By Jessie | 03 January 2019 | 0 评论

Causes and solutions for bubbles on the surface of aluminum profiles

When the aluminum extrusion press pressurizes, air remains in the aluminum profile, causing bubbles to appear inside and on the surface of the aluminum profile, resulting in defects that cannot be completely solved, and the aluminum profile becomes waste. In order to prevent air from entering the aluminum profile, you must find out why the air is being carried in. The main factors that are left inside the four extruded aluminum profiles are described below.
First, the long rod hot shear causes air residue
The shear plane formed when the rod is thermally sheared does not reach perfect and vertical. The simple thermal shearing of the industrial aluminum profile causes the bending of the column to be severe, resulting in an elliptical cross section of the aluminum profile and a very large round cut. Even with the latest long-bar hot shears, the edge angle of the sheared bar will always be rounded, and these roundings are the best places for air to remain.
Solution: Standard inspection of aluminum rods, resolutely put an end to unqualified aluminum rods.
Second, the upsetting caused the residual air
The upsetting caused the air to remain. Only when the diameter of the barrel containing the aluminum ingot is larger than the diameter of the rod, the rod can be placed into the barrel containing the aluminum ingot. After applying pressure to the column inside the aluminum ingot, the rod is enlarged to the diameter of the barrel, and the gas carried must be discharged. The gas is not discharged, and it remains in the aluminum ingot and eventually becomes a bubble.
Solution: Configure the extrusion gasket according to the minimum size of the liner lining, periodically replace the extrusion cylinder, check the extrusion cylinder, squeeze the gasket, measure the extrusion cylinder, and press the inside and outside of the gasket. Dimensions are used to configure suitable extrusion shims; the squeezing cylinders are cleaned once per shift with cleaning shims, and the extrusion cylinders are periodically etched.
Third, the two aluminum rods meet to cause air residue
The air remains due to the contact of the two aluminum rods. Because the surface of the two short studs is essentially flat, the probability of carrying in and out of the air is very small. The quality of the saw directly interferes with the amount of air carried between the two short studs. At present, there is a high-tech that prevents the two short columns from coming into contact and eliminates the possibility of air ingress.
Solution: Determine the reasonable length of the aluminum rod according to the process parameters such as the single weight of the profile and the number of discharges.
Fourth, extruded aluminum profiles lead to air residue
When extruding the aluminum profile, it is necessary to avoid the entry of air to avoid the residual air condition, which causes various defects in the post-processing.
1. Improper oiling causes air bubbles in the product.
Solution: Use the correct oiling method and reduce the amount of oil used; strengthen the training of the operating technology before the employee's post;
2. The pressure is too thin, causing the metal of the split hole to be pulled out during shearing, leaving a gap in the splitter hole.
Solution: According to the tonnage of the extruder, leave a reasonable thickness of the residual pressure, and determine the reasonable length of the aluminum rod according to the process parameters such as the single weight of the profile and the number of discharges;
3. Squeeze mold design Flat mold welding chamber, the split mold split hole is too large, causing air bubbles to flow into the cavity.
Solution: Reduce the size of the flat die welding chamber, reduce the die hole of the split mold, and distance more than 5MM from the single side of the extrusion tube.
V. Conclusion
Through the analysis and comparison of the traditional and improved aluminum rod casting, extrusion and mold design and manufacturing process, it can be known that to improve the output efficiency of extruded profiles, the control of extruded surface requirements, extruded aluminum profiles The solution to the bubbles that occur in production is critical and important.
Disclaimer: The content of this article is selected from Big Cat Network Technology. The copyright belongs to the original author. The purpose of the reprint is to convey more information. It does not mean that the public number agrees with its opinions and is responsible for its authenticity. If you are involved in the content, copyright and other issues, please call or write to us, we will deal with it in time!