Can Hybrid Machining Create More Sustainable Manufacturing?

By Jack Shaw, senior writer and editor at Modded

Hybrid manufacturing combines the best of both worlds with additive and subtractive methods. The heightened focus on sustainability has made manufacturers scrutinize their operations, so how does this impact hybrid machining? This compound approach has pros and cons regarding eco-friendliness, so perfecting operations is critical for environmental awareness. Here’s how hybrid machining contributes to sustainability.

How Hybrid Machining Can Foster Sustainability

Hybrid ideas have allowed companies to make their manufacturing more efficient. Have these strategies led to more sustainability? Here are a few reasons hybrid machining has been conducive to environmental initiatives.

Efficient Production Rates

In the past, manufacturers had to perform additive and subtractive processes separately. Thus, as each phase finished, employees had to move parts from one machine to another. Hybrid machining elevates production by allowing manufacturers to perform additive and subtractive manufacturing in one go. Products don’t have to leave the machine’s envelope, thus reducing the risk of errors.

Faster prototyping is another reason for higher production rates. Hybrid manufacturing lets companies use 3D printing to create accurate models for future projects. Subtractive processes refine the prototypes by removing materials, whether grinding, milling or drilling. Modern machines give manufacturers more flexibility for on-demand production and adjusting rates when necessary. Hybrid machining is easily customizable to meet periods of high or low demand.

Production Planning Optimization

Production planning is integral in manufacturing to limit waste as much as possible. Hybrid machining aids this objective by determining how to manufacture new products and recycle old materials. While efficient, this process can have economic ramifications through startup, production and storage costs. Hybrid manufacturing also impacts the environment through carbon dioxide (CO2) emissions.

How can manufacturing companies improve their sustainability during the planning process? A 2022 Procedia Computer Science study examined hybrid machining emissions through a new system with reduced disposal of used products. The researchers developed a mathematical model and a non-dominated sorting genetic algorithm for the experiment. Their innovations optimized product planning by minimizing economic costs and carbon output.

Minimizing the Environmental Impact

Reducing emissions is critical for manufacturing because it’s recently come under the microscope. Chemical, cement and lime, paper and other manufacturing combined for 12% of emissions in all American industries. Only electric power and transportation accounted for more. Manufacturing released 765 million metric tons of CO2 in 2021 because fossil fuel combustion and industrial processes are necessary.

How do additive and subtractive manufacturing have a role in sustainability? Subtractive processes make final products smoother and reduce the amount of materials needed. Additive manufacturing minimizes waste by emphasizing on-demand production. A 2023 Environmental Science & Technology study discussed whether additive manufacturing is conducive to sustainability. Researchers concluded the impact is minimal with low production output.

Leveraging Advanced Technologies

The future of manufacturing can become more sustainable if it leans into advanced technologies that embrace efficiency. Artificial intelligence (AI) and machine learning (ML) are integral to hybrid machining development, as these innovations leverage robotics to close human gaps. The Internet of Things (IoT) is another advancement integral to hybrid manufacturing because it lets professionals see data regarding material usage and energy consumption.

Advanced technologies let companies take advantage of different processes in hybrid manufacturing. For instance, direct energy deposition permits complex features with additive and subtractive processes. However, it can produce significant waste during production. A 2021 Advanced Industrial and Engineering Polymer Research study found the smart digital supply chain and additive manufacturing reduce waste by heightening project efficiency and accuracy.

Using the Digital Supply Chain

The digital supply chain is a relatively new concept, as technology has combined with analytics to improve manufacturing decision-making. How can hybrid machining take advantage of this modern idea? The digital supply chain starts with blockchain technology, which enhances sourcing transparency and reveals the environmental impacts of raw materials. This information guides companies to make better decisions regarding supply partners.

Drone usage is another benefit of using the digital supply chain in manufacturing. Hybrid machining and autonomous aircraft go hand in hand, allowing rapid drone fabrication. A 2022 Additive Manufacturing Letters study found hybrid additive manufacturing produced functional drones on demand in under four hours. Drones return the favor by rapidly delivering parts and monitoring equipment during manufacturing.

Reducing Energy Consumption and Emissions

Energy consumption is another statistic that is under worldwide scrutiny. Using power leads to emissions and increases a company’s footprint. The type of emissions depends on the industry and manufacturing processes. For instance, production accounts for 60% of methane emissions in the oil and natural gas sector. What role does hybrid manufacturing have in reducing energy consumption and emissions? Careful selections can make things more sustainable.

Reducing energy consumption starts with machinery. Manufacturing professionals should use efficient machines with variable-speed drives because they’re more sustainable than older models. Variable-speed drives regulate the motor to ensure it operates at the necessary speed for production. Therefore, companies benefit from less wasted energy. Smaller factors like idle time and standby mode also help hybrid machines reduce energy liabilities.

