1. Ntchito yaikulu ya efa ya cellulose
Mu matope osakaniza bwino, cellulose ether ndi chowonjezera chachikulu chomwe chimawonjezedwa pang'ono kwambiri koma chingathandize kwambiri ntchito ya matope onyowa ndikukhudza momwe matope amagwirira ntchito.
2. Mitundu ya ma ether a cellulose
Kupanga kwa efa ya cellulose kumapangidwa makamaka ndi ulusi wachilengedwe kudzera mu kusungunuka kwa alkali, kulumikiza (etherification), kutsuka, kuumitsa, kupera ndi njira zina.
Malinga ndi zipangizo zazikulu zopangira, ulusi wachilengedwe ukhoza kugawidwa m'magulu awa: ulusi wa thonje, ulusi wa mkungudza, ulusi wa beech, ndi zina zotero. Madigiri awo a polymerization amasiyana, zomwe zimakhudza kukhuthala komaliza kwa zinthu zawo. Pakadali pano, opanga ma cellulose akuluakulu amagwiritsa ntchito ulusi wa thonje (wopangidwa ndi nitrocellulose) ngati zinthu zazikulu zopangira.
Ma cellulose ethers amatha kugawidwa m'magulu a ionic ndi nonionic. Mtundu wa ionic umaphatikizapo mchere wa carboxymethyl cellulose, ndipo mtundu wosakhala ionic umaphatikizapo makamaka methyl cellulose, methyl hydroxyethyl (propyl) cellulose, hydroxyethyl cellulose, ndi zina zotero.
Pakadali pano, ma ether a cellulose omwe amagwiritsidwa ntchito mu matope osakanikirana bwino ndi methyl cellulose ether (MC), methyl hydroxyethyl cellulose ether (MHEC), methyl hydroxypropyl cellulose ether (MHPG), hydroxypropyl Methyl cellulose ether (HPMC). Mu matope osakanikirana bwino, chifukwa ionic cellulose (carboxymethyl cellulose salt) ndi yosakhazikika pamaso pa calcium ions, sagwiritsidwa ntchito kawirikawiri muzinthu zosakanikirana bwino zomwe zimagwiritsa ntchito simenti, laimu wosweka, ndi zina zotero ngati zinthu zomangira simenti. M'malo ena ku China, mchere wa carboxymethyl cellulose umagwiritsidwa ntchito ngati chokhuthala cha zinthu zina zamkati zomwe zimapangidwa ndi starch yosinthidwa ngati chinthu chachikulu chomangira simenti ndi ufa wa Shuangfei ngati chodzaza. Chogulitsachi chimakonda kugwidwa ndi bowa ndipo sichimalimbana ndi madzi, ndipo tsopano chikuchotsedwa. Hydroxyethyl cellulose imagwiritsidwanso ntchito muzinthu zina zosakanikirana bwino, koma ili ndi gawo laling'ono pamsika.
3. Zizindikiro zazikulu za ntchito ya efa ya cellulose
(1) Kusungunuka
Cellulose ndi polyhydroxy polymer compound yomwe siisungunuka kapena kusungunuka. Pambuyo pa etherification, cellulose imasungunuka m'madzi, imachepetsa alkali solution ndi organic solvent, ndipo imakhala ndi thermoplasticity. Kusungunuka kumadalira makamaka zinthu zinayi: choyamba, kusungunuka kumasiyana ndi kukhuthala, kukhuthala kutsika, kusungunuka kumakhala kwakukulu. Chachiwiri, makhalidwe a magulu omwe ayambitsidwa mu ndondomeko ya etherification, gulu lomwe layambitsidwa likukula, kusungunuka kumakhala kochepa; gulu lomwe layambitsidwa polar kwambiri, kusungunuka kwa cellulose ether kumakhala kosavuta m'madzi. Chachitatu, kuchuluka kwa kusintha ndi kufalikira kwa magulu a ether mu macromolecules. Ma cellulose ether ambiri amatha kusungunuka m'madzi pokhapokha ngati pali gawo linalake losintha. Chachinayi, kuchuluka kwa polymerization ya cellulose ether, kuchuluka kwa polymerization, kusungunuka kochepa; kuchepa kwa polymerization, kukulitsa kuchuluka kwa digiri ya kusintha komwe kungasungunuke m'madzi.
