Haasi ese mafirimu anogadzirwa akaenzana. Izvi zvinogadzira matambudziko kune vese winder uye anoshanda. Heino maitiro ekuita navo. #mazano ekugadzirisa #zvakanakisa maitiro
Pakati pemawinda epakati, kushushikana kwewebhu kunodzorwa nemadhiraivha epamusoro akabatana kune stacker kana pinch rollers kuti agone kutsemura webhu uye kugovera webhu. Winding tension inodzorwa yakazvimiririra kuti iwedzere kuoma kwecoil.
Kana uchitenderedza firimu pamhepo yepakati pemhepo, kushushikana kwewebhu kunogadzirwa nemhepo inomonereka yepakati drive. Webhu tension inotanga kuiswa kune inodiwa roll stiffness uye zvishoma nezvishoma inoderedzwa sezvo firimu rinopera.
Kana uchitenderedza firimu pamhepo yepakati pemhepo, kushushikana kwewebhu kunogadzirwa nemhepo inomonereka yepakati drive. Webhu tension inotanga kuiswa kune inodiwa roll stiffness uye zvishoma nezvishoma inoderedzwa sezvo firimu rinopera.
Kana uchitenderedza zvigadzirwa zvemufirimu pakati / pamusoro pemhepo, iyo pinch roller inomisikidzwa kudzora kushushikana kwewebhu. Iyo nguva yekupeta haibvi pane kunetsana kwewebhu.
Dai mawebhusaiti ese emufirimu aive akakwana, kugadzira mipumburu yakakwana kwaisazova dambudziko guru. Nehurombo, mafirimu akakwana haapo nekuda kwekusiyana kwechisikigo mumarasi uye inhomogeneities mukugadzira firimu, kupfekedza, uye kudhindwa nzvimbo.
Uine izvi mupfungwa, basa rekushanda kwemhepo nderekuona kuti zvikanganiso izvi hazvioneki nemaziso uye hazviwedzere panguva yekufambisa. Iyo winder opareta ipapo inofanirwa kuve nechokwadi chekuti iyo inomonereka maitiro haiwedzere kukanganisa kunaka kwechigadzirwa. Dambudziko rekupedzisira nderekutenderedza bhaisikopo rekurongedza kuti rishande zvisina mutsetse mukugadzirwa kwevatengi uye kugadzira chigadzirwa chemhando yepamusoro chevatengi vavo.
Kukosha kweFirimu Rigidity Firimu density, kana kumonereka kwemhepo, ndicho chinhu chakakosha pakuona kuti firimu rakanaka here kana kuti rakaipa. Ronda remupumburu rakapfava zvakanyanya richave "rakatenderera" kana rakakuvadzwa, rakabatwa, kana kuchengetwa. Iko kutenderera kwemaroru kwakakosha kune mutengi kuitira kuti ugone kugadzirisa aya ma rolls nekumhanya kwepamusoro kwekugadzira uku uchichengeta shanduko shoma yekunetsana.
Maronda akasimba anogona kukonzera matambudziko avo. Vanogona kugadzira dambudziko rekuvharisa dambudziko kana zvidimbu zvikasangana kana kunamatira. Paunenge uchitenderedza firimu rakatambanudzwa pane yakatetepa-yakavakirwa musimboti, kupeta roll yakaomarara kunogona kuita kuti musimboti utyoke. Izvi zvinogona kukonzera matambudziko kana uchibvisa shaft kana kuisa shaft kana chuck panguva inotevera unwind mashandiro.
Mupumburu wakakuvadzwa zvakanyanya unogona kuwedzera kukanganisa kwewebhu. Mafirimu anowanzo ane nzvimbo dzakakwirira uye dzakaderera muchikamu chemuchinjiko wemuchina uko webhu kukora kana kutetepa. Pakumoneredza dura mater, nzvimbo dzehukobvu hukuru dzinopindirana. Kana mazana kana kunyange zviuru zvezvikamu zvakakuvadzwa, zvikamu zvakakwirira zvinoumba mitsetse kana fungidziro pamupumburu. Kana iyo firimu yakatambanudzwa kune aya mafungidziro, inokanganisa. Nzvimbo idzi dzinobva dzagadzira hurema hunodaidzwa kuti "homwe" mufirimu sezvo roll inosunungurwa. Mhepo yakaoma ine sliver gobvu padivi pekatetepa inogona kukonzeresa kukanganiswa kwemhepo inonzi waviness kana tambo marks pamhepo.
