How To Optimize A Die Casting Mold?

The die cast mold, or die cast tooling, is a crucial part of the die casting process. As such, the quality of your die cast mold is very important. Mold quality will not only determine how many shots you can get out of a single mold but also influence the complexity, strength and quality of the die casted part. 

The article discusses ways to optimize tool design and steps that can be taken during tooling in order for you to get the most ROI out of your die cast mold. 

What is a die casting mold? 

The die cast mold has a cavity in which liquid metal is injected and allowed to cool and solidify. Once the metal is solid, the tooling, or mold is separated into several pieces and the casting is removed. Die casting molds come in many shapes and sizes depending on the desired end product and its complexity. 

Mold design process

The initial mold design process can be lengthy, but it is vital in order to produce high quality tooling. 

Considerations should be given on all aspects of the mold as well as the end product before the tool is manufactured. This includes material selection, tolerance stackups, cooling ports and more. Certain software can also be used to analyze design feature castability.

A thorough mold design process will not only help to prolong the life of the die cast mold, but ensure even porosity and high quality in the end casting. 

Mold design for optimum manufacturability

A high quality die cast tool will ensure optimal manufacturability. 

Designing for manufacturing, or DFM is a core concept that influences the success and longevity of the mold. Besides this, with DFM, the die cast mold becomes a high performance tool that is able to produce parts that are consistently high in dimensional accuracy and quality.  

Die cast mold care and maintenance

Besides optimizing the die cast mold via the engineering side, tooling care and maintenance should also be a top priority.

Although your supplier may have designed the die cast for long term use, repeated heating and cooling is an integral part of the die cast process. This can cause the tool to degrade over time. Gate erosion and core wear are common issues that will arise if the tool is not properly maintained. 

Scheduled maintenance programs will be able to add to the lifespan of your tool as well as ensuring the production of high-quality parts. Tool maintenance also depends on alloy selection that your product is made of. 

With proper maintenance, tooling for zinc components can be used for up to one million shots before needing to be replaced. 

Tooling for aluminium components can be used for about 200,000 shots. 

It’s important to note that the average number of shots a mold can be used depends on factors such as project requirements, materials, and product complexity. 

Here are some ways to care for your tools to ensure its longevity. These maintenance techniques will also help to produce casted components that are high in quality and dimensional accuracy.  

  1. Mold cooling system

Temperature is important when it comes to extending the service life of the die casting mold. A mold cooling system prevents cracks from forming on the surface of the mold core when it is used at high temperatures. Maintaining adequate temperature will also enhance production efficiency and maintain the quality of casted parts. 

  1. Preheating of mold

Quick exchanges of temperature occur when hot liquid metal is poured into the mold. This can result in cracks on the mold. Preheating of the die cast mold prepares the surface to accept the hot molten metal and therefore, prevent cracks due to the sudden temperature change. Die cast molds can be preheated with a blowtorch or gas.

  1. Signal line maintenance

Die cast molds can be damaged if there are faulty signals that cause automatic stoppage. Signal lines that come in contact with water during the production process can short circuit. It is important to maintain the signal line to ensure that molds remain in good condition. 

The wear and tear of your mold should be taken into account before the mold is cut. This will reduce the likelihood of replacing damaged molds. It will also help you to estimate tooling maintenance costs.

How to increase the ROI of your die cast tool?

If you are considering investing in a die cast mold to manufacture your product, here’s how you can increase the ROI of your die cast tool. 

  1. Be wary of low prices – While cheaper, lower quality tools may be tempting as they have a lower upfront price, you will have to deal with costly tool replacement and unnecessary maintenance further down the road. Low quality tools may also cause part defects and thus, increase the total production cost. Investing in high quality tooling will ensure that the die cast molds last for the project that it is intended for.
  2. Be flexible with draft angles – Allowing some flexibility for draft angles in non critical design elements will make extraction of the part easier. In turn, the tool’s longevity will be extended. 
  3. Allow lenient tolerance zones – If there are non-critical design elements, allowing lenient tolerance on these parts will help prolong your tool’s service life. 
  4. Avoid costly re-designs – It’s best to collaborate and communicate with your supplier, especially during the design phase to make any adjustments needed early on to avoid redesign costs. 

Also read our article on “Die casting defects: Causes and Solutions”. 

Conclusion

As every part is different, it is best to speak to your supplier on optimizing tool design, tool maintenance and service life at the start of the manufacturing process. 

Always be wary if the price offered seems too good to be true as you may have to fork out more for tool replacement and maintenance. High quality molds may be more expensive up front but save you a ton on production costs in the long run. 

This article is a part of our comprehensive guide on “Die casting: Process, Equipment, Uses, and More

Speak to our engineering team at EKO Industries for more information on die cast tooling optimization for your project.

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