Ntau tus neeg siv yeej muaj qee qhov kev nkag siab tsis zoo txog qhov zoo ntawmPPRtubs uas sawv daws mob siab txog. Piv txwv li, PPR cov kav dej tuaj yeem raug tsoo, qhia tias lawv qhov zoo tsis zoo. Qhov tseeb, tsis yog, qhov no tsis ua pov thawj qhov zoo ntawm cov kav dej. Qhov no yog vim qhov kub tsis tshua muaj brittleness ntawm PPR dej yeeb nkab nws tus kheej.
Cov khoom siv raw ntawm PPR yeeb nkab yog random copolymerized polypropylene, uas yog qhov peb hu ua hom III polypropylene. Nws yog tau los ntawm random copolymerization ntawm propylene monomer thiab ib tug me me ntawm ethylene monomer nyob rau hauv qhov kev txiav txim ntawm tshav kub, siab thiab catalyst. Ethylene monomers tau muab faib rau hauv cov saw ntev ntawm propylene, qhov twg ethylene monomers feem ntau tswj ntawm 3-5. Cov ntsiab lus ethylene thiab cov txheej txheem polymerization ntawm ethylene thiab propylene txiav txim siab nws qhov txias brittleness.
Nyob rau hauv cov ntaub ntawv ntawm qhov kub thiab txias, tshwj xeeb tshaj yog nyob rau hauv kev tsim kho nyob rau hauv lub caij ntuj no, qhov yooj ntawm cov yeeb nkab yog txo nyob rau hauv qis kub, lub rigidity yog txhim khu kev qha, thiab nws yog nkig. Nyob rau hauv kev cuam tshuam ntawm kev quab yuam sab nraud lossis kev sib tsoo ntau dhau, cov yeeb nkab yuav tawg rau hauv txoj kab ncaj nraim. Tsis yooj yim rau kev tsim kho. Vim li no, cov kev cai lij choj hauv tebchaws tau ua kom pom tseeb txog qhov teeb meem no.
Thaum lub sij hawm tsim kho nyob rau hauv lub caij ntuj no, yuav tsum tau them nyiaj mloog mus rau cov yam ntxwv ntawm qhov kub thiab txias brittleness ntawm lub tsev muab dej PPR kav, thiab cov kev npaj tsim yuav tsum tau tsim. GB/T50349-2005 muaj cov ncauj lus kom ntxaws txog qhov no. Thaum lub ambient kub yog tsawg, lub toughness ntawm lub PPR yeeb nkab txo, qhia brittleness. Thaum cov yeeb nkab raug cuam tshuam los ntawm kev quab yuam sab nraud los yog lub zog hnyav, yuav muaj qhov tshwm sim ntawm cov kab nrib pleb tawg, thiab qhov tshwm sim tawg pib los ntawm cov yeeb nkab sab hauv thiab txuas mus rau cov yeeb nkab sab nraud. Tom qab cov yeeb nkab tawg los ntawm lub zog ntawm ib qho taw tes, qhov tawg yuav loj hlob sai raws li qhov axis ntawm cov yeeb nkab hauv ib qho instant. Qhov no feature hu ua ceev nrooj tawg. Tsis tas li ntawd, nyob rau lub caij ntuj no, cov kav dej raug mob vim yog sab nraud quab yuam thaum lub sijhawm thauj mus los, cov chaw tsim kho thiab kev teeb tsa, thiab cov kav dej nkig thiab cov kav dej yuav tawg thaum siv.
Ntawm qhov tsis sib xws, qee qhov cuav thiab tsis zoo PPR hlab nrog lwm cov ntaub ntawv raw tau ntxiv, uas tsis yooj yim rau tawg. PPR cov kav dej uas tuaj yeem thauj cov dej kub kub thiab dej txias thiab tuaj yeem siv tau 50 xyoo tuaj yeem tawg, tshwj xeeb tshaj yog thaum qhov kub thiab txias. Qhov no yog qhov qis-kub brittleness ntawm PPR.
Yog tias cov kav dej PPR tsis tuaj yeem tawg, nws tuaj yeem xaus lus tias nws tsis yog cov khoom siv PPR. Qhov zoo ntawm cov kav dej PPR yog feem ntau cuam tshuam nrog kev nkag siab dua. Lub raj zoo ntawm cov khoom siv PPR muaj qhov kub tsis tshua muaj siab, uas yog tshwj xeeb tshaj yog pom tseeb hauv ib puag ncig qis dua 5 degree, yog li lub raj zoo tuaj yeem tawg, tab sis cov uas tsis tuaj yeem tawg yog feem ntau tsis yog PPR hlab. Qhov no txawv ntawm qee qhov kev tshaj tawm, thiab cov neeg siv yuav tsum ceev faj thaum yuav khoom.
