Focus on Cellulose ethers

Ukubaluleka kwe-hydroxypropyl methylcellulose (HPMC) odakeni oluxubile

Igama lesiShayina le-HPMC yi-hydroxypropyl methylcellulose. Ayiyona i-ionic futhi ivame ukusetshenziswa njenge-ejenti egcina amanzi odakeni oluxutshwe okomile. Kuyinto esetshenziswa kakhulu ukugcina amanzi odakeni. Umkhiqizo we-ether osuselwe ku-polysaccharide okhiqizwa i-alkalization kanye ne-etherification. Ayinayo inkokhiso ngokwayo, ayiphenduli ngama-ion ashajiwe ku-gelling material, futhi inokusebenza okuzinzile. Intengo futhi iphansi kunezinye izinhlobo ze-cellulose ethers, ngakho-ke isetshenziswa kakhulu odakeni oluxutshwe okomile.

Umsebenzi we-hydroxypropyl methylcellulose: Ingajiya udaka olusanda kuxutshwa ukuze lube ne-viscosity ethile emanzi futhi ivimbele ukuhlukaniswa. (Ukuqina) Ukugcinwa kwamanzi kuyisici esibaluleke kakhulu, esiza ukugcina inani lamanzi amahhala odakeni, ukuze ngemva kokwakhiwa kodaka, izinto zikasimende zibe nesikhathi esengeziwe sokudonsa amanzi. (Ukugcinwa kwamanzi) Inezici zokungenisa umoya, ezingakwazi ukwethula amabhamuza afanayo kanye namabhamuza amahle ukuze kuthuthukiswe ukwakhiwa kodaka.

Ukuphakama kwe-viscosity ye-hydroxypropyl methylcellulose ether, kuba ngcono ukusebenza kokugcinwa kwamanzi. Ngomkhiqizo ofanayo, imiphumela ye-viscosity elinganiswa ngezindlela ezahlukene ihluke kakhulu, futhi eminye inomehluko ophindwe kabili. Ngakho-ke, lapho uqhathanisa i-viscosity, kufanele yenziwe phakathi kwezindlela ezifanayo zokuhlola, kufaka phakathi izinga lokushisa, i-rotor, njll.

Mayelana nosayizi wezinhlayiyana, ukucoleka kwezinhlayiyana, kuba ngcono nokugcinwa kwamanzi. Ngemva kokuba izinhlayiya ezinkulu ze-cellulose ether zihlangana namanzi, indawo engaphezulu iyancibilika ngokushesha futhi yakhe ijeli ukuze igoqe into ukuvimbela ama-molecule amanzi ukuthi angaqhubeki nokungena. Ngezinye izikhathi ayikwazi ukuhlakazwa ngokufanayo futhi incibilike ngisho nangemva kokunyakaziswa kwesikhathi eside, kwakheka ikhambi eliguqubele le-flocculent noma i-agglomeration. Kuthinta kakhulu ukugcinwa kwamanzi kwe-cellulose ether, futhi ukuncibilika kungenye yezici zokukhetha i-cellulose ether. I-Fineness futhi iyinkomba yokusebenza ebalulekile ye-methyl cellulose ether. I-MC esetshenziselwa udaka lwempushana eyomile iyadingeka ukuthi ibe yimpushana, enokuqukethwe kwamanzi aphansi, futhi ukucoleka kudinga u-20% -60% wesayizi wezinhlayiyana ukuba ube ngaphansi kuka-63um. Ukucoleka kuthinta ukunyibilika kwe-hydroxypropyl methylcellulose ether. I-coarse MC ivamise ukuba yi-granular, futhi kulula ukuyincibilika emanzini ngaphandle kwe-agglomeration, kodwa izinga lokuhlakazeka lihamba kancane, ngakho-ke alifanelekile ukusetshenziswa kudaka oluyimpushana. Odakeni lwempushana eyomile, i-MC ihlakazeka phakathi kwezinto zikasimende njenge-aggregate, isigcwalisi esihle nosimende, futhi impushana enhle kuphela eyanele engagwema i-methyl cellulose ether agglomeration lapho ixutshwa namanzi.

