Presentation on theme: "Eco-Houses Based on Eco-Friendly Polymer Composite Construction Materials Conventional molding techniques applied for manufacturing of eco-composites Workshop."— Presentation transcript:
1 Eco-Houses Based on Eco-Friendly Polymer Composite Construction Materials Conventional molding techniques applied for manufacturing of eco-compositesWorkshop , Ohrid September 2007
2 Originally plastics were developed to replace natural materials, Nowadays, natural materials aredeveloped to replace plastics
3 MOLDING TECHNIQUES WHICH WERE APPLIED IN ECO-PCCM PROJECT 1. Compression moldingCM was the major method for processing plastics during the first half of the previous century.It is a process of applying heat and pressure to a plastic material in matched or open dies. The plastics melts due to the heat, then the pressure causes it to form into a desired shape.This is done in a compression molding press.This process is classified as high pressure process.Although this technology is the main processing method used with thermoset plastics, it can also be employed to process themoplastic materialsThe advantages of compression molding are short cycle time, high production rate and excellent surface finishes.
4 Materials used for CM SMC ( Sheet Molding Compounds) BMC (Bulk Molding Compounds)Pellets/granules
5 CM Techniques No mold technique - appropriate for SMC, prepregs Matched die technique – appropriate for BMC, pellets
6 1.a SMC Piston Guide No mold, single-opening press Stack of material Supporting plateHeated press platen
16 MOLDING TECHNIQUES WHICH WERE APPLIED IN ECO-PCCM PROJECT 2. Injection moldingInjection molding is a manufacturing technique for making parts from both thermoplastic and thermosetting plastic materials . Molten plastic is injected at high pressure into a mold, which is the inverse of the product's shape.Injection molding is widely used for manufacturing a variety of parts, from the smallest component to entire body panels of cars.Injection molding is the most common method of production, with some commonly made items including bottle caps and outdoor furniture.
19 Injection moldingAppropriate for rather complicated and dimensional precise shapesKenaf / PLA moldingIM is the mostly used processing technique for PHB, PLA, PLLA plastics
20 Major differences between applied forms of materials SMCPelletsAppropriate for big size panelsNo molding tool is requiredMultiple panels can be produced in one molding cycleCheaper manufacturing processBetter mechanical properties since longer fibers can be appliedApplicable only for flat and/or slightly curved shapesInappropriate for big size panelsMolding tool is requiredOne panel only per cycleExpensive manufacturing processOnly very short fibers can be used making panels with limited mechanical propertiesBetter control of fiber/resin ratioApplicable for 3D shapes
21 CONCLUSIONBiodegradable plastics can be processed as classic thermoplasticsNo exclusive technology for processing is requiredTypical processing techniques: IM, CM, extrusionNo limitation for processing on classic machinesBiodegradable plastics (PLA, PHB, PLLA) are polyesters obtained from renewable resources. The products are waterproof, heat resistant, have appealing surfaces, and are fully biodegradable. The pellets are processed on standard machines. The melt behaves like liquid crystalline polymers (LCP's). This property allows to mold thin walled or complex structures even on small machines.