Shanduko diki muhutete hwemupumburu weronda hazvizoonekwe kana mweya wakakwana wakakuvadzwa mumupumburu muzvikamu zvakaderera uye webhu haina kutambanudzwa muzvikamu zvepamusoro. Nekudaro, iyo mipumburu inofanirwa kukuvadzwa zvakasimba kuitira kuti iite denderedzwa uye irambe yakadaro panguva yekubata nekuchengetedza.
Randomization yemuchina-kune-muchina mutsauko Mamwe anochinjika ekurongedza mafirimu, angave panguva yavo extrusion process kana panguva yekuputira uye lamination, ane muchina-kune-muchina makubvu akasiyana akakurisa kuti ave akarurama pasina kuwedzeredza kukanganisa uku. Kukwenenzvera kuchinjika kwemuchina-kune-muchina winder roll, dandemutande kana slitter rewinder uye mhepo inofambisa ichienda mberi nekudzoka maererano newebhu sezvo webhu inochekwa nekukuvadzwa. Iyi lateral kufamba kwemuchina kunonzi oscillation.
Kuti ufambe zvakanaka, kumhanya kunofanirwa kunge kwakakwira zvekuti kusiyanisa ukobvu, uye kuderera zvekusaputira kana kuunyana firimu. Mutemo wechigunwe wepamusoro wekuzunungusa kumhanya i25 mm (1 inch) paminiti yega yega 150 m/min (500 ft/min) kumhanya kwemhepo. Sezvineiwo, iyo oscillation yekumhanyisa inoshanduka zvichienderana nekumhanya kwemhepo.
Webhu Stiffness Ongororo Kana mupumburu wezvinhu zvinochinjika zvekurongedza zvemufirimu wakaputirwa mukati memupumburu, pane kunetsana mupumburu kana kusara kunetseka. Kana kushushikana uku kukava kwakakura panguva yekumonereka, iyo yemukati inotenderedza yakananga kupakati inozoiswa pasi pekuremerwa kukuru. Izvi ndizvo zvinokonzeresa "bulge" kukanganisa munzvimbo dzenzvimbo dzekoiri. Paunenge uchimonerera mafirimu asiri erastic uye anotsvedza zvakanyanya, mukati memukati unogona kuregedzera, izvo zvinogona kuita kuti mupumburu umonere kana wakuvadzwa kana kutambanudza kana usina ronda. Kuti udzivise izvi, bhobho inofanira kunge yakakuvadzwa zvakasimba kumativi epakati, uye zvishoma zvakasimba sezvo dhayamita yebhobhi inowedzera.
Izvi zvinowanzonzi rolling hardness taper. Kukura kwedhayamita yebhero rakapedzwa, ndiko kunyanya kukosha kwetaper profile yebhero. Chakavanzika chekugadzira yakanaka stranded simbi kuomarara kuvaka kutanga nehwaro hwakanaka hwakasimba uye wozoisimudzira nekufamba-famba kushoma tension pamakoiri.
Kukura kwedhayamita yebhero rakapedzwa, ndiko kunyanya kukosha kwetaper profile yebhero.
Hwaro hwakasimba hwakasimba hunoda kuti mhepo itange nemhando yepamusoro, yakachengetwa musimboti. Zvizhinji zvemafirimu zvinhu zvinokuvadzwa pabepa core. Iyo musimboti unofanirwa kuve wakasimba zvakakwana kuti ukwanise kumirisana nekumanikidza kwemhepo kunokonzeresa kunoitwa nefirimu rakanyatsokuvara mukati mepakati. Kazhinji, bepa repakati rinoomeswa muchoto kusvika kune hunyoro hwe6-8%. Kana macores aya akachengetwa munzvimbo ine hunyoro hwepamusoro, anozotora hunyoro ihwohwo uye anowedzera kusvika padhayamita yakakura. Zvadaro, mushure mekushanda kwemhepo, aya macores anogona kuomeswa kune yakaderera hunyoro uye kuderedzwa muhukuru. Kana izvi zvikaitika, hwaro hwekukanda kukuvara kwakasimba huchave husisipo! Izvi zvinogona kutungamira kune hurema hwakadai se warping, bulging uye/kana protrusion of the rolls painobatwa kana kuvhurwa.
