Multipurpose ink preparation and process (2)

3. Preparation requirements

3.1 Preparation of basic requirements

(1) It is required that the ink has good fluidity and can smoothly pass through the screen, and no blocking phenomenon will occur.
(2) The ink is required to be moderately dry without causing webbing, drawing, and poor inking.
(3) It is required to adapt to the specific conditions of the season, temperature, humidity and other environments.
(4) Appropriate ink viscosity is required and no ink is produced.
(5) It is required to adapt to the specific conditions of the mesh, the mesh, the frame, and the pattern in order to achieve the desired screen printing effect.

3.2 Three Accuracy Requirements

(1) Hue deployment is accurate and should meet the original color standard.
(2) The consumption of ink consumption is accurate, and the amount of ink dispensed is determined according to the amount of printing ink and the amount of printing.
(3) The ink printability is adjusted accurately and must be made to meet the objective requirements and process requirements for printing.

4. Preparation process application

When receiving the ink assignment sheet, the first thing to do is to analyze it calmly to determine which type of specialty ink is the desired ink color and which color tone (warm or cool color) you prefer so that you can immediately A general ink transfer formula is formed. Followed by the need to understand the amount of ink with ink time. The following describes several process applications for several multi-screen printing inks.

4.1 Gold and silver ink printing process

In order to ensure the purity of ink, when the last printing of gold and silver ink, first wet the mesh with a solvent such as 783, clean the plate, wait for the solvent to completely evaporate, and then ink the job. Because gold and silver ink encounter certain uncertainties, they will react and cause ink discoloration.

Because of the poor mobility of gold and silver inks, it is often necessary to add an ink or special slow-drying agent to increase the leveling property of the ink. Adding a defoamer at the same time as adding the former is more effective. .

When printing gold or silver ink, add a special slow agent. Gold and silver will not be darkened by oxidation. If you want to bring out the quality feeling of gold and silver foil, you can add more special slow-drying agent to produce a mirror effect.
Typical applications such as photocopying of face stamping and signage refurbishment.

4.2 pearl ink printing process points

Pearlescent pigments can be combined with transparent pigments or dyes to give unique pearlescent effects, but should avoid mixing with opaque pigments and avoid mixing pearlescent pigments with complementary colors. When using silver white pearlescent pigments, a small amount of carbon black or blue pulp should be added to enhance the pearlescent effect.

Pearlescent pigments have a good dispersion, but long-term effects of strong shear forces should be avoided. If it is precipitated in low viscosity varnish, it should be lightly stirred before use, so it will not affect the use effect.

Typical application examples are the background color of makeup bottles and the printing of imitation silver characters of electronic components.

4.3 luminous ink printing process points

A certain proportion of light-storing material is added to the clear ink, and a light-emitting ink is formed after processing. The viscosity of the processed luminous ink is between 300-500Pa. s around. When printing, the viscosity of the ink should be adjusted with a thinner according to the printing speed to suit the printing needs. In screen printing, when using luminescent inks to print patterns and logos, polyester nets below 200 mesh are generally selected. In order to obtain the best luminescent effects, 80 to 120 mesh screens can be used. Luminous inks are printed on white substrates and can be improved. The brightness and afterglow time of the printed pattern or logo. When the coating thickness of the printed luminescent ink is controlled at 130-150 μm, the luminescent effect is the best. If it is printed twice with a 80-mesh screen, this thickness can be achieved.

A typical application example is the printing of fire exit signs.

4.4 Highlights of Fluorescent Ink Printing Process

For the use of screen printing in outdoor use fluorescent ink, additives 2 should be added. Fluorescent ink is suitable for printing with a screen size of 300 mesh or less, high-tension screen printing, and moderate squeegee printing. Considering that the printing ink transfer amount on the substrate is 50-60g/m2, the color and light resistance of the printing ink are ideal. . Gloss processing will slightly reduce the effect of weak fluorescence, it should use a good transparency oil.

When the substrate is a transparent object, the white ink should be printed before printing the fluorescent ink, which can improve the fluorescence effect. It is best to print on paper with high whiteness because the higher the whiteness of the paper, the better the printing effect. When the fluorescent ink is used for printing background color, if it can be printed with the color of the same color, the color saturation can be improved, and the light resistance can also be improved. When the fluorescent ink is used for printing four color printing products, such as for a magenta version, a yellow version. , can get bright prints.

Typical application examples are the printing of gas station flags, fishing rods and floats.

Source: Print Chemicals Network