Kev tshawb fawb Rapra Technology tau pom tias polycarbonate suav txog kwv yees li 1% ntawm lub ntiaj teb cov resin noj los ntawm qhov hnyav, tab sis tseem ua rau 10-15% ntawm cov ntaub ntawv pov thawj tsis ua haujlwm. Polycarbonate extrusion muab txhua yam kev ua tau zoo ntawm cov thermoplastics feem ntau tsis tuaj yeem kov, tab sis nws rau txim rau txhua txoj hauv kev ziab, kev siv, tshuaj lom neeg, thiab kev teeb tsa. Qhov sib txawv ntawm tus neeg muag khoom uas nkag siab txog cov kev ua tsis tiav no thiab ib tus uas tsuas yog melts resin los ntawm kev tuag txiav txim siab seb koj qhov chaw nyob ntev li kaum tsib xyoos lossis tawg hauv thawj lub caij ntuj sov.
Dab tsi hauv qab no suav nrog cov ntawv thov, cov txheej txheem ua haujlwm, thiab cov hom tsis ua haujlwm uas cov ntaub ntawv tshem tawm. Cov ntaub ntawv technical los ntawm ob qhov chaw: luam tawm cov ntaub ntawv (xws li siv qhov twg) thiab cov ntaub ntawv tsim tawm los ntawm peb tus kheej PC kab ntawm Dachang, qhov chaw peb tau khiav extruded polycarbonate profiles txij li xyoo 1998. Peb paub qhov txawv ntawm ob qho tib si.
PC Profile Extrusion vs Txhaj Moulding: Thaum Cov Txheej Txheem Xaiv Ib Leeg Txiav Tus Nqi los ntawm peb
Yog tias koj qhov chaw muaj qhov txuas txuas mus ntxiv -section (tubes, channels, diffuser npog, structural profiles), extrusion tuag tooling feem ntau raug nqi 60-80% tsawg dua li cov pwm sib piv, tsis muaj kab noj hniav - qhov loj me ntawm qhov ntev. Rau cov ncauj lus kom ntxaws thiab cov txheej txheem sib piv, saib pebExtrusion vs txhaj tshuaj molding tsom xam.
Qhov txiaj ntsig ntawd thim rov qab lub sijhawm koj lub geometry mus rau peb -dimensional. Txhaj tshuaj molding tuav cov thawj coj, snap fits, thiab cov phab ntsa sib txawv hauv ib qho kev txhaj tshuaj. Lub cheeb tsam grey zaum nrog cov khoom uas feem ntau yog linear tab sis xav tau cov yam ntxwv hauv cheeb tsam: mounting qhov, kawg kaus mom, integrated clips.
Case Study: European Lighting Project
Ib qhov project tsis ntev los no qhia txog tus qauv. Ib lub tuam txhab teeb pom kev zoo nyob sab Europe tau txhaj tshuaj- molding PC channel bracket ntawm € 0.85 ib thooj nrog pwm peev ntawm € 32,000. Peb thov extruding tib profile nrog ncej-machining rau lub mounting qhov. Tus nqi them: € 7,500. Chav tsev nqi ntawm tib lub xyoo ntim: € 0.55, txo 35%. Qhov kev txiav txim siab tau siv peb lub hlis, tsis yog vim kev lag luam tsis meej, tab sis vim tias tus neeg siv khoom sab hauv engineering pab pawg tsis muaj leej twg nrog cov txheej txheem extrusion kws tshaj lij los lees paub qhov kev thov.
Yog tias koj qhov feem ntau yog linear thiab koj qhov ntim txhua xyoo ntau tshaj li ob peb txhiab units, thov ob qho tib si extrusion thiab txhaj tshuaj molding quotes thaum ntxov ntawm lub voj voog tsim. Thoob plaws lub teeb pom kev zoo, cov khoom siv kho mob, thiab kev siv hluav taws xob siv hluav taws xob, peb tau pom qhov sib txawv ntawm tus nqi sib txawv. Rau kev nthuav dav ntawm cov hom profile thiab cov qauv tsim, saib peb phau ntawv qhiakev cai yas profilesnpog PC, PVC, ABS, thiab PMMA xaiv.
