The use of special inks

I. Preface

Printing ink is a type of printing equipment used to form images of various colors on substrates. A simple printing machine such as a copy printing plate has a large number of rollers, such as an offset printing machine, and the printing ink must have a correspondence. The printability of various printing presses. The addition of special inks to this line further satisfies people's five sense requirements and enables them to increase the added value of their printed products. This is called "additive value ink" or "functional ink."

As we all know, the ink is not a monomer, it is a pigment or dye, as well as an extender pigment and a binder, and other additives. The link material is made of various resins and plasticizers and solvents. Special inks need to select materials that can perform corresponding functions from the raw materials listed above, and they are sometimes specially developed and designed to meet printability.

This article is limited by space, can only briefly introduce the use of a variety of special inks, as for the use of a variety of special ink and use it to print methods, there are many involving patents and anti-counterfeiting regulations, and separate disposal.

Special ink

1. Water coating printing ink

Aquaphic printing, also known as wetting imaging, uses inks that are smeared with a water-based pen on a part of the picture printed with black one-colored rough dots and stripes to reveal red and blue. Yellow and other colors.

Water-soluble dyes are dispersed in base inks suitable for printing methods (waterless offset printing, letterpress, etc.). In the past, letterpress printing and platform gravure printing were once the mainstream. Recently, waterless offset printing has become more popular. There are two categories of "all black" and "red, yellow, and blue". They are used in the albums and appendices used by young children.

(1) Points to note in the printing process

The raw material used is preferably an offset paper which is easy to absorb water. Because the dyes are easily eluted to color, the picture is expressed with rough dots and stripes, so it is necessary to leave more white space. Black and black inks that rub in yellow, red, and blue dyes are used to print outlines and patterns using ordinary black ink, and patterns such as rough dots and stripes are printed.

If printing is made by an official printer, before printing, it is necessary to check the hue and density of printed samples by using a stick such as water. The use of waterless offset printing is not a problem with a small amount of dirt. When a water-based image is printed, the color development due to wetting causes very significant dirt. Therefore, the management of the critical temperature (CTT) is required.

(2) Printing method

Waterless offset printing is usually the most suitable, but the use of letterpress, platform gravure can also be.

2. Sublimation transfer printing ink

According to the heating up to 200 °C, it will sublime (solid → gas), use the ink made of dyes with this property, used to print on the transfer paper, attach it to the cloth and heat it with an electric iron 15-20 In the second, it was dyed with a colored pattern. This is called sublimation transfer. In terms of use, there are sporting flags, patterns printed on aprons, etc. The recent rare use of sublimation transfer printing on treated aluminum metal is the use of this ink.

(1) Points to note in the printing process

In order to prevent the generation of sticky sheets during heat transfer, it is preferable to use offset paper as the transfer paper. Regarding the fabric for transfer printing, natural fibers, polyesters, or polyester blends are not acceptable.

Because it is the final product that is transferred to the cloth, the reverse printing of the transfer paper is usually used. In addition, the color printed on the transfer paper is very different from the color printed on the cloth, because only the dye part is transferred, so the proof should be transferred when proofing.

In addition, the rotation resistance after the transfer is quite strong, but the state of the printed matter before transfer, its rotation resistance is weak, so it is better to perform the transfer operation as soon as possible after printing, and when it is necessary to save, care should be taken not to Exposure to sunlight or fluorescent lighting.

(2) Printing method

Offset printing or screen printing is preferred.

3. Scratch Printing Ink

When you wipe the print, you will see hidden text or patterns. There are many kinds of such prints.

(1) Coin printing

It seems that there is no trace of what is visible to the naked eye, but as long as a coin rubs, the text or pattern will appear. Ink is a hard white pigment (titanium oxide, etc.).

Attentions in the printing process: Try to make the printing surface and the raw material group into a non-glossy printing. In order to make invisible standards, it is better to use paper as a matte type. It's difficult to match up a group and add a layer of yellow mesh on it, or modify it with a softer, matte ink.

Insufficient ink, poor color performance, excessive ink, resulting in invisible difficulties, it requires adequate ink management. Due to the nature of such prints, the pattern is usually simple. Therefore, it is necessary to pay attention to over-emulsification. Once over-emulsification occurs, the transferability gradually deteriorates, and as a result, the color development of coin rubbing is poor.

In any case, thorough invisibility is difficult, so it is not suitable for lottery tickets related to high-priced scenery and so on.

Printing method: It is preferable to use offset printing.

(2) pencil printing

Although it is not as inconspicuous as a coin is printed, it is also a printed matter that is invisible to the naked eye and can be printed or painted with a pencil.

Use a medium containing a matt material (microsilica, extender, glass frit, etc.) to print. Chromaticity depends on the amount of matte material (certainly related to the ink) and the amount of matte material is better. However, it is necessary to pay attention to the relationship between the amount of printing and the suitability for printing (inking, ink dropping, etc.), and to make a careful judgment on general-purpose matte coatings and matte media.

Such as the above, due to poor visibility, this scenario is best suited for young children's literary activities.

In the printing process, it is important to note that in order to obtain a sufficient color effect, it is desirable to use glossy coated paper. At the same time, it is better to use a little more dots and stripes than fine dots.

Printing method: It is preferable to use offset printing.

