Introduction of printing methods for hose printing

Hose printing refers to the principle of printing an image by using an elastic rubber layer.
According to different materials used, the hose containers mainly include metal hoses, plastic hoses, laminated composite hoses, and blow-molded hoses. Due to the different materials used, various hoses have different manufacturing methods. In the following, only the metal hose is taken as an example to illustrate the main process of its manufacture and its equipment.
Metallic hose printers are printers that use metal (aluminum) hose as the main product. Due to its light weight, non-pollution, and relatively stable price, the aluminum hose is suitable for high-speed mass production and has been widely used.
1. The aluminum hose is made of aluminum core as the base material during the aluminum hose manufacturing process.
2. Annealing. Since the aluminum material is different from tin and zinc, the work hardening is likely to occur during the extrusion molding process. Therefore, the surface hardening layer should be softened by the annealing treatment, and the residual stress should be eliminated so that the crystal grains in the structure can be normalized.
Annealing is performed in the annealing furnace, and the processing conditions are determined according to the size of the hose. However, it must be heated to the softening point of the metal. Generally, the temperature is controlled in the range of 450 to 700° C., and heating is performed to cool slowly.
3. Painting. The enamel tube can be coated after being annealed.
(1) Coating generally includes inner surface coating and undercoat surface coating. In order to improve the inner resistance of the aluminum hose, the inner surface of the hose should be coated. The main purpose of the aluminum hose is to prevent corrosion of the aluminum material due to contact with the contents. On the other hand, it is also possible to prevent the contents from being affected by aluminum. The material is degraded by direct contact. Therefore, it is required that the inner surface should have chemical resistance, and the coating used should also have adhesion and wear resistance.
2 The bottom coating. The primer coating is mainly used for forming the background color of the hose printing, and the coating used is generally a white or colored coating. The bottom coating should have flexibility, light resistance, and adhesion to printing inks.
Coatings used in the basecoat are typically denatured alkyd, modified epoxy, and epoxy.
(2) Coating machine. Painting can generally use spraying and spoke coating machine to install the hose on the mandrel of the rotary disc, and the hose can rotate on the mandrel. When the rotating disc rotates, the surface of the hose is directly in contact with the applicator roller, and the coating process is completed by the frictional force driving the hose to rotate. The coating thickness can be controlled by adjusting the center distance between the discharge roller and the transfer roller.
4. Four-color hose printer. The hose can be printed after coating on the bottom layer.
At present, four-color hose printing machines are generally used for hose printing. The machine consists of a four-color printing Plate cylinder, a four-color inking device, and a blanket cylinder to form a transfer device. That is, the color pictures are first transferred to the blanket, and then the printing picture is transferred to the surface of the hose.
At the time of printing, the hose is inserted into the mandrel of the rotary disc and the hose can rotate on the mandrel. When the rotary disk rotates, a printing pressure is applied by contacting the blanket on the blanket cylinder with the surface of the hose, and the graphic on the printing plate can be printed in multicolor by the transfer of the blanket in sequence. After printing, the hose is pulled from the mandrel and sent to a drying device for drying.
The center distance between the rotary disk and the blanket cylinder should be adjustable. A reasonable printing pressure can be obtained by adjusting the center distance or changing the blanket thickness of the blanket. In addition, the mandrel should meet certain accuracy requirements, and the mandrel and hose inner diameter are interchangeable.
The printing plate used is generally made of zinc plate and aluminum plate, and a relief plate is made by a photoengraving plate-making method, and a resin relief plate can also be used.
Hose presses can use up to 150 units/minute if they use an automatic conveyor system. If the automatic packing machine is connected online, an automatic hose production line can be realized from the supply of the material to the delivery of the product to accommodate mass production.