Xaiv cov khoom ruaj khov PVC rau kev ua yeeb nkab thiab cov profile extrusion zoo

Taug kev mus rau hauv txhua qhov chaw ua vaj tse lossis lub khw kho kom zoo nkauj hauv tsev, thiab koj yuav pom PVC nyob txhua qhov chaw - los ntawm cov kav dej uas nqa dej hla cov tsev mus rau cov qhov rai uas ua rau peb pom kev. Qhov uas ntau tus neeg tsis paub yog tias cov thermoplastic no siv tau dav dav rau tus phab ej ntsiag to: PVC stabilizers. Rau cov txheej txheem extrusion, tshwj xeeb, xaiv qhov yogPVC stabilizertsis yog tsuas yog ib qho teeb meem ntawm kev ua kom tau raws li cov quotas tsim khoom xwb; nws yog qhov sib txawv ntawm cov khoom siv ruaj khov, ua raws li txoj cai thiab cov khoom uas ua tsis tiav ua ntej lub sijhawm.

Ua ntej, cia peb nkag siab tias vim li cas cov stabilizers tsis tuaj yeem sib tham rau PVC extrusion. Tsis zoo li lwm cov thermoplastics, PVC muaj Achilles 'heel: tsis ruaj khov thermal. Thaum cua sov rau 160–200 ° C kub ib txwm muaj ntawm extrusion - tshwj xeeb tshaj yog rau cov khoom khov kho xws li cov kav dej - PVC pib tso hydrogen chloride (HCl). Qhov no ua rau muaj kev sib xyaw ua ke ntawm kev puas tsuaj, ua rau muaj kev hloov pauv (xav txog daj, tom qab ntawd xim av, tom qab ntawd dub) thiab poob qis hauv lub zog kho tshuab. Yog tsis kuaj xyuas, cov khoom siv yuav tawg thiab siv tsis tau, tsis hais txog cov roj HCl corrosive uas ua rau cov khoom siv extrusion puas tsuaj. Qhov ntawd yog qhov uas PVC stabilizers nkag mus. Lawv txoj haujlwm tseem ceeb yog cuam tshuam cov txheej txheem puas tsuaj no - los ntawm kev ua kom HCl tsis muaj zog, hloov cov chlorine atoms tsis ruaj khov hauv PVC molecular saw, lossis ntes cov free radicals uas ua rau kev tawg sai. Rau cov yeeb nkab thiab cov ntawv thov profile, uas xav tau kev ruaj khov ntev (feem ntau 50+ xyoo rau cov kav dej plumbing) thiab kev ua haujlwm tas li, qhov stabilizer zoo tsis yog tsuas yog ib qho additive; nws yog ib qho tseem ceeb ntawm cov mis.

Thaum nws los txog rau kev rho tawm, tsis yog txhua yam PVC stabilizers tau tsim zoo ib yam. Kev xaiv nyob ntawm cov yam xws li qhov kub thiab txias ua haujlwm, hom khoom, cov cai tswjfwm, thiab tus nqi. Cia peb rhuav tshem cov hom feem ntau siv hauv kev tsim cov yeeb nkab thiab cov profile, nrog rau lawv cov txiaj ntsig, qhov tsis zoo, thiab cov ntawv thov zoo tagnrho:

Cov khoom ruaj khov uas muaj cov hlau leadtau ntev los ua ib qho kev siv zog hauv kev lag luam, tshwj xeeb tshaj yog rau cov kav dej PVC thiab cov profiles. Lawv qhov kev nyiam yog nyob rau hauv kev ruaj khov thermal zoo heev, tiv taus huab cua zoo, thiab tus nqi qis. Cov tshuaj xws li tribasic lead sulfate lossis dibasic lead phosphite feem ntau siv rau hauv ib pob formulations uas muaj cov roj nplua nyeem, ua rau lawv yooj yim rau kev koom ua ke rau hauv cov txheej txheem extrusion. Rau cov ntawv thov tsis-pom tseeb, tsis kov zaub mov-xws li cov kav dej ntws lossis cov profiles sab hauv tsev-cov stabilizers raws li cov hlau lead tau keeb kwm yog qhov kev xaiv mus-rau. Txawm li cas los xij, lawv hnub tau suav hauv ntau thaj chaw. Cov kev cai nruj xws li REACH thiab RoHS txwv lossis txwv cov khoom ntxiv raws li hlau lead vim yog kev txhawj xeeb txog ib puag ncig thiab kev noj qab haus huv. Yog li ntawd, cov chaw tsim khoom tau hloov mus rau lwm txoj hauv kev, tshwj xeeb tshaj yog rau cov khoom muag hauv EU, North America, thiab lwm yam kev lag luam tswj hwm.

