Dry-yakavhenganiswa dhaka inogadzirwa nekusanganisa mumuviri kusanganisa redispersible latex poda nemamwe anonamira emukati uye akasiyana aggregates, mafirita uye zvimwe zvinowedzera. Kana iyo yakaoma poda dhaka inowedzerwa kumvura uye yakabvongodzwa, pasi pekuita kwehydrophilic inodzivirira colloid uye mechanical shear simba, latex powder particles inogona kukurumidza kuparadzirwa mumvura, iyo inokwana kuumba zvizere redispersible latex powder mu film.
Kuumbwa kwe latex powder kwakasiyana, izvo zvichakanganisa rheology uye zvakasiyana-siyana zvekuvaka zvivakwa zvedhaka. Kubatana kwelatex poda kumvura kana yaparadzirwa, iwo akasiyana maviscosities elatex poda mushure mekupararira, pesvedzero pamhepo yedhaka uye kuparadzirwa kwemhepo inoputika, kudyidzana pakati pelatex poda nezvimwe zvinowedzera, nezvimwe, zvinogadzira zvakasiyana. latex poda yakawedzera fluidity. , Wedzerai thixotropy, kuwedzera viscosity uye zvichingodaro.
Mushure meiyo ichangobva kusanganiswa dhaka ine latex poda dispersion yakaumbwa, nekutorwa kwemvura nepasi pevhu, kushandiswa kwe hydration reaction, uye kuvhuvhuta kumhepo, mvura inodzikira zvishoma nezvishoma, zvimedu zvichaswedera zvishoma nezvishoma, iyo interface ichaita. zvishoma nezvishoma kusviba, uye zvishoma nezvishoma kusanganisa pamwe chete, uye pakupedzisira kuunganidza kuumba firimu. Maitiro ekuumbwa kwemafirimu epolymer akakamurwa kuita matanho matatu.
Muchikamu chekutanga, zvikamu zvepolymer zvinofamba zvakasununguka muchimiro cheBrownian motion mune yekutanga emulsion. Sezvo mvura ichinyungudika, kufamba kwezvimedu kunowanzova kwakaganhurirwa, uye kusawirirana kwezviso pakati pemvura nemhepo kunomanikidza kuti zviwirirane zvishoma nezvishoma.
Muchikamu chechipiri, kana zvimedu zvasangana, mvura iri mumambure inoputika kuburikidza necapillary tubes, uye kushushikana kwakanyanya kwecapillary kunoiswa pamusoro pezvimedu kunoita kuti deformation ye latex spheres isanganise pamwechete, uye mvura yakasara inozadza pores, uye firimu inenge yakaumbwa.
Yechitatu, yekupedzisira nhanho inogonesa kupararira kwemapolymer mamorekuru kuita firimu rechokwadi rinoenderera. Munguva yekugadzira firimu, yakasarudzika nharembozha latex masisitimu anobatana kuita chikamu chitsva chefirimu chine kushushikana kwakanyanya. Zviripachena, kuitira kugonesa redispersible latex poda kuti iite firimu mudhaka rakaomeswa, zvinodikanwa kuve nechokwadi chekuti tembiricha yekuumba firimu yakaderera pane yekurapa tembiricha yedhaka. .
Zvinowanzotendwa kuti iyo redispersible latex powder inovandudza kushanda kwedhaka itsva: latex powder, kunyanya inodzivirira colloid, ine hukama hwemvura uye inowedzera viscosity ye slurry uye inovandudza kubatanidzwa kwevhu rekuvaka. Mudhaka, ndeye kuvandudza brittleness, yakakwira elastic modulus uye kumwe kusasimba kwechinyakare simende dhaka, uye kupa dhaka resimende nekushanduka kuri nani uye kusimba kwechisungo chesimba, kuitira kuramba uye kunonoka chizvarwa chekutsemuka kwesamende. Sezvo iyo polymer uye dhaka zvinoumba interpenetrating network chimiro, inoenderera polymer firimu inoumbwa mumapores, iyo inosimbisa chisungo pakati peaggregates uye inovhara mamwe pores mudhaka, saka yakagadziridzwa dhaka mushure mekuoma iri nani pane simende dhaka. Pane kuvandudzika kukuru.
Nguva yekutumira: Mar-20-2023