Polypropylene pellets sawv cev rau lub hauv paus kev lag luam daim ntawv ntawm polypropylene polymers, feem ntau tshwm raws li cov khoom granules ob peb millimeters inch. Daim ntawv no tsis yog cov khoom siv lub xeev kawg tab sis yog cov khoom nruab nrab tsim los pab txhawb kev khaws cia, thauj, thiab kev ua haujlwm tom ntej. Polypropylene yog tsim los ntawm polymerizing propylene monomers nyob rau hauv lub xub ntiag ntawm ib tug catalyst; daim ntawv pellet khaws cov polymer cov qauv tshuaj lom neeg yooj yim, ua cov khoom siv raw rau ntau cov txheej txheem downstream molding.
Los ntawm kev tsim khoom, kev tsim cov pellets polypropylene muaj ob theem tseem ceeb: polymerization thiab pelletization. Thaum lub sij hawm polymerization, propylene roj tau dhau los ua cov tshuaj tiv thaiv kab mob hauv lub reactor los ua cov qauv ntev - saw molecular; Cov txheej txheem pelletization tom ntej hloov cov molten polymer rau hauv cov granules sib xws los ntawm kev txiav thiab txias. Qhov no pelletization imparts ruaj khov ntim thiab ntws cov yam ntxwv rau cov khoom, ua rau nws yooj yim los ntsuas precisely dua hmoov raw cov ntaub ntawv thiab txo cov plua plav paug thaum lub sij hawm tsim khoom. Piv rau polyethylene pellets, polypropylene pellets feem ntau pom muaj zog dua thiab kub tsis kam, tab sis lawv hloov tau me ntsis ntawm qhov kub thiab txias.
Cov khoom ntawm polypropylene pellets nyob ntawm qhov kev npaj ntawm lawv cov saw hlau molecular. Raws li qhov kev npaj ntawm methyl sab chains, lawv tau muab faib ua peb hom stereochemical: isotactic, syndiotactic, thiab atactic. Qhov feem ntau ntawm cov qauv isotactic feem ntau ua rau muaj ntau dua crystallinity thiab txhua yam muaj zog. Los ntawm kev kho cov txheej txheem polymerization, cov tuam txhab lag luam tuaj yeem tswj cov kev ntsuas xws li yaj ntws Performance index thiab molecular hnyav faib kom haum rau cov kev xav tau tshwj xeeb. Piv txwv li, siab -melt-index pellets yog qhov zoo dua rau kev txhaj tshuaj molding ceev, qhov qis-melt-index pellets feem ntau yog siv rau daim ntawv extrusion.
Nyob rau hauv cov nqe lus ntawm kev ua tau zoo ntawm cov ntaub ntawv, cov tshuaj tiv thaiv inherent ntawm polypropylene pellets kom ruaj ntseg tiv thaiv feem ntau acidic thiab alkaline daws; Tsis tas li ntawd, lawv qhov ntom ntom yog qis dua li cov dej, tso cai rau lawv ntab. Cov yam ntxwv no txawv lawv ntawm ntau lwm yam yas yas, txawm hais tias lawv qhov kev tiv thaiv UV tsis zoo, yuav tsum tau ntxiv cov stabilizers rau ntev - siv sab nraum zoov. Additives xws li antioxidants thiab lub teeb stabilizers feem ntau yog siv los txhim kho kev ua tau zoo, ua tib zoo dispersed nyob rau hauv lub polymer matrix thaum lub sij hawm pelletization theem.
Thaum lub sij hawm ua thiab daim ntawv thov, polypropylene pellets tuaj yeem yaj thiab zoo li hauv txhua daim ntawv. Thaum molten, cov khoom siv yog siv rau hauv cov txheej txheem xws li txhaj tshuaj molding, tshuab moulding, thiab extrusion los tsim cov khoom xws li ntim thiab kav mus rau fibers. Piv nrog rau PVC, polypropylene yuav tsum tsis muaj plasticizers thaum lub sij hawm ua thiab nws cov khoom yog yooj yim rau recycle; Txawm li cas los xij, nws poob qis ntawm polycarbonate nyob rau hauv cov nqe lus ntawm pob tshab thiab cuam tshuam lub zog. Daim ntawv granular ua kom cov khoom zoo ib yam ntawm cov khoom siv, uas yog qhov tseem ceeb rau kev tswj xyuas cov khoom zoo.
Los ntawm qhov kev xav ntawm cov khoom ncig, qhov rov ua dua ntawm polypropylene granules yog qhov tsim nyog. Cov khoom pov tseg polypropylene tuaj yeem raug ntxuav, txiav, thiab rov ua dua -granulated rau rov siv dua, lub voj voog uas txo cov peev txheej siv tau zoo. Txawm li cas los xij, cov saw hlau molecular hauv cov khoom siv rov ua dua tshiab feem ntau ua rau degradation, ua rau cov khoom siv qis dua me ntsis piv rau cov khoom siv nkauj xwb -ib qho teeb meem uas tuaj yeem txo tau los ntawm kev kho cov txheej txheem los yog sib xyaw nrog cov khoom siv nkauj xwb. Nyob rau hauv sib piv, thermosetting plastics tsis tuaj yeem remelted los yog reprocessed ib zaug kho, hais txog qhov zoo ntawm thermoplastic polypropylene nyob rau hauv cov nqe lus ntawm recyclability.
Kev ua tau zoo ntawm cov khoom kawg yog txiav txim siab loj los ntawm qhov zoo ntawm granules. Metrics xws li particle loj uniformity, noo noo cov ntsiab lus, thiab impurity theem ncaj qha cuam tshuam kev ua tau zoo thiab cov khoom zoo. Piv txwv li, granules uas muaj cov dej noo ntau dhau los ua npuas thaum txhaj tshuaj molding, thaum cov duab tsis zoo tuaj yeem ua rau tsis sib xws. Cov ntaub ntawv ntau lawm no txoj haujlwm polypropylene granules tsis yog cov khoom siv raw, tab sis raws li qhov tseem ceeb ntawm kev sib txuas ntawm cov tshuaj tsim khoom thiab cov khoom tiav.
Hauv cov khoom siv toj roob hauv pes, polypropylene granules- cais raws li cov khoom siv yas- txuas qhov sib txawv ntawm siab -kev ua tau zoo engineering yas thiab qis- kawg dav dav - cov khoom siv. Thaum nws tsis muaj qhov hnav tsis kam ntawm nylon lossis cov tshuaj tiv thaiv huab cua ntawm PTFE, nws muaj qhov zoo sib xws hauv kev tswj tus nqi, kev ua haujlwm yooj yim, thiab qhov sib npaug ntawm tag nrho cov khoom. Qhov nyiaj tshuav no ua rau nws muaj kev xaiv nrov rau cov ntawv thov xws li cov khoom siv thiab cov khoom lag luam mus rau cov khoom ntim.
Hauv cov ntsiab lus, tus nqi ntawm polypropylene granules raws li kev lag luam nruab nrab nyob rau hauv yuav ua li cas lawv cov qauv qauv optimizes kev tsim khoom. Hom ntawv granular no sib npaug cov kev xav tau sib tw-xws li kev ruaj ntseg cia, kev thauj mus los, thiab kev ua haujlwm yooj yim- ua kom muaj kev siv ntau ntawm polypropylene thoob plaws ntau qhov chaw. Kev xaiv cov khoom siv suab nrov feem ntau hinges ntawm kev ntsuam xyuas ntawm tag nrho cov saw hlau, suav nrog cov qauv ntawm cov khoom siv, tsis yog qhov sib piv yooj yim ntawm qhov kawg ntawm kev ua tau zoo.