Cov tshuaj stabilizers Calcium-zinc (Ca-Zn)tau tshwm sim los ua tus thawj coj hauv kev xaiv ib puag ncig rau cov hlau txhuas. Cov tshuaj tsis muaj tshuaj lom, tsis muaj hlau txhuas no tam sim no yog tus qauv rau ntau daim ntawv thov extrusion, suav nrog cov kav dej haus thiab cov profile sab nraum zoov. Cov Ca-Zn stabilizers niaj hnub no, feem ntau yog tsim los ua cov txheej txheem sib xyaw, muab kev ruaj khov thermal zoo thaum ua ke nrog cov khoom siv ntxiv xws li epoxides lossis phosphites. Piv txwv li, cov Ca-Zn stabilizer ua haujlwm siab (xws li qib RJ-702 siv hauv qee cov qauv) ntawm 3.5 phr (qhov ib puas resin) tuaj yeem tiv thaiv kev daj txawm tias nyob rau qhov kub siab extrusion. Ib qho ntawm cov txiaj ntsig tseem ceeb ntawm Ca-Zn stabilizers yog lawv qhov sib xws nrog cov yas yas zoo ib puag ncig xws li DOTP, uas yog qhov tseem ceeb rau kev ua tau raws li qhov xav tau qis-VOC thiab tsis muaj tshuaj lom. Txawm li cas los xij, lawv muaj kev txwv: cov txheej txheem Ca-Zn ib txwm muaj peev xwm tawm tsam nrog kev ruaj khov thermal ntev ntawm qhov kawg siab tshaj plaws ntawm qhov kub extrusion (saum toj no 190 ° C) thiab tej zaum yuav xav tau kev sib txuas lus roj nplua nyeem kom tsis txhob muaj teeb meem xws li phaj-tawm lossis qhov chaw tsis zoo. Txawm hais li ntawd los, kev nce qib hauv kev tsim cov qauv - xws li kev ntxiv cov khoom sib xyaw ua ke - tau ua rau cov Ca-Zn stabilizers ua haujlwm tau zoo rau txawm tias cov txheej txheem extrusion nyuaj.

Cov tshuaj stabilizers ntawm Organotinyog qhov kev xaiv zoo tshaj plaws rau cov ntawv thov uas qhov meej thiab kev ua tau zoo tsis tuaj yeem sib tham tau. Cov tshuaj xws li methyltin lossis octyltin muab kev ruaj khov thermal zoo heev, pob tshab zoo heev, thiab kev hloov pauv qis, ua rau lawv zoo tagnrho rau cov ntaub ntawv PVC pob tshab lossis cov kav dej tshwj xeeb. Lawv kuj ua raws li FDA, uas yog vim li cas lawv thiaj siv rau hauv cov ntawv thov PVC uas kov zaub mov, txawm hais tias lawv cov nqi siab txwv lawv txoj kev siv hauv cov yeeb nkab txheem thiab cov khoom tsim profile. Rau cov txheej txheem extrusion uas xav tau lub qhov rais ua tiav dav (piv txwv li, kev ywj pheej ntau dua hauv kev tswj qhov kub), organotin stabilizers nyuaj rau yeej. Txawm li cas los xij, lawv tus nqi - feem ntau 3-5 npaug ntawm cov hlau lead lossis Ca-Zn lwm txoj hauv kev - txhais tau tias lawv feem ntau yog tseg rau cov khoom muaj nqis siab dua li cov kav dej khoom lag luam lossis cov ntaub ntawv.