Qhov twg Extruded PC Profiles yeej ntawm cov txheej txheem, tsis yog cov khoom siv xwb
Cov npe "kev tsim kho, tsheb, hluav taws xob" qhia rau tus kws tshaj lij kev muag khoom tsis muaj txiaj ntsig. Cov lus nug zoo dua: nyob rau hauv daim ntawv thov twg cov txheej txheem extrusion nws tus kheej tsim kom zoo dua tias kev txhaj tshuaj molding lossis casting tsis tuaj yeem rov ua dua?
LED teeb pom kev zoo diffusers
Lub PC diffuser npog rau linear LED fixtures yuav tsum nruj optical tolerances: lub teeb kis tau tus mob siab tshaj 85% ( ntsuas ib ASTM D1003), tswj haze rau uniform diffusion. Peb khiav cov no ntawm peb46mm siab - cuam tshuam PC teeb npog kab.
Architectural glazing
Multiwall PC ntawv muab thermal tiv thaiv ib puag ncig R-1.5 rau R-1.6. Khoom vaj huam sib luag hnyav kwv yees li 7.2 kg / m², xa qhov cuam tshuam tsis kam 250x ntab iav. Saibru tsev vaj huam sib luag cov khoom siv.
Precision films rau kev kho mob thiab tsheb ventingsawv cev rau thaj tsam tshiab. Covestro's Makrofol TF kab qhia tau hais tias extruded PC zaj duab xis tam sim no tuaj yeem ncav cuag 15 μm tuab rau kev taug qab -etched membranes siv hauv kev kuaj mob thiab lub tshuab ua pa, hloov cov txheej txheem yav dhau los kaw rau hauv hnyav- nrum zaj duab xis tshuab.
Busbar rwb thaiv tsev thiab hlau channel profilespuag ncig qhov siab - ntu nqi. Peb tsim PC busbar npog rau ob lub hluav taws xob hloov hluav taws xob OEMs nyob rau sab hnub tuaj Asia,co-extruding PC + ABS ntawm kev sib txuas sib txuasqhov twg cuam tshuam kuj tseem ceeb tshaj plaws. Cov nplaim hluav taws yuav tsum tau ntsuas ntawm cov khoom no yog UL 94 V-0, ua tiav nrog Covestro Makrolon FR qib ntawm phab ntsa thicknesses mus rau 1.2 hli. Standard unfilled PC qib feem ntau xav tau 1.5 hli lossis ntau dua kom dhau V-0, yog li kev xaiv qib ntawm no ncaj qha txiav txim siab seb qhov profile raws li spec lossis tsis.
PC Resin Drying Ua ntej Extrusion: Vim li cas 0.02% Yog Lub Rooj Sib Tham Hard, Tsis Qhia
Moisture hauv polycarbonate resin ua rau irreversible hydrolytic saw scission thaum lub sij hawm yaj ua. Thaum qhov hnyav molecular poob lawm, tsis muaj tus nqi ntawm kev tshaj tawm - ua cov khoom rov qab.
Lub hauv paus tsis muaj: resin yuav tsum ncav cuag tsawg dua los yog sib npaug rau 0.02% noo noo cov ntsiab lus, qhuav ntawm 120℃rau qhov tsawg kawg nkaus ntawm 2-4 teev nyob rau hauv ib tug desiccant tshuab ziab khaub ncaws nrog ib tug dew point ntawm los yog qis dua -18 degree. Cov lej no yog los ntawm kev tshaj tawm cov lus qhia ua haujlwm.
Kev Pom Zoo Tshaj Tawm los ntawm Dachang (Dongguan)
Dab tsi tsis tshwm sim hauv cov lus qhia ua haujlwm yog li cas lawv hloov nrog cov xwm txheej tiag tiag. Hauv peb qhov chaw Dongguan, lub caij ntuj sov ambient av noo tsis tu ncua tshaj 80% RH. Raws li cov xwm txheej no, peb lub voj voog ziab kom qhuav rau Makrolon 2858 khiav 40% ntev dua li cov ntaub ntawv yam tsawg kawg nkaus (ze li 3.5 teev ntawm 65 hli ib leeg- cov kab ntsia hlau), thiab peb rov qab- txheeb xyuas cov dej noo nrog Karl Fischer titration ua ntej ntau nkag mus rau hauv extruder.
Qhuav resin raug rau siab ambient humidity tuaj yeem rov- nqus dej mus rau 0.5% nyob rau hauv peb mus rau plaub teev, txaus los tsim npuas pom. Qhov kev txhim kho yog txheej txheem: cov khoom qhuav tam sim no hloov mus rau cov hoppers kaw tam sim ntawd, nrog lub sijhawm tuav ntau tshaj 90 feeb ua ntej rov- yuav tsum tau kuaj.