Ngokuvamile, ukuphakama kwe-viscosity, kuba ngcono umphumela wokugcina amanzi. Kodwa-ke, ukuphakama kwe-viscosity futhi ukuphakama kwesisindo samangqamuzana e-MC, ukwehla okuhambisanayo kokuncibilika kwawo kuzoba nomthelela omubi emandleni nokusebenza kokwakhiwa kodaka. Ukuphakama kwe-viscosity, kusobala kakhulu umphumela wokuqina odongeni, kodwa awulingani ngokuqondile. Ukuphakama kwe-viscosity, i-viscous yodaka olumanzi luyoba ngaphezulu, okungukuthi, ngesikhathi sokwakhiwa, kubonakala njengokunamathela ku-scraper nokunamathela okuphezulu ku-substrate. Kodwa akusizi ukwandisa amandla esakhiwo sodaka olumanzi ngokwalo. Okusho ukuthi, ngesikhathi sokwakhiwa, ukusebenza kwe-anti-sag akubonakali. Ngokuphambene, i-viscosity ethile emaphakathi nephansi kodwa eshintshiwe ye-methyl cellulose ethers inokusebenza okuhle kakhulu ekuthuthukiseni amandla esakhiwo sodaka olumanzi.

Ukugcinwa kwamanzi kwe-HPMC nakho kuhlobene nezinga lokushisa elisetshenzisiwe, futhi ukugcinwa kwamanzi kwe-methyl cellulose ether kuncipha ngokunyuka kwezinga lokushisa. Kodwa-ke, ekusetshenzisweni kwezinto zangempela, udaka lwempushana olomile luvame ukusetshenziswa ezindaweni ezishisayo emazingeni okushisa aphezulu (angaphezu kwama-degrees angu-40) ezindaweni eziningi, njengokupulasikwa kwe-putty yangaphandle ngaphansi kwelanga ehlobo, okuvame ukusheshisa Ukuphulukiswa kukasimende kanye ukuqina kodaka lwempuphu eyomile. Ukwehla kwezinga lokugcinwa kwamanzi kuholela emuzweni osobala wokuthi kokubili ukusebenza nokumelana nokuqhekeka kuyathinteka, futhi kubaluleke kakhulu ukunciphisa umthelela wezici zokushisa ngaphansi kwalesi simo. Mayelana nalokhu, izithasiselo ze-methyl hydroxyethyl cellulose ether njengamanje zibhekwa njengezihamba phambili ekuthuthukisweni kobuchwepheshe. Nakuba inani le-methyl hydroxyethyl cellulose linyusiwe (ifomula yasehlobo), ukusebenza kahle nokumelana nokuqhekeka akukakwazi ukuhlangabezana nezidingo zokusetshenziswa. Ngokuphathwa okuthile okukhethekile ku-MC, njengokwandisa izinga le-etherification, njll., umphumela wokugcina amanzi ungagcinwa ezingeni lokushisa eliphezulu, ukuze ukwazi ukunikeza ukusebenza okungcono ngaphansi kwezimo ezinzima.

Ngokuvamile, i-HPMC inezinga lokushisa lejeli, elingahlukaniswa cishe libe izinhlobo ezingama-60, izinhlobo ezingama-65, nezinhlobo ezingama-75. Emabhizinisini asebenzisa isihlabathi somfula udaka olujwayelekile oluxubekile, kungcono ukusebenzisa i-HPMC yohlobo lwe-75 enezinga lokushisa eliphezulu lejeli. Umthamo we-HPMC akufanele ube phezulu kakhulu, ngaphandle kwalokho uzokwandisa isidingo samanzi osimende, uzonamathela ku-trowel, futhi isikhathi sokumisa sizoba side kakhulu, okuzothinta ukwakhiwa. Imikhiqizo ehlukene yodaka isebenzisa i-HPMC enamaviscosity ahlukene, futhi ayisebenzisi i-HPMC ene-viscosity ephezulu ngokunganaki. Ngakho-ke, nakuba imikhiqizo ye-hydroxypropyl methylcellulose imihle, ishayelwa ihlombe uma isetshenziswe kahle. Ukukhetha i-HPMC efanele kuwumthwalo wemfanelo oyinhloko wabasebenzi baselabhorethri yebhizinisi.


Isikhathi sokuthumela: Apr-07-2023
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