Yuav kom pab pom tau qhov kev lag luam, ntawm no yog kev sib piv sai ntawm peb hom stabilizer tseem ceeb rau kev siv extrusion:

Tam sim no, cia peb hloov mus rau sab ua tau tiag tiag: yuav ua li cas xaiv cov PVC stabilizer zoo rau koj cov txheej txheem extrusion, txawm tias koj ua cov kav dej lossis cov profile. Kauj ruam thawj zaug yog ua kom koj qhov kev xaiv sib haum nrog cov kev cai lij choj. Yog tias koj muag rau hauv EU, North America, lossis lwm lub khw nruj, cov stabilizers ua los ntawm cov hlau lead tsis yog qhov zoo tshaj plaws - pib nrog Ca-Zn lossis organotin. Rau cov kav dej haus, koj kuj yuav tsum xyuas kom ua raws li cov qauv xws li NSF / ANSI 61, uas hais txog kev tsiv teb tsaws chaw tsawg ntawm cov khoom ntxiv.

Tom ntej no, xav txog koj cov xwm txheej ua tiav. Cov kav dej PVC ruaj khov xav tau qhov kub siab dua (180–200 ° C) dua li ntau cov profiles, yog li koj yuav xav tau lub stabilizer nrog lub zog thermal stability. Lub kaw lus Ca-Zn sib xyaw nrog epoxide synergists lossis lub organotin stabilizer ua haujlwm siab yuav yog qhov kev xaiv zoo dua ntawm no dua li qhov sib xyaw Ca-Zn yooj yim. Yog tias koj cov kab extrusion khiav ntawm qhov ceev ceev lossis muaj lub sijhawm tsis ua haujlwm ntau zaus, nrhiav cov stabilizers uas muaj lubricity zoo (kom txo qhov kev sib txhuam thiab cua sov tsim) thiab cov khoom tiv thaiv lub sijhawm tsis ua haujlwm. Piv txwv li, qee cov qauv Ca-Zn yog tsim los tiv thaiv kev lwj ntawm cov pwm thaum lub sijhawm tsis ua haujlwm ntev - tseem ceeb rau kev zam kev ntxuav kim thiab cov khoom tsis zoo.

Cov kev cai ua haujlwm ntawm cov khoom yog lwm yam tseem ceeb. Cov profile sab nraum zoov xav tau kev tiv thaiv UV kom tiv thaiv kev hloov pauv thiab kev puas tsuaj los ntawm lub hnub ci, yog li xaiv cov pob khoom stabilizer uas suav nrog UV absorbers (xws li benzotriazoles) lossis hindered amine light stabilizers (HALS). Rau cov kav dej uas yuav nqa cov kua dej corrosive (xws li kev ntws dej hauv kev lag luam), lub stabilizer nrog kev tiv thaiv tshuaj zoo - xws li lub kaw lus Ca-Zn ua los ntawm cov hlau lead lossis kev ua haujlwm siab - yuav tseem ceeb. Cov profile pob tshab, ntawm qhov tod tes, xav tau lub stabilizer uas tsis cuam tshuam rau qhov meej, uas taw qhia rau organotin lossis cov stabilizers Ca-Zn pob tshab tshwj xeeb.

Tus nqi yeej ib txwm yog qhov yuav tsum xav txog, tab sis nws yog ib qho tseem ceeb kom sib npaug cov nqi ua ntej nrog kev ua tau zoo mus sij hawm ntev. Txawm hais tias cov tshuaj stabilizers uas siv lead pheej yig, tus nqi ntawm kev tsis ua raws li (kev nplua, kev rov qab xa khoom) lossis kev puas tsuaj rau lub koob npe nrov tuaj yeem ntau dua li kev txuag. Cov tshuaj stabilizers Ca-Zn muab qhov chaw zoo rau feem ntau daim ntawv thov: lawv pheej yig dua li organotin thiab ua raws li cov cai thoob ntiaj teb. Ntau lub tuam txhab tsim khoom pom tias kev nqis peev rau hauv cov tshuaj stabilizer Ca-Zn zoo txo ​​cov nqi tsim khoom tag nrho los ntawm kev txo qis qhov tsis zoo (xws li cov seem daj lossis cov seem tawg) thiab txhim kho kev ua haujlwm zoo.

