| Flexure modulus: Just required in the complete sandwich homologation (under ASTM C393) not in the core's material approval. Major shear resistance better flexure strength. Biodegradability: when left as waste in nature, some polymers will be destroyed by microorganisms and concerted into biomass, minerals and humus. Oil-based polymers and bio-plastics can be biodegradable. The KYOTO Convention encourages all countries to use "sustainable" technologies, which have no negative impact on our environment. Chlorine content: STRUCT-CORE didn't contain chlorine. PVC is different; there we could find 25 Kg chlorine per each 100 Kg of PVC. That's why STRUCT-CORE could be recycled and considered like urban waste. However PVC is considered special waste and it's more expensive to be disposed of. Means a great extra cost in great volume markets like wind turbines, where each 4 years blades must be changed. No Outgassing: STRUCT-CORE didn't contains chlorine acid or isocianate like PVC, and for this reason even when curing or sandwich lamination is already done, is not possible to reactive the polymer in a steam atmosphere like PVC does. Delaminating is for this reason not possible using STRUCT-CORE. Vacuum Infusion Process (VIP, VART, VARI, VARTM, INFUSION,..): Similar to hand lamination process. Encapsulation ofthe fabric reinforcement in a plastic bag and apply the vacuum (determined by fabric composition and resin viscosity) on a open mould. This pressure on the bag it would compact the fibre layers and the core material to each other. Steps to follow: 1. Mould preparation (mould quality is very important). Application of extrudable mould paste, gel coat layer, all components are pre-impregnated (fibbers and core). 2. On the sandwich apply the peel ply, the release film, the breather and the vacuum bag. 3. Installation offeeder lines to allow the resin flow. Connect from one side the mould to the vacuum pump, and in the other side, the resin source. 4. Close hermetically the bag. 5. Apply the vacuum. Advantages: • Easy to infuse large areas faster. • Example: infuse a 52' hull ( = 116m2) means around 105 minutes in one shot. • low styrene emission to the ambient. • no waste of material. • avoid trapping any air between layers causing dry spots and delamination. Free ofvoids. • elimination of resin excess means less weight for same performance • core material could be grooved for the optimal distribution ofthe resin. • All cores will absorb more resin during vacuum infusion than when hand laminated (where just the roughness of the foam surface is solely responsible for resin absorption). • final high quality sandwich more compacts with uniformity ofthickness in all area • Saving production times, potential reduction in cost |