Study on Printing Quality of Different Properties by Ink Jet Printing(2)

è´°, literature discussion

First, inkjet technology

(A) The characteristics and advantages of inkjet printing

Inkjet printing is a type of digital printing, which has the advantages of high speed, small amount of replication, and ease of use in combination. It uses digital data to store images and can be output directly without the printing plate. Therefore, as long as the content of the output can be arbitrarily changed before being output, the process of imposition and printing, as well as the time and consumables required for these processes, are eliminated. This is for the printing staff and their customers. It's nothing more than a great gospel. In addition, because of its non-contact printing method, it also eliminates the problems that traditional printing such as pressure adjustment of printing plates, dot gain, ink balance (lithography) and paper surface smoothness can not escape (Zhang Fuguo, 1992). Features become a weapon for inkjet printing in the future market. The following are the main characteristics of inkjet printing mentioned by Mr. Zheng Wanyuan in his 1997 paper:

1. Advantages:

(1) The printing method is non-contact, so it can be applied to rugged materials without noise.
(2) No printing plate is required to make the ink jet printing faster, and at the same time, the printing material cost can be saved.
(3) Inkjet printing usually uses water-based inks of direct or acid dyes. Although these inks have the advantages of flame-retardant fire resistance and reduced pollution, they have the disadvantage of poor drying, so they must be made on the material of the printed materials. Special considerations.
(4) The device can be miniaturized to save space.
(5) High-resolution, high-speed printing, non-coated paper and coated paper can be printed.

2 disadvantages:

(1) Poor adaptability to environmental conditions It is easy to change or pseudo-aggregate ink composition for temperature changes.
(2) Dust, paper dust, air, etc. often cause nozzle clogging.
(3) The machine has weak resistance to vibration during transportation.

(b) Microneedle point piezoelectric ink jet technology

In recent years, various inkjet technologies have developed rapidly. EPSON has also developed the use of the conductivity of the crystal. Microneedle point piezoelectric ink-jet technology effectively utilizes the expansion of the crystal when energized, pulls back when the power is stopped, and stabilizes the control of multilayer piezoelectric plates. The voltage is on the crystal. You can control the density and size of ink dots precisely and reach a stunning realm of 1440dpi. Compared with the bubble jet method, the reaction rate of the possible impurities in the bubbles generated by heating and the action of the heating and the jet re-cooling itself is not as fast as the voltage change. Regardless of speed or fineness, the bubble technology has reached a bottleneck, and the "piezoelectricity" is about to begin. EPOSN PerfectPictureImaging System Technology: Everyone knows that the more finely divided the data is, the more accurate the original image can be reproduced; and the fundamental element of EPSON's ability to display higher image output quality time and time again is: The power of resolution. In addition to the high resolution, EPSON integrated accurate color conversion, ink, and paper into the technology category, making the EPSON PerfectPicture Imaging System a comprehensive technical standard for thinking. The main technologies are micro-needle point piezoelectric ink-jet technology, true color conversion technology, intelligent control ink dots, and quick-drying ink. (EPSON website)

(III) Thermal Bubble Inkjet Technology

Both Canon and HP are using similar technologies to develop, and HP has developed a unique color-level inkjet technology! In simple terms, the color gamut technique is a technique that allows an ink jet printer to have multiple color variations on the dots that are ejected. This includes the use of the six-color ink series, which adds two light colors, light magenta and light blue, in addition to the four colors (CMYK) so that each ink dot can exhibit more color changes (2 x 2 x 2 x 2 x 2 = 32 types) to reduce the disadvantages of using halftone simulation and improve print quality. In addition, HP has also improved the nozzles with only two variations of spray and no spray, so that each color printhead can be sprayed and sprayed with 16 drops in a total of 17 levels of change and mixed with each other on the same ink dot. Each color is mutually exclusive. The hierarchy can reach a high level of 4913. This is called PhotoREt II - the second-generation photo-based technology, used only on HP high-end models. Through the development of this technology, HP no longer needs high dpi technology, so that the printer can display the continuous tone that the photo should have. Not only that, HP also claims to be able to express photo quality on plain paper! Therefore, the main technologies are the enhancement of “color rank capability”, the printing of photo quality assurance on plain paper, and the sRGB color management standard. (Pan Bingwei, 2000)

Second, for inkjet paper properties

(a) paper types

Coating type paper is mainly used for color printing. Different proportions of binders, fixatives and other additives will affect the ink absorption speed, absorption capacity, dot diameter, dot shape, printing density, color, and water resistance.

(B) Print quality characteristics of inkjet paper

From the point of view of the papermakers, to satisfy the so-called perfect print quality, it is necessary to review the contents of the paper cited below.

1. Physical properties: voidage, void volume, surface roughness, smoothness, void shape, air permeability, paper roughness index Kr, absorption coefficient Ka, contact angle (dynamic, static)
2. Chemical properties: dye affinity
3. Optical properties: S value, opacity
4. Other: review of various additives, friction coefficient, stiffness, flexural strength, paper curl, tensile strength, tear strength, basis weight thickness, degree of sizing, surface strength whiteness, immersion elongation, dimensional stability (Expanding), Moisture, above include the requirements for inkjet paper. In addition, the differences between inkjet paper and other papers can be summarized in the following three points:

1. The paper must be able to absorb the ink without being pressed into a plate, that is, the paper itself has a good ink absorption.
2. The ink dots have a strong contrast and a bright shade on the paper.
3. The paper must have good smoothness and gloss in order to obtain good color performance and sharpness of dots. (Zheng Wanyuan, 1997).