HPMC (hydroxypropyl methylcellulose) chinhu chinowedzera chinoshanda uye chinoshandiswa zvakanyanya mukugadzira mapendi nependi. Rimwe remabasa ayo makuru nderekuwedzera viscosity control, iyo isingangogadzirise rheology yekupfeka uye pendi, asi zvakare inovandudza kuita kwekuvaka uye yekupedzisira firimu mhando.
1. Zvinhu zvakakosha zveHPMC
HPMC isiri-ionic cellulose ether ine mvura yakanaka yekunyungudika uye organic solvent solubility. Inogona kunyungudika uye kuumba yakagadzikana colloidal mhinduro patembiricha dzakasiyana uye pH kukosha. Iyo huru meshini yekuita yeHPMC ndeyekugadzira network chimiro kuburikidza neintermolecular hydrogen bond uye van der Waals masimba, nekudaro kukanganisa rheological zvimiro zvejasi kana pendi. Viscosity yaro inoshanduka nekuchinja kwekutarisa, tembiricha, shear rate uye zvimwe zvinhu, izvo zvinoita kuti kushandiswa kwayo mukuputira uye pendi kuve nenzvimbo yakakura yekugadzirisa.
2. Basa reHPMC mune coatings uye pendi
Kugadziriswa kweViscosity: Basa guru reHPMC nderekugadzirisa viscosity yehurongwa. Mune machira uye pendi, viscosity yakakosha paramende inobata zvakananga kuvaka, kuyera, uye yekupedzisira firimu mhedzisiro yezvinhu. HPMC inogona kunyatso kudzora viscosity yejasi nekushandura mamorekuru chimiro kana kutarisisa, kuve nechokwadi kugadzikana uye kushanda kwejasi panguva yekuchengetedza, yekufambisa uye kuvaka.
Rheological control: HPMC inopa rukuvhute kana pendi yakanaka rheological properties, kuitira kuti ichengetedze yakakwira viscosity kana yakamira kudzivirira sedimentation, uye inogona kuderedza viscosity pasi pekuveura, zvichiita kuti zvive nyore kushandisa. Iyi thixotropy yakakosha pakuita kwekuvaka kwekuputira uye pendi, kunyanya pakupfapfaidza, kupuruzira kana kukunguruka, izvo zvinobatsira kuwana yunifomu uye yakatsetseka coating.
Anti-sagging performance: Kana mapendi kana pendi akaiswa panzvimbo yakatwasuka, sagging inowanzoitika, kureva kuti, iyo yekupfeka inoyerera pasi pechiito chegiravhiti, zvichikonzera kusaenzana kwefirimu ukobvu uye kunyange kuyerera mamaki. HPMC inonyatso kudzvanya iyo sagging chiitiko nekusimudzira viscosity uye thixotropy yehurongwa, kuve nechokwadi kugadzikana kwejasi kana yaiswa panzvimbo dzakamira.
Anti-sedimentation effect: Mune machira ane mamwe pigment kana mafirita, pigment kana mafirita anowanzoita sedimentation, zvichikanganisa kufanana kwejasi. HPMC inodzika pasi sedimentation rate yezvimedu zvakasimba nekuwedzera viscosity yehurongwa. Panguva imwecheteyo, inochengetedza kumira kwayo mupende nekubatana ne pigment particles, kuve nechokwadi chokuti pende inofanana uye inopindirana panguva yekuvaka.
Kuvandudza kugadzikana kwekuchengetedza: Panguva yekuchengetedza kwenguva refu, pendi inowanzoita stratification, coagulation kana sedimentation. Kuwedzerwa kweHPMC kunogona kunyatso kuvandudza kugadzikana kwepende, kuchengetedza kufanana uye viscosity yepende, nekudaro ichiwedzera hupenyu hwayo hwesherufu uye kudzivirira kusvibiswa kwemhando yechigadzirwa kunokonzerwa nekusachengetwa kwakakodzera.
3. Zvinhu zvinokanganisa viscosity control neHPMC
Concentration: Iko kusungirirwa kweHPMC chinhu chakananga chinokanganisa viscosity yepende kana pendi. Sezvo huwandu hweHPMC huchiwedzera, iyo viscosity yehurongwa inowedzera zvakanyanya. Kune machira anoda yakakwirira viscosity, zvakakodzera kuwedzera huwandu hweHPMC inogona kuwana yakanakira viscosity level. Nekudaro, yakawandisa yekumisikidza inogona zvakare kukonzera iyo sisitimu kuti ive yakanyanya viscous uye inokanganisa kuita kwekuvaka. Naizvozvo, zvinodikanwa kunyatso kudzora huwandu hweHPMC hwakawedzerwa zvinoenderana neiyo chaiyo application mamiriro uye zvinodiwa zvekuvaka.
