CompositesWorld

JUN 2017

CompositesWorld

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JUNE 2017 46 CompositesWorld FOCUS ON DESIGN specified to ensure ample stability and to keep the nose from diving into ocean waves. To further help with rider stability, the standing area or deck was sunken and thinner than the rest of the board, to help lower the board's center of gravity — yet overall board stiffness was maintained by placing raised rail profiles around the deck area. e "rockers," referring to the degree of upturn at the front and back, were rela- tively "relaxed," with slightly more upturn up front than in back, enabling the board to glide easily on flat water, maintaining momentum between waves and reducing rider effort. e board's front was crowned slightly, to better shed water, and its tail was tapered to provide extra control in high winds and large swells. e designers also wanted a carbon fiber-reinforced, foot-operated steering system, to enable the rider to change fin position during the race. e CAD-designed fin itself was produced by wet layup, supported by a stainless steel shaft that could fit into a reinforced steering box molded directly into the foam core. Material selection Cobra's task was to produce the race SUP — first as a one-off custom board for Grant, and later, as one of NSP's ProCarbon Technology production race boards — with tolerances, shape characteristics, stiffness and the price point appropriate to each. "Board weight links to market segment and price level." Chotikapanich points out. "Recreational boards are heavier, but less fragile and less expen- sive, while race boards are lighter, more expensive and require careful handling to prevent dings." He says that Cobra's designers play with foam core density, replace glass fiber with carbon or aramid, use higher modulus carbon in some cases for high stiffness, create alternative sandwich structure and, he adds, change fiber Performance and sustainability goals The Molokai Pro Carbon board weighs only 14.5 kg, at a length of 5.44m. Its matrix, a bio-based epoxy resin supplied by Sicomin (Chateauneuf les Martigues, France), is now used in at least half of Cobra's board products to meet the company's sustain- ability goals. Note the carbon fiber-reinforced foot-operated steering system, near the front of the standing area. Source | NSP Proprietary foam core methodology Cobra makes its surfboard and paddleboard foam cores in-house at its facility in Thailand. Here a milling machine shapes an EPS foam "blank" for the core of a production board. Source | Cobra International

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