What’s the Purpose of Adding a Coating on UV Flatbed Printer?
UV flatbed printer UV printing technology is bringing a quiet revolution to advertising, painting and other industries due to the diversity of printable materials. On many transparent materials, such as glass and acrylic plates, a common printing technique is to add a white coating after UV color printing to give off vivid colors of the picture. Usually this layer of white back coating is made by a special nozzle on the printer to spray white UV ink. During our contact with customers, we found that after printing for a period of time, this layer of white ink will crack and cause pattern damage.
The main factor of white ink cracking is that the UV white ink has low strength and is relatively brittle. At the same time, due to the different thermal expansion coefficient of the ink layer and the substrate, the ink layer is stretched during the process of heating up the temperature of the material. UV curing technology has been developed in the past 20 years. Its main advantages are fast curing and environmental protection. The disadvantages are also obvious. Because the curing is fast, the internal stress of the material is relatively large and the strength is not high. This problem is even more pronounced in white ink. Usually, in order to achieve a certain coverage rate, white ink usually contains a relatively large amount of whitening filler such as titanium dioxide. The presence of these fillers will further reduce the toughness of the ink. Therefore, to avoid cracks caused by white ink, higher toughness materials should be selected.
There are two main types of flat printer coating, one is flat printer coating, the other is UV flatbed printer coating. No matter what the coating’s role is in the adhesion of the ink.
1.Flat Printer Coating
There are many kinds of flat printer coating. They are roughly divided into two categories according to the different printing materials: one is the metal coating. One is ABS coating.
- The metal coating is mainly divided into metal 4000-metal 5000. The materials used for this type of coating are ceramic tile, glass and metal. All materials with high surface density need metal coating.
- ABS coating, mainly divided into 22800, BL-BH. This type of coating is for acrylic, PVC, ABS and the like surface density is not large.
- The other is some of the more special coatings, such as melamine coating, silicone coating. Because these materials are special, special coatings are used.
- UV flatbed printer coating
Generally speaking, UV flatbed printers do not use coatings. But they still need to be coated with a layer of coating when they come into contact with metal. The coating of UV flatbed printers is rubbed. The main purpose of rubbing coating is to adsorb and clean the surface. Mainly due to the density of the surface of the metal, glass, tile is too large. And the ink can not completely penetrate into the inside, so you need a layer of coating.