Ib daim ntawv tshuaj ntsuam xyuas los ntawm SPE Extrusion Division: yog cov npuas tshwm sib faib thoob plaws lub vev xaib es tsis yog tsiv mus rau cov npoo, lub hauv paus ua rau tsis muaj dej noo tag nrho tab sis hollow pellets ntxiab cua hauv qhov tsis muaj -vented chim. Misdiagnosing uas yog ib qho teeb meem ziab ua rau dhau- ziab, uas degrades cov resin los ntawm qhov opposite direction.
Melt Temperature Control rau PC Profiles: Lub 5-8℃Qhov rai uas hloov nrog txhua yam resin
Ntawm peb 65 hli ib zaug - ntsia hlau kab khiav Makrolon 2858, lub qhov rais ua qhov twg ob qho tib si wavy nto kev ntxhib los mos thiab pom cov kab ntws ib txhij tsis tuaj yeem yog kwv yees li 6℃dav, ntawm 274℃thiab 280℃ntawm qhov tuag. Tso rau hauv qab 274℃thiab cov kab ntws tshwm. Tshaj 280℃thiab qhov saum npoo tsim cov qauv pom ripple.
Lub qhov rais ntawd tsis kho. Thaum peb hloov mus rau SABIC Lexan 141R, qhov kev siv tau txav mus los ntawm kwv yees li 8 degree. Thaum lub ambient khw kub nce siab tshaj 30℃nyob rau hauv lub caij ntuj sov, lub qhov rais zoo compresses los ntawm 1-2℃vim hais tias chim txias yuav tsawg npaum li cas. Cov ntsia hlau hnav sib txuas qhov teeb meem: tom qab kwv yees li 18 lub hlis ntawm kev ua haujlwm tas mus li, qhov ntsuas qhov ntsuas ntawm peb cov ntsia hlau tau pom qhov hnav txaus los hloov cov shear tshav kub profile, yuav tsum tau txo qhov kub ntawm 3 degrees kom muaj qhov zoo tib yam yaj.
Ntsia hlau geometryQhov tseem ceeb rau PC ntau dua li cov khoom siv feem ntau. Adual - hloov metering ntsia hlau nrog compression piv ntawm 2.5: 1 rau 3: 1tuav lub siab yaj viscosity yam tsis tsim cov shear kub ntau dhau. Rau lub tshuab 50 hli (2-nti), qhov ntsuas qhov tob yog nyob ze ntawm 3.8 hli (0.150 hauv) nrog rau qhov tob tob ntawm 15.2 hli (0.600 hauv). Tau txais qhov compression tsis ncaj ncees lawm yog tshaib plab tuag, ua kom tsis sib haum ntawm phab ntsa thickness, los yog overshears lub yaj, degrading molecular hnyav ua ntej cov resin tawm ntawm daim di ncauj tuag.
Co-extruded UV cap txheejyog standard rauib qho sab nraum zoov - cov khoom ntsuas. Lub hau txheej ntawd feem ntau yog 50-80 μm, sib koom ua ke ntawm ib sab nkaus xwb. Peb kos lub UV sab ntawm txhua daim ntawv peb tsim. Txawm li cas los xij, peb tseem tau txais cov lus nug txog kev lav phib xaub los ntawm cov neeg tsim khoom uas tau teeb tsa cov vaj huam sib luag nrog UV txheej sab hauv sab hauv, lav pom pom daj hauv ob mus rau peb xyoos. Yog tias koj tab tom teev cov PC extruded rau kev siv sab nraum zoov, paub meej tias UV sab kos npe raws tu qauv nrog koj tus neeg muag khoom thiab sib txuas lus ncaj qha rau koj cov neeg ua haujlwm installation.
Environmental Stress Cracking nyob rau hauv Polycarbonate: Lub Hom Phiaj Ua Tsis Tau Los Txog Tom Qab QC Kos Npe -Tawm
Ib puag ncig kev ntxhov siab tawg (ESC) yuav tsum muaj ob qho tib si ib txhij: kev ntxhov siab thiab kev sib cuag nrog cov tshuaj lom neeg ua phem. Tsis yog ib leeg ua rau kev ua tsis tiav. Lub PC vaj huam sib luag nyob rau hauv khoov load tuav indefinitely nyob rau hauv cov huab cua huv si. Tib lub vaj huam sib luag so nrog isopropyl cawv thaum lub sijhawm teeb tsa tuaj yeem txhim kho pom cov kab nrib pleb hauv feeb.
