The use of gold and silver powder ink and the future development trend of gold and silver powder ink printing technology

When printing gold and silver ink, the choice of printing material is very important, because there are many pores on the surface, and the permeable substrate will absorb the transparent resin liquid, especially when the viscosity of the ink is low, the resin will be absorbed, and the pigment particles will be Leaving on the surface of the substrate, the resin composition is small, which causes the silver powder to appear gray, while the gold powder appears brown. If you have no choice but to use absorbent materials, it is best to print a layer of ink (like a traditional transparent varnish) to seal the pores on the surface of the substrate and then print gold on it. Silver ink. A layer of varnish is printed on the metal ink film to resist the detachment and abrasion of particles in the ink. However, the more transparent varnish on the metallic pigment particles, the weaker the reflective properties and gloss of the ink film. Metallic pigments such as copper gold powder and aluminum silver powder are easily oxidized. Taking gold powder pigment as an example, oxidation occurs on copper and zinc particles, resulting in a decrease in gloss of the ink layer. In some cases, the ink may even appear pale green. The aluminum pigment in the aluminum silver powder pigment is easily grayed and whitened after oxidation. Oxidation is one of the reasons why color consistency of gold and silver powder inks is difficult to achieve. Another reason why color consistency is difficult to guarantee is the arrangement of the pigments, especially the layered gold-silver powder ink, which floats on the surface of the ink film to form a lot of voids (the coarser the size of the color particles, the larger the voids). After printing, the appearance of these small voids causes the color of the substrate or the color of the underlying ink to appear visually through the surface color of the metal layer. For example, a silver ink on a blue background will appear light blue; if a yellow or green ink film is pre-printed under the gold ink, the gold color of the ink will be changed. This problem can be alleviated by using achromatic colors such as white or bright gray as the primary color. Silver pigments usually exhibit a dark hue, while gold powder can not only exhibit dark tones, light tones, and various shades between the two, but can also be used to obtain a series of "oxidized tones", meaning that the pigments are allowed and controlled. The resulting oxide is reacted, and the reaction results include a golden color with a lemon yellow or light orange color.

Gold pigments can also produce light shades such as green or purple, which are obtained by adding pigments of various colors to the gold powder ink. However, these colors are more unstable, and they are very uncoordinated compared to pure metallic colors, and are also prone to fading. Light-colored silver powders are often used as transparent colorants so that they look like gold powder pigments. This method also solves the problem of oxidation of gold powder. Such silver powder can be used for non-layered gloss inks, but the color is not as clear as the standard layered silver ink. In addition to traditional colors, most color grading systems point to a range of metallic inks. Silver powder metallic pigment is used as the primary color and then colored with red, yellow or orange ink. The challenge in making this ink is that some red, orange, yellow and other pigments used for color matching may react with metallic pigments, thus destroying the printed graphic. Producers need to be extremely careful when formulating metal colors to avoid these problems. The use of toned gold and silver powder inks increases the coverage area and enables more accurate blending of special colors. However, some of the ingredients added for toning will reduce the luster of the gold and silver pigments. When customers ask for maximum reflection, it is recommended to use dark, pale gold, like silver powder, in their purest form. Another factor that affects post-press gloss is the color purity or clarity of the resin used in ink manufacture. The higher the clarity of the resin, the more light is reflected and the better the gloss of the ink. When discussing the appearance of gold-silver ink, we should notice a phenomenon: since metallic pigments are used in gold and silver inks, the appearance of the printed ink film changes with the viewing angle. This is why it is generally not recommended to use traditional printed spectrophotometers to measure gold and silver prints. The accurate measuring tool is a spectrophotometer for the automation industry. The device recognizes the color from multiple angles and finally obtains an average value, which can accurately determine the color, but the price of such a device is usually unaffordable for screen printing companies.

Copper gold powder, aluminum silver powder metal pigment particles are purchased separately from the binder. They should be very slow and careful when mixing; because rapid mixing will generate heat, which will promote oxidation, cause decomposition of metal foil, turn silver into gray, and turn gold into gold. Browning also reduces reflection and gloss. The ratio of pigment mixing varies depending on the size of the pigment flakes, and is also related to the desired post-printing ink film. In general, it is safe to start mixing with 8% silver pigment or 15% gold pigment by weight. According to the recommended value of the ink producer to ensure the adhesion and appearance of the ink. If possible, the least amount of pigment should be the most desirable. Because the result will be better transfer performance of the ink and higher durability. The idea of many printers - adding more pigment powder to the mixture does not increase the gloss of the ink. The fact is that the smaller the amount of pigment, the better the adhesion, the more uniform the ink film, the more uniform it means the smoother the surface, the better the reflection performance, and of course the better the gloss. Therefore, the minimum amount of pigment is used under the premise that the target color and coverage area can be achieved. When mixing silver powder inks, extreme care must be taken if the aluminum pigment is in powder form. Because aluminum powder reacts with water or moisture to release hydrogen, it can cause an explosion. Therefore, if you insist on using aluminum powder to make silver ink, be sure to store the aluminum powder in a dry, temperature-friendly place. In contrast, aluminum is safer in the form of a paste, and all aluminum powder producers supply a variety of solvent-based, water-based and UV-dried ink-compatible paste pigments.

The use of gold and silver powder ink and its future development trend

Screen-printed ink manufacturers are continually striving to refine gold and silver inks to make them easier to use and produce shocking results. In recent developments, metal-effect ink types have included new appearances that provide chrome-like appearance. But in order to get real examples of the chromium effect, the printer must carefully test to determine how much pigment is needed. The less pigment you usually use, the better the effect.

    Gold and silver powder inks, especially silver powder inks, are completely impenetrable to radiation, making them ideal inkjet printing applications, such as selective blocking of light in certain instruments. However, when metallic silver having a strong reflective property is used as a protective coating, the color of the graphic printed thereon changes.

    The good results of screen printing of gold and silver inks can increase the value of many products related to printed matter, including binding, labeling, packaging decoration, and eye-catching graphics.

As with any other product, screen printers understand the composition, production process, and limitations of the performance of the gold and silver ink. The advantages of this ink can be introduced to the customer as much as possible, so the gold and silver ink is printed. Another golden opportunity for the people!