The Top Energy Efficiency Tips for Reducing Plastic Extrusion Energy Costs


Historically, the plastic extrusion process consumes a fair amount of energy. Fortunately, recent advancements in plastic extrusion machines, more commonly known as plastic extruders, have lessened energy consumption through energy-efficient measures.

The advancements over the last decade include shifting focus to plastic extrusion lines’ quality, reliability, and throughput. These measures have also led to more energy-efficient plastic extruders for plastics manufacturers.

However, many older plastic extruders in plastics manufacturing facilities across the U.S. do not possess modern measures and, therefore, still cause facilities to consume more energy than necessary. That said, all is not lost, as there are programs in place to help manufacturers reduce the energy costs of their plastic extruders.

What are Plastic Extruders?

Plastic extruders are extrusion machines that shape plastic polymers into specific elongated forms using dies — electric motors and gearboxes power extruders to provide high torque for the plastic-forming extrusion process. The efficient operation of extrusion screws is vital for the cost-effective functioning of a significant portion of the plastics processing sector.

The Energy Consumption of the Plastic Extrusion Process

Plastic extrusion is primarily an electrical process, with a substantial portion of the energy consumed directly linked to the operation of the extrusion screw. Approximately half of the total energy in the plastic extrusion process is utilized to drive the screw, while the remaining portion is allocated to heating, ancillaries, and utilities.

Much of the energy required for plasticizing and heating the polymer in the plastic extrusion process is generated through the shear heating as the polymer moves along the extruder barrel, with some cases requiring no additional heating and necessitating barrel cooling instead.

Energy-Efficient Tips for the Operation of Plastic Extruders

The energy-efficient operation of the plastic extrusion process involves selecting the right plastic extruder for the job and ensuring that the screw diameter and design are suitable for the polymer and desired product. Plastic extruders operate most efficiently when running at their design conditions, with the extruder set to its maximum design speed, which is typically the most energy-efficient setting.

Optimizing plastic extruder speed maximizes mechanical work heat and minimizes the electrical energy needed for plastic heating, potentially reducing energy consumption by nearly 50 percent by doubling the rotational speed.

Maintaining proper temperature control is essential for successful plastic extrusion, as overheating from shearing can adversely affect product quality and energy costs. Insulating the barrel with insulation jackets reduces energy consumption and temperature fluctuations. APenergy works with utilities like ComEd to offer programs that usually pay for the entire cost of insulation jackets for plastic extruders.

Retrofitting hydraulic-driven machines with servo motors saves a significant amount of energy on existing assets for some clients. Fifteen years ago, the market for injection molding machines was completely different, and all-electric machines were not as widely available. A few companies have specialized in converting some older machines into hybrid units. This modification is a low-cost solution to garnishing some electric savings on aging assets.

Additionally, implementing smart technology in the plastic extrusion process can lead to significant energy savings and help monitor machine condition, as increased energy consumption can serve as an early warning sign of deterioration and the need for maintenance.

More Tips for Finding Energy Efficiency with Plastic Extruders

Energy-efficient consultants adopt diverse approaches to optimize energy efficiency within a plastic extrusion system. In many instances, upgrading the extruder drive alone significantly improves energy efficiency, reducing energy consumption. Moreover, scrutinizing individual plastic extrusion production process steps and their interconnections reveals avenues for minimizing energy usage and costs.

Harnessing energy from pelletizing water and reintegrating it into the plastic extrusion production process for melting raw materials is another viable strategy. Altering the heating mechanisms of plastic extruder barrels and tweaking the screw configuration are minor adjustments that can yield substantial energy savings.

In assessing the potential for a more energy-efficient plastic extrusion line, energy-efficiency consultants thoroughly evaluate the whole plastic extrusion production process, including plastic extruders, material transfers, feeding, and pelletizing systems. A comprehensive understanding of the functioning of each plastic extrusion component helps consultants quickly identify and implement energy-saving measures in plastic extrusion systems.

Minimizing the Energy Demand in Ancillary Systems of Plastic Extrusion

Plastic injection molding facilities require other indirect sub-systems to operate the facility that don’t directly produce products, including ancillary systems like cooling towers, compressed air, condensate management, lighting, and other energy-using systems that keep the plant in operation. Incorporating energy efficiency considerations during the design phase of handling and ancillary systems can yield rapid payback on any additional costs incurred.

By optimizing the design and operation of ancillary equipment, such as cooling and calibration units, energy consumption can be significantly reduced, particularly when the main plastic extruder is set correctly, thus minimizing downstream cooling and calibration requirements.

Minimizing demand and optimizing supply are recommended for utilities such as cooling water, compressed air, and vacuum supply. Setting the maximum acceptable plastic extrusion process temperature after cooling and adjusting the cooling water temperature accordingly helps prevent overcooling of the product, reducing energy waste.

Ensuring cooling water is not circulated unnecessarily through idle calibrators and is treated, chilled, and distributed efficiently further contributes to energy efficiency. Similarly, optimizing the generation and distribution of compressed air and vacuum supplies to meet the minimum plastic extrusion process requirements while avoiding supply to idle machines helps minimize energy consumption.

New Energy-Efficient Plastic Extruders

The latest plastic extruders are designed with a focus on sustainability and innovation. While these extruders may require a higher initial investment, they offer long-term benefits regarding energy savings and environmental impact for the plastic extrusion process.

Extruders equipped with features like high-efficiency motors and variable-speed drives (VSDs) help reduce the plastic extrusion process’ energy consumption and costs. These plastic extruders are also well-suited for recycling post-industrial and post-consumer waste materials such as HDPE, LDPE, and PP, making the new energy-efficient extruders a valuable asset for environmentally conscious businesses.

The latest extruder models are engineered with a strong emphasis on energy efficiency. Some include smart energy system integration, which can significantly reduce energy consumption by up to 35 percent. These types of plastic extrusion systems utilize innovative contactless barrel heating technology powered by an alternating electromagnetic field, ensuring rapid and uniform heating of plastic materials while minimizing energy waste.

As the plastic extrusion industry evolves, plastic extruder manufacturers continue expanding their offerings to meet the demand for sustainable plastic manufacturing solutions, including software enabling real-time extruder performance monitoring. By embracing these innovations and adopting sustainable practices, businesses can not only enhance the energy efficiency of their plastic extrusion processes but also contribute to a more sustainable future.

Contact APenergy, the Energy Efficiency Experts of Plastic Extrusion, Today

APenergy has over 35 years of experience working with industrial plastics manufacturers to identify areas of inefficiency and make data-driven decisions to reduce energy consumption and costs. By utilizing utility incentives and rebate programs for plastic extruders, including insulation jackets, VSDs, VFDs, and other practical energy-saving solutions, APenergy guides manufacturers toward energy efficiency.

Through our incentive management service, APenergy helps companies set energy-saving goals, track progress, and achieve favorable ROIs. Our expert team is ready to assist companies with energy-efficient solutions. For more information, contact the APenergy team, the leading energy efficiency consultants, at 740-862-4112 or message us.