There is a high demand for plastic products, and sometimes it can be challenging to meet demand. That’s why you should consider some of the innovative production methods, such as stack molding.
You may have heard that many production engineers now prefer stack molding for making multiple identical plastic products. This is one of the significant advantages.
What Is a Stack Mold?
A stack mold has two or more parting lines placed back to back in one mold base, so one press cycle fills two (or more) levels of cavities. Because both levels share the same projected area, a two-level stack mold can roughly double output per cycle without needing a press with double the clamp force; it does need more mold opening stroke.
Again, we need to point out that the stack molding process consistently yields high-quality results if you use a good mold.
In the marketplace, you will find so many types of molds. New users can find it challenging to identify the best molds for stack molding. This is where we come in. Our experts can guide you to select the most suitable mold for stacking molten plastic during production.
Who can do stack molding?
It is a complex process that is best handled by experienced production engineers. You should hire experts who understand the process and how to avoid common issues that may be encountered during stack molding.
How a Stack Mold Is Built
First, let’s discuss the process of making a stack mold.
Stack molds typically use a hot runner in the center section to feed both cavity levels, so no runner is ejected between them. A sprue bar carries melt from the press nozzle to the center section, and a synchronized opening mechanism such as rack-and-pinion opens both parting lines evenly. Each level has its own ejection, and cooling has to be balanced between levels so parts on both faces come out the same.
You must ensure that only the highest quality of alloys is used to produce your stack molds for the best results. This is what we do.
Our manufacturing processes use only the best alloys to make stack molds. We never compromise on quality because we want to ensure you do not waste your resources while using stack molding to produce plastic products.
Stack Mold Applications
To give you a better idea about the stack molding process, we have outlined some of the essential ways the plastic production process is used to manufacture excellent products.
Consumer plastics
Stack molding is also used to make plastics for packaging foods and drinks.
Caps and closures
The high demand for caps and closures makes stack molding the best production method. It can be used to make these products with varying wall thicknesses.
Since the results are consistently excellent, many factories now use stack molding during manufacturing.
Which Parts Suit a Stack Mold?
Stack molds work best for flat or shallow parts made in high volumes, such as lids, closures, thin-wall food containers and other packaging. See our thin-wall food container molds for the packaging tools we build.
Benefits of Stack Molding
We have also identified reasons you should consider using the stack molding method for your plastic production process. They include the following;
High yield
With stack molding, you can double or even triple the number of plastic products you get from your factory. Stack molds are built to last long, so you are assured of making significant profits through the process for many years to come.
Mass production of high-quality products
You can produce different plastic products to meet demand. The number of cavities in the stack mold makes this possible. That is why stack molding is becoming popular.
Lower production costs
Since you will increase your production figure with stack molding, you get much more output without spending more money. In addition to helping you save costs, you will also avoid compromising quality if the stack molding process is done well.
Also, we should add that you will not need to increase the cooling time with this method. When you make plastics using stack molds, all the plastic products poured into the different cavities will dry and form simultaneously. This is an excellent feature because it helps you avoid exhausting more energy which can increase your bills.
Risks and Limits
Well, regarding risks, you can avoid them. Making one mistake during the stack molding process can ruin dozens of products. That is why you must do everything possible to avoid mistakes.
Knowing how to troubleshoot the system before you proceed to start stack molding.
Stack Mold Example: Multi-Level Hamburger Packaging
Our multi-level hamburger packaging stack mold uses synchronized mold levels and balanced cooling to increase packaging output per machine cycle.
Why Choose Moldie for Your Stack Mold
Moldie has designed and built injection molds in Ningbo, China, since 2008, and is certified to ISO 9001 and IATF 16949. Our plastic injection mold maker team builds high-output packaging tools such as the multi-level hamburger packaging stack mold shown above.
Not sure whether a stack mold or a higher-cavity single-face mold is the better fit? Contact us with your part and annual volume, and we will compare both options.
