Do you know about color inkjet printing paper?

With the rapid development of digital technology, the demand for high-quality digital printing continues to grow, and color inkjet printing methods have been widely used, and color inkjet printing paper as the main consumable for inkjet printing is due to its huge market potential. And broad development prospects have attracted people's attention. In 2000, the annual consumption of color inkjet printing paper in China was less than 15,000 tons, but by 2006, the output of color inkjet printing paper was close to 100,000 tons, which shows its rapid development.

(1) Classification of color inkjet printing paper

Inkjet printing paper can be specifically divided into two categories: one is coated inkjet printing paper, and the other is plain paper that has not been processed by a coating machine. There are two main types of coated inkjet printing paper on the market, namely general color inkjet printing paper and high-gloss photo paper. Color inkjet printing paper is generally used to print renderings, advertising posters, etc., mainly highlighting the brilliant colors and realistic effects; in addition to photo paper, it also requires a certain mirror gloss and good ink absorption, It is an organic combination of strong absorption and high gloss, so as to achieve clear and gradation of the printed image, saturated colors, strong color expression, and similar to photo-level image effects. Photo paper is the highest-grade inkjet printing paper widely used in the commercial field, but its speed of absorbing liquid is low and its water resistance is poor.

The types and characteristics of commonly used color inkjet printing paper are as follows:

(1) High-gloss inkjet printing paper. The support is based on RC (plastic coated paper) paper, which is suitable for image output with bright colors, photo effects and high resolution. The images printed with it are clear and bright, with good gloss, good light resistance and color fastness, and are generally equipped with high-end inkjet printers.

(2) Matte inkjet printing paper. The support is based on RC paper, with medium gloss, suitable for image output with photo effects and high resolution, bright and saturated colors, and good light resistance.

(3) Special special inkjet printing paper. The support is RC paper-based, contains fluorescent agent and magnetic material, and has security functions such as anti-counterfeiting and anti-copying. It can resist ultraviolet rays and light resistance.

(4) PVC inkjet printing paper. The support is a composite product of plastic film and paper. It has good mechanical strength, high output quality, good ink absorption, and good indoor light resistance. It is suitable for image output with photo effects.

(5) High-gloss inkjet printing paper. The support is a thick paper base, which has the same gloss as the photo, the whiteness of the paper is extremely high, and it has good ink absorption. Especially suitable for photo image output and advertisement display board production. The output image is rich in layers and full of colors.

(2) Performance requirements of color inkjet printing paper

Color inkjet printing paper is a receiver for ink jetted from inkjet printer nozzles and a carrier for recording images or characters. Its basic characteristics are fast ink absorption and non-dispersion of ink droplets. Specific requirements include the following aspects.

(1) It has good recordability, strong ink absorption force, fast ink absorption speed, small ink droplet diameter, and approximately circular shape.

(2) Fast recording speed, that is, high density, continuous tone and clear picture.

(3) Good storage, the screen has certain water resistance and light resistance, and has certain storage properties indoors or outdoors.

(4) The coating has a certain fastness and strength, the coating is not easy to scratch, no static electricity, has a certain smoothness, and is resistant to bending and folding.

(5) The color reproduction is good, and the original color can be reproduced truly. The dot density is high, the saturation is good, and it has sufficient color difference density.

(3) Factors affecting the ink absorption of color inkjet printing paper

The ink absorbability of color inkjet printing paper includes two aspects: the amount of ink absorption and the speed of ink absorption.

In addition to the nature of the ink itself, the main factor affecting the ink absorption of color inkjet printing paper is the porosity of the ink-absorbing layer. The porosity of the ink-absorbing layer depends on the internal porosity of the coated pigment particles and the porosity between the pigment particles The internal porosity of the pigment particles is usually measured by the oil absorption value of the pigment particles. The porosity between the pigment particles mainly depends on the particle size of the pigment particles, so the larger the particle size, the larger the porosity formed by the pigment particles when they are stacked. .

Secondly, in order to make the color inkjet printing paper have better ink absorption performance, the size, shape and distribution of the coating gap should also be well controlled.

In addition to the direct relationship between the ink absorption rate and the porosity, the shape, size and distribution of the voids in the coating, it is also related to the paint-to-paint ratio and the type of adhesive. The larger the gel-to-color ratio, the worse the hydrophilicity of the coating and the slower the ink absorption speed. The better the water resistance of the adhesive, the slower the ink absorption speed of the coating.