After aluminum tube is formed by stamping, there are many processing procedures such as internal spraying, primer, printing, tail glue, tail sealing and capping. But not all packaged aluminum tubes need to go through all these processes. Which processing procedure should be used for aluminum hose depends on the nature of the filling content and the requirements of product design.
Although the processing procedure of aluminum hose is not high-tech, in order to produce high-quality aluminum tube for packaging, every procedure must be paid attention to in order to make the finished product perfectly presented to consumers.
The first step; Stamping, trimming and annealing of aluminum tubes
The raw material of aluminum hose is aluminum plate with aluminum purity of 99.7%. After the aluminum plate is formed into a tubular shape in the punching machine, it is trimmed, and the nozzle and tail are cut together to cut the required thread at the nozzle. Because of the high hardness of the perforated aluminum tube, it must be sent to a high temperature oven at 3500 degrees Celsius for softening, which is called annealing.
Step 2: Internal spraying
If the filler may react chemically with the aluminum pipe metal, it is necessary to coat a protective film on the inner wall of the aluminum pipe, and its raw material is usually epoxy phenolic resin. In practice, whether to carry out internal spraying or not and whether to carry out double-layer internal spraying will be determined according to the properties of the contents, such as corrosiveness and sensitivity to metal interaction.
Step 3: Priming and printing
The outer wall of aluminum hose is usually coated with a protective polyester resin, usually white, called primer. Its purpose is to form a protective film on the surface of aluminum hose, which can provide buffer in case of slight collision and reduce scratches, dents and damage. After priming and cooling, the aluminum tube is sent to an offset press to print words and patterns, and the pre-designed brand logo, explanatory text and warning are printed on the aluminum tube. Special printing methods, such as hot stamping and silver printing, have become very common.
Step four: cover.
After the aluminum hose is printed, cover it again. The cover is usually made of PP or PS plastic with various colors and styles, but it is usually selected according to the product attributes and customer's design, which is both functional and aesthetic.
Step 5: Stick your tail.
If the contents of the product easily react with air or water vapor, or are worried about the leakage of the contents, and want to improve the sealing performance, it is recommended to apply tail glue to the inner wall of the tail of the pipe body. Sealing the tail after applying tail glue can improve the sealing performance, effectively isolate air and moisture, and ensure the shelf life of the product. The width of the tail glue can be adjusted according to the actual demand. The wider the width, the better the sealing effect.