What are the printing methods for plastic packaging bags?

2022-09-14 16:30:06 Kristal

Plastic printing includes gravure printing, letterpress printing, screen printing, flexographic packaging printing, indirect gravure printing and composite packaging printing according to the structure and method of the plate.


(1) Gravure printing is mainly used for packaging and printing plastic films, which are used to manufacture various types of plastic packaging bags. Gravure printing is one of the four packaging printing methods. Gravure printing is a type of direct packaging printing method. 


It directly presses the printing ink contained in the gravure dents onto the substrate, and the depth of the printed image is determined by the size and depth of the dents. If the dent is deeper, it contains more printing ink, so the ink layer left on the substrate after pressing is thicker; conversely, if the dent is shallower, the amount of printing ink contained is less, so after pressing The ink layer left on the substrate is thinner.


MetInfo enterprise content manager system | MetInfo CMSThe printing plate of gravure printing is composed of dents and the surface layer of the printing plate corresponds to the paper manuscript image one after another. When packaging and printing, the printing ink is first filled into the dents, and then the printing ink on the surface layer of the printing plate is scraped off with an ink scraper. 

There is a certain pressure contact between the printing plate and the substrate, and the printing ink in the dent is transferred to the substrate to complete the packaging printing. Gravure printing, as a type of printing technology, has the advantages of a thick ink layer, bright colors, high color saturation, high printing plate durability, relatively stable quality of printed products, and fast packaging and printing speed in packaging printing and text graphics. It occupies a very important leading position in the publishing industry.


(2) Letterpress printing is mainly flexographic packaging printing. The flexographic packaging printing plate uses a photosensitive resin material plate as the plate material to be fixed on the printing plate cylinder with adjustable repeatable size. Then, the ink is applied by a metal ink roller with ink holes engraved by a computer, and the anilox ink transfer roller is controlled by another ink roller or ink scraper to control the amount of ink.


MetInfo enterprise content manager system | MetInfo CMSFlexographic packaging printing is to transfer liquid or grease printing ink to various printing materials. It can print up to 12 colors at a time, and it is easy to use. It is a new type of packaging printing method developed in the plastic printing industry. Flexographic packaging printing still belongs to the scope of letterpress printing, but because its printing plate, oil and printing process are different from traditional letterpress printing, it has extensive adaptability to substrates, and the cost of packaging and printing is cheap. , And has excellent packaging and printing effects, widely applicable to various types of plastic packaging bags, flexible packaging, composite packaging, and so on.


(3) Screen printing is mainly used to package and print plastic films and various containers that have been extruded, and it can also print transfer materials to transfer text on special-shaped plastic products.


Screen printing refers to the use of screen mesh as the plate base, and the use of light induction printing plate-making method to make a screen printing plate containing text and graphics. Screen printing consists of five basic elements, screen printing plate, squeegee, printing ink, packaging printing table, and its substrate. Part of the mesh of the screen printing plate can pass the printing ink, and some meshes of the non-text can not pass the printing ink to complete the packaging printing. 

When packaging and printing, pour the printing ink on one side of the screen printing plate, use a scraper to add a certain pressure to the printing ink position on the screen printing plate, and at the same time move toward the other end of the screen printing plate at a uniform speed, and the printing ink is moved during the movement. Squeegee extrudes from the mesh in part of the text onto the substrate


MetInfo enterprise content manager system | MetInfo CMS

(4) Special packaging printing is other packaging printing that is different from traditional packaging printing methods, including inkjet packaging printing, gold, and silver ink packaging printing, barcode packaging printing, liquid crystal packaging printing, magnetic packaging printing, pearlescent packaging printing, Hot stamping anodized aluminum, etc.


As shown on the left is the printing method of bronzing.