I. Qhov tshwm sim thiab kev soj ntsuam kev hnov qab (tseem siv tau rau kev tshuaj xyuas niaj hnub)
Qhov no yog txoj hauv kev yooj yim tshaj plaws thiab ua tau zoo, tsim nyog rau kev soj ntsuam ceev rau hauv pem teb ntau lawm:
1. Kev hloov xim: PVC conveyor siv siv feem ntau pom pom kev tsis zoo tom qab kev laus, xws li maj mam hloov ntawm cov xim dawb los yog lub teeb xim mus rau xim daj, xim av, lossis txawm dub dub. Qhov kev hloov no feem ntau pib hauv zos thiab kis mus rau tag nrho txoj siv sia thaum lub sijhawm, feem ntau tshwm sim los ntawm daim duab -oxidation thiab thermal degradation.
2. Nto Cracking thiab Powdering: Nyob rau hauv cov theem thaum ntxov ntawm kev laus, cov kab nrib pleb zoo (hairline) tshwm, uas txuas ntxiv mus rau hauv cov kab nrib pleb. Nyob rau hauv cov xwm txheej hnyav, qhov chaw blisteres, tev, lossis hmoov, poob nws txoj kev ncaj ncees.
3. Txo Gloss: Cov hlua tshiab muaj qhov du thiab ci ntsa iab, tab sis tom qab kev laus, vim kev puas tsuaj ntawm microstructure, lawv dhau los ua ntxhib thiab npub, nrog kev txo qis.
4. Muaj zog Hardness: Khoov txoj siv ntawm txhais tes qhia tau hais tias lub hardening thiab brittleness, tshwj xeeb tshaj yog nyob rau hauv qis kub qhov twg txawm me ntsis khoov yuav ua rau tawg; resilience tsis zoo.
II. Kev Ntsuas Lub Cev thiab Mechanical Performance Testing (Accurate Assessment Basis) Standardized test quantifies the℃of aging, ua kom haum rau kev txiav txim saib xyuas thiab tswj kom zoo:
1. Tensile Strength and Elongation at Break: Aging leads to molecular chain breakage or cross -linking, could txo tensile strength by more than 30% and elongation at break by up to 44%, ho txo cov khoom toughness.
2. Hardness Hloov: Ntsuas siv lub Shore hardness tester, lub hardness nce ntau tshaj 15 degrees tom qab laus, qhia txog ib tug qauv ntawm cov khoom embrittlement.
3. Impact and Tear Strength: Impact resistance txo qis tom qab kev laus, nrog cov nqi qis dua pom hauv cov nqaj yooj yim lossis cantilever beam kev ntsuam xyuas, ua rau nws yooj yim rau tawg ntawm cov ntsiab lus kev ntxhov siab.
4. Kev hloov hluav taws xob rwb thaiv tsev kev ua tau zoo: Hauv kev siv tshuaj tiv thaiv- zoo li qub, chloride ion deposition tom qab kev laus tuaj yeem ua rau muaj qhov ua kom muaj zog ntxiv lossis txo qis dielectric zog, cuam tshuam rau kev nyab xeeb kev ua haujlwm.
III. Kev Tshawb Fawb Kev Tshawb Fawb Txog Kev Tshawb Fawb (High-Txoj Kev Tshawb Nrhiav Precision) Rau kev ua haujlwm tseem ceeb lossis kev tsis sib haum xeeb, nws raug nquahu kom siv cov txheej txheem kuaj xyuas kom zoo thiab ntsuas ntau:
1. Fourier Transform Infrared Spectroscopy (FTIR): Tshawb xyuas cov khoom siv oxidation xws li carbonyl thiab hydroxyl pawg tsim thaum lub sij hawm laus, thiab ntsuas qhov℃ntawm oxidation los ntawm carbonyl index.
2. Thermal Analysis Techniques:
Differential Scanning Calorimetry (DSC): Txheeb xyuas qhov hloov pauv hauv iav hloov kub (Tg). Tg feem ntau nce tom qab kev laus, qhia txog kev txo qis hauv cov saw hlau molecular.
Thermogravimetric Analysis (TGA): Txiav txim siab cov khoom siv lub thermogravimetric nkhaus los txiav txim seb qhov decomposition kub tau siab heev thiab ntsuas qhov poob ntawm thermal stability.
3. Scanning Electron Microscopy (SEM): Saib xyuas qhov chaw thiab tus ntoo khaub lig-sectional microstructure los soj ntsuam cov keeb kwm tawg, muab tub lim dispersion, thiab theem qauv evolution.
4. Gel Permeation Chromatography (GPC): Txiav txim siab qhov nruab nrab molecular hnyav thiab kev hloov pauv hloov los txiav txim seb cov saw tawg lossis hla -kev sib txuas tau tshwm sim.
IV. Environmental and Operational Factors to Auxiliary Judgment
Kev sib xyaw ua haujlwm keeb kwm tuaj yeem txhim kho qhov tseeb ntawm kev txiav txim:
1. Kev Pabcuam Lub Neej: Raws li kev ua haujlwm ib txwm muaj, lub neej ntev ntawm PVC conveyor siv feem ntau yog 1-3 xyoos. Rau cov menyuam yaus hnub nyoog qis dua 5 xyoos, kev pheej hmoo ntawm kev laus yuav tsum tau ua tib zoo tshawb xyuas.
2. Exposure Conditions: Long-term exposure to high temperatures (>60 degree), muaj zog ultraviolet hluav taws xob, av noo, los yog tshuaj lom neeg corrosion ib puag ncig yuav ua rau kom cov txheej txheem laus.
3. Tej yam kev ua haujlwm txawv txav: Kev tsis sib xws tsis tu ncua, plam, suab nrov txawv txav, lossis kev sib koom ua ke tuaj yeem yog cov cim qhia tsis ncaj ntawm kev ua haujlwm tsis zoo.
