How To Properly Use And Repair Aluminum Extrusion Dies
The life of aluminum extrusion die has become the main bottleneck in the development of aluminum profile industry in China. The design and manufacturing cost of aluminum extrusion die accounts for about 20% of the total production cost. It is one of the key technologies for the aluminum extrusion extrusion industry with many variables and rapid development. It also involves materials, design, manufacturing, testing, mold repair, management and many other aspects, and is also one of the areas with great development potential.
Different aluminum alloy mold design use limit times are also very different, generally ranging from thousands to hundreds of thousands of times. This has a lot to do with the material and heat treatment of the mold, the material, shape and accuracy requirements of the aluminum alloy.
Regarding how to use this type of shunt mold more rationally, we can start from the following aspects:
1. Strict implementation of aluminum profile production process regulations
It must be carried out in strict accordance with the corresponding aluminum extrusion process. During the start-up process, the temperature of the middle section of the aluminum rod furnace is set at 530-550 °C, and the temperature of the outlet section is set at 480-500 °C. The holding time should be sufficient to ensure that the aluminum rod is warm and transparent (ie, the heart and surface are warm enough). Avoid the increase of the elastic deformation of the mold due to the difference in the temperature of the aluminum rod (the temperature of the core is insufficient), thereby aggravating the phenomenon of “biasing” and “different lengths”, and even causing the plastic deformation of the extrusion die to be scrapped.
2. Ensure “three hearts in one”
The center of the extrusion barrel, the center of the extrusion rod, and the center of the mold base must be concentric. Significant eccentricity is not allowed, otherwise it will affect the flow rate throughout the product. It even affects the molding of the product or makes the difference between the lengths of the left and right of the extruded product larger and cannot be extruded.
3. Reasonable use of support pads
A double-hole special support pad of appropriate size must be selected to reduce the elastic deformation of the lower mold, so that the extruded product is stably formed and the dimensional change is small. Moreover, it is necessary to find a special support pad for the double hole before the mold is released, so as to avoid problems caused by excessive cooling of the mold after the mold is taken out due to excessive time.
4. Mold damage check
(1) When selecting materials for forming mold parts, materials that are not suitable for the working conditions of the mold may cause deformation, corrosion or severe wear after working for a period of time.
(2) When installing or disassembling the parts in the molding die, tapping the parts with a hammer may cause deformation of the mold parts or damage of the clean surface, and impact damage on the working surface.
(3) If the taper angle of the mold is too large, the flow resistance to the melt becomes large, causing the splitter cone to be broken.
(4) The hardness of the working surface of the die and mandrel is low, which will cause serious wear on the clean surface and cause rough surface.
(5) When the mold is adjusted, the operation error may cause the mold adjustment screw to be broken, and the die or the sizing sleeve may be deformed, so that the mold cannot be used normally.
5. Strengthen the feedback of aluminum extrusion process
(1) Information feedback of the extrusion die
There are many reasons for plugging molds. It is generally difficult for people without special training to express clearly. It is best to go through the corresponding mold repairers and find out the reasons before they can be modeled.
(2) feedback of material forming conditions
In addition to having a clear head number for the extrusion die number, it is also necessary to identify the overall flow direction of the material head that is difficult to see on the material head, as follows.
1) “Intersection and discharge” (indicating that the inner side of the two holes is slow and the outer side is fast during the actual extrusion process);
2) “phase separation” (indicating that the inner side of the two holes is slow and slow in the actual extrusion process);
3) “Left long and short short” means that the left branch is short and the right branch is short, and the amount of the length difference should be indicated. Since the distance from the saw to the discharge port is about 6 meters, the form of “A meter / 6 meters” usually means that the difference in length and length is about A meters every 6 meters. This perfect and accurate expression is conducive to the correct judgment and maintenance of the molder.
(3) Information feedback of oversize
In the case of normal forming of the discharge but the size is too poor, a sample must be taken to complete the correct identification (extrusion die number, discharge direction, dimensional defects, etc.). Any one of the wrong marks may result in the wrong mold, so it must be highly noticed.
Only such complete feedback on the use situation will be beneficial to the correct judgment and maintenance of the molder, in order to improve the efficiency of mold repair, and to reduce the number of mold repairs and unnecessary test.