Abstract: Umgomo wokuxhumanisa, ukuhlukaniswa, ukwakhiwa, inqubo kanye nemishini ye-silane cross-linked polyethylene insulating material yocingo nekhebula kuchazwe kafushane, futhi ezinye izici ze-silane ngokwemvelo zixhumeke ku-polyethylene insulating impahla ekusetshenzisweni nasekusetshenzisweni kanye izici ezithinta isimo sokuxhumanisa kwezinto ezibonakalayo ziyethulwa.
Amagama angukhiye: Silane cross-linking; Ukuxhumanisa kwemvelo; I-polyethylene; I-Insulation; Intambo nekhebula
I-Silane cross-linked polyethylene cable material manje isetshenziswa kabanzi embonini yezintambo kanye nekhebula njengendawo yokuvikela izintambo zamandla anamandla aphansi. Izinto zokwakha izintambo ezixhumene nentambo nekhebula, kanye ne-peroxide cross-linking kanye ne-irradiation cross-linking uma kuqhathaniswa nemishini yokukhiqiza edingekayo ilula, kulula ukuyisebenzisa, izindleko eziphelele eziphansi kanye nezinye izinzuzo, isibe yimpahla ehamba phambili ephansi. -voltage cross-linked cable ne-insulation.
1.Isimiso sokuxhumanisa intambo ye-Silane cross-linked cross-linking
Kunezinqubo ezimbili eziyinhloko ezihilelekile ekwenzeni i-polyethylene exhumene ne-silane: ukuxhunyelelwa nokuxhumanisa. Enqubweni yokuxhunyelelwa, i-polymer ilahlekelwa i-athomu ye-H ku-athomu ye-carbon ephakeme ngaphansi kwesenzo se-initiator yamahhala kanye ne-pyrolysis ibe ama-radicals mahhala, asabela nge- - CH = CH2 iqembu le-vinyl silane ukukhiqiza i-polymer exhunyelelwe equkethe i-trioxysilyl ester. iqembu. Enqubweni yokuxhumanisa, i-graft polymer iqala i-hydrolyzed phambi kwamanzi ukuze ikhiqize i-silanol, futhi i-OH ihlangana neqembu eliseduze le-Si-OH ukuze kwakhe ibhondi ye-Si-O-Si, ngaleyo ndlela ixhumanisa i-polymer. ama-macromolecules.
2.Izinto zekhebula ezixhumene neSilane kanye nendlela yayo yokukhiqiza ikhebula
Njengoba wazi, kunezindlela ezimbili kanye nesinyathelo esisodwa sokukhiqiza izintambo ze-silane ezixhumene ngokuphambana kanye nezintambo zazo. Umehluko phakathi kwendlela yezinyathelo ezimbili kanye nendlela yesinyathelo esisodwa ulele lapho inqubo yokuxhunyelelwa kwe-silane yenziwa khona, inqubo yokuxhunyelelwa kumkhiqizi wezinto zekhebula ngendlela yezinyathelo ezimbili, inqubo yokuxhunyelelwa embonini yokukhiqiza ikhebula indlela yesinyathelo esisodwa. I-polyethylene insulating eyizinyathelo ezimbili exhumene ne-cross-linked polyethylene enesabelo esikhulu semakethe yakhiwe ngezinto ezibizwa ngokuthi u-A no-B, kanye nokokusebenza okungu-A okuyi-polyethylene exhunyelelwe nge-silane kanye ne-B eyinqwaba ye-catalyst master. I-insulating core ibe isixhunywa emanzini afudumele noma isitimu.
Kukhona olunye uhlobo lwe-silane enezinyathelo ezimbili ezixhumene ne-polyethylene insulator, lapho i-A material ikhiqizwa ngendlela ehlukile, ngokwethula i-vinyl silane ngqo ku-polyethylene ngesikhathi sokuhlanganiswa ukuze kutholwe i-polyethylene ngamaketanga e-silane branched.
