Common sense of tube printing

Flexible tube printing is a printing method on metal tubes (tin-lead alloy, aluminum, etc.), laminated tubes, plastic tubes, etc.

Metal tube printing is done by using the principle of indirect squeegee roll transfer of graphics and text.

The toothpaste tube printing currently used in China is made by assembly line. The tin and lead raw materials are input into the eight entrances. The tube is flushed, threaded, background color is printed, graphics and text are printed, baked, capped, and filled and sealed. Finally, the packing is complete.

The printing plate used for tube printing is usually a copper plate, because the copper plate has a higher printing resistance, and the plate making method is the same as that of the ordinary copper-zinc plate.

The tube printing machine is mainly composed of a printing plate cylinder, a rubber cylinder, an impression cylinder plate with a tube, a conveying mechanism, an ink fountain, etc.

Because the substrate is non-ferrous metal, the tube must be printed with a layer of white ink or other background ink before printing the graphics and text. Then the graphics and text can be formally printed. After the background color is printed, it is necessary Make the ink dry quickly. Only the next few colors can be printed, so the printing color is dried by the infrared drying device and then the graphics and text are printed. The overprinting of graphics and text is not realized like traditional printing on the paper of embossing Zhuangjian, but the imprint on the three printing plate cylinders, and at the same time overprinting on the rubber quilt (because the imprint is solid, it is overprinted and combined. No overlap), and then transfer the three-color ink print to the tube on the embossing roller at a time. The impression roller on the impression cylinder disk is covered with a tube, but it does not rotate by itself. Only after it comes into contact with the squeegee, can it rotate at the same linear speed as the squeegee. The diameter of the impression cylinder is the same as the diameter of the blanket cylinder. , But the operation is different. The blanket cylinder rotates once and the impression cylinder rotates 90° to complete the printing of a tube.

After the tube rotates once, it is separated from the rubber cylinder, and the overprinting work of the tube printing comes to an end. Then, it is irradiated with infrared rays to quickly dry the print and increase the brightness of the print.

Toothpaste tube, tube shoe polish and medical ointment tube are printed in this way.

The printing ink for metal tubes should not only have heat resistance and light resistance, but also because the tube will encounter squeeze and twists during use, and often encounter water and moisture, the ink should also meet the above conditions. The materials inside the tube are different, and the ink must also be able to resist the erosion of these materials.

Laminated tubes have the respective advantages of the two materials of the sharp angle. Laminated synthetic tubes make it a tube with both advantages. For example, a laminated tube made of aluminum foil and plastic film has moisture resistance and weather resistance. Advantages: it can be printed first and then laminated, so that the graphics and text are in the plastic film layer, and the appearance is very beautiful. At the same time, it can be processed and formed after printing, and the method of first forming and then curved printing is changed, so that the photogravure method can be adopted. Carry out plastic printing, laminating and forming into a laminated tube.

Because of the poor adhesion of plastic ink in plastic tube printing, surface treatment is required for printing. At present, the hot press transfer method is used in foreign countries to print pictures and texts on transfer paper (that is, coated kraft paper), the color sequence is the opposite color sequence of color printing, and then a layer of heat treatment is applied on the printing surface. Substances that can produce adhesion, and then the transfer paper with graphics and text is contacted with the curved surface, and the transfer is carried out under heat and pressure.


Post time: May-11-2021