Precautions for Testing Aluminum Extrusion and Casting Molds

What is a trial mold:

1. Extend the processing running time to stabilize the temperature of the molten glue and hydraulic oil.

2. Adjust the machine settings according to whether the finished product dimensions are too large or too small. If the shrinkage rate is too high and the product appears underfilled, you may also refer to increasing the gate size.

3. Correct the sizes of each mold cavity if they are too large or too small. If the mold cavity and gate sizes are correct, then try adjusting the machine settings, such as the filling speed, mold temperature, and various pressures, and check whether some cavities are filling slowly.

4. Make individual corrections according to the fit of the finished product in each cavity or any core displacement. You can also try adjusting the filling rate and mold temperature again to improve uniformity.

5. Inspect and repair malfunctions of the injection machine. Defects in the oil pump, oil valve, temperature controller, etc., can all cause changes in processing conditions. Even the most well-made mold cannot achieve good efficiency on a poorly maintained machine.

After checking all the recorded values, keep a set of samples for verification to compare whether the corrected samples have improved.

1. During the trial of aluminum extrusion dies and the aluminum extrusion process, special attention should be paid to the following aspects:

A. Determining the die and temperature rod temperatures before aluminum alloy profile extrusion, ensuring they reach the required extrusion temperature, and checking whether the heating is thorough (the placement of dies in the heating furnace is very important, and there should be some spacing between dies for proper heating).

B. For aluminum extrusion dies, first check whether key parts of the new die are qualified, such as the clamp slot, cooling water, etc. After the die clamp is adjusted, find the zero point by trial pressing, calculate the positions for boosting pressure, second fast, and first block based on the zero point, then adjust the length of the ejector pin. Determine the cooling time and press time according to the wall thickness of the product. Decide on the size and amount of the ladle based on the product size. Start with slow pressing and spraying; remember, if there is a risk of die sticking, preheat the die first. When slow pressing, apply oil without spraying water, and spray water only after the die is heated. Align to the center position to avoid collapsing or die jamming.

C. Choose the appropriate extrusion speed for different aluminum alloy profile dies to prevent issues with material flow due to excessive speed.

D. During the extrusion of aluminum alloy profiles, attention should also be paid to the quality of the aluminum billet to avoid die damage caused by impurities in the aluminum billets, etc.

2. Repairing aluminum extrusion dies is a very important process, but the first consideration in die repair is its strength. Repairs should be carried out on the premise of ensuring the strength of the aluminum extrusion die. Generally, welding is not used until it becomes absolutely necessary, as welding can significantly affect the die's lifespan. This is especially true for welding on the working surface, which can easily shorten the die's lifespan. For repairing profiles that have slow or fast extrusion areas, the usual practice is to speed up the slow areas rather than slow down the fast ones. In this way, reducing the load in the die structure can to some extent ensure its longevity. Of course, improving repair skills and reducing trial extrusion cycles is also a method to extend die service life.

3. During the die conditioning process, special attention should be paid to the blanking stage, especially in screw holes or more fragile areas; otherwise, it is easy to damage the die.

4. The handling of aluminum extrusion dies must be done carefully to avoid bumps or impacts on the working surface and other areas. Before storing the die, it must be thoroughly cleaned and meticulously inspected for any tiny cracks or damage.

5. For dies that have completed production, it is essential to effectively manage their process data, such as repair plans, processing details, extrusion procedures, etc. This information can serve as a reference for future die supplementation or the replication of similar dies, which can effectively improve the success rate of die setup during production.

The improvement of the lifespan of extrusion molds relies on the perfect connection of processes such as design, manufacturing, usage, and subsequent maintenance. Relying on a single link cannot effectively achieve the goal; through the effective integration of each link, it is believed that a corresponding improvement in mold lifespan can be achieved.