Indlela yesinyathelo esisodwa nayo inezinhlobo ezimbili, inqubo yendabuko yesinyathelo esisodwa iyinhlobonhlobo yezinto ezingavuthiwe ngokwefomula esilinganisweni sohlelo olukhethekile lwemitha lokunemba, ibe i-extruder ekhethekile eklanywe ngokukhethekile ngesinyathelo esisodwa ukuqedela ukuxhunyelelwa nokukhipha I-cable insulation core, kule nqubo, akukho granulation, asikho isidingo sokubamba iqhaza kwesitshalo sekhebula, yifekthri yekhebula ukuqedela yedwa. Le mishini yokukhiqiza ikhebula ye-silane enesinyathelo esisodwa kanye nobuchwepheshe bokubunjwa ithengwa kakhulu kwamanye amazwe futhi iyabiza.
Olunye uhlobo lwe-silane-step-linked cross-linked polyethylene insulation material lukhiqizwa abakhiqizi bezinto zekhebula, zonke izinto ezingavuthiwe ngokwefomula ngokwesilinganiso sendlela ekhethekile yokuxuba ndawonye, ihlanganiswe futhi ithengiswe, ayikho impahla engu-A kanye no-B. impahla, isitshalo ikhebula kungaba ngqo extruder ukuqedela isinyathelo ngesikhathi esifanayo ngokuxhunyelelwa kanye extrusion of cable ukwahlukanisa core. Isici esiyingqayizivele sale ndlela ukuthi asikho isidingo sama-extruder akhethekile abizayo, njengoba inqubo yokuxhunyelelwa kwe-silane ingaqedwa ku-extruder evamile ye-PVC, futhi indlela yezinyathelo ezimbili iqeda isidingo sokuxuba izinto ze-A no-B ngaphambi kokukhishwa.
3. Ukwakheka kokwakheka
Ukwakhiwa kwe-silane cross-linked polyethylene cable material ngokuvamile kwakhiwa i-base material resin, initiator, silane, antioxidant, polymerization inhibitor, catalyst, njll.
(1) I-base resin ngokuvamile iyinhlaka ye-polyethylene ephansi (LDPE) enenkomba yokuncibilika (MI) ka-2, kodwa muva nje, ngokuthuthukiswa kobuchwepheshe be-resin yokwenziwa kanye nezingcindezi zezindleko, i-linear low density polyethylene (LLDPE) nayo iye yenziwa. isetshenziswe noma isetshenziswe kancane njenge-resin eyisisekelo yalolu lwazi. Ama-resin ahlukene avame ukuba nomthelela omkhulu ekuxhumeni nasekuxhumaniseni ngenxa yomehluko wesakhiwo sawo sangaphakathi se-macromolecular, ngakho ukwakheka kuzolungiswa ngokusebenzisa ama-base ahlukene noma uhlobo olufanayo lwe-resin evela kubakhiqizi abahlukene.
(2) Isiqalisi esivame ukusetshenziswa i-disopropyl peroxide (DCP), isihluthulelo siwukubamba inani lenkinga, okuncane kakhulu ukubanga ukuxhunyelelwa kwe-silane akwanele; kakhulu ukubangela polyethylene cross-okuxhumanisa, okunciphisa fluidity yayo, ebusweni extruded ukwahlukanisa core rough, kunzima ukukhama uhlelo. Njengoba inani le-initiator elengeziwe lincane kakhulu futhi liyazwela, kubalulekile ukulihlakaza ngokulinganayo, ngakho-ke ngokuvamile lihlanganiswa kanye ne-silane.
(3) I-Silane ngokuvamile isetshenziswa i-vinyl unsaturated silane, okuhlanganisa i-vinyl trimethoxysilane (A2171) ne-vinyl triethoxysilane (A2151), ngenxa yesilinganiso esisheshayo se-hydrolysis esingu-A2171, ngakho khetha i-A2171 abantu abengeziwe. Ngokufanayo, kunenkinga yokwengeza i-silane, abakhiqizi bezinto zekhebula zamanje bazama ukufeza umkhawulo wabo ophansi ukuze banciphise izindleko, ngoba i-silane ithunyelwa kwamanye amazwe, intengo ibiza kakhulu.
