Views: 0 Author: Site Editor Publish Time: 2025-11-21 Origin: Site
In the world of plastic manufacturing, one of the most widely used pieces of equipment is the injection molding machine. Whether you’re producing packaging, automotive parts, medical components, or consumer goods, the machine you choose, its drive system, cycle time, and operational strategies all play a significant role in its power consumption. In this article, we’ll explore how much power an injection molding machine consumes, the factors that influence that consumption, how to estimate it, and what steps manufacturers are taking to reduce energy use.
An injection molding machine (IMM) is the device used to inject molten plastic into a mold, holding it under pressure while cooling and solidification occurs, and then ejecting the finished part once the mold opens. The machine consists of four main subsystems: the injection unit, the clamping unit, the drive unit (electric/servo/hydraulic), and the control systems.
Energy is consumed in several areas:
The drive motors (for clamp movement, injection screw movement, or ram).
Heaters (barrel heaters, hot runner heaters, mold heaters).
Cooling and auxiliary systems (chillers, mold water systems, conveyors, robots).
Idle losses (when the machine is on but not actively producing parts).
It’s important to recognize that total energy consumption is more than just the machine’s drive; in fact, some reports indicate that the machine drive accounts for less than half of the total system energy consumption. Often, the power consumption of the entire injection-molding cell is significantly higher when including cooling, heating, and auxiliary equipment.
So, how much power do injection molding machines typically consume? Recent estimates give us a general idea of the energy usage:
For electric injection molding machines (clamp force ranging from 90T to 460T), the power consumption can range from 3.8 kWh to 17.9 kWh per cycle, depending on the machine size and process conditions.
Globally, injection molding operations consume a significant amount of energy. Some reports indicate that these operations contribute to a substantial portion of industrial energy usage annually.
To put this into perspective, let’s consider an example: If you have a machine rated at 7.2 kW operating 24 hours a day, the daily energy consumption is approximately 173 kWh. Over the course of a month (30 days), that would total around 5,190 kWh. At an electricity cost of $0.10 per kWh, this would result in a monthly electricity cost of $519 for just one machine's operation.
When scaling up to larger machines or higher production volumes, energy consumption can quickly add up, making it crucial for manufacturers to consider energy efficiency when selecting equipment.
Several factors affect the power consumption of an injection molding machine. Here are the major influences:
1. Machine Drive Type
Fully electric machines tend to be more energy-efficient than hydraulic machines because they don’t require the continuous operation of hydraulic pumps.
Electric machines can save 20-40% more energy compared to hydraulic alternatives, making them a preferable choice for energy-conscious manufacturers.
In some cases, hybrid servo-hydraulic machines also offer an energy-saving advantage by using electric drives for specific motions, reducing hydraulic losses.
2. Machine Size and Tonnage
Larger machines, with higher clamping forces and bigger shot volumes, will inherently require more power. This includes energy for heating, moving larger platens, longer cycle times, and more cooling. For instance, a smaller machine (e.g., 90T) will consume less energy than a larger one (e.g., 1,000T).
3. Cycle Time and Shot Weight
Shorter cycle times (more parts per hour) can reduce the energy consumption per part because the fixed energy overhead is spread over more parts. Conversely, longer cycle times or thicker parts will increase the energy required for each part.
Thus, cycle time and shot weight directly impact how much energy is consumed during the production process.
4. Idle Time and Machine Utilization
Even when an injection molding machine is not actively producing parts, it still consumes energy. Machine idle times can result in wasted energy, particularly if heaters, cooling systems, and control systems are left on unnecessarily. Optimizing the idle time and machine utilization can help reduce electricity costs.
5. Peripheral Systems and Mold Cooling/Heating
Often, peripheral systems such as mold temperature control units, cooling systems, chillers, robots, and conveyors consume significant energy. In many cases, the machine itself consumes less than half of the total system energy.