Nhanho inotevera pakuwana iyo inodiwa yakanaka coil base kutanga kumonereka nekuoma kwepamusoro-soro kwekoiri. Zvadaro, sezvo mupumburu wezvinhu zvemufirimu uchikuvadzwa, kuomarara kwemupumburu kunofanira kuderera zvakaenzana. Iyo inokurudzirwa kudzikiswa kwekuomarara kwemupumburu padhayamita yekupedzisira inowanzoita 25% kusvika 50% yekuomarara kwepakutanga kuyerwa pakati.
Kukosha kwekuoma kwemupumburu wekutanga uye kukosha kwetaper yemhepo inoputika inowanzoenderana nehuwandu hwekuvaka-up reronda roll. The rise factor ireshiyo yedhayamita yekunze (OD) yepakati kusvika padhayamita yekupedzisira yerunyoro rweronda. Iyo yakakura iyo yekupedzisira dhayamita inomonereka yebhero (iyo yakakwirira chimiro), iyo inonyanya kukosha inova kutanga neyakanaka hwaro hwakasimba uye zvishoma nezvishoma mhepo yakapfava mabhero. Tafura 1 inopa mutemo wechigunwe weiyo yakakurudzirwa dhigirii rekuomarara zvichibva pane yakawedzera chinhu.
Zvishandiso zvinomonereka zvinoshandiswa kuomesa dandemutande isimba rewebhu, kudzvanya pasi (kudzvanya kana stacker rollers kana winder reels), uye torque inomonereka kubva pakati pedhiraivha kana ichimoneredza firimu webs pakati/pamusoro. Aya anonzi TNT mhepo misimboti inokurukurwa mune chinyorwa muna Ndira 2013 chinyorwa chePlastiki Technology. Inotevera inotsanangura mashandisiro ezvishandiso izvi kugadzira zviyereso zvekuomarara uye inopa mutemo wechigunwe kune yekutanga kukosha kuti uwane inodiwa roll yekuomarara ma tester akasiyana anochinjika ekurongedza zvinhu.
Nheyo yeweb winding force. Kana uchitenderedza mabhaisikopo elastiki, webhu tension ndiyo musimboti wemhepo unoshandiswa kudzora kuomarara kwemupumburu. Iyo yakasimba iyo firimu yakatambanudzwa isati yapepereswa, iyo yakaoma ronda roll ichave. Dambudziko nderekuita shuwa kuti huwandu hwekunetsana kwewebhu haukonzerese kushushikana kusingaperi mufirimu.
Sezvinoratidzwa mufig. 1, kana ichitenderedza firimu pane yakachena yepakati winder, kushushikana kwewebhu kunogadzirwa neinotenderedza torque yepakati drive. Webhu tension inotanga kuiswa kune inodiwa roll stiffness uye zvishoma nezvishoma inoderedzwa sezvo firimu rinopera. Simba rewebhu rinogadzirwa nepakati drive rinowanzodzorwa muvharo yakavharwa nemhinduro kubva kune tension sensor.
Kukosha kwekutanga uye kwekupedzisira blade simba kune chimwe chinhu kunowanzo kutsanangurwa empirically. Mutemo wakanaka wechigunwe wewebhu simba renji i10% kusvika 25% yekusimba kwemufirimu. Zvinyorwa zvakawanda zvakadhindwa zvinokurudzira humwe huwandu hwesimba rewebhu kune zvimwe zvinhu zvewebhu. Tafura 2 inodonongodza makakatanwa ezvakawanda zvewebhu zvinoshandiswa mukurongedza zvinochinjika.
Pakupeta pamhepo yakachena yepakati winder, kushushikana kwekutanga kunofanirwa kunge kuri pedyo nepamusoro peiyo inokurudzirwa tension range. Zvadaro zvishoma nezvishoma deredza mhepo inoputika kusvika kune yakaderera yakakurudzirwa mararamiro inoratidzwa mutafura iyi.
Kukosha kwekutanga uye kwekupedzisira blade simba kune chimwe chinhu kunowanzo kutsanangurwa empirically.
