Dzina lachi China la HPMC ndi hydroxypropyl methylcellulose. Ndiwopanda ionic ndipo nthawi zambiri amagwiritsidwa ntchito ngati chosungira madzi mumatope osakaniza owuma. Ndizomwe zimagwiritsidwa ntchito kwambiri posunga madzi mumatope.
Kapangidwe ka HPMC makamaka ndi polysaccharide-based ether product opangidwa ndi alkalization ndi etherification wa thonje fiber (zapakhomo). Zilibe mtengo wokha, sizimayenderana ndi ma ion opangidwa mu gelling, ndipo zimakhala zokhazikika. Mtengowu umakhalanso wotsika kuposa mitundu ina ya ma cellulose ethers, choncho amagwiritsidwa ntchito kwambiri mumatope osakaniza owuma.
Ntchito ya hydroxypropyl methylcellulose: Imatha kukulitsa matope osakanikirana kuti akhale ndi kukhuthala konyowa ndikuletsa tsankho. (Thickening) Kusungirako madzi ndi khalidwe lofunika kwambiri, lomwe limathandiza kusunga madzi aulere mumatope, kotero kuti matope atapangidwa, zinthu za simenti zimakhala ndi nthawi yochuluka ya hydrate. (Water retention) Lili ndi zinthu zolowetsa mpweya, zomwe zimatha kuyambitsa yunifolomu komanso mpweya wabwino kuti upangitse kupanga matope.
Kukwezera kukhuthala kwa hydroxypropyl methylcellulose ether, kumapangitsa kuti madzi asungidwe bwino. Viscosity ndi gawo lofunikira la magwiridwe antchito a HPMC. Pakali pano, opanga osiyana HPMC ntchito njira zosiyanasiyana ndi zida kuyeza mamasukidwe akayendedwe a HPMC. Njira zazikulu ndi HaakeRotovisko, Hoppler, Ubbelohde ndi Brookfield.
Kwa mankhwala omwewo, zotsatira za viscosity zoyezedwa ndi njira zosiyanasiyana ndizosiyana kwambiri, ndipo zina zimakhala zosiyana kawiri. Choncho, poyerekeza mamasukidwe akayendedwe, ziyenera kuchitidwa pakati pa njira zoyesera zomwezo, kuphatikizapo kutentha, rotor, ndi zina zotero. Ponena za kukula kwa tinthu, tinthu tating'onoting'ono, timasunga bwino madzi. Pambuyo pa tinthu tating'ono ta cellulose ether takumana ndi madzi, pamwamba pake nthawi yomweyo amasungunuka ndikupanga gel osakaniza kuti ateteze mamolekyu amadzi kuti asapitirire kulowa. Nthawi zina sangathe kumwazikana mofanana ndi kusungunuka ngakhale atagwedezeka kwa nthawi yaitali, kupanga njira yothetsera mitambo kapena agglomeration. Zimakhudza kwambiri kusungidwa kwamadzi kwa cellulose ether, ndipo kusungunuka ndi chimodzi mwazinthu zomwe zimasankha cellulose ether.
Fineness ndiwonso index yofunikira ya methyl cellulose ether. The MC ntchito youma ufa matope chofunika kukhala ufa, ndi okhutira madzi otsika, ndi fineness amafunanso 20% ~ 60% ya tinthu kukula kukhala zosakwana 63um. Kuchita bwino kumakhudza kusungunuka kwa hydroxypropyl methylcellulose ether. Coarse MC nthawi zambiri imakhala granular, ndipo ndiyosavuta kusungunuka m'madzi popanda agglomeration, koma kusungunuka kumakhala pang'onopang'ono, kotero sikoyenera kugwiritsidwa ntchito mumatope a ufa wouma.
Mu matope owuma a ufa, MC imamwazikana pakati pa zinthu zopangira simenti monga zophatikiza, zodzaza bwino ndi simenti, ndipo ufa wokwanira wokwanira ungapewe methyl cellulose ether agglomeration mukasakaniza ndi madzi. Pamene MC ikuwonjezeredwa ndi madzi kuti asungunuke ma agglomerates, zimakhala zovuta kwambiri kumwazikana ndi kupasuka. Coarse fineness wa MC sikungowononga, komanso kumachepetsa mphamvu yakomweko ya matope. Pamene matope owuma owuma akugwiritsidwa ntchito m'dera lalikulu, kuthamanga kwa machiritso a matope owuma a m'deralo kudzachepetsedwa kwambiri, ndipo ming'alu idzawoneka chifukwa cha nthawi zosiyanasiyana zochiritsira. Kwa matope opopera omwe amapangidwa ndi makina, kufunikira kwa fineness ndipamwamba chifukwa cha nthawi yochepa yosakaniza. Nthawi zambiri, kukwezeka kwa mamachulukidwe kumapangitsa kuti madzi asungidwe bwino. Komabe, kukwezeka kwa mamachulukidwe apamwamba komanso kulemera kwa mamolekyu a MC, kutsika kofananirako kusungunuka kwake kudzakhala ndi zotsatira zoyipa pamphamvu ndi ntchito yomanga ya matope.