Peb ntsib qhov no ntawm ib pawg ntawm extruded PC tiv thaiv npog xa mus rau cov khoom siv hluav taws xob sib dhos hauv lub teb chaws Yelemees. Txhua chav dhau peb QC cov khoom seem: kev kuaj xyuas qhov ntsuas, qhov ntsuas qhov cuam tshuam, pom qhov pom tseeb. Peb lub lis piam tom qab kev teeb tsa, tus neeg siv tau tshaj tawm cov kab plaub hau tawg ntawm kwv yees li 15% ntawm qhov chaw. Kev tshuaj xyuas hauv paus ua rau siv rau lub lis piam. Cov lus teb: tus neeg siv khoom tu raws tu qauv suav nrog cov kuab tshuaj-raws li degreaser uas muaj 2% methyl ethyl ketone (MEK), thiab cov kev ntxhov siab seem los ntawm xovxwm- haum cov npog rau hauv cov vaj tsev aluminium pib tawg tawg ntawm lub snap- haum nta.
Qhov kev daws teeb meem tau lees paub qhov kev kuaj mob. Tus neeg siv tau hloov mus rau ib qho kev pom zoo uas tsis yog- cov tshuaj ntxuav cov kuab tshuaj, rov- sim cov khoom seem tom qab 48-teev kev ntxhov siab-txhim kho anneal ntawm 125℃, thiab tag nrho cov units tau dhau mus. Tus neeg siv khoom ntawd tau txuas ntxiv xaj los ntawm peb rau plaub xyoos txij li, thiab kev hloov pauv tu raws tu qauv tau tuav nrog xoom ESC rov tshwm sim.
Cov lus pom zoo:
Txij li thaum qhov xwm txheej ntawd, peb cov txheej txheem RFQ suav nrog qhov yuav tsum tau ua: "Qhia tag nrho cov tshuaj uas yuav tiv tauj rau lub sijhawm tsim khoom, teeb tsa, thiab xaus- siv kev pabcuam." Hauv ob xyoos txij li, lo lus nug no cuam tshuam ESC kev pheej hmoo ntawm tsawg kawg ob txoj haujlwm tshiab.
Cov tshuaj blacklist rau PC suav nrogMEK, acetone, toluene, ammonia-cov tshuaj ntxuav tes, thiab cov kuab tshuaj tsw qab tshaj plaws. Ib qhov dej-cov ntaub ntawv tsis ua haujlwm nyob rau hauv cov ntaub ntawv engineering vaj huam sib luag: siab-molecular- hnyav PC kev loj delineator posts uas dhau txhua lub Hoobkas cuam tshuam kev xeem, tom qab ntawd snapped hauv teb. Cov hauv paus ntsiab lus tau taug qab mus rau MEK-raws li hnub tim- stamp number case siv thaum tsim khoom. Cov kab nrib pleb ib txwm pib los ntawm qhov chaw tus cwj mem.
Yog tias koj daim ntawv thov cuam tshuam nrog PC cov khoom hauv kev sib cuag nrog cov nplaum, sealants, lossis cov tshuaj ntxuav, thov cov ntaub ntawv tshuaj sib raug zoo los ntawm koj tus neeg muag khoom ua ntej cog lus rau kev tsim khoom. Peb tuav ib qho kev sib raug zoo hauv cov ntaub ntawv uas npog 60+ cov tshuaj muaj tshuaj ntsuam xyuas tawm tsam peb cov qib profile thiab tuaj yeem ua qhov kev xeem raug raws li kev thov.Hu rau peb pab pawg engineeringnrog koj cov ntaub ntawv thov.
Txhim kho Extruded Polycarbonate Panels: Thermal Expansion Math uas tiv thaiv kev lav lav
Polycarbonate tus coefficient ntawm linear thermal expansion yog kwv yees li 0.065 mm / m /℃(ib ASTM E831), kwv yees li ntawm 6 npaug ntawm cov hlau thiab yim npaug ntawm iav. Lub vaj huam sib luag 2-meter raug rau 55℃qhov kub thiab txias ntawm lub caij nplooj ntoos hlav yuav loj hlob los yog ntsws los ntawm kwv yees li 7.15 hli.
