Printing 

Printing is an important way of information transmission and an effective means of beautifying commodities. The popularization and application of plastic products have promoted the development of plastic printing, and the development of plastic printing has made the application of plastic products richer and more sufficient. However, not all plastics have good natural printability. Some plastics are collectively referred to as hard-to-print plastics due to their non-polar molecular structure, too low surface tension, or too smooth surface and stable chemical properties, which affect the adhesion of inks. The plastic surface is introduced into polar groups, or the surface tension is increased, or the surface roughness is increased by plasma treatment. This process provides a new way for the printing of difficult-to-print plastics !

The surface characteristics of the substrate are an important factor affecting the adhesion of the ink. People engaged in printing know that the surface of commonly used printed paper has undergone various post-treatments to obtain good process results. The surface of the paper printing layer is covered with some coating, some cover and transfer aluminized metal foil, and some surface is coated with varnish or varnish, and even the surface is filmed. Ordinary white cardboard ink is easy to adhere, generally do not need special treatment ; when the surface of the substrate is a transfer metal aluminum foil ( transfer laser ), the adhesion is low due to the poor ability of the metal surface to absorb ink. Therefore, when the above situation occurs, it is necessary to consider whether the paper surface dyne value meets the printing requirements ; generally, the film factory or paper factory will detect and process the dyne value of the paper surface during production, so that it can meet the printing requirements. The surface dada value test technology of paper uses the dada pen to judge. In general, the surface dada value is large, the surface tension is large, and the printing ink is firmly attached ; if the surface tension is too low, ordinary ink or varnish cannot adhere firmly.

Therefore, before printing, surface treatment must be carried out to activate the plastic surface to form new chemical bonds to roughen the surface, so as to improve the adhesion fastness of the ink to the product surface. At the same time, in the process of manufacturing some granules, a certain amount of additives, additives, and lower opening agents are added according to different requirements. When the suction film is finalized, these additives float on the film surface to form an oil layer that is invisible to the naked eye. These oil layers are completely unfavorable to printing, making the film surface difficult to adhere, and the adhesion force decreases. Therefore, the materials with these oil layers must undergo surface treatment to remove the oil on the film surface and improve the adhesion of the ink and coating. 

After plasma treatment, the surface molecular structure, surface roughness, surface wettability and adhesion of printing materials such as plastics have changed significantly. Plasma causes free radical reaction on the surface of printing materials to crosslink the polymer, roughen the surface and increase its wettability to polar solvents. These plasmas enter the surface of the printed body by electric shock and penetration to destroy its molecular structure, and then oxidize and polarize the treated surface molecules, activate the surface, so as to increase the adhesion ability of the printed surface.

Paste box paste box 

In the packaging and printing process, in order to ensure that the printed matter is not rubbed in the circulation process, as well as to improve the waterproof performance and product grade of the printed matter, some protective treatment, such as glazing or filming, will generally be done on the surface of the printed matter. At present, in the polishing process, due to the poor affinity between UV varnish and paper, it is easy to open the glue in the paste box or paste box. After the film is coated, the surface tension and surface energy of the film will be different under different conditions, and the bonding properties of different brands of adhesives are different, and the phenomenon of glue opening often occurs.

In order to deal with the phenomenon of opening glue, some packaging and printing enterprises do not hesitate to increase the cost of purchasing imported or domestic high-grade paste box adhesives, but if the adhesive is improperly stored, or for other reasons, sometimes there will be a phenomenon of opening glue. To this end, the major carton pasting machine manufacturers are equipped with a grinding machine on their respective equipment, grinding the pasting part of the UV light oil, which can effectively solve the glue opening phenomenon, but there are still the following problems : 1 When grinding, a part of the ground paper powder will not only pollute the surrounding environment of the equipment, but also increase the wear and tear of the equipment ; because the direction of the linear speed of the grinding wheel is opposite to the direction of the product operation, it is bound to affect the running speed of some products, thus reducing the work efficiency. However, the products after coating can not be polished, so the method of cutting tooth line is generally adopted, or the position of the paste is avoided when the film is coated ( suitable for larger size products ), and the high-quality adhesive can also be used to effectively solve the problem of opening glue, but there will also be process problems and increase the cost of the knife plate. The low temperature plasma treatment technology does not need to grind or grind the surface of the product, and when conditions permit, it can also use low-cost adhesives to save costs, and can effectively solve the problems in the above traditional paste box process.

The role of plasma treatment mainly comes from two aspects. The first is to clean the surface and remove various pollutants. The second is to activate the surface, and perform certain physical and chemical modification on the surface film, UV coating or plastic sheet to improve its adhesion. It is as easy to bond as ordinary paper. The plasma itself is electrically neutral, so it will not burn the surface when dealing with some aluminized surfaces. And the plasma is still low temperature, it will not have any thermal effect on the surface. Treated under normal process settings, no traces of any treatment will be found on the surface. 

The low temperature plasma treatment technology has the following advantages : 1. The product quality is more stable, and there is no glue opening phenomenon ; the cost of the paste box is reduced, and the ordinary adhesive can be used directly under conditions, which can save more than 30 % of the cost ; 3.Directly eliminate the impact of paper wool powder on the environment and equipment ; 4, improve work efficiency ; 5.For customers in the northern region, the use of its role in winter is more obvious.