Paul Spurlock monitors a B-1B Lancer part being manufactured Oct. 2 at Tinker Air Force Base, Okla. Mr. Spurlock is a numerical controlled machining cell machinist.
Can Hybrid Machining Create More Sustainable Manufacturing?
A “numerical controlled machining cell machinist” monitors a B-1B aircraft part being manufactured.
Credit: U.S. Air Force photo/Margo Wright

Does Hybrid Machining Have Sustainability Challenges?

Hybrid machining can lead to sustainability by reducing energy consumption and using advanced technologies. However, manufacturers must address the pitfalls associated with these challenges.

Energy-Intensive Processes

Reducing energy consumption is a goal for hybrid manufacturing, and companies can achieve it through technology like variable-speed drives. However, something could go wrong in the manufacturing process or inefficiencies could arise with the machinery. For example, consider laser sintering equipment needed for melting materials. A 2020 Heliyon study found direct metal laser sintering hybrid milling (DMLS-HM) required 84% more energy than electron beam melting (EBM) and conventional machining (CM).

Energy intensity can lead to a larger carbon footprint without proper protocol. A 2022 Materials Today study compared closed impeller production between hybrid and investment casting. The researchers used laser-directed energy deposition and milling for the manufacturing and performed life-cycle assessments for each group. The study concluded that energy-intensive atomization fostered a larger carbon footprint for hybrid manufacturing than investment casting.

Sourcing Unsustainable Materials

While process improvements can foster sustainability, manufacturers must also consider the materials and how they source them. The environmental impact is higher than a company suspects if hybrid manufacturing requires energy-intensive extractions. For example, a business could generate prototypes from acrylonitrile styrene butadiene, a thermoplastic polymer. This material derives from oil, thus reducing overall sustainability in hybrid manufacturing.

Unsustainable sourcing has ramifications for other industries as they adopt hybrid manufacturing processes. For instance, the automotive sector uses lithium-ion batteries, requiring energy-intensive extraction processes. Auto manufacturing also requires oil-based polymers and other nonrenewable resources. Hybrid manufacturing can lead to waste through scrap metal and powder if companies don’t identify ways to recycle or repurpose their materials.

Fewer Recycling Opportunities

The materials companies use in hybrid manufacturing also raise concerns through their recyclability. Some components are complicated and nearly impossible to repurpose due to their tiny size and contamination. For example, consider the powders used in laser sintering and other energy-intensive processes. Research shows virgin powder is easy to recover and recycle, but used substances differ because of their chemical and physical properties.

Hybrid manufacturing should look toward metal for the most sustainable path forward. A 2020 Journal of Materials Research and Technology study reviewed the circular economy of resources and the sustainability of the components. The researchers found metals were the most sustainable choice when optimizing the circular economy due to their recyclability. However, their energy consumption still needs improvement because it does not support sustainable levels. Conversely, plastics hurt manufacturing due to their negative impact.

High Costs

Cost is another barrier to sustainability for hybrid machining. Hybrid equipment can be expensive because it combines additive and subtractive functions. High prices limit the ability of smaller companies to make the upfront investment. Manufacturing businesses also must consider the cost of training employees or hiring new workers to operate these complex machines. The low production volumes could also hinder bottom lines.

The Environmental Science & Technology study discussed additive manufacturing and its associated costs. The researchers argued this process is too costly and less sustainable in high-volume mass production because of its energy usage and material waste. Lessening the cost of additive manufacturing relies on material feedstocks, energy intensity and other factors. Efficiency increases in additive manufacturing when creating small parts that traditional manufacturing would waste.

Quality Control

Another sustainability issue for hybrid manufacturing comes from the post-production processes. After creating the desired product, the company must spend as much time and resources on quality control as the original production. For example, thermal treatments may be necessary to improve mechanical properties using large amounts of power. Energy-intensive machines may also be required when polishing and deburring final products.

While some improvements have helped post-production sustainability, hybrid manufacturing has a long way to go. What technology can help the industry reduce its carbon footprint while producing worthwhile products? A 2021 Journal of Manufacturing and Materials Processing study reviewed post-processing technologies and concluded robotics could be a future solution. Autonomous technology can replace manual labor and promote continuous production while optimizing post-production sustainability.

Promoting Sustainability in Hybrid Manufacturing

Manufacturing has come a long way, thanks to technological advances and more efficient practices. Hybrid concepts let companies streamline additive and subtractive manufacturing with one machine, thus increasing production rates. However, these improvements don’t always increase sustainability. Manufacturers must be conscious of their materials, energy consumption, quality control and costs to ensure their carbon footprint doesn’t rise with hybrid machining.

Author Bio

Jack Shaw, the senior writer and editor at Modded, specializes in weaving together the threads of health and wellness with greater concerns about sustainability best practices and industry developments. With a commitment to providing actionable insights and empowering readers, Through his writing, Jack seeks to educate and inspire individuals on their journey toward more eco-friendly decisions. Feel free to connect with him via LinkedIn.