Bolt nws los ntawm qhov drilled mus rau qhov tseeb ntsia hlau txoj kab uas hla thiab lub vaj huam sib luag tsis muaj qhov txav mus los. Qhov tshwm sim: kev ntxhov siab nyob rau txhua qhov chaw fastener, ua rau radial tawg uas zoo li kev tsim khoom tsis xws luag tab sis yog qhov yuam kev ntawm kev teeb tsa nkaus xwb.
Daim Ntawv Qhia nthuav dav
ΔL = L × × ΔT
L: Vaj huam sib luag ntev hauv meters
Qhov siab: 0.065mm / m / degree
ΔT: Qhov kub ntawm lub caij nyoog sib txawv
Txoj kev kho: ua ntej-xov tag nrho cov fastener qhov 2-3 hli loj dua cov ntsia hlau shank, siv EPDM-gasketed washers, thiab tsis txhob torque fasteners kom tag nrho compression. Rau cov panels ntev dua 1.5 meters, slotted qhov ntawm tsawg kawg yog ib kawg kom haum longitudinal expansion zoo dua oversized round qhov.
Yog tias koj xav tau kev pom zoo ua ntej -drilled qhov sib nrug rau koj qhov ntev, peb pab neeg tuaj yeem suav tau los ntawm koj cov duab kos.
Yuav Ua Li Cas Ntsuam Xyuas Kev Cai PC Extrusion Supplier: Cov Lus Nug Koj RFQ Yuav Tsum Muaj
Cov khoom siv ceev ceev - qib sib piv rau acrylic: PC khiav 30-40% kim dua ib kilogram, tab sis xa tawm kwv yees li 250 npaug ntawm qhov cuam tshuam lub zog ntawm iav piv rau acrylic 17 zaug (ob qho tib si cov duab tau hais thoob plaws hauv kev lag luam xws li A&C Plastics thiab ASTM Izod cov ntaub ntawv cuam tshuam). Nyob rau hauv cov ntawv thov uas vaj huam sib luag tsis ua hauj lwm muaj kev nyab xeeb los yog poob nqi, lub neej kev lag luam yuav luag ib txwm nyiam polycarbonate. Rau kaum ob - khoom sib piv, saib pebacrylic vs polycarbonate phau ntawv qhia.
Thaum soj ntsuam cov chaw muag khoom rau kev cai PC profiles, cov lus nug uas kwv yees qhov zoo tshaj tus nqi ib 'meter':
Puas yog tus neeg muag khoom tau txheeb xyuas cov dej noo noo ua ntej txhua qhov kev khiav, lossis cia li tso siab rau lub tshuab ziab khaub ncaws?
Lawv puas tuaj yeem muab cov lus qhia txog kev sib haum xeeb rau koj qhov kawg - siv tshuaj?
Lawv puas co-extrude UV tiv thaiv hauv- kab, lossis outsource nws li txheej txheej thib ob?
Lawv phab ntsa thickness kam rau ua ntawm optical -qib profiles yog dab tsi? (Yog tias lawv tsis tuaj yeem teb nrog tus lej, qhov ntawd qhia koj tias koj yuav tsum paub dab tsi.)
Lawv puas yuav khiav ib pawg tsav tsheb ntawm koj qhov kev ua siab ntev ua ntej cog lus rau tag nrho cov cuab yeej tsim khoom?
Precision
Profile kam rau ua:± 0.05 hli ntawm phab ntsa thickness rauoptical{0}}qib PC diffusers; ± 0.10 hli rau cov qauv profiles
Hauv -kev sim hauv tsev:Karl Fischer pov thawj noo noo, lub teeb kis ntawm ASTM D1003, yellowness Performance index tom qab QUV laus
Khoom siv
Resins:Covestro Makrolon, SABIC Lexan, LG Chem Infino, Chi Mei Wonderlite
Advanced:Co-extrusion UV cap txheej, PC + ABS, tri-extrusion
Lub sijhawm
Custom die lead time:72 teev (std) / 15-20 hnub ua haujlwm (optical)
Kev tsim tawm:7-12 hnub ua haujlwm nyob ntawm qhov ntim
Ua raws
Cov ntawv pov thawj:ISO 9001, RoHS raws, REACH sau npe
MOQ:1,000 meters (std) / 500 meters (kev cai)
Yog tias koj qhov project cuam tshuamLED-qib optical diffusers, structural tubing, los yog co-extruded multi-cov ntaub ntawv profiles, xa peb cov duab kos thiab cov ntsiab lus ntawm ib puag ncig tshuaj. Peb yuav lees paub cov khoom xaiv, kev ua tau zoo, thiab lub sijhawm ua haujlwm tiag tiag ua ntej hais.