(4) I-Anti-oxidant iwukuqinisekisa ukuzinza kokucutshungulwa kwe-polyethylene kanye nekhebula elilwa nokuguga futhi wanezela, i-anti-oxidant enqubweni yokuxhunyelelwa kwe-silane inendima yokuvimbela ukusabela kokuxhunyelelwa, ngakho inqubo yokuxhunyelelwa, ukungezwa kwe-anti-oxidant. ukuze uqaphele, inani elingeziwe lokucabangela inani le-DCP ukuze lifane nokukhethwa. Enqubweni yokuxhumanisa okuyizinyathelo ezimbili, iningi le-antioxidant lingangezwa ku-catalyst master batch, enganciphisa umthelela enqubweni yokuxhunyelelwa. Enqubweni yokuxhumanisa isinyathelo esisodwa, i-antioxidant ikhona kuyo yonke inqubo yokuxhunyelelwa, ngakho ukukhethwa kwezinhlobo nenani kubaluleke kakhulu. Ama-antioxidants asetshenziswa kakhulu yi-1010, 168, 330, njll.
(5) I-Polymerization inhibitor yengezwa ukuze kuvinjwe inqubo yokuxhunyelelwa kanye nokuxhumanisa okuphambene kokusabela okuseceleni kwenzeka, enqubweni yokuxhunyelelwa ukwengeza i-ejenti ephikisana nokuxhumanisa, inganciphisa ngempumelelo ukwenzeka kokuxhumanisa kwe-C2C, ngaleyo ndlela kube ngcono. i-fluidity yokucubungula, ngaphezu kwalokho, ukungezwa kwe-graft ezimweni ezifanayo kuzokwandulelwa i-hydrolysis ye-silane ku-polymerization inhibitor inganciphisa i-hydrolysis ye-polyethylene exhunyelelwe, ukuthuthukisa ukuzinza kwesikhathi eside kwe-graft material.
(6) Ama-Catalysts avamise ukuphuma kokuphuma kwe-organotin (ngaphandle kokuxhumanisa okungokwemvelo), okuvame kakhulu i-dibutyltin dilaurate (DBDTL), ngokuvamile engezwa ngendlela ye-masterbatch. Enqubweni yezinyathelo ezimbili, i-graft (i-A) kanye ne-catalyst master batch (impahla engu-B) ihlanganiswa ngokuhlukana futhi izinto ezi-A no-B zihlanganiswa ndawonye ngaphambi kokwengezwa ku-extruder ukuvimbela ukuphambana kwangaphambili kwempahla engu-A. Endabeni yezinyathelo ze-silane ezine-cross-linked polyethylene insulations, i-polyethylene ephaketheni ayikakaxhunywanga, ngakho-ke ayikho inkinga yangaphambi kokuxhumanisa ngakho-ke i-catalyst ayidingi ukupakishwa ngokwehlukana.
Ngaphezu kwalokho, kukhona ama-silane ahlanganisiwe atholakala emakethe, okuyinhlanganisela ye-silane, i-initiator, i-antioxidant, amanye ama-lubricant nama-anti-copper agents, futhi ngokuvamile asetshenziswa ezindleleni zokuxhumanisa i-silane yesinyathelo esisodwa ezitshalweni zamakhebula.
Ngakho-ke, ukwakhiwa kwe-silane cross-linked polyethylene insulation, ukwakheka kwayo akubhekwa njengento eyinkimbinkimbi kakhulu futhi itholakala kulwazi olufanele, kodwa ukwakheka kokukhiqiza okufanelekile, kuncike ekulungiseni okuthile ukuze kuphothulwe, okudinga ukugcwaliswa okuphelele. ukuqonda indima yezingxenye ekwakhiweni kanye nomthetho womthelela wazo ekusebenzeni kanye nomthelela wazo ofanayo.
Ezinhlotsheni eziningi zezinto zekhebula, i-silane cross-linked cable material (okungaba yizinyathelo ezimbili noma isinyathelo esisodwa) ibhekwa njengewukuphela kwezinqubo zamakhemikhali ezenzeka ku-extrusion, ezinye izinhlobo ezifana ne-polyvinyl chloride (PVC) impahla yekhebula kanye I-polyethylene (PE) ikhebula lezinto zekhebula, inqubo ye-extrusion granulation iyinqubo yokuxuba ngokomzimba, noma ngabe izinto zekhebula ezixhumanisa amakhemikhali kanye ne-irradiation cross-linking, kungakhathaliseki ukuthi kuyinqubo ye-extrusion granulation, noma i-extrusion system Cable, ayikho inqubo yamakhemikhali eyenzekayo. , ngakho-ke, uma kuqhathaniswa, ukukhiqizwa kwe-silane cross-linked cable material kanye ne-cable insulation extrusion, ukulawulwa kwenqubo kubaluleke kakhulu.