Yuav kom piav qhia txog cov ntsiab cai no hauv kev ua haujlwm, cia peb saib ib qho piv txwv tiag tiag: kev tsim cov kav dej haus uas muaj peev xwm extrusion. Lub hom phiaj ntawm no yog los tsim cov kav dej uas tsis muaj tshuaj lom, ruaj khov, thiab ua raws li NSF/ANSI 61. Ib qho kev tsim qauv ib txwm muaj xws li: 100 phr PVC-SG5 resin, 35 phr DOTP (plasticizer uas zoo rau ib puag ncig), 3.5 phr composite Ca-Zn stabilizer (qib ua haujlwm siab), 20 phr coated calcium carbonate (filler), thiab 0.3 phr EVA (compatibilizer). Lub composite Ca-Zn stabilizer muab qhov ruaj khov thermal tsim nyog los tiv taus extrusion ntawm 185–195 ° C, thaum DOTP thiab EVA ua kom muaj kev ntws zoo thiab sib xws. Qhov kawg yog cov kav dej uas ua tau raws li txhua tus qauv kev nyab xeeb, muaj qhov tiav du, thiab tswj nws cov khoom siv kho tshuab rau ntau xyoo.

Lwm qhov piv txwv yog qhov rai sab nraum zoov profile extrusion. Cov profiles no yuav tsum tiv taus ob qho tib si kub extrusion siab thiab ntev UV raug. Ib qho formulation siv cov khoom sib xyaw Ca-Zn stabilizer ua ke nrog UV absorbers thiab HALS. Lub pob stabilizer yog tsim los tiv thaiv kev puas tsuaj thermal thaum lub sijhawm extrusion (170–185 ° C) thiab qeeb UV-induced laus. Ntxiv cov roj nplua nyeem rau hauv stabilizer pab txhim kho cov dej ntws thiab txo kev sib txhuam, ua rau cov profiles nrog cov duab zoo sib xws thiab qhov chaw ci ntsa iab. Cov formulation no ua tau raws li REACH cov kev cai thiab ua kom cov profiles yuav tsis daj lossis ua brittle txawm tias tom qab ntau xyoo raug tshav ntuj.

Thaum kawg, nws tsim nyog sau tseg tias qhov kev xaiv stabilizer zoo tshaj plaws feem ntau yuav tsum koom tes nrog tus neeg muag khoom uas muaj npe nrov. Txhua txoj kab extrusion yog qhov tshwj xeeb - cov khoom siv sib txawv, cov qib resin, thiab cov txheej txheem ua haujlwm tuaj yeem cuam tshuam rau kev ua haujlwm ntawm stabilizer. Tus neeg muag khoom zoo yuav ua haujlwm nrog koj los kho cov pob stabilizer rau koj cov kev xav tau tshwj xeeb, muab cov ntaub ntawv kev tshaj lij (TDS) thiab kev txhawb nqa hauv tsev. Lawv kuj tseem tuaj yeem pab koj taug kev hauv cov toj roob hauv pes kev cai lij choj nyuaj, xyuas kom meej tias koj cov khoom ua tau raws li txhua tus qauv hauv zos thiab thoob ntiaj teb.

Cov tshuaj stabilizer PVC yog cov neeg tseem ceeb uas tsis tau paub txog kev ua cov yeeb nkab thiab cov profile. Lawv hloov cov resin uas tsis ruaj khov rau hauv cov khoom siv uas ruaj khov thiab siv tau ntau yam uas tseem ceeb rau kev tsim kho niaj hnub no. Thaum xaiv cov tshuaj stabilizer PVC rau kev ua cov yeeb nkab, tsom mus rau kev ua raws li txoj cai, cov xwm txheej ua cov txheej txheem, cov kev cai ua haujlwm ntawm cov khoom, thiab kev sib npaug ntawm tus nqi. Rau feem ntau ntawm cov ntawv thov niaj hnub no, cov tshuaj Ca-Zn stabilizers sib xyaw ua ke muab kev ua tau zoo tshaj plaws, kev ua raws li txoj cai, thiab tus nqi. Los ntawm kev nkag siab txog koj cov kev xav tau thiab ua haujlwm nrog tus neeg muag khoom ntseeg siab, koj tuaj yeem ua kom koj cov txheej txheem ua cov yeeb nkab khiav tau zoo, koj cov khoom ua tau raws li cov qauv siab tshaj plaws, thiab koj cov neeg siv khoom tau txais kev ua haujlwm ntev uas lawv xav tau.