FAQ
Q: Puas yog polycarbonate yuav tsum tau qhuav ua ntej extrusion?
A: Yog. PC resin yuav tsum ncav cuag tsawg dua lossis sib npaug li 0.02% cov ntsiab lus noo noo ua ntej ua, lossis cov khoom raug kev txom nyem mus tas li molecular degradation. Cov xwm txheej txheem yog 120℃rau 2-4 teev nyob rau hauv lub tshuab ziab khaub ncaws, tab sis lub sij hawm voj voog tiag tiag nyob ntawm cov av noo thiab cov resin ntau. Peb qhov chaw txuas ntxiv lub sij hawm ziab kom txog li 40% thaum lub sij hawm siab -humidity hli. Cov ntsiab lus kuaj xyuas kom paub qhov txawv ntawm qhov tsis xws li noo noo los ntawm cov ntxiab-cov npuas huab cua tau npog hauv ntu ziab saum toj no.
Q: Dab tsi ua rau tawg hauv extruded polycarbonate qhov chaw tom qab kev teeb tsa?
A: Feem ntau cov ntawv tshaj tawm - kev txhim kho cov kab tawg mus rau ib qho ntawm ob qho laj thawj: ib puag ncig kev ntxhov siab tawg tshwm sim los ntawm kev sib cuag tshuaj nyob rau hauv cov khoom siv thauj khoom, lossis thermal expansion stress los ntawm undersized fastener qhov. Ob qho tib si tsis ua haujlwm thiab lawv txoj kev tiv thaiv tau piav qhia hauv ESC thiab ntu kev teeb tsa.
Q: Puas yog polycarbonate extrusion tus nqi ntau dua -zoo dua li kev txhaj tshuaj molding?
A: Rau qhov chaw uas muaj qhov txuas txuas mus ntxiv -section, extrusion tuag tooling khiav 60-80% qis dua cov pwm txhaj tshuaj thiab tshem tawm qhov txwv ntev. Tshaj li ob peb txhiab units txhua xyoo, extruded profiles nrog post-machining tuaj yeem txo tus nqi ntawm ib qho ntawm 30-40% piv rau kev txhaj tshuaj molding. Cov txheej txheem kev txiav txim siab, suav nrog qhov chaw txhaj tshuaj molding tseem yeej, tau tham hauv cov txheej txheem sib piv nyob rau sab saum toj ntawm tsab xov xwm no.
Q: Dab tsi kub yog siv rau extruding polycarbonate profiles?
A: Tuag- qhov kawg kub feem ntau poob rau hauv 260-290℃ntau, tab sis lub qhov rais siv tau qhov twg qhov chaw tsis tuaj yeem tuaj yeem nqaim li 5-8℃rau qib qib resin thiab tshuab teeb tsa. Qhov ntsuas kub ntawm qhov ntsuas kub tau teeb tsa, thiab qhov kev pom zoo hloov pauv nrog cov resin ntau, ambient tej yam kev mob, thiab ntsia hlau hnav. Qib- cov ntaub ntawv ntsuas kub tshwj xeeb los ntawm peb cov kab ntau lawm yog nyob rau hauv qhov ntsuas kub saum toj no.
Q: Kuv yuav tiv thaiv yellowing nyob rau sab nraum zoov polycarbonate panels li cas?
A: Xyuas kom koj cov vaj huam sib luag muaj co-extruded UV- cov txheej txheem ruaj khov (feem ntau 50–80 μm) thiab paub meej tias UV sab sab nraud sab nraud thaum lub sijhawm teeb tsa. Yog tsis muaj kev tiv thaiv UV, tus qauv PC pib pom daj daj nyob rau hauv 2-3 xyoo ntawm sab nraum zoov raug. Nco ntsoov xyuas UV- cov cim sab ntawm cov yeeb yaj kiab tiv thaiv lossis vaj huam sib luag ntug ua ntej txhim kho.