Izitywino zakho zeevalvu ziyawa ngenxa yobushushu obuphantsi kwetropiki kunye nelanga. Oku kukhokelela ekuvuzeni okubizayo, ukungasebenzi kwenkqubo, kunye nabathengi abangonwabanga ababuza umgangatho wemveliso yakho kunye nodumo lwakho.

Kwimozulu eshushu, i-EPDM ingcono kakhulu kuyo nayiphi na indlela yokusebenzisa amanzi evezwe elangeni nakwimozulu ngenxa yokumelana kwayo ne-UV kunye ne-ozone. Sebenzisa i-NBR kuphela xa usebenzisa iioyile zangaphakathi, apho ikhuselwe khona elangeni.

Bendincokola neqabane lam uBudi wase-Indonesia malunga nengxaki eqhubekayo omnye wabathengi bakhe awayejongene nayo. Babephethe ifama enkulu yezolimo zasemanzini apho amakhulu eevalvu zethu ayefakelwe ngaphandle. Emva kweenyanga ezintandathu kuphela, ezininzi zaqala ukuvuza. Iivalvu zazilungile, kodwa izitywino ze-NBR eziqhelekileyo ngaphakathi zaziqhekeka kwaye ziqhekeka. Le yingxaki eqhelekileyo kwiimeko zemozulu ezishushu. Ukudibana kwelanga elinamandla, ubushushu obuphezulu, kunye nokufuma kwakonakalisa irabha. Sabanceda batshintshele kwiivalvu zethu.Izitywino ze-EPDM, kwaye ingxaki yanyamalala. La mava abonisa kakuhle ukuba kutheni ukukhetha izinto eziphathekayo kubaluleke kangaka kwiindawo ezishushu.

Yeyiphi eyona ingcono kakhulu kwiindawo ezishushu, i-NBR okanye i-EPDM?

Iiseal ze-NBR zibiza kancinci, nto leyo ebonakala intle xa icatshulwa. Kodwa ngaba oku kuya kunceda xa iiseal ziwohloka ngokukhawuleza phantsi kwelanga elishushu kakhulu kunye nobushushu obuphezulu?

Kwinkqubo zamanzi ashushu, i-EPDM ngokuqinisekileyo ingcono. Ulwakhiwo lwayo lweekhemikhali lwakhiwe ukuze lukwazi ukumelana ne-UV, i-ozone, kunye nobushushu. Ukumelana nemozulu embi kwe-NBR kuyenza ibe lukhetho olunobungozi obukhulu kuyo nayiphi na indlela yokusetyenziswa ngaphandle kummandla oshushu.

Oku akuyonto yoluvo, yingxaki yekhemistri. I-EPDM inento ebizwa ngokuba yi-umqolo wepolymer ogcweleyo. Esi sakhiwo sizinzileyo siyakwazi ukumelana nokuhlaselwa yimitha ye-UV kunye ne-ozone, izinto ezimbini ezifumaneka kakhulu kwimozulu enelanga neshushu. I-NBR, kwelinye icala, inomqolo ongagcwaliyo onemixokelelwane ephindwe kabini. Ezi mixokelelwane ephindwe kabini ziindawo ezibuthathaka eziqhekeka lula yimitha ye-UV, nto leyo ebangela ukuba izinto zibe buthathaka kwaye ziqhekeke. Kwindawo efana ne-Indonesia okanye iVietnam, inkqubo yokunkcenkceshela yangaphandle okanye yokunyanga amanzi ijongene nokukhanya kwelanga okungapheliyo. Itywina le-NBR linokungaphumeleli ngaphantsi konyaka. Itywina le-EPDM kwindawo efanayo linokuhlala iminyaka emininzi. Ixabiso lokuqala eliphezulu kancinci le-EPDM lixabiso elincinci lokuhlawula ukuthembeka kwexesha elide kunye nokuphepha ukungaphumeleli kwenkqubo. Uhlalutyo lweendleko-inzuzo lukhetha kakhulu i-EPDM kuyo nayiphi na indlela yokusebenzisa ngaphandle.

Zithini iingxaki zerabha ye-EPDM?

I-EPDM ibonakala ifanelekile kwimigca yamanzi yangaphandle. Kodwa kwenzeka ntoni ukuba ulwelo luqulethe iioyile okanye iikhemikhali ezisekelwe kwi-hydrocarbon? Ukusetyenziswa gwenxa kunokubangela ukuba isitywini singaphumeleli ngokupheleleyo.

Eyona ngxaki iphambili ye-EPDM kukungakwazi kwayo ukumelana nolwelo olusekelwe kwi-petroleum olufana neeoyile, iigrisi, kunye nezinye izinyibilikisi ezininzi. Ukudibana nezi zinto kuya kubangela ukuba isitywini se-EPDM sidumbe, sithambe, kwaye silahlekelwe ngamandla aso okuvala.