4. Inqubo yokukhiqiza i-silane enezinyathelo ezimbili exhumene ne-polyethylene
Inqubo yokukhiqiza yokufakwa kwe-silane enezinyathelo ezimbili ezixhumene ne-polyethylene A impahla ingamelwa kafushane nguMfanekiso 1.
Umfanekiso 1 Inqubo yokukhiqiza ye-silane enezinyathelo ezimbili ezixhumene ne-polyethylene insulating material A
Amanye amaphuzu abalulekile enqubweni yokukhiqiza ye-silane enezinyathelo ezimbili exhunywe nge-polyethylene insulation:
(1) Ukomisa. Njengoba i-polyethylene resin iqukethe inani elincane lamanzi, lapho ikhishwa emazingeni okushisa aphezulu, amanzi asabela ngokushesha ngamaqembu e-silyl ukuze akhiqize ukuxhumanisa okuphambene, okunciphisa ukuncibilika kokuncibilika futhi kukhiqize ukuxhumanisa kwangaphambili. Izinto eziqediwe nazo ziqukethe amanzi emva kokupholisa kwamanzi, okungase futhi kubangele i-pre-crosslinking uma ingasuswa, futhi kufanele futhi yomiswe. Ukuze kuqinisekiswe ikhwalithi yokomisa, iyunithi yokomisa ejulile isetshenziswa.
(2) Ukulinganisa. Njengoba ukunemba kokwakhiwa kwempahla kubalulekile, isikali sesisindo sokulahlekelwa kwesisindo esingenisiwe ngokuvamile sisetshenziswa. I-polyethylene resin kanye ne-antioxidant iyalinganiswa futhi yondliwe ngembobo yokuphakelayo ye-extruder, kuyilapho i-silane ne-initiator ijovwa ngepompo lempahla ewuketshezi emgqonyeni wesibili noma wesithathu we-extruder.
(3) Ukuxhunyelelwa kwe-Extrusion. Inqubo yokuxhunyelelwa kwe-silane iqedwa ku-extruder. Izilungiselelo zenqubo ye-extruder, okuhlanganisa izinga lokushisa, inhlanganisela yesikulufu, isivinini sokukulufa kanye nesilinganiso sokuphakelayo, kufanele silandele isimiso sokuthi izinto ezisesigabeni sokuqala se-extruder zingancibilika ngokugcwele futhi zixutshwe ngokufanayo, lapho ukubola ngaphambi kwesikhathi kwe-peroxide kungafiswa. , nokuthi impahla efanayo ngokuphelele esigabeni sesibili se-extruder kufanele yonakale ngokuphelele futhi inqubo yokuxhunyelelwa iqedwe, Amazinga okushisa esigaba esijwayelekile se-extruder (LDPE) aboniswa kuThebula 1.
Ithebula 1 Amazinga okushisa ezindawo ezinezinyathelo ezimbili zokuphuma
| Indawo yokusebenza | Indawo 1 | Indawo yesi-2 | Indawo 3 ① | Indawo yesi-4 | Zone 5 |
| Izinga lokushisa P °C | 140 | 145 | 120 | 160 | 170 |
| Indawo yokusebenza | Zone 6 | Indawo 7 | Indawo 8 | Indawo 9 | Umlomo uyafa |
| Izinga lokushisa °C | 180 | 190 | 195 | 205 | 195 |
① yilapho i-silane yengezwa khona.
Isivinini se-screw screw sinquma isikhathi sokuhlala kanye nomphumela wokuxuba wezinto ezibonakalayo ku-extruder, uma isikhathi sokuhlala sifushane, ukubola kwe-peroxide akuphelele; uma isikhathi sokuhlala siside kakhulu, i-viscosity yezinto ezikhishwe iyanda. Ngokuvamile, isilinganiso sesikhathi sokuhlala se-granule ku-extruder kufanele silawulwe ku-initiator yokubola kwesigamu sempilo izikhathi ezingu-5-10. Ijubane lokudla aligcini nje ngokuba nomthelela othile ngesikhathi sokuhlala sezinto ezibonakalayo, kodwa futhi ekuxubeni nasekugundweni kwezinto ezibonakalayo, khetha isivinini sokudla esifanele kubaluleke kakhulu.
