Concept scope and category II of the hottest flexo

Concept, scope and types of flexographic printing inks (II)

the following reference formula is modified nitrocellulose ink, which has good gloss and heat resistance, and is suitable for printing foil, coated cellophane and paper:

component

weight%

polyphthalamine resin

10

s/s nitrocellulose

5

* organic pigment

15

filler

5

plasticizers Wax

10

ethanol

50

ester

5

100

if you need ink for printing coated cellophane, you should replace the film-forming agent in the above formula, that is, modified rosin, with acrylic resin, so as not to affect heat sealing

at present, flexible plastic film for composite packaging is developing rapidly, which requires an ink, that is, composite ink is suitable for printing this plastic film, and then compounded with another plastic film or paper to make sealed packaging with good printing and heat sealing performance. The composite ink used for printing here does not contact the inner packaging or the air. This composite ink does not need gloss, nor does it require scratch resistance and friction resistance (because they are protected by the composite film). This kind of ink contains no wax or very little, so it will not reduce the adhesion between composite films

generally, high-performance composite inks are based on polyphthalamide resin, while economical composite inks are based on nitrocellulose. All compound inks must have very low residual solvents, because this compound ink is usually used in the packaging and printing of food, such as chocolate, cookies and sugar

in addition, from the perspective of environmental protection, VOC (volatile organic solvent) emitted by this ink needs to be recycled or incinerated. Of course, recycling and incineration will involve huge investment costs, and this kind of ink also needs to use air flow system to achieve VOC collection. Therefore, they have their own limitations:

A. solvent recovery method: it is not applicable to those mixtures of different solvents, which limits the flexibility of the formula

b. incineration involves the use of a catalyst whose life will be shortened by the components in some inks - such as siloxane. Therefore, the flexibility of the formula is limited

2. water based flexographic ink: water based flexographic ink is mainly suitable for absorbent substrate surfaces, such as kraft paper, corrugated packaging boxes, multi-layer paper bags, etc. now it has developed into plastic films and foils. New materials affect the power equipment industry & inspect the oil window on the left of the control cabinet amp; nbsp; Graphene printing with increasing heat. Generally, the resins used in water-based flexographic ink are modified acrylic copolymer and rosin, and there are several other products. These resins are solubilized with ammonia or an ammonia compound (or occasionally even with sodium hydroxide). Lotion polyester is also used. This lotion polyacetic acid is a good pigment grinding resin (because it has good wettability and high viscosity. The experimental force shows overload), and makes the ink have good re solubility. Its lotion can also improve the fixation, toughness, gloss and some durability of the ink

when printing absorbent substrate surfaces with this kind of ink, such as corrugated paper packaging, the following typical reference ink formula can be used:

component

weight%

acrylic resin

20

organic pigments

12

fillers, amines, defoamers and biocides

water

60

100

of course.The above formula is simplified. Because mixed raw materials are used in various non-aqueous components, however, it is important to pay attention to the need for defoaming AIDS in water-based inks, because there is a mixing process in the printing process. There is also the need to add biocides to prevent the growth of microorganisms in products

when printing non porous substrate surface with water-based ink, the addition of solvent or volatile organic solvent can improve the wettability. The addition amount of volatile components can reach 25% (typically 12-13% of the weight of the overall ink formula). These products are called quasi water-based inks

flexible products with volatile organic solvents (VOC) content of 5% and sometimes as low as 1-2% have also been launched. These products often use surfactants to improve their wettability. These products also contain a small amount of ethylene glycol ether. In the case of the drying furnace used in the current flexographic printing, the evaporation speed is slow, but it can meet the requirements of production speed. In addition, although some water-based inks are used in some composite products, they are mainly adhesive structures. Because they are used with water-based inks in composite products, the binder (with high fixation fastness) of shoulder samples adopts suspension structure, etc.) is solvent-based, due to the volatilization of volatile organic solvents. Moreover, water-based inks often cannot withstand the high temperature encountered in the extrusion process