Paunenge uchitenderedza webhu yakashongedzwa yakaumbwa nezvinhu zvakasiyana-siyana, kuti uwane iyo yakakurudzirwa yakanyanya kusimba yewebhu kune iyo laminated chimiro, ingo wedzera iyo yakanyanya kusimba yewebhu kune yega yega chinhu chakavezwa pamwe chete (kazhinji zvisinei nekupfeka kana adhesive layer) uye shandisa iyo chidimbu chinotevera chemakakatanwa aya. sekunyanya kunetseka kwewebhu laminate.
Chinhu chakakosha mukukakavadzana kana laminating flexible film composite ndechekuti mawebhu ega ega anofanirwa kunge akatsikirirwa pamberi pelamination kuitira kuti deformation (kurebesa kwewebhu nekuda kwekunetsekana kwewebhu) kunenge kwakangofanana kune yega yega webhu. Kana dandemutande rimwe rikadhonzwa zvakanyanya kupfuura mamwe mawebhu, matambudziko ekupeta kana delamination, anozivikanwa se "tunneling", anogona kuitika mumambure akacheneswa. Huwandu hwekunetsana hunofanirwa kunge huri reshiyo yemodulus kune ukobvu hwewebhu kudzivirira kupeta uye / kana kutenderedza mushure mekuita lamination.
Nheyo yekurumwa nespiral. Paunenge uchipepeta mafirimu asiri-elastic, kusungirira uye torque ndiwo misimboti mikuru yemhepo inoshandiswa kudzora kuomarara. Iyo clamp inogadzirisa kuoma kwemupumburu nekubvisa muganhu wemhepo unotevera webhu kupinda mukutora-up roller. Iyo clamp zvakare inogadzira kukakavara pamupumburu. Kusimba kunoita chisungiso, ndiko kuomarara kunoita mupumburu unomonereka. Dambudziko rekumonereka bhaisikopo rekurongedza ndere kupa yakaringana pasi kumanikidza kubvisa mweya uye kuvhuvhuta yakaomesesa, yakatwasuka roll pasina kugadzira yakawandisa mhepo tension panguva yekumonereka kudzivirira mupumburu kubva pakusunga kana kumonereka munzvimbo dzakakora dzinokanganisa webhu.
Clamp loading haina kutsamira pazvinhu pane kunetsa kwewebhu uye inogona kusiyanisa zvakanyanya zvichienderana nechinhu uye inodiwa kuoma kweroller. Kuti udzivise kuunyana kwefirimu reronda rinokonzereswa nenyuchi, mutoro munip ndiwo udiki unodiwa kudzivirira mweya kuti usabatwa mumupumburu. Iyi nip load inowanzo chengetwa iri pakati pema winders nekuti zvisikwa zvinopa inogara iri nip mutoro simba rekumanikidza koni mu nip. Sezvo dhayamita yemupumburu ichikura, nzvimbo yekusangana (nzvimbo) yemukaha pakati pemhepo inotenderera uye yekumanikidza roller inova yakakura. Kana hupamhi hwenjanji iyi hukachinja kubva pa6 mm (0.25 inch) pahupamhi kusvika pa12 mm (0.5 inch) pakazara roll, mhepo yemhepo inongodzikiswa ne50%. Mukuwedzera, sezvo hupamhi hwemhepo inoputika inowedzera, huwandu hwemhepo hunotevera pamusoro peiyo roller inowedzerawo. Uyu muganho wemhepo unowedzera hydraulic pressure mukuedza kuvhura gap. Iyi yakawedzera kudzvanywa inowedzera taper yemutoro we clamping sezvo dhayamita inowedzera.
Pamamhepo akafara uye anokurumidza mhepo anoshandiswa kuvhuvhuta dhayamita yakakura, zvingave zvakafanira kuwedzera mutoro pane inomonereka clamp kudzivirira mweya kupinda mupumburu. Pamusoro pemuonde. 2 inoratidza yepakati firimu mhepo ine mhepo-yakarodha kudzvanywa roll inoshandisa tension uye clamping maturusi kudzora kuoma kweinomonereka roll.