(4) Ukupakisha. Izinto zokuvikela i-silane ezinezinyathelo ezimbili ezixhumene kufanele zifakwe ezikhwameni eziyinhlanganisela ye-aluminium-plastic emoyeni oqondile ukuze kuqedwe umswakama.
5. Isinyathelo esisodwa se-silane exhumene ne-polyethylene insulating inqubo yokukhiqiza impahla
Isinyathelo esisodwa se-silane exhunywe nge-cross-linked polyethylene insulation material ngenxa yenqubo yokuxhunyelelwa ku-extrusion yefekthri yekhebula ye-cable insulation core, ngakho-ke izinga lokushisa lokufakwa kwe-cable insulation liphakeme kakhulu kunendlela yezinyathelo ezimbili. Nakuba ifomula yokufakelwa kwe-silane enesinyathelo esisodwa exhumene ne-polyethylene iye yacatshangelwa ngokugcwele ekuhlakazweni okusheshayo kwe-initiator kanye ne-silane kanye nokugunda kwempahla, kodwa inqubo yokuxhunyelelwa kufanele iqinisekiswe izinga lokushisa, okuyisinyathelo esisodwa se-silane exhunywe nge-polyethylene. isitshalo sokukhiqiza i-insulation sigcizelele ngokuphindaphindiwe ukubaluleka kokukhetha okulungile kwezinga lokushisa le-extrusion, izinga lokushisa elinconywayo elijwayelekile le-extrusion liboniswa kuThebula 2.
Ithebula 2 I-extruder yesinyathelo esisodwa sokushisa yendawo ngayinye (iyunithi: ℃)
| Indawo | Indawo 1 | Indawo yesi-2 | Indawo yesi-3 | Indawo yesi-4 | I-Flange | Ikhanda |
| Izinga lokushisa | 160 | 190 | 200-210 | 220-230 | 230 | 230 |
Lobu obunye bobuthakathaka benqubo ye-polyethylene enesinyathelo esisodwa se-silane, ngokuvamile engadingeki lapho ukhipha izintambo ngezinyathelo ezimbili.
6.Imishini yokukhiqiza
Imishini yokukhiqiza iyisiqinisekiso esibalulekile sokulawula inqubo. Ukukhiqizwa kwezintambo ze-silane ezixhumene ngokuphambana kudinga ukunemba okuphezulu kakhulu kokulawula inqubo, ngakho ukukhethwa kwezinto zokukhiqiza kubaluleke kakhulu.
Ukukhiqizwa kwe-silane enezinyathelo ezimbili ezixhumene ne-cross-linked polyethylene insulation material I-material production, okwamanje i-isotropic parallel twin-screw extruder yasekhaya eyengeziwe enesisindo esingenasisindo esingenisiwe, lezo mishini zingahlangabezana nezidingo zokunemba kokulawula inqubo, ukukhetha ubude nobubanzi besisindo. i-twin-screw extruder ukuze kuqinisekiswe ukuthi isikhathi sokuhlala esibonakalayo, ukukhethwa kwesisindo esingenasisindo esingenisiwe sokuqinisekisa ukunemba kwezithako. Yebo miningi imininingwane yemishini edinga ukunakwa ngokugcwele.
Njengoba kushiwo ngaphambili, i-silane-step-linked cross-linked cable production equipment in the cable plant are imported, eqolo, abakhiqizi bemishini yasekhaya abanayo imishini yokukhiqiza efanayo, isizathu ukuntuleka kokubambisana phakathi kwabakhiqizi bemishini kanye nefomula kanye nabacwaningi benqubo.
7.I-Silane yemvelo exhumene ne-polyethylene insulation material
I-Silane yemvelo exhumene ne-polyethylene insulating impahla eyakhiwe eminyakeni yamuva ingaxhunyaniswa ngaphansi kwezimo zemvelo ezinsukwini ezimbalwa, ngaphandle kwesitimu noma ukucwiliswa kwamanzi afudumele. Uma kuqhathaniswa nendlela yendabuko yokuxhumanisa i-silane, le nto inganciphisa inqubo yokukhiqiza yabakhiqizi bezintambo, iphinde yehlise izindleko zokukhiqiza futhi ikhulise ukusebenza kahle kokukhiqiza. I-Silane ngokwemvelo i-cross-linked polyethylene insulation iya ngokuya ibonwa futhi isetshenziswa abakhiqizi bezintambo.
