Advantages and uses of offset film inks and film oils

With the development of society, people's demand for fine prints is getting higher and higher. Lithographic offset printing materials have also become increasingly diversified from single paper, PVC, PE, PP, PET, synthetic paper, gold and silver cards, etc. Non-absorbent materials are also increasingly used as substrates. In recent years, the rapid development of UV offset printing technology has met this demand to a large extent, but UV offset printing currently has some limitations: the cost of UV offset printing machinery and equipment is relatively high; the cost of ink and consumables is relatively high; Management, process technology, technical personnel, and related supporting warehousing and production requirements are relatively high. Offset film inks are based on the basic principle of oxidized conjunctiva drying. The printing of non-absorbent printing materials such as plastic film and gold and silver cardboard is completed on ordinary offset machines. This solves the problem that many printing companies without UV offset printing equipment cannot engage in plastic films. The printing of printing materials such as gold and silver cardboard has greatly facilitated printing companies and expanded the scope of the printing business.

Offset film ink is characterized by: the ink is dried by oxidation conjunctiva, no UV or IR is required on non-absorbent substrates; after printing, the surface is dried and fixed faster than ordinary offset ink, and the printing is not easy to stick; good for the substrate Adhesion, colorful; Compared with UV offset ink, the printing ink layer of film ink is relatively thin and fine dot.

Offset film ink should pay attention to the following matters in use: PVC, PE, PP, PET and other plastic film should be corona treated before printing, in line with printing requirements; fountain solution PH value should be controlled at about 6 can not be too acid , otherwise it will affect the drying of the ink; the amount of alcohol in the fountain solution can be appropriately increased, can be controlled at about 15%, printing should minimize the amount of water used in the production, the layout of the amount of water caused by excessive ink emulsification will lead to ink Slow-dry or even dry; to use dusting, each stack should not be too high, so as not to cause sticky, printed parts should be placed in relative humidity below 60% in order to facilitate ink drying; should be cleaned immediately after printing The ink fountain and the ink roller prevent the ink from drying on the ink roller.

In addition to the basic four-color and bottom white, offset printing film inks are available in a variety of spot colors. It is a good realization of printing non-absorptive printing materials such as plastic film and gold and silver cards with ordinary offset printing presses. However, film inks also have deficiencies. The main manifestations are: Post-printing inks have a longer drying time on non-absorbent substrates. Drying of inks generally takes 5 to 6 hours or even longer. The inks are easy to scratch before printing. Dirty, prone to defective products during production operations. In response to this situation, the printing industry personnel have been painstakingly researched and successfully launched water-based gloss-film water oils that are specifically designed for use on non-absorbent substrates such as plastic films, thereby greatly facilitating printing operations, improving and Improve the quality of production.

According to the different coating methods, film water and oil can be divided into two types: film oil and water that are suitable for connecting to online optical machines and film water and oil that are suitable for independent coating machines. The light film water and oil on the line can be coated on the printing machine with an on-line optical unit to complete the ink color printing, and the printing and coating are completed once. Film water oil after infrared drying to reach the surface of the initial dry state, by hand gently press the surface of the ink and varnish will not stick hands, so that you can avoid dusting, to prevent the printed parts scratch and stick back. The film water oil is different from ordinary water oil used in paper, and has air permeability after drying and film formation, which is beneficial to the contact between the ink and the air, and does not affect the drying basic principle of the film ink oxidized conjunctiva. Film water and oil can effectively increase the adhesion of film ink on substrates, protect printing ink layers from scratching and improve resistance in all aspects. In addition, the film of water and oil can not only be fully coated on the light machine, but also can be used on the local coat resin coating for local coating, so that the print to achieve a very beautiful effect. For some films on the substrate after the printing ink is dry, wear and scratch resistance performance is poor. The independent coating film water and oil can enhance the ink's wear resistance, scratch resistance, and achieve a good adhesion effect. Convenient, ordinary infrared or hot air drying independent oiling machine can be coated.

Film inks are used in combination with film water and oil to print non-absorbent materials such as plastic film on ordinary offset presses, especially for printers with on-line optical units, which is an ideal choice for printing companies without UV offset equipment, and can also become Backup plan for printing companies with UV printing equipment.


Source: Graphic Arts