Formulation and printing performance of the hottes

2022-08-22
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Solvent based gravure composite digestible bag ink formula and printing performance (Part 2)

4. Selection of wax powder for high temperature digestible bag ink

some special high temperature resistant wax powder is usually added to the compound high temperature digestible bag ink formula for gravure printing, which can provide excellent abrasion resistance and scratch resistance for the high temperature resistant ink film of printing products, prevent adhesion and increase the machine fluidity of ink, improve printing suitability and improve post-processing performance. Because the diameter of these special wax particles is about 5 microns, which is larger than the diameter of pigment particles and the thickness of ink film, these wax particles can protrude the ink film after ink printing and drying, making the surface of the ink film rough. When the ink on the plastic film is placed for a long time after being rolled up, the rough ink film is conducive to preventing the printing surface from adhering to the back of the plastic film; It is also conducive to the uniform coating of glue on the post-processing composite to enhance the composite fastness of the film. Adding these special wax powders to the ink can also eliminate the disadvantage that the ink film is easy to fall off on the roller due to excessive pressure in the process of high-speed printing

when designing the formula of composite high-temperature cooking resistant bag ink for gravure printing, most of them should choose molecular linear synthetic polyethylene wax with high melting point and strong hardness. There are two ways in the ink production process: pre addition and post addition, and the general addition amount is 0% of the total weight of the ink. 5--1。 0%。 Under normal circumstances, it is under the rough ink grinding. 1. The usefulness and advantages of this experimental machine of Jinan new era Gold Testing Instrument Co., Ltd. are reflected in its addition before grinding, which is conducive to dispersion and improve liquidity; However, it should be noted that the grinding temperature should not be too high to avoid deformation and condensation of these wax particles, which will affect their performance. There are also pastes made of ink system resin and organic solvents - wax slurry, which are added in the viscosity and color adjustment stage of inking to make the cycle performance of lithium manganate battery material reach 3000 times; However, in doing so, it is necessary to prevent some highly permeable organic solvents from dissolving wax powder particles, resulting in recrystallization and coarsening, and losing the proper performance of special wax powder

5. Selection of antistatic agent for high-speed printing

Gravure plastic ink during high-speed printing, due to the accumulation of static electricity, it will cause offset, blur, spots, beard, edge exclusion and other problems, and even fire, explosion and other malignant events will occur in serious cases. Therefore, the purpose of adding antistatic agent to the ink is to reduce the surface resistance of plastic film in the printing process and eliminate static electricity to solve the above problems in printing. Generally, anionic anti-3 and humidity range are used in plastics and inks. The humidity indicators given by environmental test boxes at home and abroad are mostly 20 ~ 98% RH or 30 ~ 98% RH electrostatic agents, including higher fatty acid salts, alkyl phosphate salts, alkyl sulfate salts and sulfonate salts, etc. this type of compounds can be dissolved in water, ketones, alcohols, benzene and other organic solvents, The products are sold in organic solvent aqueous solutions containing 30-60% of active substances. The compound high-temperature cooking resistant bag ink used for gravure printing mainly uses isopropanol solution of ethyl phosphate as the antistatic agent, and the addition amount accounts for 0.1--0.4% of the total ink, which has no adverse effect on the inkability

6. Selection of adhesion promoting resin and fumed silica powder

in the ink system of polyurethane and chloroacetic resin in the composite high temperature cooking resistant bag ink for gravure printing, due to the insufficient flexibility of chloroacetic resin itself, it is necessary to use adhesion promoting resin to improve its flexibility; Some modified chlorinated polypropylene resin solution with a solid content of about% should be added to the formula of composite high-temperature cooking resistant bag ink for gravure printing, so as to improve the adhesion of polyurethane ink on plastic film and enhance the dispersion effect and fluidity

fumed silica powder, also known as matte powder, is generally dispersed easily after organic surface treatment. Its role in the composite high temperature cooking resistant bag ink for gravure printing: A. prevent pigment sedimentation and maintain the long-term rheological properties and fineness of the ink; B. Improve the sagging performance of the ink film when printing on the machine to prevent the generation of water marks; C. Like wax powder, it is also conducive to the uniform coating of adhesive and improve the composite fastness

