Aluminum tube is an environmentally friendly and economical packaging material, which is widely used in medicine, food, cosmetics, chemical and other industries. Its biggest feature is that the tube body will collapse after being squeezed, making it impossible for air to flow into the inside of the hose. Therefore, oxidation or contamination of the contents is not prone to occur, and the shelf life of the product can be prolonged.

Although aluminum tube is closely related to our daily life, many people are very unfamiliar with its production process. So, today I will share with you the main process flow for producing aluminum tubes.

Step 1: Flipped aluminium sheet

In order to increase the deformation and flow capacity of the aluminum sheet, reduce the deformation force required for the punching tube, and reduce the wear of the mold, it is necessary to coat a layer of lubricant on the surface of the aluminum sheet evenly. For a long time, most aluminum tube manufacturers choose zinc stearate powder as a lubricant for aluminum flakes.

Step 2: Aluminum tube stamping

The aluminum sheet is reciprocated by the punch in the cold extruder to squeeze the aluminum sheet and deform it to fill the entire mold cavity. The aluminum material flows along the direction of the punch and the punch where the resistance is the least, and passes through the annular gap between the bottom die and the punch to form a basically shaped aluminum tube. At this time, the aluminum tube has not been modified, the tail and nozzle are not neat, and there is no thread on the tube neck.

Step 3: Modification

The basically formed aluminum tube is sheathed on the expansion mandrel of the modifier through the conveying chain and mechanical device. The expansion mandrel drives the aluminum tube to rotate with itself at a high speed. In the process of rotating, the nozzle and tail of the aluminum pipe are cut in line, and the thread is cut out of the required thread.

Step 4: Annealing

Since the aluminum tube punched out by the punching machine has hardened and lost its flexibility, the original flexibility of the aluminum tube must be restored by annealing. At the same time, the high temperature gas during annealing can also evaporate the excess lubricant on the inner and outer surfaces of the aluminum tube. The aluminum tube enters the annealing Shanghai through the annealing furnace ship trough, and is sent to the annealing furnace after high temperature annealing for 3 to 5 minutes Cooling zone. The annealing temperature is generally set at 390℃～450℃, the annealed aluminum tube becomes very soft, so as to meet the requirements of use.

Step 5: Internal spraying

Since aluminum is a lively metal, in order to avoid chemical reactions between the filling content of the aluminum tube and aluminum, a chemically stable protective film must be sprayed on the inner wall of the aluminum tube to isolate the material contained in the tube from the inner wall of the aluminum tube. Epoxy phenolic resin is generally used as the inner coating material.

Step 6: Primer and Printing

The outer wall of the aluminum tube is often coated with a layer of protective polyester resin, usually white, called primer. Its purpose is to form a protective film on the surface of the aluminum tube, which can provide it in the event of a slight collision. Buffer, reduce scratches, dents and damage. After the primer is finished and cooled, the aluminum tube is sent to the offset printing machine for text and pattern printing. The pre-designed brand logo, explanatory text and warnings are printed on the aluminum tube. Special printing methods, such as bronzing and silver, are also very common.

Step 7: Screw cap

After the aluminum tube is printed, Screw cap it again. The Screw cap is usually made of PP or PS plastic material, with various colors and styles, but it is usually selected according to the attributes of the product and the customer's design, which has both functionality and beauty.

Step 8: Putting on the tail glue

In order to improve the sealing performance of the aluminum tube after filling, a layer of viscous material one by one glue must be applied to the end of the tube. After the tail glue is applied, the tail can be sealed, which can improve the sealing performance, more effectively isolate the air and moisture, and ensure the shelf life of the product. The width of the tail glue can be adjusted according to actual needs. The wider the width, the better the sealing effect.

At this point, the empty tube of the aluminum tube has been completed.