Theepoxyresinshavesteadilygrownintheiruseintheplasticsandrelatedindustriesduetothevarietyofformsinwhichtheymaybeprocessed.Asthermosettingmaterials,theyarecuredorcross-linkedbytheadditionofahardenertotheoriginalliquidresin+①.Therepeatingmolecularstructurei...[繼續(xù)閱讀]

    ThermosettingMaterials:Thermosettingmaterialsdifferfromthermoplasticsinmanyways.Basicallythedifferencesareduetothechemicalcondensationpolymerizationprocessthroughwhichthethermosettingmaterialsareproducedthatresultsintheirspecialcharacteristics+①.Thedefini...[繼續(xù)閱讀]

    Ofallthematerialsprovidedbynatureformantouseasamaterialofconstruction,naturalrubberisunique.Thecharacteristicofhighreversibleextensibilityfascinatestheenquiringmind.AstheyearshavepassedsinceitsintroductiontotheEasternHemispherebyColumbusandhisfellowexplor...[繼續(xù)閱讀]

    Thematerialsusedinthesecategoriesallhavefinitedutiestoperformwithinarubberformulation.Therefore,eachwillbediscussedinthesequencealreadylistedearlierinlasttwolessons.Rubbers(hydrocarbon):　Reclaimrubbercanplayanimportantpartinthefunctionofgeneralorspecialis...[繼續(xù)閱讀]

    Syntheticfiberscanbeproducedfromawidevarietyofsubstances:polyesters,polyamides,vinyls,etc.Thesamematerialcanoftenbeusedinmoldingaswellasspinningprocesses.Someofthepolymers,especiallythosewhicharesuitablethermoplastics,arelargelyofpetroleumorigin;others,su...[繼續(xù)閱讀]

    Adhesiveshavebeenatechnologicallyimportantapplicationofpolymersforthousandsofyears.Manyoftheearlynaturaladhesivesarestillused.Theseincludestarchandprotein-basedformulationssuchashydrolyzedcollagenfromanimalhides,hooves,andbonesandcaseinfrommilk.Asnewadhes...[繼續(xù)閱讀]

    Theresinmanufacturingindustriesarethoseconcernedwithconvertingrawmaterialsintochemicalcompoundswhicharefurtherprocessedintothevariousplasticsresins.Theseresinsareproducedinmanyforms;asgranules,powders,liquidsorpastes,readytobesoldtocompanieswhichwillproce...[繼續(xù)閱讀]

    Manydifferentprocessesareusedtotransformplasticgranules,powders,andliquidsintofinalproducts.Theplasticmaterialisinmoldableform,andisadaptabletovariousformingmethods.Inmostcasesthermoplasticmaterialsaresuitableforcertainprocesseswhilethermosettingmaterials...[繼續(xù)閱讀]

    Thermoplasticitemswithauniformcrosssectionareformedbyextrusion.Thisincludesmanyfamiliaritemssuchaspipe,hoseandtubing,gaskets,wireandcableinsulation,sheeting,window-framemoldingsandhousesiding.Moldingpowderisconveyeddownanelectricallyoroil-heatedbarrelbyar...[繼續(xù)閱讀]

    Blowmoldingisaprocessusedtoproducethin-wallhollowthermoplasticparts.Acylinderortubeofplastic,calledaPARISON,isplacedbetweenthejawsofamold.Themoldisclosedtopinchofftheendsoftheheatedplasticandcompressedairpressureisusedtoforcethematerialagainstthemoldfaces...[繼續(xù)閱讀]