Analysis of Color Matching of Gravure Printing Inks(2)

Dark and light color inks are blended

The deployment of ink can be divided into dark ink and light ink deployment. The so-called dark ink means that only the primary ink is used for preparation without any diluting agent. According to the amount of ink consumed during printing, the main color ink and the auxiliary color ink determined by the color analysis are uniformly blended. There are three types of dark ink: monochrome, inter-color, and poly-color. Monochromatic refers to a primary color 1 made of ink. Inter-color refers to: from the two primary color ink deployment. Duplex means: three inks are mixed and formulated.

All inks formulated by adding diluting agents are called light-colored inks. Attention should be paid to three points when dispensing: 1 Use white ink without thinner; 2 Use white ink as the main color, and add a little color ink to white ink; 3 Select colors should be accurate.

How to improve the luster of ink film

1 Add appropriate amount of varnish within the allowable range of color density.

2 Apply varnish or varnish to the surface of the printed film.

3 increase the transparency of ink, use high transparency ink or add a certain amount of withered oil, the use of smooth, reflective surface of the substrate printing surface smooth degree.

4 to prevent the substrate surface adsorption, and reasonably improve the smoothness of the substrate printing surface.

5 Pay attention to the temperature and humidity of the printing environment. When the plastic gravure printing is performed under high humidity and low temperature, the solvent volatilizes quickly and the heat around the ink film is absorbed, which causes the water vapor in the air to condense abruptly to form a mist on the surface of the printing ink film, resulting in the loss of the ink layer. luster.

During the rainy season, special attention must be given to controlling the temperature and humidity of the printing environment to ensure good printing results. Usually room temperature is best at 21-23°C and humidity is 40%, which is helpful for true reproduction of color.

Making special colors

1 gold, silver ink production: the use of withered oil to add appropriate amount of gold powder, silver powder can be mixed evenly, should pay attention to the choice of the fineness of the gold powder and silver powder, but also to meet the printing substrate of the varnish. It should also be formulated during printing to prevent precipitation and delamination of the ink due to excessive rotation time. The gold ink can also be mixed using silver powder, transparent yellow, and withered oil. The author used gold powder (glaucoma) when using gold ink: withered gold oil: transparent yellow equals 1:3:2, and the unit works well. If you want to make red hue, just change the gold powder to red light. The selection should be based on the customer's requirements.

2 pearlescent ink: pearlescent pigments and a suitable proportion of high transparency ink or varnish mixed evenly. The hiding power of the ink is strong and the pearlescent effect of the application may be lost.

3 Luminous ink: Ink has the effect of absorbing light energy and then emitting light for a certain period of time, so it can often emit light at night, so it is called luminous ink or phosphorescent ink. Usually, the luminous pigment is dispersed in the high-viscosity oil foam. Stir evenly. The above inks cannot grind gold ink, silver ink will damage the grinding equipment, and pearlescent and luminous ink grind will destroy the surface or crystal structure and lose the effect of hue.

Plastic printing palette notes

(1) Ink grading should be adopted as much as possible. The chromaticity of the styling ink produced by the ink factory is the same as that of the styling ink, which is higher than the chromaticity of the two-color ink.

2 If you want to use one or two kinds of ink color matching, you should use color inks that are close to the color to make deployment.

3 When color matching, the type of ink should be reduced as much as possible, because the more types of color matching ink, the higher the proportion of blue color, and the lower the brightness and saturation of the ink color. Therefore, it is not necessary to use three colors to blend with two colors.

4 plastic film is non-absorbent material, can not use thinner to dilute the color ink, white ink should be added to dilute.

5 different manufacturers, different types of ink mix, which will affect the white ink luster, purity and drying speed, the different types of ink mix will directly change the original resin hue change, ink deterioration, so we have to pay more attention.

Summary: With the ink color, we must carefully grasp every key, in order to deploy a good color, the final result is in line with the requirements of customers, the quality to ensure that the different batches of ink remain - caused.

(author/Chen Quandong)
Source: <China Packaging News>