(2) Kusunga madzi
Kusunga madzi ndi ntchito yofunika kwambiri ya cellulose ether, ndipo ndi ntchito yomwe opanga ufa wouma ambiri m'nyumba, makamaka omwe ali m'madera akum'mwera komwe kutentha kwambiri, amasamala. Zinthu zomwe zimakhudza mphamvu yosunga madzi ya matope ndi monga kuchuluka kwa cellulose ether yomwe yawonjezeredwa, kukhuthala, kusalala kwa tinthu tating'onoting'ono ndi kutentha kwa malo ogwiritsidwa ntchito. Kuchuluka kwa cellulose ether yomwe yawonjezeredwa, kumakhala bwino kwambiri; kukhuthala kwakukulu, kumakhala bwino kwambiri; tinthu tating'onoting'ono tikamasungunuka, kumakhala bwino kwambiri.
(3) Kukhuthala
Kukhuthala ndi gawo lofunika kwambiri la zinthu za cellulose ether. Pakadali pano, opanga ma cellulose ether osiyanasiyana amagwiritsa ntchito njira ndi zida zosiyanasiyana poyesa kukhuthala. Pa chinthu chomwecho, zotsatira za kukhuthala zomwe zimayesedwa ndi njira zosiyanasiyana zimakhala zosiyana kwambiri, ndipo zina zimakhala ndi kusiyana kawiri. Chifukwa chake, poyerekeza kukhuthala, ziyenera kuchitika pakati pa njira zomwezo zoyesera, kuphatikizapo kutentha, rotor, ndi zina zotero.
Kawirikawiri, kukhuthala kwa madzi kukakhala kwakukulu, kumakhala bwino kwambiri. Komabe, kukhuthala kwa madzi kukakhala kwakukulu, kulemera kwa maselo a cellulose ether kumakhala kwakukulu, ndipo kuchepa kofanana kwa kusungunuka kwake kudzakhala ndi zotsatira zoyipa pa mphamvu ndi magwiridwe antchito a matope. Kukhuthala kwa madzi kukakhala kwakukulu, kukhuthala kwa matope kumakhala koonekera bwino, koma sikufanana mwachindunji. Kukhuthala kwa madzi kukakhala kwakukulu, kukhuthala kwa matope onyowa kumakhala kolimba kwambiri. Pakumanga, kumaonekera ngati kumamatira ku scraper ndi kumamatira kwambiri ku substrate. Koma sizothandiza kuwonjezera mphamvu ya matope onyowa okha. Pakumanga, mphamvu yotsutsana ndi kusagwa siidziwika. M'malo mwake, ma ether ena apakatikati ndi otsika koma osinthidwa a methyl cellulose ali ndi magwiridwe antchito abwino kwambiri pakukweza mphamvu ya matope onyowa.
(4) Kusalala kwa tinthu tating'onoting'ono:
Cellulose ether yomwe imagwiritsidwa ntchito pa matope osakaniza bwino imafunika kukhala ufa, wokhala ndi madzi ochepa, ndipo kusalala kwake kumafunanso 20% mpaka 60% ya kukula kwa tinthu kuti ikhale yochepera 63 μm. Kusalala kumeneku kumakhudza kusungunuka kwa ether ya cellulose. Ma ether a coarse cellulose nthawi zambiri amakhala ngati ma granules, omwe ndi osavuta kufalitsa ndi kusungunuka m'madzi popanda kusonkhana, koma kuchuluka kwa kusungunuka kumakhala kochedwa kwambiri, kotero sikoyenera kugwiritsidwa ntchito mu matope osakaniza bwino (zinthu zina zapakhomo zimakhala zosalala, sizosavuta kufalitsa ndi kusungunuka m'madzi, ndipo zimakhala zosavuta kuziyika). Mu matope osakaniza bwino, ether ya cellulose imafalikira pakati pa ma aggregates, fillers zabwino ndi simenti ndi zinthu zina zomangira simenti. Ufa wokwanira wokha ndi womwe ungapewe kusonkhana kwa ether ya cellulose ikasakanikirana ndi madzi. Cellulose ether ikawonjezedwa ndi madzi kuti isungunuke, zimakhala zovuta kwambiri kufalitsa ndi kusungunuka.
