Aluminum foil bag production for special film of ink printing requirements
In the process of printing on aluminum foil film, the main problem is that the printing is clear and accurate without loss, so the ink particularly high requirements for use, whether the traditional solvent ink or new type of environmentally friendly water-based ink, it of ink viscosity, adhesion, gloss, dry and printing adaptability is the key factor. Special gravure printing ink printing eligibility analysis of aluminum foil membrane was mostly metal, molecular density is big, adsorption is poor, so can't like paper can fully absorb ink and water, can only increase pressure plate and aluminum foil with the largest area of contact surface, improve the ink adhesion, and then by printing equipment of drying system to evaporate moisture, oxidation of conjunctival dry. This requires a ink viscosity is strong, fast drying speed. Due to the high temperature drying, requires both ink connection material and pigment with high heat resistance, and require the printing ink and heat sealing off, do not change color. Ink, gravure ink is liquid viscosity is one of the important indicators of rheological properties, determination of commonly used viscosity cup ink out of time to represent the viscosity. Ink viscosity is closely related to the transfer rate, viscosity, color, etc. Under normal viscosity of ink transfer of net point is good, print dot not empty, not the tail. Low viscosity, printing ink resin, pigment composition is relatively small, poor print gloss; If the viscosity is too low, can cause print color piece, large area by weak, flat screen water ripple, ink, ink and other quality problems; Viscosity is too large, the ink in the supersaturated state, pigment dispersion, cluster accumulation, liquidity, cause scratches, small white spots, network loss, blocking version, print color becomes shallow. Solvent ink solvent ink connection performance analysis of material most commonly used chlorate resin and acrylic resin, the resin can provide good adhesion and good heat resistance, and bright color, high concentration and strong adhesion, good transparency. The disadvantage is that: in the process of printing, large amount of solvent evaporation and not environmental protection, health hazards related to staff, also easy to cause cave in gravure net ink deposition stem node, lead to paste version, so you need to through the ink mixing or increase the warm bath of ink deposition and agitation necessary preprocessing, the ink viscosity control in 17 ~ 26 s (usually 25 ℃, 4 # viscosity cup) Range. Water-based ink performance analysis water do solvent is made of environmentally friendly liquid inks, with non-toxic, without excitant odour, no combustion, stable, bright colors, no corrosion after print, printing good adhesion, etc. Water-based ink pigment has strong alkali resistance, good dispersibility, high saturation, good wettability, and do not change color and fade phenomenon. By printing eligibility comparison showed that the water-based ink performance basic solvent ink, and even some performance than solvent-based inks, such as polymer emulsion water-based ink replaces the traditional solvent-based inks (30% ~ 70% of toxic organic solvents, so the less volatile in the printing process, the related staff's health had no adverse effect, will not cause pollution of the atmosphere environment. But also have high energy consumption of the dry ink, drying, such as low efficiency and poor drying performance shortcomings.