Polymer and Ceramic ProcessingOutlineSlide 3Processing DetailsPolymer FormationSlide 6Polymer AdditivesMore AdditivesProcessing Plastics – Compression MoldingProcessing Plastics – Injection MoldingPlastic Injection MoldingProcessing Plastics – ExtrusionExtrusion of PlasticsProcessing Plastics – Blown-Film Extrusionc14f15GlassGlass Properties: Viscosityc14f17Glass PropertiesLog Glass Viscosity vs. Temperaturec14f18Sheet Glass FormingHeat Treating GlassTempered GlassTempering ProcessShattered Tempered GlassSlide 27Annealed GlassSlide 29Slide 30Slide 31Mechanical Properties of Advanced CeramicsCEREC TechnologyCeramic MaterialsSlip CastingHydroplastic FormingDrying and FiringKaoliniteKaolinSlide 40Sinteringc14f28Ceramic Fabrication Methods - CementationPolymer and CeramicProcessingOutline Polymer Processing TechniquesPolymer AdditivesCeramic Fabrication MethodsGlass FormingParticulate FormingCementationForming Processes for Polymers Compression MoldingInjection MoldingExtrusion Blow MoldingProcessing Details Blow Molding Techniques Extrusion [hose and tubing, belts, rope and cable covers, sheeting and films] Foaming Techniques Foam molding offers the possibility of increasing the size of a part without increasing weight and reducing the weight of a part with controlled change of properties. Chemical foaming involves mixing a chemical blowing agent with pellets prior to the pellets being fed into the feed throat of the molding machine. Injection Molding Most engineering thermoplastic parts are fabricated by injection molding. http://www2.dupont.com/Plastics/en_US/Knowledge_Center/Processing/processing_methods.html5Polymer FormationThermoplastic - can be reversibly cooled & reheated, recycled; heat until soft, shape, then cool.examples: polyethylene, polypropylene, polystyrene.Thermoset - when heated, forms a molecular network (chemical reaction), degrades (doesn’t melt) when heated.examples: urethane, epoxyAdditives for PlasticsFillersPigmentsStabilizersAntistatic AgentsFlame RetardantsPlasticizersReinforcementsCatalystsImprove mechanical properties, processing, durability.Fillers - Added to improve tensile strength & abrasion resistance, toughness & decrease cost. Examples: carbon black, silica gel, wood flour, glass, limestone, talc.Plasticizers - Added to reduce the glass transition temperature Tg below room temperature. Presence of plasticizer transforms brittle polymer to a ductile one. Commonly added to PVC.Stabilizers – Antioxidants, UV protectionLubricants - Added to allow easier processing polymer “slides” through dies easier (sodium stearate).Colorants - Dyes and pigmentsFlame Retardants - Substances containing chlorine, fluorine and boron. Polymer AdditivesMore AdditivesAntimicrobials: Used to control the build up of bacteria, fungi and algae on the surface of plastic products. A wide range of chemical and natural compounds are used as antimicrobials. An example would be naturally occurring silver ions used in products like cell phones or organic acids in food-related products. Antistatics: Used to minimize static electricity. These types of additives can be mixed with the resin or applied to the surface of the product. Antistatic additives are common to a wide variety of products ranging from cosmetics to industrial goods to sensitive electronic parts.Fibers: Used to increase strength and stiffness. The most common type of fibers added for strength would be carbon and glass. Glass-reinforced plastic is more commonly known as fiberglass.99Processing Plastics – Compression MoldingThermoplastics and thermosetspolymer and additives placed in mold cavitymold heated and pressure appliedfluid polymer assumes shape of mold1010Processing Plastics – Injection MoldingThermoplastics and some thermosets•when ram retracts, plastic pellets drop from hopper into barrel•ram forces plastic into the heating chamber (around the spreader) where the plastic melts as it moves forward•molten plastic is forced under pressure (injected) into the mold (die) cavity where it assumes the shape of the moldBarrelhttp://en.wikipedia.org/wiki/Injection_moldPlastic Injection MoldingOperate 30 plastic injection molding machines from 22 tons to 550 Tons and 60 oz. shot capacity. Many machines are capable of multiple core pulls for complex plastic injection molded parts. Plastic injection molding group services mid-sized manufacturing companies in the energy, electronics, life science, aerospace, food and beverage, industrial and construction markets. As a custom plastic injection molder we seek diversity in many markets and focus our skills on part geometry for molding, material and product application.Our plastic injection molding group processes most commodity and engineering injection molded resins including PS, PE, PP, ABS, SAN, PC, PVC, PBT, PPS, TPO, TPU, POM, Nylon 66, Nylon 11 and many custom compounded engineering resins.http://www.blackwellplastics.com/PlasticRodExtrusion.html1212Processing Plastics – ExtrusionThermoplastics•plastic pellets drop from hopper onto the turning screw•plastic pellets melt as the turning screw pushes them forward by the heaters•molten polymer is forced under pressure through the shaping die to form the final product (extrudate)Extrusion of PlasticsIn the extrusion of plastics, raw thermoplastic material in the form of small beads (resin) is gravity fed from a top mounted hopper into the barrel of the extruder. Additives (colorants and UV inhibitors in either liquid or pellet form) are often used and can be mixed into the resin prior to arriving at the hopper.The material enters through the feed throat (an opening near the rear of the barrel) and comes into contact with the screw. The rotating screw (normally turning at up to 120 rpm) forces the plastic beads forward into the barrel which is heated to the desired melt temperature of the molten plastic (which can range from 200°C/400°F to 275°C/530°F depending on the polymer). In most processes, a heating profile is set for the barrel where three or more independent PID controlled heater zones gradually increase the temperature of the barrel from the rear (where the plastic enters) to the front. This allows the plastic beads to melt gradually as they are pushed through the barrel and lowers the risk of overheating which may cause degradation in the