(5) Kusintha kwa ether ya cellulose
Kusintha kwa ether ya cellulose ndiko kukulitsa magwiridwe ake, ndipo ndi gawo lofunika kwambiri. Makhalidwe a ether ya cellulose amatha kukonzedwa kuti azitha kunyowa, kufalikira, kumamatira, kukhuthala, kusakaniza, kusunga madzi ndi kupanga filimu, komanso kusalowerera mafuta.
4. Zotsatira za kutentha kwa malo ozungulira pa kusunga madzi mu matope
Kusunga madzi kwa cellulose ether kumachepa ndi kuwonjezeka kwa kutentha. Mu ntchito zothandiza, matope nthawi zambiri amagwiritsidwa ntchito pa zinthu zotentha pa kutentha kwambiri (koposa 40°C) m'malo ambiri. Kutsika kwa kusunga madzi kunapangitsa kuti ntchito igwire bwino ntchito komanso kukana ming'alu. Kudalira kutentha kudzapangitsa kuti matope ayambe kufooka, ndipo ndikofunikira kwambiri kuchepetsa mphamvu ya kutentha pansi pa vutoli. Maphikidwe a matope adasinthidwa moyenera, ndipo kusintha kwakukulu kunapangidwa m'maphikidwe a nyengo. Ngakhale kuti kuchuluka kwa mlingo (njira yachilimwe), kulimba kwa ntchito ndi kukana ming'alu sikungakwaniritse zosowa zogwiritsidwa ntchito, zomwe zimafuna chithandizo chapadera cha cellulose ether, monga kuwonjezera kuchuluka kwa etherification, ndi zina zotero, kuti mphamvu yosunga madzi ikwaniritsidwe pa kutentha kwakukulu. Imasunga mphamvu yabwino ikakhala yokwera, kotero kuti imapereka magwiridwe antchito abwino m'mikhalidwe yovuta.
5. Kugwiritsa ntchito mu matope osakaniza kale
Mu matope osakaniza bwino, cellulose ether imagwira ntchito yosunga madzi, kukhuthala komanso kukonza magwiridwe antchito omanga. Kugwira bwino ntchito yosunga madzi kumatsimikizira kuti matopewo sadzayambitsa kuchekeka, kupukutidwa ndi ufa komanso kuchepetsa mphamvu chifukwa cha kusowa kwa madzi komanso kusakwanira kwa madzi. Kukhuthala kumeneku kumawonjezera kwambiri mphamvu ya matope onyowa. Kuwonjezera kwa cellulose ether kumatha kusintha kwambiri kukhuthala kwa matope onyowa, ndipo kumakhala ndi kukhuthala kwabwino kuzinthu zosiyanasiyana, motero kumawongolera magwiridwe antchito a khoma la matope onyowa ndikuchepetsa zinyalala. Kuphatikiza apo, ntchito ya cellulose ether m'zinthu zosiyanasiyana ndi yosiyana. Mwachitsanzo, mu zomatira za matailosi, cellulose ether imatha kuwonjezera nthawi yotsegulira ndikusintha nthawi; mu matope opopera ndi makina, imatha kusintha mphamvu ya matope onyowa; pakudzilinganiza, imatha kuletsa kukhazikika, Kulekanitsa ndi kugawa. Chifukwa chake, monga chowonjezera chofunikira, cellulose ether imagwiritsidwa ntchito kwambiri mu matope owuma.
Nthawi yotumizira: Januwale-11-2023