New Preforming Method and Binder for Carbon Fiber and Fiberglass Liquid Molding Processes Daniel T. Buckley Manager of CompForm R&D American GFM
Outline Historical Preforming Methods Historical Binders CompForm CompForm Light Curable Binders New Method and Binders
Historical Preforming Methods and Binders Directed Fiber Oldest method and P4/3 Thermoset and Thermoplastic Binders Liquid, Powdered and String Thermoforming CompForm Light Curable Binders
CompForm Using Light 1 Very fast and Efficient Works on all Fiberglass Materials Engineering Fabrics Continuous and Chopped Strand Mats All Veils Works with Directed Fiber Preforming Selective Curing
CompForm Using Light 2 Energetic Stitching Complex Preforms Virtually no Heating of Materials Low Energy usage Flexible Cell Designs Binders are Compatible with all common Matrix Resins
Demo Machine
Viper Preform Machine
Viper Preform Machine
Viper Preform Machine
Large Preform Machine
Large Preform Machine
Large Preform Machine
Light Cure Disadvantages Single Step Thickness Limited Anything Opaque Liquid Binder Application Capital Cost of High Intensity Lighting
Ford Taurus Floorpan
ACC Pickup Box Tailgate
Need for Carbon Fiber and Hybrid Preforms
Carbon Fiber Preforming Light Cure has very limited application with Carbon Fiber Single layer or with Fiberglass Traditional Heating to cure or melt Binders is time consuming and wasteful of energy Direct Cure of Binder is most desirable
New Method and Binder Low energy Targets Scalable for low volume and High Volume Compatible with all fibers and resins No Thickness Limitations Usable with all Fiber Placement methods
New Method uses Anaerobic Binders Binder is a Liquid Cured by the removal of Air Vacuum is applied to the Material Can be cured under pressure by tool or held in place by the vacuum during cure Cycle times are much slower than UV but competitive to Heating processes
Test Equipment Simple Vacuum Chamber Capability to vary the level of the Vacuum Capability to elevate temperature
Vacuum Table and Fixture
Vacuum Fixture
Vacuum Fixture
Small Test Pieces
Small Test Pieces
Small Test Pieces
Anaerobic Advantages 1 Will work with all fibers There may be No Thickness Limitations Can cure all the way around cores and inserts Chemistry can be made to be compatible with most resins
Anaerobic Advantages 2 Flexible Processing Capable Progressive Preforming Subassembly routines Single sided or two sided tooling can be used Can be Combined with Light Cure
Anaerobic Disadvantages 1 High level of Vacuum Required May need to add some heat to speed up cycles No Selective curing as in Light curing Binder is aggressive and can be difficult to release from tool
Anaerobic Disadvantages 2 At this time a two part resin system Chemistry can be unstable Requires special resin handling equipment Binder is very expensive at this time
Problems Works very well when mass of binder is higher than practical Needs to work in very small discrete quantities Balancing reaction rate and stability
Results First test results gave cures in the 10 minute plus range Recent tests results gave cures in 2.5 minutes range Binder acts very stiff, therefore may require less binder than other processes More binder is required for Fiberglass than Carbon Fiber Works well with Hybrids of Reinforcements
Conclusion Works with Carbon and Glass fibers Appears to be close to commercialization Binder Development needs more work May be good option for Dry Fiber cutting Looks to be Scalable for all Production Rates Could be Major Breakthrough
Questions?