Dzimwe nguva mhepo ishamwari yedu. Mamwe mafirimu, kunyanya "anamira" mafirimu epamusoro-soro ane matambudziko nekufanana, anoda gap winding. Kupeta kwegap kunobvumira mweya mudiki kuti udhonzerwe mubhero kudzivirira matambudziko edandemutande mukati mebhero uye zvinobatsira kudzivirira kuputika padandemutande kana mitsetse yakakora yashandiswa. Kuti ubudirire mhepo iyi mafirimu gap, kushanda kwemhepo kunofanirwa kuchengetedza diki, gaka rinogara riri pakati pekumanikidza roller uye yekuputira zvinhu. Iri mukaha mudiki, unodzorwa unobatsira kumita ronda remhepo parunyoro uye rinotungamira dandemutande rakananga mumhepo kudzivirira kuunyana.
Torque winding musimboti. Iyo torque chishandiso chekuwana kuomarara kweroll isimba rakagadzirwa nepakati peinomonereka roll. Simba iri rinofambiswa kuburikidza nemesh layer parinokweva kana kukweva mukati mekuputira mukati mefirimu. Sezvambotaurwa, torque iyi inoshandiswa kugadzira simba rewebhu pamhepo yepakati. Kune aya marudzi emawinders, webhu tension uye torque zvine imwechete inotenderera musimboti.
Paunenge uchimoneredza zvigadzirwa zvemufirimu pakati / pamusoro pemhepo, mapinch rollers anofambiswa kudzora tension yewebhu sezvakaratidzwa muFigure 3. The web tension inopinda muwinder inozvimiririra kubva kune mhepo inovhuvhuta inogadzirwa neiyi torque. Nekunetsekana nguva dzose kwedandemutande ichipinda muwinder, tension yewebhu inopinda inowanzochengetwa nguva dzose.
Paunenge uchicheka nekudzosera kumashure firimu kana zvimwe zvinhu zvine chiyero chePoisson chakakwira, pakati / pamusoro pemhepo inotenderedza inofanira kushandiswa, hupamhi hunosiyana zvichienderana nekusimba kwewebhu.
Paunenge uchitenderedza zvigadzirwa zvemufirimu pamushini wepakati / wepamusoro unomonereka, mhepo inotenderera inodzorwa mune yakavhurika loop. Kazhinji, iyo yekutanga mhepo inovhuvhuta inosvika 25-50% yakakura kupfuura tension yewebhu inouya. Zvadaro, sezvo dhayamita yewebhu inowedzera, mhepo inoputika inoderedzwa zvishoma nezvishoma, inosvika kana kunyange kuderera kudarika mhirizhonga yewebhu inouya. Kana iko kutenderera kwemhepo kwakakura kupfuura kunouya kwewebhu tension, iyo yekumanikidza roller surface drive inovandudza kana kuburitsa yakaipa (braking) torque. Sezvo dhayamita yemhepo inoputika inowedzera, dhiraivha yekufambisa ichapa zvishoma uye zvishoma mabhureki kusvika zero torque yasvika; ipapo mhepo inoputika ichave yakaenzana newebhu tension. Kana simba remhepo rakarongwa pazasi pesimba rewebhu, dhiraivha yepasi inodhonza torque yakanaka kutsiva mutsauko uripo pakati pemhepo yakaderera uye simba rewebhu repamusoro.
Paunenge uchicheka nekupeta firimu kana zvimwe zvinhu zvine reshiyo yePoisson yakakwira, nzvimbo yepakati/yepamusoro pemhepo inofanira kushandiswa, uye hupamhi huchachinja nesimba rewebhu. Mafenda epakati pepamusoro anochengetedza anogara akaiswa mupumburu wakafara nekuti inogara ichinetsa yewebhu inoiswa kune winder. Kuomarara kwemupumburu kunozoongororwa zvichibva pane torque iri pakati pasina matambudziko nehupamhi hwetaper.
Mhedzisiro yefirimu friction factor pakupeta Iyo firimu's interlaminar coefficient of friction (COF) zvimiro zvine simba rakakura pakugona kushandisa iyo TNT musimboti kuwana inodiwa roll kuomarara pasina kukanganisa roll. Kazhinji, mafirimu ane interlaminar friction coefficient ye 0.2-0.7 roll zvakanaka. Nekudaro, mhepo inomonereka-isina firimu inotenderera ine yakakwira kana yakaderera kutsvedza (yakaderera kana yakakwira coefficient yekupokana) kazhinji inopa akakosha mapeji matambudziko.