Umthetho kwikhemistri uthi “njengokunyibilika okufana.” I-EPDM yinto engekho polar, kwaye kunjalo nangeoyile ze-hydrocarbon. Xa zidibana, i-EPDM ifunxa ioyile, iyenze idumbe njengesiponji. Oku kudumba kuyenza buthathaka kakhulu le nto kwaye kutshabalalise amandla ayo okugcina isitywino phantsi koxinzelelo. Oku kuyenza ingafanelekanga ngokupheleleyo kwizicelo ezibandakanya imigca yamafutha, iinkqubo ze-hydraulic, okanye iinkqubo ezininzi zeekhemikhali zoshishino. Enye ingxaki yindleko. I-EPDM yipolymer ephucukileyo, ngoko ke iindleko zayo zemveliso ziphezulu kune-NBR. Yingakho ihlala ibonwa njengokhetho oluphezulu. Nangona kunjalo, kubalulekile ukujonga le ndleko kumxholo wesicelo. Ukuze ufumane umsebenzi ofanelekileyo (amanzi, imozulu, ubushushu), ixabiso lokuqala eliphezulu likuthenga iminyaka yenkonzo engenangxaki, nto leyo eyenza ixabiso layo lilonke lobunini libe liphantsi kakhulu.

Ziziphi iingxaki eziphambili ze-NBR?

I-NBR yeyona ndlela ingabizi kakhulu kwiindlela ezininzi zokusetyenziswa. Kodwa ukumelana kwayo nemozulu embi kunokubangela ukuqhekeka nokungaphumeleli, umngcipheko omkhulu kuyo nayiphi na indawo engaphandle yetropiki.

Eyona ngxaki inkulu ye-NBR kukungakwazi kwayo ukumelana nelanga (UV), i-ozone, kunye nokutshintsha kwemozulu ngokubanzi. Oku kubangela ukuba iqine kwaye ibe buthathaka. Ikwanayo neqondo lobushushu eliphantsi kune-EPDM, nto leyo ekhawulezisa ukuguga kwayo kwiindawo ezishushu.

Kwimarike efana neBudi's eIndonesia, le yeyona nto ibalulekileyo ekufuneka uyiqonde. Ukudibana kwelanga elinamandla, unyaka wonke kunye nobushushu obuphezulu obujikeleze umhlaba yeyona ndawo imbi kakhulu kwi-NBR. Imitha ye-UV ihlasela ngokuthe ngqo imixokelelwane yepolymer, ngelixa ubushushu bukhawulezisa le nkqubo yokwaluphala. Oku kubangela ukuba izinto zilahlekelwe bukuguquguquka kwazo, okuwumsebenzi wazo ophambili. Itywina elibuthathaka alinakucinezelwa ukunqanda ukuvuza; liqhekeka nje phantsi koxinzelelo. Yingakho sibona ukusilela okuninzi kweevalvu ezivaliweyo ze-NBR kwizolimo zasetropiki nakwimibhobho yangaphandle. Olu buthathaka lukwasebenza nakwi-ozone. I-Ozone iveliswa ngokwemvelo lilanga kwaye ikwasetyenziswa nakwezinye iinkqubo eziphambili zokucoca amanzi. Kwanoxinzelelo oluncinci lwe-ozone luya kunciphisa i-NBR ngokukhawuleza. Ngamafutshane, ukusebenzisa i-NBR kuyo nayiphi na indlela esetyenziswa ngaphandle kwiindawo zasetropiki kukudlala ngokuthembeka kwemveliso yakho kunye nodumo lwakho.

Ngaba irabha ye-NBR iyamelana nobushushu ngokwenene kwiindawo ezishushu?

Ubona umlinganiselo wobushushu ngerabha ye-NBR kwiphepha leenkcazo. Kodwa ngaba olo mgangatho lunokuthenjwa kwindawo yokwenyani yetropiki apho amaqondo obushushu asezantsi sele ephezulu kakhulu?

I-NBR ayinyamezeli ubushushu ngendlela ephakathi, idla ngokufikelela kwi-120°C (248°F). Nangona kunjalo, lo mda uyancipha xa ubonakala rhoqo. Ukudibana kobushushu obuphezulu kunye nobushushu obusebenzayo kwiindawo ezishushu kunokunyusa i-NBR kwimida yayo, nto leyo ebangela ukungaphumeleli kwangaphambi kwexesha.

Iphepha leenkcukacha linokukhohlisa ukuba alifundwanga ngononophelo. Elo nqanaba le-120°C lidla ngokuba lobushushu obungenaziphene, hayi obungaguquguqukiyo. Kwimozulu yetropiki, ubushushu obuphakathi busenokuba sele buyi-35°C. Ivalvu ehleli elangeni ngqo eluphahleni inokufikelela ngokulula kubushushu obungaphezulu kwe-70°C nangaphezulu, nangaphambi kokuba amanzi ashushu adlule kuyo. Lo mthwalo wobushushu obungapheliyo ubeka izinto ze-NBR phantsi koxinzelelo oluhlala luhleli. I-EPDM, enomgangatho wayo oqhelekileyo we-150°C, inomda omkhulu wokhuseleko. Ingakwazi ukusingatha ngokulula uxinzelelo oludibeneyo lobushushu obuphakathi obuphezulu kunye nolwelo olushushu ngaphandle kokuwohloka. Oku kuphezulu kakhulu.uzinzo lobushushusesinye isizathu esibalulekileyo sokuba sincome kakhulu i-EPDM ukuze isebenze ixesha elide kwiindawo ezishushu.

Isishwankathelo sokuSebenza kweMozulu yeTropiki

Isiphelo

Kwiindawo ezisetyenziswa emanzini ashushu, i-EPDM's UV kunye nokumelana nobushushu kubalulekile. Gcina i-NBR kuphela kwiinkqubo zangaphakathi, ezikhuselekileyo eziphatha iioyile. Ukukhetha okulungileyo kuqinisekisa ukusebenza okuthembekileyo nokuhlala ixesha elide.