Plastic package printing types and characteristics

There are many printing methods for plastic packaging box printing materials. Toppan, gravure, screen, and offset printing are widely used in the printing of plastic packaging boxes.

Topographic printing features

In flexo printing, flexo plates are mainly used in plastic packaging printing, mainly printing plastic films.

The printing part of the letterpress printing plate is higher than the blank part, and all the printing parts are on the same plane. When printing, the printing part is coated with ink, because the blank part is lower than the printing part, so the ink is adhered and then the printing is made. The object is brought into contact with the printing plate, and a certain pressure is applied so that the printed portion on the printing plate is transferred onto the printing material and the printed product is obtained. Since the blank portion is concave, the blank portion of the print is slightly raised during the pressurization to form a printed product. The surface of relief printing has unobvious unevenness, which is characteristic of letterpress prints.

Flexo is the main force of letterpress printing. It is widely used in newspapers, books, and box printing fields and is showing continuous development trend. For example, carton printing, box printing, cardboard printing, plastic printing, metal foil printing, napkins, toilet paper and facial tissues. Printing and so on.

Gravure printing features

The advantages of gravure printing are high printing quality, bright colors, thick ink layers, clear picture layers, and high resistance to printing, but the plate making cost is high and the cycle is long.

Gravure printing is also called engraving gravure. The intaglio graphic part is lower than the blank part. The degree of depression is related to the level of the image, that is, the darker the image, the deeper it is. When printing, the layout is first coated with ink, and ink is used to scrape off the ink on the blank part of the layout so that the ink remains only in the recessed image. In some cases, the ink is transferred to the substrate under the pressure of printing to obtain the printed product. Due to different depths of depression, the amount of oil is different, and the thickness of the ink on the print is not the same. Where there is a large amount of ink, the color appears dark, and where the ink is light, the color is light, so that the tone level of the image is reproduced.

Gravure printing is widely used in large-volume prints, such as paper box printing, magazines, newspapers, and plastic box printing, as well as securities and stamps. Gravure printing has a high market share due to its high color saturation and rich image hierarchy.

Screen printing features

Screen printing is characterized by a thick ink layer and a wide variety of substrates. Substrates can be made of various materials or in various shapes. They are now widely used in the printing of metal plates, plastics, and fabrics, especially in the printing of high-grade packaging boxes.

On the printing plate of a stencil printing, the printing part is composed of holes of different sizes or meshes of the same size but of different sizes, the holes can penetrate the ink, and the blank part cannot penetrate the ink. During printing, the ink passes through holes, stencil printing or mesh printing on paper or other substrates to form printed products. The stencil printing product has a thicker ink, and has a larger amount of ink than gravure printing. Screen printing is the main method of stencil printing. Its printing plate consists of screen (nylon, polyester, metal) and frame. The screen is tightly stretched on the frame, and the graphic is printed by the screen mesh leaking ink.

Lithographic features

Offset mainly prints plate-printed paper, offset paper, and color graphics on the packaging cardboard. The products mainly include high-grade prints such as calendars, product advertisements, pictures, books and magazines.

Pure plastic box printing basically does not use offset printing, but paper-plastic composite cardboard has offset printing.

Lithographic printing (mainly offset printing) has no significant difference between the printed part and the blank part, and it is almost on the same plane. The printing part has oleophilicity by means of sensitization or transfer: the blank part is hydrophilic by chemical treatment. When the box is printed, the principle of repelling oil and water is used. First, water is applied to the plate surface to make the blank part absorb moisture, and then the ink is transferred to the plate so that the graphic part is attached to the ink, and the packaging box is printed. At this time, the blank part has been adsorbed. Moisture, and can not absorb ink, and then the substrate directly and in contact with the printing plate contact, the ink transferred to the substrate.