(3) Scraping printing

The concealed silver ink is removed with a coin or a nail varnish, and the original hidden words and designs are revealed. Widely used to scrape lottery tickets. The ink used is very resistant to scratches on contact with the surface, and only points and lines can be removed by the place where they were rubbed, and a special resin ink is used.

Attention in the printing process: In order to improve the concealment degree, the black ground is printed on the reverse side, and the pattern printing on the base should be carried out in light gray. The pattern of the substrate was offset and a brightening oil was added on top of it. At this time, OP printing hopes to print a bit larger than the silver ink that was overprinted. If there is insufficient drying of the OP, silver ink will not be peeled off, so care must be taken. Compared with "oily + oily OP + silver ink", "UV + UVOP + silver ink" is less likely to cause poor peeling.

Printing Method: Offset Printing (Pattern, Stripped Gloss) + Screen Printing (Ink) $ Page Break $

4. Aroma printing ink

Disperses fragrance oils or microencapsulated fragrances into the ink, allowing the print to scent. Recently, it has been used for advertisements such as perfumes, perfumes, and telegrams.

Although the method of microcapsules has a high fragrance-preserving effect, there is a limit to the amount of achievable encapsulated perfume, and it is necessary to confirm in advance. If the flavor oil (floral, fruity, etc.) is good, the material (food, etc.) containing water-soluble and water-soluble ingredients cannot be encapsulated.

Printing methods: Recently, despite the fact that there are prints printed using offset printing, it is better to use screen printing because of poor preservation.

5. Offset conductive ink

The resistance value is higher than that of the conductive ink used for brushing in the conductive paste and net in the bamboo body, but by using offset printing, a pattern imparting conductivity may be printed. According to the use of non-conductive ink and conductive pen, for the printing of learning materials.

The conductive carbon black was dispersed into offset printing materials to make ink. Conductive ink according to the usual ink, the resistance is 104Ω ~ 105Ω, non-conductive ink is more than 1010Ω. This resistance value belongs to the value of glossy coated paper, which is higher if matte coated paper or offset paper is used. According to the contact pattern with the pen tip, different lights and sounds are emitted depending on the range of resistance values, and a pen having such a function is required.

Although the glossy coating paper can obtain a low resistance value, it has the disadvantage of easily identifying the difference between the conductive and non-conductive inks. As for the matt coated paper and offset paper, the difference between the conductive and non-conductive inks is not easily recognized. Although the advantages of this project can be demonstrated, due to the high resistance value, the specification of the conductive pen becomes difficult. When adopting this project, you should consider the above balance to select paper.

The point of attention in the printing process is that the resistance value will vary depending on the pattern of the ink, the type of raw material, etc. The story of the first experiment is to be done more fully. In addition, the resistance values ​​of Wet (after printing) and Dry (after drying) are also different. Therefore, it is necessary to use the printed matter after drying in a dryer to confirm that the color hue of conductive ink and non-conductive ink should be kept consistent.

Printing method: It is better to use offset printing.

6. Uplift printing ink

(1) Uplift

Commonly used for business card printing and so on. The so-called uplift printing is derived from the use of the uplift printing machine by the American Barco Company. The resin powder is heated and melted (140-150°C) to swell, but the ink of the base can be used with ordinary offset printing inks and letterpress printing inks. Raw materials should be heavy offset paper, and light or coated paper will wrinkle or foam due to heating.

Printing method: Offset or letterpress + bump printing.

(2) thick thick oil

Overprint UV varnish on the raised part with screen printing. The type of lacquer is lacquer, matt, or wood grain. Applied to a variety of product samples and three-dimensional sealing and so on. Recent product samples of building materials do not use authentic products but are printed using this method.

Printing method: screen printing. $Page break $

7. Fluorescent and light-storing ink

(1) Twilight fluorescent ink

Now it is widely used, it seems that there is nothing special, in fact, from the perspective of color effects, it is a kind of fluorescent ink with a bright color that general ink can not get. Twilight fluorescent ink absorbs ultraviolet and short wavelength ends, and has the property of converting to long-wave color light, equal to the use of pigments with achromatic light amplification.

With this brightness, high-brightness printing can be achieved, that is, using the same pattern is generally compared with 4-color (yellow, red, blue, black) printing, 4-color + fluorescent (1 to 2-color) printing, can be more For a vivid reproduction. Recently, printing industries around the world have actively introduced flip-type 8-color printing presses. With the popularity of personal computers, the color reproduction area of ​​paper media can be expanded. As a result, multi-color printing of more than 5 colors is becoming more and more popular. . As a result, this technology will undoubtedly be further developed. However, since the anti-rotation property of the fluorescent pigment (solid solution dissolved by dissolving the fluorescent dye into the resin) is poor, if offset printing is used, the ink film will be thin and easy to cause discoloration. Therefore, it is necessary to fully pay attention to the selected type. For items such as advertising that require high spin-rotation resistance, screen printing that can print thick ink film is preferred.

Printing methods: offset printing, screen printing, gravure printing can be.

(2) colorless fluorescent ink

Because of its security, it is often used to print stocks or tickets. The pigment used for this ink is different from that used for daylight fluorescence. Usually (in the case of fluorescent light or fluorescent light) it is white or slightly yellow, but once it is projected with a certain wavelength such as invisible light