7. Selection of organic solvent for gravure high temperature resistant cooking bag ink system

plastic gravure ink mainly depends on solvent evaporation and drying to form a film. When the ink is printed on the surface of the substrate, the thickness of the ink film decreases and shrinks due to solvent evaporation. The evaporation of ink solvent into film is mainly divided into two stages: the first is the "wet stage", which is controlled by the surface layer; The second is the "dry stage", in which the solvent evaporation rate is controlled by the diffusion of the solvent in the overall ink film. When there is real solvent, ensure that the resin and other polymers are fully extended and interact with each other, and have good leveling performance. If the real solvent volatilizes too fast and the residual solvent is only a cosolvent, the polymer molecules tend to form tight curls, or even precipitate. It is particularly important that the solvent volatilization causes endothermic cooling and the rise of polymer concentration, which increases the surface tension of the ink film, resulting in the flow of the solution from the low surface tension area to the high surface tension area. This is peak to trough flow, which is easy to produce "orange peel" and floating color phenomenon. Therefore, maintaining the necessary amount of true solvent is an important condition to ensure the smoothness of the ink film

for the ink system of polyurethane and chloroacetic resin, toluene, xylene, ethyl acetate, butanone, isopropanol are common solvents, but also choose acetone, methyl isobutyl ketone, ethylene glycol monobutyl ether, propylene glycol methyl ether and other special organic solvents. Among them, benzene and alcohol are only cosolvent for polyurethane and chloroacetic resin. Although ketones and esters are real solvents, they volatilize too fast. Therefore, special solvents such as methyl isobutyl ketone, ethylene glycol monobutyl ether and propylene glycol methyl ether should be used to adjust the volatilization rate and solubility, enhance the dispersion force of the mixed solvent, improve the dissolution parameters, make the ink always present a good fluid state, and ensure the smooth progress of the printing work

brief introduction of the application performance of solvent based gravure composite high temperature cooking resistant bag ink

the composite high temperature cooking resistant bag ink for solvent based gravure printing uses the relevant ternary chloroacetic resin with high chlorine content and medium viscosity, and the special high temperature resistant polyurethane resin as the main connecting material, and then adds a series of special additives and organic solvents, together with the organic pigment with high temperature resistance, which is evenly stirred, dispersed, ground It is made by adjusting viscosity and color. It is suitable for low-speed to high-speed high-temperature resistant plastic film (composite) printing. The base materials are generally high-temperature resistant composite plastic films such as rcpp, pet, BOPP, nylon (nylon) and Al (aluminized film). The film products printed with this kind of ink can be used in both ordinary composite processes and high-temperature cooking composite processes. This kind of ink film solvent residue is low, odorless, non-toxic, environmental protection and safety. It can be used in the packaging of food and drugs, which meets the health requirements

gravure composite high temperature cooking resistant bag ink has the following characteristics:

1, low viscosity, good leveling, high solid content, bright color, high color concentration, good point reproducibility, suitable for chromatic printing of layered edition

2. High adhesion fastness, suitable for a variety of printing films

3. Excellent printability, good ink transfer, suitable for different machine speeds and plate depths

4. Prints can withstand high-temperature cooking, and single component can be boiled in water (℃) and high-temperature cooking (℃); Adding curing agent (%) during two-component printing can improve the high temperature resistance, film-forming performance, printability, composite fastness and so on

5. Good composite performance. The ink film has high peel strength, up to 5n/15mm-10n/15mm; Moreover, after 120 ℃ high temperature cooking, the peel strength increases instead of decreasing

conclusion

some scholars have said that market information breeds industrial opportunities, market demand stimulates technological innovation, and technological innovation changes the market pattern; Our factory also has such a slogan "market needs are instructions, and first-class quality is the goal". In order to develop and surpass the world level, our ink workers are required to have cutting-edge technical design, brave technological innovation and reasonable production management. We must not avoid the challenges of these three, but we should face them, study them and improve them. This is why we hope to discuss with your colleagues the formulation, material selection and printing use of composite high temperature and cooking resistant bag ink for gravure printing

source: fine chemicals in the 21st century

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