How to Create an Energy Saving Injection Molding Process

Date: December 7, 2022
Category: Injection Molding

Machines used in the injection molding process can easily consume a lot of energy. After all, they’re giant machines that use massive amounts of force to inject plastic into a mold. But with energy consumption on everyone’s mind and the costs of energy on the rise, it makes you stop to think. Should I work to be more energy efficient? Today we discuss how to do just that, along with why it matters, and the benefits you can achieve from doing so.

Why Does Energy Consumption Matter?

The short and obvious answer is cost. The cost to produce your parts. The cost to run machines. The costs to operate your business. The more energy your overall process consumes the more expensive it is, period. Did you know that electricity often accounts for more than 90% of the total energy cost of the injection molding molding process? That’s thousands of dollars that if saved, could be utilized in other areas of the business. Or even help reduce the overall cost of parts.

Benefits of an Energy Saving Process

By now, some of the benefits of an energy saving injection molding process are probably obvious. However, there is a long list of benefits that both molders and consumers can experience.

Benefits to the Injection Molding Facilities

Less energy consumption means lower operating costs.
Lower costs mean higher profit margins or the ability to invest in other areas.
Machines can be better optimized for their capabilities.
Lower overall life cycle costs.
Increased efficiency allowing for better cycle times.

Benefits to Clients

Less energy means less expensive parts.
Faster turnaround times with an optimized process.
The ability to market your product as energy conscious and environmentally friendly

7 Methods to Increase Energy Savings

Now that we’ve covered the benefits, I’m sure you have one question on your mind. How? How can I create an energy efficient injection molding process? Truth be told there are many ways to not only optimize your machine, but also make the overall process much more efficient. If you’re looking for a great place to start, consider the following.

Consider Your Startup Sequence

If you have several machines in your shop, this is one of the first places where you can increase your efficiency. Simply creating the proper startup sequence of your machines can easily reduce the energy consumed. For example, starting several machines at once will increase the Maximum Demand (MD) and as a result consume more energy. Thus, it’s best to avoid doing so if at all possible.

Insulating Your BarreL

Installing proper insulation around the barrel of your machine can improve overall thermal efficiency. The insulation helps maintain operating temperatures that are much more consistent and thus not as wasteful. An additional benefit is that it can also reduce startup time. Which as we just learned above, is a critical time for energy saving.

Monitor Your Machine’s Idle Time

Your machine is consuming energy even while idling between cycles or jobs. Potentially up to 97% of the energy consumption during operation. Needless to say it’s important that you look to minimize your machines idle time. However, if you do have to let it sit idle, consider shutting down systems such as your heaters and ancillaries or even your compressed air.

Opt for an All-Electric Injection Molding Machine

All-Electric machines like this one from Milacron aren’t for everyone, however, they carry a lot of benefits. First and foremost, their startup process consumes far less energy than hydraulic models. Additionally the use of electric drive motors means no more hydraulic fluids. Last but certainly not least, these machines can perform multiple operations concurrently, reducing cycle times and providing an energy efficient process.

Investigate and Optimize Your Cooling System/CYCLE

Your machine’s cooling time can often account for over 50% of the cycle time. Ensuring proper cooling procedures will help reduce cycle times and as a result energy consumed. Don’t just set and forget your cooling. Instead, look into the following.

Ensure cooling lines are clean. Scale/rust build up will cause less heat transfer and part will take longer to cool or cool unevenly.
Optimize the part/tool design for cooling. Often times, the runner is the deciding factor for the cooling time, right sizing the runner reduces cooling time.
Check your melt temperature. If you overheat your material you create longer cooling times.
Check the temperature of the mold surface, not the cooling water/oil temperature, to determine the mold temperature. Molds are often times hotter than the water flowing through them, which can cause longer cooling time. Keep in mind that you should stay at or above the recommended mold temperature for the material your processing.

Use The Right Machine For The Job

Matching your machine capacity to the product your producing is key in creating an energy saving injection molding process. Even though most molding machines can dial back the tonnage, larger machines simply use more energy. Furthermore, having a barrel too large for a part can degrade the material and waste energy. You can also use our guide to injection molding to ensure your part is designed properly.

Consider Energy Costs When Purchasing A Machine

While the previous 6 methods will help with the process, this last one should be considered before you even buy a machine. Take time to consider the parts you intend to produce and the necessary capabilities your machine should have. Then calculate your costs using a whole life costing method. Getting your research right and selecting the perfect machine for your shop is sure to save you a lot of money in the long run.

Start Saving Energy and Money Today

As we’ve discussed, creating an energy saving injection molding process provides a myriad of benefits to both production facilities and the end consumer. Everything from saving money, to less expensive parts, and let’s not forget about helping the environment. Even better, it’s not difficult to get started. Simply pick one of the seven strategies above.

If you have questions on creating energy efficient parts or need assistance with an injection molding quote please reach out. Simply contact us, or request a quote, and a member of our team will be happy to assist you!

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