Chapter 3 -2Chemical Fibers
Chapter 3 -2 Chemical Fibers
Contents.3.1 What's Fiber3.2Historyofchemical fibers: 3.3 The classification of chemical fibers:3.4 Basic structure and properties3.5Manufacturingtechnology: 3.6 Fiber products and their applications. 3.7 Fibers and the environment
Contents • 3.1 What’s Fiber • 3.2 History of chemical fibers • 3.3 The classification of chemical fibers • 3.4 Basic structure and properties • 3.5 Manufacturing technology • 3.6 Fiber products and their applications • 3.7 Fibers and the environment
ManufacturingTechnologies>The procedure to convert polymers to fibers is calledspinning.FiberTypeSpinning MethodNylon 6Melt spinningNylon 66Polyolefin, PolyesterSolvent spinningCellulose acetateCellulosetriacetateDry solvent spinningAcrylicModacrylicVinyonSpandexWet solvent spinningModacrylic,Acrylic,Rayon(viscoseprocess)Reaction spinningSpandex
Manufacturing Technologies ➢The procedure to convert polymers to fibers is called spinning. Spinning Method Fiber Type Melt spinning Solvent spinning Dry solvent spinning Wet solvent spinning Reaction spinning Nylon 6 Nylon 66 Polyolefin, Polyester Cellulose acetate Cellulose triacetate Acrylic Modacrylic Vinyon Spandex Modacrylic, Acrylic, Rayon (viscose process) Spandex
ManufacturingTechnologies> Meltspinning:thefiber-forming substanceis meltedfor extrusionthroughthe spinneretandthendirectlysolidifiedbycoolingPolymer★Screw8MeteningPunpExtruderFilterSpinneret三丰AirQuenchConvergenceGudeGodetsFinishApplicatorSpin Bobbin
Manufacturing Technologies ➢ Melt spinning: the fiber-forming substance is melted for extrusion through the spinneret and then directly solidified by cooling
Principal process variables in melt-spinningPrimarySecondaryResultingvariablesvariablesvariablesMaterial-chemicalExtrusionvelocityTake-uptensioncomposition, molecularTake-upstressAverage diameterandUltimatephysicalfilamenttiterof as-spunfilamentstructure,behaviourSpin-drawratiotemperatureTexture and physicalExtrusiontemperatureDimensionand numberproperties of as-spunfibersof spinneretorificesMassoutflowLength of the spinningpathTake-upvelocityCooling condition
Primary variables Secondary variables Resulting variables Material-chemical composition, molecular structure, physical behaviour Extrusiontemperature Dimension and number of spinneret orifices Mass outflow Length of the spinning path Take-up velocity Cooling condition Extrusionvelocity Average diameter and titer of as-spunfilament Spin-drawratio Take-up tension Take-up stress Ultimate filament temperature Texture and physical properties of as-spun fibers Principal process variables in melt-spinning
Typical Melt-spun fibersAlternativeMeltingRemarksChemical name of extrudateSpinningDesignationPoint (C)Temperature,(°C)220Nylon-6MonofilamentPolypentamethylene carbonamide260280-290Nylon-6,6Polyhexamethylene adipamide2602GT:PET280-300Poly(ethylene terephthalate)2244GT:PTMT:PBT240-260Poly(tetramethylene terephthalate)130225-300Polyethylene170250-300Polypropylene175Saran120-140Poly(vinylidenechloride)MonofilamentcopolymersPolyurethanesPolysulfides
Typical Melt-spun fibers Chemical name of extrudate Alternative Designation Melting Point ( oC) Spinning Temperature, ( oC) Remarks Polypentamethylene carbonamide Nylon-6 220 Monofilament Polyhexamethylene adipamide Nylon-6,6 260 280-290 Poly(ethylene terephthalate) 2GT; PET 260 280-300 Poly(tetramethylene terephthalate) 4GT; PTMT; PBT 224 240-260 Polyethylene 130 225-300 Polypropylene 170 250-300 Poly(vinylidene chloride) copolymers Saran 120-140 175 Monofilament Polyurethanes Polysulfides
Manufacturing Technologies> Wet spinning process is a fundamental method ofspinningfrom solutionsSolventPolymerSolution VesselFilterFeed VesselFilterMetening PumpToWashing andWindupor StretchingSpinneretHeatExchangerSpin Bath Containing Coagulant本Spent CoagulantFresh Coagulant