Molecular uremu: Huremu hwemamorekuru hweHPMC zvakare chinhu chakakosha chinokanganisa viscosity. HPMC ine huremu hwema molecular inoumba denser network chimiro mumhinduro, iyo inogona kuwedzera zvakanyanya viscosity yekuputira; nepo HPMC ine yakaderera molecular uremu inoratidza yakaderera viscosity. Nekusarudza HPMC ine uremu hwakasiyana hwemamorekuru, iyo viscosity yekupotera kana pendi inogona kugadziridzwa kuti isangane nezvinodiwa zvekuvaka zvakasiyana.
Tembiricha: Iyo viscosity yeHPMC inoderera nekuwedzera tembiricha. Naizvozvo, kana uchivaka munzvimbo ine tembiricha yakakwira, zvinodikanwa kusarudza mhando dzeHPMC dzine tembiricha yakakwira kana kuwedzera zvakakodzera dosage kuti ive nechokwadi chekuita kwekuvaka uye firimu remhando yekupfeka pasi pemamiriro ekushisa.
pH kukosha: HPMC yakagadzikana muhupamhi pH renji, asi yakanyanyisa asidhi uye alkali mamiriro anozokanganisa kugadzikana kwayo viscosity. Munzvimbo yakasimba yeasidhi kana alkali, HPMC inogona kuderedza kana kukundikana, zvichiita kuti kuderera kwe viscosity. Naizvozvo, kana uchigadzira fomula, ita shuwa kuti iyo pH kukosha kweiyo system iri pakati nepakati kuchengetedza viscosity yekudzora maitiro eHPMC.
Shear rate: HPMC is a shear-thinning thickener, kureva kuti, viscosity yayo ichaderedzwa zvakanyanya pakukwirira kweshear rates. Ichi chivako chakakosha zvikuru mukugadzirisa kwekuvaka, nokuti kana uchikwesha, kukunguruka kana kupfapfaidza, kuvhara kunoiswa pasi pesimba guru rekuveura, uye HPMC inogona kuvandudza kushanda kwekuvaka nekuderedza viscosity. Mushure mekunge kuvakwa kwapera, simba reshear rinonyangarika, uye HPMC inogona kudzoreredza viscosity yejasi kuti ive nechokwadi chekufanana uye ukobvu hwefirimu rekuvhara.
4. Kushandiswa kweHPMC mune zvakasiyana coating systems
Mvura-based coatings: HPMC inoshandiswa zvakanyanya mumvura-based coatings. Iyo haigone kungoshandiswa seyakakora chete, asiwo seyamuro yekugadzira firimu uye stabilizer. Mumvura-yakavakirwa masisitimu, HPMC inogona zvinobudirira kuwedzera viscosity yejasi, kuvandudza rheology yayo uye kuyera, uye kudzivirira sedimentation uye sagging. Panguva imwecheteyo, inogonawo kuvandudza kudzivirira kwemvura uye kukwesha kupikisa kwefirimu yekuputira uye kuwedzera hupenyu hwebasa rejasi.
Solvent-based coatings: Kunyangwe HPMC isinganyanyi kushandiswa mukunyungudutsa-based coatings, inogona kushandiswa seyakakobvu uye nhanho yekubatsira. Kunyanya mune yakaderera volatile organic compound (VOC) machira, HPMC inogona kupa inodiwa viscosity control uye rheology kugadzirisa, nekudaro kuderedza kushandiswa kwezvinonyungudutsa uye kusangana nekuchengetedza nharaunda zvinodiwa.
Powder coatings: Muhupfu hwehupfu, HPMC inogona kushandiswa sebhainda uye thickener kuvandudza fluidity uye firimu-kugadzira zvinhu nekuwedzera viscosity yehupfu. HPMC inogona kuve nechokwadi chekuti poda yekuputira haisi nyore kubhururuka panguva yekuvaka, uku ichivandudza kufanana uye kuwanda kweiyo firimu rekuvhara.
HPMC inowana yakanakisa viscosity kudzora mune coating uye pendi kuburikidza neayo akasiyana emuviri nemakemikari zvimiro. Iyo haigone chete kunyatso gadzirisa iyo viscosity yehurongwa, asi zvakare kuvandudza rheology yejasi, kusimudzira anti-sagging uye anti-kugadzirisa zvivakwa, uye kugadzirisa kuchengetedza kugadzikana. Zvinoenderana neakasiyana masisitimu ekupfekedza uye zvinodiwa zvekuvaka, nekugadzirisa iyo yekumisikidza, mamorekuru huremu, tembiricha, pH kukosha uye zvimwe zvinhu zveHPMC, iyo viscosity inogona kudzorwa zvakanaka, nekudaro ichivandudza kuvakwa kwejasi uye yekupedzisira yekupfeka mhando.
Nguva yekutumira: Sep-14-2024