Eminyakeni yamuva nje, ukufakwa kwe-silane yemvelo okuxhumene ne-polyethylene yemvelo sekukhulile futhi kukhiqizwe ngobuningi, ngezinzuzo ezithile ngentengo uma kuqhathaniswa nezinto ezithunyelwa kwamanye amazwe.
7. 1 Imibono yokwakhiwa kwe-silane ngokwemvelo exhunywe nge-polyethylene insulations
Ukufakwa kwe-polyethylene yemvelo ye-Silane yemvelo exhunywe ngesiphambano kukhiqizwa ngenqubo yezinyathelo ezimbili, ngokubunjwa okufanayo okuhlanganisa i-base resin, i-initiator, i-silane, i-antioxidant, i-polymerisation inhibitor kanye ne-catalyst. Ukwakhiwa kwezivikeli ze-silane zemvelo ezixhumene ne-polyethylene kusekelwe ekwandiseni izinga lokuxhunyelelwa kwe-silane yento engu-A kanye nokukhetha i-catalyst esebenza kahle kunezigqugquzeli ze-polyethylene eziphambanweni zamanzi afudumele e-silane. Ukusetshenziswa kwempahla engu-A enezinga eliphezulu lokuxhunyelelwa kwe-silane kuhlanganiswe ne-catalyst esebenza kahle kuzokwenza isivikelo se-polyethylene esixhumene nesiphambano se-silane sikwazi ukuxhumanisa ngokushesha ngisho nasezingeni eliphansi lokushisa futhi sinomswakama onganele.
I-A-materials yama-silane angenisiwe ngokwemvelo axhumene ne-polyethylene insulators ahlanganiswa nge-copolymerisation, lapho okuqukethwe kwe-silane kungalawulwa ezingeni eliphezulu, kuyilapho ukukhiqizwa kwe-A-materials enezinga eliphezulu lokuxhunyelelwa ngokuxhunyelelwa i-silane kunzima. I-resin eyisisekelo, i-initiator kanye ne-silane esetshenziswe ku-recipe kufanele ihluke futhi ilungiswe ngokuya ngezinhlobonhlobo nokwengeza.
Ukukhethwa kwe-resistance kanye nokulungiswa komthamo wayo nakho kubalulekile, njengoba ukwanda kwezinga lokuxhunyelelwa kwe-silane nakanjani kuholela ekuphenduleni okuningi kwe-CC crosslinking side. Ukuze kuthuthukiswe uketshezi olucutshungulwayo kanye nesimo esingaphezulu sento engu-A yokukhishwa kwekhebula okulandelayo, inani elifanelekile le-polymerization inhibitor liyadingeka ukuze kunqandwe ngempumelelo ukuphambana kwe-CC kanye nangaphambi kokuxhumanisa ngaphambili.
Ngaphezu kwalokho, ama-catalyst adlala indima ebalulekile ekwandiseni izinga lokuxhumanisa futhi kufanele akhethwe njengama-catalyst asebenzayo aqukethe izinto ezishintshayo ezingenazo insimbi.
7. 2 Isikhathi sokuxhumanisa i-silane ngokwemvelo ephambanise i-polyethylene insulations
Isikhathi esidingekayo ukuze uqedele ukuxhumanisa kwe-silane yemvelo exhunywe nge-polyethylene insulation esimweni sayo semvelo sincike ekushiseni, umswakama kanye nokushuba kongqimba lokufakelwa. Uma izinga lokushisa liphezulu kanye nomswakama, kuya kuba mncane ukujiya kongqimba olufakwayo, isikhathi sokuxhumanisa sincipha esidingekayo, futhi kuba side okuphambene. Njengoba izinga lokushisa nomswakama kuhluka ngokwesifunda nesifunda kanye nezinkathi zonyaka, ngisho nasendaweni efanayo nangesikhathi esifanayo, izinga lokushisa nomswakama namuhla nakusasa kuzohluka. Ngakho-ke, ngesikhathi sokusebenzisa impahla, umsebenzisi kufanele anqume isikhathi sokuxhumanisa ngokuya ngezinga lokushisa lendawo kanye nomswakama okhona, kanye nokucaciswa kwekhebula kanye nobukhulu bongqimba bokufakelwa.
Isikhathi sokuthumela: Aug-13-2022