Manufacturing Technologies ➢ Wet spinning process is a fundamental method of spinning from solutions
Typical Wet-spinning solvents and CoagulantsCoagulantISOFiberChemicalConcentratiClassSolventStructure ofFiberon,%CoagulantCelluloseWaterCuprocuprammoniumaqueoushydroxideacidicAlginatecalciumsaltaqueous solution of sodiumslightlyofaqueousalginic acidsalt ofalginic acidcalcium hydroxideProteinarachin,zein,dilute sodium hvdroxidedilute sulfuric acid + sodiumorcaseinsulfate17-25Acrylicof50%aqueousCopolymerdimethylformamide(<85acrylonitriledimethylformamide%)20withwt50%aqueousdimethylacetamide(DMA)dimethylacetamideothermonomers20Dimethyl sulfoxide50%aqueousdimethylsulfoxide10-1550%sodiumthiocyanate10%sodiumthiocyanate1060%zinc chloride30%zincchloride1070%nitric acid30%nitric acid15-2090% ethylene carbonate30%ethylene carbonate
Typical Wet-spinning solvents and Coagulants ISO Fiber Class Chemical Structure of Fiber Solvent Coagulant Coagulant Concentrati on, % Cupro Cellulose aqueous cuprammonium hydroxide Water Alginate calcium salt of alginic acid aqueous solution of sodium salt of alginic acid slightly acidic aqueous calcium hydroxide Protein arachin, zein, or casein dilute sodium hydroxide dilute sulfuric acid + sodium sulfate Acrylic Copolymer of acrylonitrile (<85 wt %) with other monomers dimethylformamide dimethylacetamide (DMA) Dimethyl sulfoxide 50%sodium thiocyanate 60%zinc chloride 70%nitric acid 90%ethylene carbonate 50 % aqueous dimethylformamide 50% aqueous dimethylacetamide 50% aqueous dimethylsulfoxide 10% sodium thiocyanate 30% zinc chloride 30% nitric acid 30% ethylene carbonate 17-25 20 20 10-15 10 10 15-20
Typical Wet-spinning solvents and CoagulantsCoagulantISOFiberChemicalConcentratioClassSolventn, %Structure ofFiberCoagulantViscoseCelluloseaqueous solution of sodiumdilute sulfuric acid + sodium7-10salt andxanthate estersulfate+zinc sulfatewaterModalaqueous solution of sodiumdilute sulfuric acidsodium+10sulfate + zinc sulfatesaltandxanthate ester50%15-25Modacryliofcopolymertoacetone,upacrylonitrile, 35-85acrylonitrileCaqueousacetonewithwt%,dimethylformamide(DMF)>50%acrylonitrileothermonomersaqueousdimethylformamideVinylalWater10-18aqueous sodium sulfatepoly(vinyl alcohol),posttreatedwithformaldehydepoly(p-phenylene-20Aramid100%sulfuricacidwater or dilute sulfuric acidterephthalamide)DMFsegmented30%aqueousDMFDMA18-30elastinepolyurethane30%aqueousDMA
Typical Wet-spinning solvents and Coagulants poly(p-phenyleneISO Fiber Class Chemical Structure of Fiber Solvent Coagulant Coagulant Concentratio n, % Viscose Cellulose aqueous solution of sodium salt and xanthate ester dilute sulfuric acid + sodium sulfate + zinc sulfate water 7-10 Modal aqueous solution of sodium salt and xanthate ester dilute sulfuric acid + sodium sulfate + zinc sulfate 10 Modacryli c copolymer of acrylonitrile, 35-85 wt%, with other monomers acetone, up to 50% acrylonitrile dimethylformamide (DMF) >50%acrylonitrile aqueous acetone aqueous dimethylformamide 15-25 Vinylal poly(vinyl alcohol), posttreated with formaldehyde Water aqueous sodium sulfate 10-18 Aramid 100%sulfuric acid water or dilute sulfuric acid 20 terephthalamide) elastine segmented polyurethane DMF DMA 30%aqueous DMF 30%aqueous DMA 18-30
ManufacturingTechnologies> When a polymer is soluble in a volatile solvent, adry-spinning procedure is applied.PolymerSohent4SolventSolution VesselRecoveryFilterFeed VesselMetering PunpHeatExchangerFilterHotSolvent-RichSp inneretGasSpinning Cab iteHotSolvent-PooyGasFinishApplicatorToWinduporDrawingHaul-OffRoll
➢ When a polymer is soluble in a volatile solvent, a dry-spinning procedure is applied. Manufacturing Technologies