The apamwamba mamasukidwe akayendedwe, ndi zoonekeratu kwambiri thickening zotsatira pa matope, koma si mwachindunji molingana. Kukwera kwa mamasukidwe akayendedwe, m'pamenenso matope onyowa amakhala owoneka bwino kwambiri, ndiye kuti, pakumanga, amawonetsedwa ngati kumamatira ku scraper ndi kumamatira kwakukulu ku gawo lapansi. Koma sizothandiza kuwonjezera mphamvu zamapangidwe a dothi lonyowa palokha. Ndiko kuti, panthawi yomanga, ntchito yotsutsa-sag sizowonekera. M'malo mwake, ma viscosity ena apakati komanso otsika koma osinthidwa a methyl cellulose ethers ali ndi ntchito yabwino kwambiri pakuwongolera mphamvu zamapangidwe amatope onyowa.
Kusungidwa kwa madzi kwa HPMC kumagwirizananso ndi kutentha komwe kumagwiritsidwa ntchito, ndipo kusunga madzi kwa methyl cellulose ether kumachepa ndi kuwonjezeka kwa kutentha. Komabe, muzinthu zenizeni, matope a ufa wowuma nthawi zambiri amagwiritsidwa ntchito kumalo otentha kwambiri (oposa madigiri 40) m'madera ambiri, monga kunja kwa khoma la putty pulasitala pansi pa dzuwa m'chilimwe, zomwe nthawi zambiri zimathandizira Kuchiritsa simenti ndi kuumitsa kwa simenti. ufa wouma matope. Kutsika kwa kuchuluka kwa madzi osungira madzi kumabweretsa kumverera koonekeratu kuti zonse zogwira ntchito komanso kukana kwa ming'alu zimakhudzidwa, ndipo ndizofunikira kwambiri kuchepetsa mphamvu ya kutentha pansi pa chikhalidwe ichi.
Pachifukwa ichi, zowonjezera za methyl hydroxyethyl cellulose ether panopa zimaganiziridwa kuti zili patsogolo pa chitukuko chaukadaulo. Ngakhale kuchuluka kwa methyl hydroxyethyl cellulose kumachulukitsidwa (chilinganizo cha chilimwe), kugwira ntchito ndi kukana kwa crack sikungakwaniritse zosowa zogwiritsidwa ntchito. Kupyolera mu chithandizo chapadera pa MC, monga kuonjezera mlingo wa etherification, ndi zina zotero, zotsatira zosungira madzi zimatha kusungidwa pa kutentha kwakukulu, kotero kuti zitha kupereka ntchito yabwino pansi pa zovuta.
Mlingo wa HPMC suyenera kukhala wokwera kwambiri, mwinamwake udzawonjezera kufunikira kwa madzi a matope, kumamatira ku trowel, ndipo nthawi yoikika idzakhala yaitali kwambiri, zomwe zidzakhudza kumangidwanso. Zogulitsa zosiyanasiyana zamatope zimagwiritsa ntchito HPMC yokhala ndi ma viscosities osiyanasiyana, ndipo musagwiritse ntchito kukhuthala kwakukulu kwa HPMC mwachisawawa. Choncho, ngakhale mankhwala a hydroxypropyl methylcellulose ndi abwino, amayamikiridwa akagwiritsidwa ntchito bwino. Kusankha HPMC yoyenera ndi udindo waukulu wa ogwira ntchito mu labotale. Pakadali pano, ogulitsa ambiri osakhulupirika akuphatikiza HPMC, ndipo khalidweli ndi losauka kwambiri. Posankha cellulose inayake, labotale iyenera kuchita ntchito yabwino pakuyesa kutsimikizira kukhazikika kwa chinthu chamatope, ndipo musakhale aumbombo wotchipa ndikupangitsa kutaya kosafunikira.
Nthawi yotumiza: Dec-16-2022