Theepoxyresinshavesteadilygrownintheiruseintheplasticsandrelatedindustriesduetothevarietyofformsinwhichtheymaybeprocessed.Asthermosettingmaterials,theyarecuredorcross-linkedbytheadditionofahardenertotheoriginalliquidresin+①.Therepeatingmolecularstructurei...[继续阅读]

    ThermosettingMaterials:Thermosettingmaterialsdifferfromthermoplasticsinmanyways.Basicallythedifferencesareduetothechemicalcondensationpolymerizationprocessthroughwhichthethermosettingmaterialsareproducedthatresultsintheirspecialcharacteristics+①.Thedefini...[继续阅读]

    Ofallthematerialsprovidedbynatureformantouseasamaterialofconstruction,naturalrubberisunique.Thecharacteristicofhighreversibleextensibilityfascinatestheenquiringmind.AstheyearshavepassedsinceitsintroductiontotheEasternHemispherebyColumbusandhisfellowexplor...[继续阅读]

    Thematerialsusedinthesecategoriesallhavefinitedutiestoperformwithinarubberformulation.Therefore,eachwillbediscussedinthesequencealreadylistedearlierinlasttwolessons.Rubbers(hydrocarbon):　Reclaimrubbercanplayanimportantpartinthefunctionofgeneralorspecialis...[继续阅读]

    Syntheticfiberscanbeproducedfromawidevarietyofsubstances:polyesters,polyamides,vinyls,etc.Thesamematerialcanoftenbeusedinmoldingaswellasspinningprocesses.Someofthepolymers,especiallythosewhicharesuitablethermoplastics,arelargelyofpetroleumorigin;others,su...[继续阅读]

    Adhesiveshavebeenatechnologicallyimportantapplicationofpolymersforthousandsofyears.Manyoftheearlynaturaladhesivesarestillused.Theseincludestarchandprotein-basedformulationssuchashydrolyzedcollagenfromanimalhides,hooves,andbonesandcaseinfrommilk.Asnewadhes...[继续阅读]

    Theresinmanufacturingindustriesarethoseconcernedwithconvertingrawmaterialsintochemicalcompoundswhicharefurtherprocessedintothevariousplasticsresins.Theseresinsareproducedinmanyforms;asgranules,powders,liquidsorpastes,readytobesoldtocompanieswhichwillproce...[继续阅读]

    Manydifferentprocessesareusedtotransformplasticgranules,powders,andliquidsintofinalproducts.Theplasticmaterialisinmoldableform,andisadaptabletovariousformingmethods.Inmostcasesthermoplasticmaterialsaresuitableforcertainprocesseswhilethermosettingmaterials...[继续阅读]

    Thermoplasticitemswithauniformcrosssectionareformedbyextrusion.Thisincludesmanyfamiliaritemssuchaspipe,hoseandtubing,gaskets,wireandcableinsulation,sheeting,window-framemoldingsandhousesiding.Moldingpowderisconveyeddownanelectricallyoroil-heatedbarrelbyar...[继续阅读]

    Blowmoldingisaprocessusedtoproducethin-wallhollowthermoplasticparts.Acylinderortubeofplastic,calledaPARISON,isplacedbetweenthejawsofamold.Themoldisclosedtopinchofftheendsoftheheatedplasticandcompressedairpressureisusedtoforcethematerialagainstthemoldfaces...[继续阅读]