If Air Becomes Trapped in the Die Casting Mould


Your first step should be to maintain the same pour rate and shot delay time. This is particularly important at times when the fill is below 50%, because at this percentage of fill a wave may be generated by the act of pouring. The

air wave may travel from the parting line to the shot to and back again. When the plunger tip starts to move, its speed and acceleration are pre-designed to prevent trapped air bubbles.

If the wave collides as it moves forward, extra splashing is generated, capturing some bubbles. However, if the tip starts to move forward after the wave has been redirected away, the tip follows the wave, providing your best opportunity to minimize trapped air. A timer that establishes the time delay between end of pour and commencement of the shot will influence when the tip starts to move forward in relationship to the wave.

The acceleration of the plunger to slow shot speed is another contributor to trapped air. The plunger’s rate of acceleration should be slow enough to keep the metal from tumbling over, or surfing, but fast enough to stop air from getting trapped between the wave that’s generated and those waves that are redirected away from the die.

The acceleration rate will vary based on the percent of fill and length of the sleeve. The typical range is between two and less than three inches per second, per inch of travel.

How to Reduce Air in the Shot Sleeve

If you need to reduce Die Casting Parts in the shot sleeve, adjust the following settings until you have the problem resolved. Each of these settings alone may not seem significant, but there are interactions between them, and we recommend that you be as consistent as possible once you find a combination of settings that works for you.