There are many types of varnish, but commonly used varnishes can be roughly divided into three categories: oil-based varnish, water-based varnish and UV varnish. According to the practical application trend of varnishing oil and the improvement of environmental protection requirements, the use of oil-based varnishing will be reduced day by day, while the application space of water-based varnishing oil and UV varnishing oil is very broad. The following mainly introduces the water-based varnishing oil and UV Polishing oil. Water-based varnish (called WATER BASE DVARNISH in English, also called DISPEERSE DVARNISH), is mainly composed of water-soluble resin and water-dispersed resin. Water-based varnish is non-toxic and odorless, eliminating harm to the human body and harmful effects on the human body. Environmental pollution, it has the characteristics of fast drying speed, good film transparency, stable performance, wide equipment adaptability, good wear resistance and flatness of the glazing surface, wide post-printing processing adaptability, good heat sealing performance, safe and reliable use, and storage Features such as convenient transportation have attracted more and more attention from food, medicine, and tobacco carton packaging and printing companies. When using UV water-based varnish, you should pay attention to the following typical issues:

① How to ensure that the underlying ink can be fully dried after applying the water-based varnish. First, ensure the breathability of the water-based varnish. The wet ink layer can be exposed to the air to dry the oxidized conjunctiva; in addition, this problem can also be solved by appropriately increasing the hot air temperature.

② The glossiness of the water-based varnish coating is lower than that of UV varnish. In practice, a small amount of high-boiling point solvent can be added to the water-based varnish to swell the emulsion particles and promote smoothness. Better coating film, thereby improving the surface smoothness of the coating film, and ultimately achieving the purpose of improving the gloss of the water-based varnish coating. UV glazing is a method of curing glazing paint using UV (abbreviation for Ultraviole) irradiation. It has the characteristics of rapid curing of coatings and low-temperature curing inks that are not easy to fade, which helps to solve many problems in the gloss processing of paper printed matter. Therefore, it has been widely used in the gloss processing of paper containers, trademarks, book covers, packaging boxes and other printed matter. application.

UV varnishing oil contains almost no solvents and produces very little organic volatile emissions, thus reducing air pollution; UV varnishing oils do not contain solvents and do not require heat energy during curing. Consumption is relatively small. In addition, UV varnishing oil has strong affinity for ink and adheres firmly; UV varnishing oil has high active ingredients, less volatilization, and relatively economical usage; the printed surface after UV glazing curing is more wear-resistant, chemical-resistant and resistant It has good chemical properties and stability, and can be scrubbed with water and ethanol; UV glazing products are not easy to stick and can be stacked after curing, which is beneficial to post-processing operations.

When using UV varnish, you should pay attention to the following typical issues:

①UV varnish is not suitable for operation on permeable paper. Because the low-molecular materials in UV coatings easily penetrate into the paper, causing the paper to darken or even soak through. At present, most UV varnishes are used on printing papers with aluminum coating.