izindaba

Njengoba ubungako be-resin esekwe emanzini buphansi kakhulu, ayikwazi ukuhlangabezana nezidingo zokugcina nokusebenza kokwakhiwa kwengubo, ngakho-ke kuyadingeka ukusebenzisa isithambisi esifanele ukulungisa ubungako bengubo esekwe emanzini ibe sesimweni esifanele.

Kunezinhlobo eziningi zezithina. Lapho ukhetha izithina, ngaphezu kokusebenza kahle kwazo kokujiya kanye nokulawula i-rheology yokumboza, ezinye izici kufanele zicatshangelwe ukuze zenze isithina sibe nokusebenza okuhle kakhulu kokwakhiwa, ukubukeka okuhle kakhulu kwefilimu yokumboza kanye nokuphila isikhathi eside kakhulu kwenkonzo.

Ukukhethwa kwezinhlobo ze-thickener kusekelwe kakhulu esidingweni kanye nesimo sangempela sendlela yokwakheka.

Uma ukhetha futhi usebenzisa izithisi, lokhu kubalulekile.

1. Isisindo sama-molecule aphezulu i-HEC inezinga elikhulu lokubanjwa uma kuqhathaniswa nesisindo sama-molecule aphansi futhi ibonisa ukusebenza kahle okukhulu kokujiya ngesikhathi sokugcina. Futhi lapho izinga lokujiya likhuphuka, isimo sokugoba siyabhujiswa, izinga lokujiya likhula, umphumela wesisindo sama-molecule ku-viscosity uba mncane. Le ndlela yokujiya ayinalutho oluhlobene nezinto eziyisisekelo, imibala kanye nezithasiselo ezisetshenziswayo, kudingeka nje ukhethe isisindo sama-molecule esifanele se-cellulose futhi ulungise ukuhlushwa kwe-thickener kungathola i-viscosity efanele, futhi ngaleyo ndlela isetshenziswe kabanzi.

2.Isithambisi se-HEUR siyisisombululo samanzi esiqinile esine-diol noma i-diol ether njenge-co-solvent, esinokuqukethwe okuqinile okungu-20% ~ 40%. Indima yesithambisi esihlanganisiwe ukuvimbela ukunamathela, ngaphandle kwalokho izithambisi ezinjalo zisesimweni sejeli ngokugxila okufanayo. Ngesikhathi esifanayo, ukuba khona kwesithambisi kungagwema umkhiqizo ukuthi uqandeke, kodwa kumele ufudumale ebusika ngaphambi kokusetshenziswa.

3. Imikhiqizo eqinile nengaqinile kakhulu kulula ukuyilahla futhi ingathuthwa futhi igcinwe ngobuningi. Ngakho-ke, ezinye izithina ze-HEUR zinokuqukethwe okuqinile okuhlukile kokunikezwa komkhiqizo ofanayo. Okuqukethwe kwe-co-solvent kwe-co-solvent ye-low viscosity thickeners kuphakeme, futhi i-mid-shear viscosity yopende izoba ngaphansi kancane uma isetshenziswa, okungancishiswa ngokunciphisa i-co-solvent engezwe kwenye indawo ekwakhiweni.

4. Ngaphansi kwezimo zokuxuba ezifanele, i-HEUR ene-viscosity ephansi ingafakwa ngqo kupende we-latex. Uma usebenzisa imikhiqizo ye-viscosity ephezulu, i-thickener idinga ukuxutshwa ngengxube yamanzi kanye ne-co-solvent ngaphambi kokuba ifakwe. Uma ufaka amanzi ukuze uxube i-thickener ngqo, izonciphisa ukugcwala kwe-co-solvent yokuqala kumkhiqizo, okuzokwandisa ukunamathela futhi kubangele i-viscosity ikhuphuke.

5. Ukwengeza i-thickener ethangini lokuxuba kufanele kube okuzinzile futhi okuhamba kancane, futhi kufanele kubekwe eceleni kwethangi lodonga. Ijubane lokufaka akufanele libe ngokushesha kangangokuthi i-thickener ihlale phezu koketshezi, kodwa kufanele idonswe oketshezini bese izungezwa phansi izungeze umgodi wokuxuba, ngaphandle kwalokho i-thickener ngeke ixutshwe kahle noma i-thickener izoqina kakhulu noma i-flocculated ngenxa yokugcwala okuphezulu kwendawo.

6. Isithambisi se-HEEUR singezwa ethangini lokuxuba upende ngemva kwezinye izingxenye zoketshezi nangaphambi kokufakwa kwe-emulsion, ukuze kuqinisekiswe ukucwebezela okuphezulu.

7. Izithambisi ze-HASE zengezwa ngqo kupende ngesimo se-emulsion ekwenziweni kopende we-emulsion ngaphandle kokuxutshwa kwangaphambili noma ukuncishiswa kwangaphambi kokwenziwa. Zingangezwa njengengxenye yokugcina esigabeni sokuxuba, esigabeni sokusabalala kombala, noma njengengxenye yokuqala ekuxubeni.

8. Njengoba i-HASE iyi-emulsion ene-asidi ephezulu, ngemva kokuyifaka, uma kukhona i-alkali kupende we-emulsion, izoncintisana nale alkali. Ngakho-ke, kuyadingeka ukwengeza i-emulsion ye-HASE thickener kancane kancane, bese uvuselela kahle, ngaphandle kwalokho, kuzokwenza uhlelo lokusabalala kwe-pigment noma i-emulsion binder lungabi namandla endaweni, futhi lokhu kokugcina kuzinziswe yiqembu elingaphansi komhlaba elingasebenzi kahle.

9. I-alkali ingafakwa ngaphambi noma ngemva kokufakwa kwe-ejenti yokujiya. Inzuzo yokwengeza ngaphambi kokufaka ukuqinisekisa ukuthi akukho ukungazinzi kwendawo kokusabalala kwe-pigment noma i-emulsion binder okuzobangelwa yi-thickener ebamba i-alkali ebusweni be-pigment noma i-binder. Inzuzo yokwengeza i-alkali ngemuva kwalokho ukuthi izinhlayiya ze-thickener zihlakazeka kahle ngaphambi kokuba zivuvuke noma zincibilikiswe yi-alkali, okuvimbela ukuqina kwendawo noma ukuhlangana, kuye ngokwakhiwa, imishini kanye nenqubo yokukhiqiza. Indlela ephephile kakhulu ukuxuba i-HASE thickener ngamanzi kuqala bese uyinciphisa nge-alkali kusengaphambili.

10. Isithambisi se-HASE siqala ukuvuvukala ku-pH engaba ngu-6, futhi ukusebenza kahle kokujiya kudlala indima ephelele ku-pH engu-7 kuya ku-8. Ukulungisa i-pH yopende we-latex ibe ngaphezu kuka-8 kungavimba i-pH yopende we-latex ukuthi yehle ngaphansi kuka-8, ngaleyo ndlela kuqinisekiswe ukuzinza kwe-viscosity.