Method for Correcting the Flatness of Aluminum Alloy Extruded Plates

1. Improving the flatness of the product through effective mold correction

Mold repair is the most commonly used method at home and abroad to address poor flatness in extruded materials. The advantage of this method is its wide applicability, as virtually all extruded materials can be treated this way. Its disadvantage is that production must be halted, and once the mold is repaired, trial extrusion must be conducted again, which is time-consuming and labor-intensive, and it is also not conducive to energy saving and consumption reduction. Poor flatness in this type of plate material is mainly related to uneven flow rates in the mold. By adjusting the size or angle of the flow guide grooves, or by changing the length of the working strip, the metal flow rate can be effectively adjusted to make it uniform, thereby eliminating the defect of poor flatness. This method is generally used in the initial production stage of such plate materials. For some molds, one repair can solve the flatness issue, while others may require three or even more repairs to completely resolve the flatness problem. This is related not only to the mold itself but also significantly to the technical skill level of the mold repair workers.

2. Using offline finishing to correct the flatness of products

based on the specific flatness deviation characteristics of the board, reasonably configure the rollers of the offline finishing machine. Then, use a product with flatness deviation to set the rollers. By continuously adjusting the height and position of the rollers, once the flatness of this product meets the standard, fix the height and position of the rollers, and then carry out offline finishing for the batch of products. Offline finishing is generally time-consuming and labor-intensive, and it may also have some impact on the appearance of the products. Figure 3 shows an example of offline finishing for this board. The flatness condition of the board is convex on the top and concave on the bottom, with a flatness deviation. Using the roller configuration shown in the figure, as the product passes through the rollers, the middle and edges of the product are subjected to certain pressure from the rollers, which helps correct the flatness gap of the product.

3. Using Online Finishing to Correct Product Flatness

Considering that the order quantity is relatively large, using offline finishing would greatly reduce production efficiency and waste a significant amount of manpower. After a period of discussion and exploration, combined with the principles of offline finishing, the concept of online finishing was proposed, and it was decided to create a small online finishing device. If successful, it would not affect production efficiency and would save a considerable amount of manpower. Figure 4 is a schematic diagram of the online finishing device designed for this sheet material. It is based on the principles of offline finishing, adding bearing seats and rollers to the original guide device at the extrusion machine outlet. By adjusting the height and position of the rollers, the pressure on the product can be changed, causing a certain amount of deformation and keeping the product flatness within a reasonable range, thus achieving the purpose of online finishing.