Ibiti n'ibyuma karemano byabaye ibikoresho by'ingenzi mu bwubatsi ku bantu mu myaka ibihumbi ishize. Polymeri zikozwe mu buryo bw'ubukorano twita pulasitiki ni ibintu biherutse kuvumburwa byaturitse mu kinyejana cya 20.
Ibyuma na pulasitiki byombi bifite imiterere ikwiriye gukoreshwa mu nganda no mu bucuruzi. Ibyuma birakomeye, birakomeye, kandi muri rusange bihangana n'umwuka, amazi, ubushyuhe, n'umuvuduko uhoraho. Ariko, bisaba kandi amikoro menshi (bivuze ko bihenze cyane) kugira ngo bikore kandi binoze ibicuruzwa byabyo. Plasitike itanga imwe mu mirimo y'ibyuma mu gihe isaba uburemere buke kandi ihendutse cyane kubikora. Imiterere yabyo ishobora guhindurwa kugira ngo ikoreshwe hafi ya byose. Ariko, pulasitiki zihendutse zikora ibikoresho bibi cyane: ibikoresho bya pulasitiki si ikintu cyiza, kandi nta muntu ushaka kuba mu nzu ya pulasitiki. Byongeye kandi, akenshi bitunganywa n'ibicanwa.
Mu bikorwa bimwe na bimwe, imbaho karemano zishobora guhangana n'ibyuma na pulasitiki. Ingo nyinshi z'imiryango zubatswe ku mbaho. Ikibazo ni uko imbaho karemano zoroshye cyane kandi zoroshye kwangirika n'amazi ku buryo akenshi zitashoboraga gusimbura pulasitiki n'ibyuma. Inyandiko iherutse gusohoka mu kinyamakuru Matter ivuga ku ikorwa ry'ibikoresho bikomeye by'imbaho bitsinda izo mbogamizi. Ubu bushakashatsi bwarangiye hakozwe ibyuma n'imisumari by'imbaho. Ese icyuma cy'imbaho ni cyiza gute kandi uzagikoresha vuba aha?
Imiterere y’ibiti ifite uduce duto igizwe na selulosi hafi 50%, polymer karemano ifite ubushobozi bwo gukomera neza. Igice gisigaye cy’imiterere y’ibiti ahanini ni lignin na hemicellulose. Nubwo selulosi ikora uduce turerure kandi dukomeye dutanga igiti urufatiro rw’imbaraga zacyo karemano, hemicellulose ifite imiterere mike cyane bityo ntacyo itanga ku mbaraga z’igiti. Lignin yuzuza icyuho kiri hagati y’uduce duto twa selulosi kandi igakora imirimo y’ingirakamaro ku giti. Ariko kugira ngo abantu bafatanye ibiti no guhuza imiyoboro ya selulosi kurushaho, lignin yabaye imbogamizi.
Muri ubu bushakashatsi, ibiti karemano byakozwe mu giti gikomeye (HW) mu ntambwe enye. Ubwa mbere, ibiti bitekwa muri sodium hydroxide na sodium sulfate kugira ngo bikureho bimwe muri hemicellulose na lignin. Nyuma y’ubu buryo bwo kuvura imiti, ibiti birushaho kuba byinshi iyo bikandagiye mu gikoni mu gihe cy’amasaha menshi ku bushyuhe bw’icyumba. Ibi bigabanya icyuho cyangwa imyenge karemano mu giti kandi byongera uburyo imiti ihuza imigozi ya selulose yegeranye. Hanyuma, ibiti bishyirwamo igitutu kuri 105° C (221° F) mu gihe cy’amasaha make kugira ngo birunduke burundu, hanyuma byumishwe. Amaherezo, ibiti bishyirwa mu mavuta ya minerale mu gihe cy’amasaha 48 kugira ngo umusaruro urangiye udapfa amazi.
