Dab tsi ua si hauv INK Deposit?
Ink .... rau 20%
Hauv cov txheej txheem no, peb yuav pom,
• Internal molecular cohesion ntawm tus number case,
• capillarity,
• ionic thiab molecular attraction,
• sab hauv thiab sab nraud shearing,
• uas txuas rau "qhov deb",
• Kev tsis ncaj ncees...
1 Nws yog qhov pom tseeb lub luag haujlwm ntawm cov neeg tsim khoom lag luam kom paub tswj cov ntsiab lus no.
Tab sis rau lub tshuab luam ntawv tshuaj ntsuam koj yuav tsum paub tias qhov kev xaiv ntawm pigments, fineness ntawm kev sib tsoo, lub
additives siv xws li ziab retarders yog qhov tseem ceeb heev.
Piv txwv li, nrog dej-raws li inks, kuv pom zoo kom siv glycerol ntawm ib tug concentration ntawm 82%, es
dua dej. Nws zoo heev txwv kom qhuav hauv qhov screen mesh.
Yog tias diluted nrog dej, ceev faj ntawm "limestone" dej: qhov me me ntawm limestone (dej tawv)
muaj cov micro-grains uas tuaj yeem txuas mus rau cov xov ntawm lub vijtsam ntaub thiab ua rau kom qeeb
down qhov zoo khoob qhov mesh.
Tsis tas li ntawd, cov khoom nyuaj no cuam tshuam los ntawm kev txav ntawm cov squeegee thiab dej nyab-bar kev pheej hmoo.
ua rau qhov screen ntaub.
TSEEM CEEB: Tus cwj mem "zoo" yuav tsum muaj kev sib koom ua ke sab hauv muaj zog dua li molecular cohesion nrog
cov ntaub ntawm qhov screen thiab ntug, ntug ntawm emulsion los yog capillary zaj duab xis.
Screen luam ntawv inks yuav tsum muaj cov khoom rheological uas tuaj yeem ua qhov tsis sib xws yog tias qhov ntau npaum li cas
ob yam hauv qab no tsis yog tswj tau zoo kawg nkaus:
• pseudo-yas kom dhau los ntawm qhov screen: tus number case yuav tsum muaj viscosity tsawg dua 500 poise hauv qab
shear ntawm 100 s -1, (rau cov neeg uas muaj "viscometer").
• thixotropic: tus cwj pwm tsim nyog kom tau txais cov ntsiab lus zoo tom qab dhau los ntawm lub mesh ntawm lub vijtsam.
Qhov zoo ntawm lub cev no txhais tau hais tias tus number case muaj viscosity tsawg thaum nws agitated (xws li los ntawm kev txav ntawm
dej nyab-bar hniav ces los ntawm nws shearing thaum lub squeegee muab tso rau hauv kev sib cuag nrog underside ntawm lub
screen) "tsawg" nws agitation ("gelling") sai li sai tau thaum nws so,
Tab sis yog hais tias nws yog pom tseeb hais tias lub rheology ntawm tus number case (20%) yuav tsum tau txiav txim siab nyob rau hauv lub thickness ntawm lub
ink deposit...
... Nws tseem yog ib qho tseem ceeb kom xav txog tag nrho cov lwm yam thiab cov yam ntxwv uas
Thaum kawg txiav txim siab qhov tuab ntawm nws cov nyiaj tso rau ntawm kev txhawb nqa.