Mafirimu epamusoro anotsvedza ane yakaderera coefficient ye interlaminar friction (kazhinji pazasi 0.2). Aya mafirimu anowanzo tambura kubva mukati mewebhu kutsvedza kana matambudziko ekumonereka panguva yemhepo uye / kana anotevera ekusunungura maoparesheni, kana matambudziko ekubata kwewebhu pakati peaya mabasa. Uku kutsvedza kwemukati kweblade kunogona kukonzera kuremara senge blade scratches, dents, telescoping uye/kana star roller defects. Mafirimu ekukwenya akaderera anoda kukuvadzwa zvakasimba sezvinobvira pane yakakwirira torque core. Ipapo mhepo inotenderera inogadzirwa neiyi torque inodzikiswa zvishoma nezvishoma kusvika kune yakaderera kukosha kwetatu kusvika ina yekunze dhayamita yepakati, uye iyo inodiwa roll rigidity inowanikwa uchishandisa iyo clamp inotenderera musimboti. Mhepo haizombove shamwari yedu kana zvasvika pamhepo yakakwira inotsvedza firimu. Mafirimu aya anofanirwa kugara achikuvadzwa nechisimba chakakwana kudzivirira mweya kuti usapinde mupumburu panguva yekumonereka.
Firimu yakaderera inotsvedza ine yakakwira coefficient ye interlaminar friction (kazhinji pamusoro pe 0.7). Aya mafirimu anowanzo tambura nekuvharira uye / kana kuunyana nyaya. Kana mabhaisikopo emhepo ane yakakwira coefficient yekukweshana, roll ovality pakumhanya kwakaderera kwemhepo uye matambudziko ekubhomba pakumhanya kukuru kwemhepo anogona kuitika. Mipumburu iyi inogona kunge yakasimudza kana wavy kuremara kunowanzozivikanwa sekuti slip knots kana kutsvedza wrinkles. Mafirimu ekukweshera akanyanya kukuvadzwa zvakanyanya aine mukaha unoderedza mukaha uripo pakati pekutevera uye kutora-up rolls. Kupararira kunofanirwa kuve nechokwadi sepedyo sezvinobvira kunzvimbo yekuputira. FlexSpreader inopfeka zvakanaka-maronda idler rolls isati yapepereswa uye inobatsira kudzikisa kutsvedza kunotsvedza hurema kana uchimonereka nekupokana kwakanyanya.
Dzidza zvakawanda Chinyorwa ichi chinotsanangura zvimwe zvemipumburu zvinokanganisika zvinogona kukonzerwa nekuomarara kwakashata. Iyo itsva The Ultimate Roll uye Webhu Defect Troubleshooting Guide inoita kuti zvive nyore kuziva nekugadzirisa izvi uye zvimwe roll uye webhu kukanganisa. Iri bhuku ishanduro yakagadziridzwa uye yakawedzerwa yeinotengeswa Roll uye Webhu Defect Glossary neTAPPI Press.
Iyo Enhanced Edition yakanyorwa uye yakagadziridzwa ne22 nyanzvi dzeindasitiri ine anopfuura 500 makore echiitiko mune reel uye mhepo. Inowanikwa kuburikidza neTAPPI, tinya pano.
R. Duane Smith is the Specialty Winding Manager for Davis-Standard, LLC in Fulton, New York. With over 43 years of experience in the industry, he is known for his expertise in coil handling and winding. He received two winding patents. Smith has given over 85 technical presentations and published over 30 articles in major international trade journals. Contacts: (315) 593-0312; dsmith@davis-standard.com; davis-standard.com.
Mari yemidziyo ndiyo yakakura mutengo wezvinhu zvakawanda zvakawedzerwa, saka ma processor anofanirwa kukurudzirwa kudzikisa mitengo iyi.
Chidzidzo chitsva chinoratidza kuti rudzi uye huwandu hweLDPE hwakasanganiswa neLLDPE hunokanganisa sei kugadzirisa uye kusimba / kuomarara zvivakwa zvefirimu rinoputika. Data inoratidzwa ndeyemusanganiswa wakafumiswa neLDPE neLLDPE.
Kudzoreredza kugadzirwa mushure mekugadzirisa kana kugadzirisa dambudziko kunoda kushanda nesimba. Heano maitiro ekugadzirisa mapepa ekushanda uye kuasimudza uye kumhanya nekukurumidza sezvinobvira.
Nguva yekutumira: Mar-24-2023
