In this paper, a kind of edible inkjet ink was successfully prepared using flower of redbud as pigment, edible alcohol as resolvent, edible salt, arabic gum and polylysine as additives. Then, the performance parameter and printability of edible inkjet ink were tested. The results showed that the performance indexes of edible inkjet ink are fineness 0.45µm, viscosity 2.0mPa•s,density 1.06, conductivity 4980µs/cm, surface tension 30N/m, drying speed 5s, pH value 5.8, respectively. The ink can printing smoothly, and ink layer deposits on the substrate firmly. The nozzle is not blocked by the ink. The technical index of the ink can meet the requirements of the inkjet device and the printing product. The edible inkjet ink can be used in the field of food and medicine packagingAt present, food, medicine packaging on the production date mainly by the birthManufacturers through inkjet printing in food, medicine packaging
As edible ink, in addition to ensure the safety and health of materialsIn addition, it must meet the technical conditions of inkjet printing, includingThe following points.
1) Raw material safety and health
Ink raw materials are all food grade, to ensure safety and health.The production process should also ensure safety and health, to prevent doping impuritiesAs pollution.
2) Small fineness, moderate conductivity
Ink-jet ink fineness to be small enough, and do not produce precipitation toEnsure that ink drops can pass through the nozzle smoothly without ink blocking. On the otherIn addition, the ink also needs to have the right conductivity, so that the ink is easy to fillThe electronically controlled fuel injection system.
3) The density is within a certain range
In order to ensure that the color of the image is clearly visible after printing ink, inkThe density should be within a certain range.
4) Fast drying time
In order to ensure that the ink printing image hierarchy is clear, and does not occurRub dirty, ask ink drying time fast.
5) Small surface tensionAfter
printing ink layer on the substrate to be easy to adhere to, with a certainFastness, especially on paper or plastic packaging, not to be wiped Fade, ink surface tension should be small enough.
Preparation of edible inkjet ink
Jet printing ink is mainly composed of pigments, binders, auxiliaries and other groupsInto. Concentrated bauhinia pigment prepared in laboratory was used as pigment in this studyMaterial; Considering that alcohol can dissolve bauhinia pigment solution, it has a waveHair, and has reduced surface tension and defoaming effect, so to food Grade alcohol as solvent; In order to improve the film - forming ink layer and substrate
For fastness to adhesion, a small amount of acacia gum or chitosan should be addedAs a film forming agent.
The viscosity of chitosan aqueous solution was found in the experiment Larger, not conducive to the flow of inkjet ink, so the use of gum ArabicResin as a binder; Finally add salt water (improve ink jetInk conductivity), food grade preservative polylysine (preservative,Prevent ink-jet ink deterioration and decay at room temperature) as additives prepared edibleSex ink jet ink.The specific preparation method is as follows: First, use deionized water respectivelyMake 8% water-soluble gum Arabic, 20% salt water and 5% waterSoluble polylysine. Take 100ml of concentrated pigment solution of bauhinia and place it inIn a beaker, pour in 100ml of 75% alcohol, stir well,Then add 5ml of 8% water-soluble acacia gum and 5ml of acacia gum respectively20% salt water, 5ml of 5% water soluble polylysine, stirringWell. Finally, the resulting ink is passed under vacuum conditions at room temperatureThe final ink-jet ink is produced by filtration of 0.45µm aperture membrane and can be putRefrigerated cabinet for storage .