6. Material Melt Temperature & Process Efficiency
The type of material being used and its melt temperature also play a role in energy consumption. Materials with higher melting points or processes requiring thicker parts or slower cooling times will demand more energy to produce.
7. Maintenance and Machine Condition
Proper maintenance is essential for ensuring energy efficiency. Machines that are poorly maintained may waste energy due to hydraulic losses, inefficient heaters, poor insulation, or inadequate cooling systems. Regular checks and proper servicing can reduce energy waste and extend the life of the equipment.
If you’re looking to estimate the electricity consumption of your injection molding machine, here’s a straightforward method you can follow:
Find the Rated Power: Look at the machine’s nameplate or technical specifications for its rated power (in kW).
Estimate Load Factor: The load factor represents the percentage of the machine's rated power that is actually used during operation. Machines don’t typically run at full power all the time. A load factor of 60-70% is common.
Calculate Energy Usage: Multiply the machine’s rated power by the operating hours per day and the load factor to estimate energy consumption.
Consider Downtime: If your machine is idle for long periods, make sure to account for the energy consumed during these idle times.
Include Peripheral Equipment: Don't forget about energy consumption from cooling systems, robots, and conveyors, which also contribute to your overall energy cost.
For example, a 50 kW machine operating 16 hours a day with a load factor of 60% would consume approximately 12,000 kWh per month. At an electricity cost of $0.12 per kWh, the monthly cost would be $1,440. If you produce 100,000 parts per month, the cost per part would be approximately $0.0144.
Energy cost is a major factor in the overall cost of injection molding. Here are several strategies to help you reduce energy consumption:
1. Choose the Right Machine Type
Electric machines are generally more energy-efficient than hydraulic machines, especially when used for applications that don’t require extremely high tonnage. If you are operating smaller runs, an electric machine can provide significant energy savings.
2. Optimize Cycle Time and Shot Size
By reducing cooling time, optimizing the heating and injection process, and refining cycle times, you can minimize energy consumption per part. Machine settings and process optimization can have a large impact on reducing energy use.
3. Implement Smart Shutdown Strategies
If a machine is idle for more than 45 minutes, it may be more energy-efficient to turn it off rather than leaving it on. Automating shutdown and startup procedures can also reduce unnecessary energy use.
4. Improve Mold Temperature Control
Ensuring that mold temperature control is efficient can reduce the energy required to maintain the right conditions during the molding process. This could involve upgrading to advanced temperature control systems or using energy-efficient cooling technologies.
5. Regular Maintenance
Maintaining machine parts such as heaters, cooling systems, and drives ensures that the machine operates efficiently. Scheduled maintenance can help prevent energy waste due to equipment wear and tear.
6. Consider System-Level Efficiency
Don’t just focus on the injection molding machine itself. Peripheral systems, including chilling, material handling, and robotic arms, all contribute to energy use. Optimizing these systems for energy efficiency can make a significant difference in overall power consumption.
As you look to optimize your energy usage and improve cost-efficiency, consider the following practical tips:
Request detailed energy data from suppliers when specifying new machines.
Choose the right machine size that matches your part size and production volume to avoid wasting energy on oversized equipment.
Track energy usage in real-time to identify inefficiencies or areas where you could optimize.
Factor energy costs into product pricing to ensure that energy usage is accurately reflected in your overall cost structure.
So, how much power does an injection molding machine consume? The answer depends on several factors, including the machine type, size, cycle time, and process conditions. However, by understanding and optimizing these variables, manufacturers can significantly reduce their energy costs. If you're interested in exploring energy-efficient injection molding machines or learning more about optimizing your equipment, I recommend reaching out to Zhangjiagang Dawson Machine Co., Ltd. Their team can provide insights into selecting machines that best fit your energy efficiency needs, tailored to your specific production processes.
By choosing the right equipment and implementing efficiency strategies, you can reduce both your energy costs and environmental impact, improving the overall sustainability of your operation.
