing technique. Our material model is an essential part of the process leading to our success for building the part right the first time.

Once your design is checked and simulated on our modeling tools, we submit the model to our fabrication center. A tool steel drum insert, or roll die, is fabricated to this model and your pattern is machined onto the complex curve die surface. Embossing dies, once completed, are installed onto our assembly processing station. The graphite material is embossed using your fabricated roll-die, with full attention paid to materials, process measures, and production requirements, manufacturing your component.

How the different processes compare:

         
  Compression Molding Injection Molding Machining Roller Embosser
Equipment Standard process used in today’s industry for molding graphite materials. High load is required for this process. 500 ton and higher presses are not uncommon. Process is extremely complicated for bipolar plates since extreme forces are required for flowing high graphite composite materials. Not normally used for graphite plate with fine features. CNC machine very common and practical for low volume samples. Labor and setup time very critical for this process. Some adaption required for cutting graphite, eg high spindle speeds and graphite dust protection for motors. Roll drums offer precise ‘line’ compression with plate materials so load is considerably less than compression molding.
Materials Graphite material requires additives (resins or fillers) to allow material flow during compression. Graphite material requires additives to assist material flow in injection molded equipment. Pure carbon or molded plate blanks are used. Materials uses roll or sheet forms of exfoliated graphite, which is a pure blend of graphite flakes.
Tooling Tool cost for dies considerably expensive with long lead times. Limited tool life, due to high graphite particles is extremely harsh on tool surface. Also long lead times for tooling. Standard NC tools Special technique required for machining roll steel dies used in this process.
Process Higher throughput requires additional dies hence increased tonnage for press or more presses. Multiple cavity tools also add to tool die complexity. For standard injection molded process, long cyle times are needed for completing the molding process. NC programming direct from CAD, standard CNC tools are used. Not a reasonable process for volume scale up. Roll embossing is readily adaptable for high volume and easily scale ups with increased orders.
Post Treatment Compression molding plates may require additional post treatment process to bring plate to fuel cell grade May require additional post treatment processes for improving surface conductivity. Machined plate usually ready for operation, some cleaning may be required or stress reliefed depending on fuel cell blank material used. Depending on user application, additional resin treatment can be added as in line process.