Imwe mu miterere y’ibikoresho by’ubwubatsi ni ubukana bw’inyongera, ari na cyo gipimo cy’ubushobozi bwabyo bwo kurwanya ubukana iyo bikandagiwe n’imbaraga. Diyama irakomeye kurusha icyuma, irakomeye kurusha zahabu, irakomeye kurusha igiti, kandi irakomeye kurusha ifuro ryo gupakira. Mu bizamini byinshi by’ubuhanga bikoreshwa mu kumenya ubukana, nk’ubukana bwa Mohs bukoreshwa muri gemology, ikizamini cya Brinell ni kimwe muri byo. Igitekerezo cyacyo ni cyoroshye: umupira ukomeye w’icyuma ushyirwa ku buso bw’ikizamini hakoreshejwe imbaraga runaka. Pima umurambararo w’inyongera uruziga yakozwe n’umupira. Agaciro k’ubukana bwa Brinell kabarwa hakoreshejwe formula ya mibare; mu buryo burambuye, uko umwobo umupira ukubita ni ko ibikoresho byoroha. Muri iki kizamini, HW irakomeye inshuro 23 kurusha ibiti karemano.
Ibiti karemano byinshi bitavuwe bizamura amazi. Ibi bishobora kwagura ibiti ndetse bigasenya imiterere yabyo. Abanditsi bakoresheje imyunyu ngugu mu minsi ibiri kugira ngo bongere ubushobozi bwo kwirinda amazi bwa HW, bigatuma irushaho kuba mbi ku mazi ("gutinya amazi"). Ikizamini cyo kudatinya amazi gikubiyemo gushyira igitonyanga cy'amazi ku buso. Uko ubuso burushaho kudatinya amazi, ni ko ibitonyanga by'amazi birushaho kuba uruziga. Ku rundi ruhande, ubuso bukunda amazi ("bukunda amazi") bukwirakwiza ibitonyanga mu buryo burambuye (kandi nyuma bugakurura amazi byoroshye). Kubwibyo, kuroba amabuye y'agaciro ntabwo byongera gusa ubushobozi bwo kudatinya amazi bwa HW, ahubwo binabuza igiti kwinjiza amazi mu buryo buhagije.
Mu bizamini bimwe na bimwe by’ubuhanga, ibyuma bya HW byakoze neza gato kurusha ibyuma by’icyuma. Abanditsi bavuga ko icyuma cya HW gityaye inshuro eshatu kurusha icyuma kigurishwa. Ariko, hari icyo umuntu yakwitaho kuri iki gisubizo gishimishije. Abashakashatsi barimo kugereranya ibyuma byo ku meza, cyangwa icyo twakwita ibyuma by’amavuta. Ibi ntibigenewe kuba bityaye cyane. Abanditsi berekana videwo y’icyuma cyabo batema inyama, ariko umuntu mukuru ukomeye ashobora gukata inyama imwe n’uruhande rudakomeye rw’icyuma, kandi icyuma cya nyama cyakora neza cyane.
Bite se ku byerekeye imisumari? Umusumari umwe wa HW ushobora gukubitwa byoroshye mu murundo w'imbaho eshatu, nubwo utari mu buryo burambuye nkuko byoroshye ugereranije n'imisumari y'icyuma. Imisumari y'imbaho ishobora gufata imbaho hamwe, ikarwanya imbaraga zashoboraga kuzicamo ibice, ifite imbaraga zingana n'iz'ibyuma. Ariko, mu bizamini byabo, imbaho zombi zarananiwe mbere yuko umusumari umwe unanirwa, bityo imisumari ikomeye ntiyagaragaye.
Ese imisumari ya HW ni myiza mu bundi buryo? Imisumari y'ibiti ni yoroshye, ariko uburemere bw'inyubako ntabwo buterwa ahanini n'uburemere bw'imisumari iyifata. Imisumari y'ibiti ntizagwa ingese. Ariko, ntabwo izapfa kuvogerwa n'amazi cyangwa ngo ibore.
Nta gushidikanya ko umwanditsi yashyizeho inzira yo gutuma ibiti bikomera kurusha ibiti bisanzwe. Ariko, akamaro k'ibikoresho ku murimo uwo ari wo wose gasaba inyigo yimbitse. Ese bishobora kuba bihendutse kandi bidafite umutungo nk'uwa pulasitiki? Ese bishobora guhangana n'ibintu bikomeye, byiza cyane, kandi bishobora kongera gukoreshwa mu byuma bitagira iherezo? Ubushakashatsi bwabo butera ibibazo bishimishije. Ubuhanga bukomeje (kandi amaherezo isoko) buzabisubiza.
Igihe cyo kohereza: 13 Mata 2022
