Umeco Raw Materials Production Intermediate Processing Parts Manufacture Reinforcement Fibre Preparation Glass Aramid Carbon Unidirectional Woven Chopped Mat Prepregging Moulding (Layup) Resin Curing Basic resins Polyester Epoxy Phenolic Bismaleimide Cynate Ester Resin Formulation Polyester Epoxy Phenolic Bismaleimide Cynate Ester Hot melt Solution Mould Tooling Dry fibre (resin infused or applied by brush) Prepreg Oven Autoclave Hot press Umeco Activity Metal Composite None Vacuum Bagging Some Extensive Consumable (one use only) Re-usable (multiple use) Materials Production Materials Processing Component Manufacture
Historically little has been done to reduce CFRP System cost on Motor racing and Supercars due to low production volumes and exotic complexity of products used to manufacture parts.
Prepreggers Do Not Control carbon fiber pricing Generally control base resin pricing Prepreggers Do Formulate resins Innovate materials and formats that affect all other downstream processing steps
What Is Dform? Cross Plied Uni-Directional tape Selective slits provides conformity Unlimited selection of fibers and areal weights
What DForm Does Eliminates problems with resin pooling typical in press molding traditional fabric materials under high pressure. Conformability without sacrificing structural performance. Snap cure capable resins provide for cycle times as short as a few minutes. Customizable fiber types and areal weights allow for the design of a single ply layup. Customizable shapes allow for reduction of additional processing steps prior to use. Ease of use allows for de-skilling of techniques.
DForm Concept - Conformance Compare the conformability of a long-fibre uni-directional to DForm. Standard hemisphere formability test used to evaluate drape and formability of textile composites. The amount of wrinkling and distortion that occurs as the prepreg is formed into the tool is an indication of how easily it can be draped and formed. Shorter fiber lengths enhance conformability. 60 mm Fiber Lengths 40 mm Fiber Lengths 20 mm Fiber Lengths Typical Cross Plied Unidirectional Note: White Lines are paint lines to enhance visual conformance
DForm Conformance over complex details Splices-open up to permit conformance over complex details without cutting and tailoring Eliminating the need for detail laminating. Delta E4 Coupe EV Carbon DForm Chassis with Front and Rear Aluminium Sub-frames Total Mass <85Kg. Primary structure made of 15 major panels and 16 reinforcing panels.
DForm Conformance over complex details 90 slashes 45 slashes
DForm Mechanical Testing How do the cut fibres affect mechanical properties, and what is the influence of fibre length? UD test panels, MTM57/34-700 36% Rw 150 gsm. Slashed at 45 o and with fibre lengths of 20mm, 40mm, 60mm and continuous. Tensile modulus and strength, compression modulus and strength, flexural modulus and strength and ILSS were measured.
DForm Mechanical Testing
DForm Mechanical Testing Summary results Strength values are reduced in line with fiber length. Modulus values are nearly unchanged. For 0/90 properties apart from tensile and compressive modulus the strength and modulus values are marginally lower for the 60mm fiber length materials than for the woven material. The use of cut UD fibers in a 0/90 laminate gives a material that is stiffer, but not as strong as a woven material.
DForm Resin Systems Available supply with virtually any resin system. Press forming resin systems. Part cycle time is related to T g development and cure rate. High T g reduces/eliminates cool down and heat up cycles. Potential resin system choices for press forming. VTM240 Customizable tack and drape variants. 21 day out-life Tg development in excess of 360 F/182 C.
DForm Resin Systems Potential resin system choices for press forming. VTM240 0.125 in./3.18 mm thick laminates, 320 F/160 C and 350 F/177 C target temperatures, 3 min hold times Loading and unloading hot Gel times 320 F/160 C 37 seconds 350 F/177 C 21 seconds Tg development, Onset via DMA 320 F/177 C for 3 minutes 352 F/178 C 350 F/177 C for 3 minutes 363 F/184 C
DForm Reinforcement options Available supply with virtually any reinforcement, various carbon fibers, glass fibers. Available in areal weights from 300 gsm to >1000 gsm. (depends on selection of fibre and resin system) Allows for custom design of correct material weight and thickness in order to optimize for single ply layups and structural properties.
DForm Summary De-skills the laminating technique, no cutting and tailoring Lowest cost converted broad good Carbon input No Crimp Flatter Surface Finish No telegraphing Supplied in machine cut squares or custom shapes for handling convenience No bulky rolls to store or cut Retention of Material Stiffness Cost Reduction Potential Faster to layup
Productionization of DForm and Cost Reduction The production of hand laminated DForm square blanks is labor intensive and scrap rates are high unless the part is perfectly square Automation is required to remove labor, speed the process and reduce scrap Flat blank is made to the near net shape of the part and thickness changes can be accommodated low scrap and low weight Novel Pre-Forming technologies to eliminate hand laminating for complex shapes. Part is pressed and cured using a snap cure resin uses existing automotive manufacturing equipment and techniques Cured part is transferred to a trimming station and completed Lower cost raw materials Lower cost carbon fibers or glass Lower cost epoxy resins, thermoplastics, vinyl esters, etc