This is a guest post from one of our active members of the PLM Green Global Alliance, Roger L. Franz.

Roger is supporting industry inquiries on regulated substances, sustainable product design and life cycle management, including carbon footprint.

He is a recognized authority on supply chain reporting for compliance with worldwide regulations. Roger brings decades of experience with engineering tools and enterprise IT systems.

Introduction. 

More than just unsightly “plastic pollution,” the volume of consumer plastics and lack of closed-loop recovery have created a significant micro- and nano-plastics problem. These invisible plastic particles are found around the world, including in animal and human tissues.

For several reasons, including a much smaller volume of plastic used in electrotechnical products compared to consumer plastics and the generally longer life of hardware compared to the rapid turnover of consumer goods and packaging, the microplastics problem is not typically tagged as a major electronics problem- or at least not yet. Now is the time to be proactive.

The United Nations Environment Programme has posted summaries of recent discussions on using life cycle assessment (LCA) to address the global problem of plastic pollution.  These Life Cycle Initiative areas relate to plastic products, chemicals of concern in plastic products, and plastic product design.  The documents are about possible approaches to managing plastics with recommendations but are not detailed prescriptions, methods, or regulations.

While the studies did not specifically mention electrotechnical products, this industry will need to accelerate focus on engineering design tools and engineering plastics choices to avoid significantly adding on to the consumer plastic product problems.

Within the UNEP product design discussion, the section on “General considerations on possible approaches to product design, focusing on recyclability and reusability” included the following important point, which bears repeating:  Product design approaches should include eco-design and circularity principles.

Product design approaches should include
eco-design and circularity principles.

But what does this mean? In the following discussion, we hope to break these approaches down into more tangible design choices. Even within the electrotechnical product category, there are many product variations, so no claim is made here to cover all of them.

Options for lower carbon footprint plastics already exist to some extent.  Except for packaging, electronic components and products are typically made with engineering resins rather than the common consumer plastic “recycling arrow” types.   Alternative types of lower carbon footprint engineering resins may be available to use rather than others with higher carbon footprints.

Many plastic manufacturers are currently conducting LCA to quantify the cradle-to-gate carbon footprint of their materials. Different polymer types have inherent differences in carbon footprint due to their different monomeric starting materials and manufacturing processes.

For many plastics, these flows are detailed by Plastics Europe.  Polycarbonate, ABS, and several Polyamides, for example, are included. What is missing in these publicly available sources, as well as LCA inventory databases themselves, are many other engineering plastics; for example, while consumer PET is widely modeled, PBT (Polybutylene terephthalate) is not. These are just some of the data gaps that need to be resolved.

More sustainable feedstock is a good option since a given end polymer may be made from different monomeric chemicals, so the more sustainable plastic performs exactly like its classic version because it is the same.  One of the growing alternatives includes feedstocks based on renewable, bio-based sources.

These need some evaluation, again using LCA, to ensure they are free of downsides like increased water use, eutrophication, and chemical pollution due to the use of herbicides, pesticides, fertilizers, and so on. Marketing claims of being a “green material” will need backup data! For guidelines on acceptable environmental benefits claims, refer to the US FTC Green Guides.

Reducing the amount of plastic by design is not only a good practice for sustainability, it also saves money.  Some designs using parts with enough material to be modeled using generative design may be able to reduce the amount of material while reducing material usage and weight.  Reducing factory scrap from injection molding processes leaving sprues in runners and use of captive regrind are other good options.

Choosing manufacturers using renewable fuels– and even benefits like reduction of water use during processing- is another area of choice for sustainability.  Local sourcing is also a way to reduce the overall carbon footprint of a material by reducing the contribution of transportation.

Identify large plastic parts.  Historical guidelines on eco-design have actually been around for years.

One good example is the ECMA 341 Standard, “Environmental Design Considerations for ICT & CE Products (4th Edition / December 2010), which says, “All plastic parts weighing 25 g or more and with a flat area of 200 mm2 or more are marked with the type of polymer, copolymer, polymer blends or alloys in conformance with ISO 11469.”  This practice enables the identification of plastic types of large parts, while in practice, the ability to sort becomes less useful when a variety of goods are mixed in a production recycling facility.  Success here depends either on manual sorting or more sophisticated methods like infrared spectroscopy to be effective. Some equipment recyclers have such capability.

Keep it clean.   More useful guidance from ECMA 341 is to avoid the following: non-recyclable composites; coatings and surface finishes on plastic parts; adhesive-backed stickers or foams on plastic parts; if stickers are required, they should be separable; and metal inserts in plastic parts unless easily removable with common tools.  These are common sense from a clean recycling stream perspective and should not be difficult to implement.

Closing the end-of-life loop.   Recycling is imperfect, and as far as this author has seen, is rarely in place for engineering plastics.

Processes under development to decompose plastics back to new monomer feedstocks, called chemical recycling or tertiary recycling. This approach is achieving some success with a limited number of materials, mostly for high-volume consumer plastics rather than engineering types.

LCA is needed to validate that achieving plastic circularity this way with the necessary processing energy and chemicals will have a net environmental benefit.  The obvious problem with all approaches is that plastics were never designed for the environment in the first place.

Selecting More Sustainable Additives is another area where product engineers have some choices.  There are thousands of possible additives used in plastic, usually specified for a given grade and end application.  These include flame retardants, processing aids, fillers, colorants, ultraviolet stabilizers, plasticizers for flexibility, and so on and on.   While these choices are primarily the responsibility of the resin manufacturer, pressure from regulators and industry demand can influence the use of more sustainable additives.

Whenever possible, new products should avoid regulated substances by design, which may include Substances of Very High Concern (SVHC) as defined by the European Chemicals Agency (ECHA) and, more recently, polyfluorinated substances called PFAS.  This is easier said than done but definitely belongs on the checklist of ecodesign considerations.

Besides plastics?  While the present discussion is about plastics, choices of using altogether different materials may be possible in some cases.

High-volume hardware is probably unable to use alternative materials like wood, glass, bamboo, etc.   Historically, though, until the rise of both solid-state and plastic technology in the 1950s, radios and televisions featured wooden cases and consoles.  Miniaturization in the solid-state era brought in mostly plastic housings.  One recent example that the author worked on was an audio teleconferencing system that featured either oak or walnut to blend with the executive conference room.

While the intent was not specifically to avoid using plastic, it is an interesting example to think outside the plastic box. Wood avoids many of the issues with plastics, but of course, the plastics in the circuitry content remain to be addressed.

Other large household electrical/electronic goods are likely to use recyclable steel and/or stainless steel cabinets.  And if you consider an automobile to be an electronic product, these metals come into play in high volume in automobile shredder residue. Using metal rather than plastic housings may be possible for some products; for example, aluminum may be used for personal communications and IT devices, bringing a tradeoff between initial cost and the potential advantage of aluminum being more highly recyclable for use in new equipment than any plastic.

Only LCA can quantify the tradeoffs. We should also mention toys, which increasingly incorporate some electronics and use colored plastics extensively.

New material technology.  One of the many emerging material technologies is Engineered Wood.  The cited research hardly suggests that a wood-based material could be a drop-in, for example, injection molded thermoplastics, but the possibility is most intriguing.  However, just having a material of natural origins is not automatically a panacea for replacing plastics. Quite the contrary, significant cautions remain; for example,

“Chemical and thermal modifications are usually applied to adapt the wood structure and impart necessary functionalities. Most of these treatments use substantial amounts of chemicals, energy, and water. They also innocently incorporate unwanted chemically bonded structures into the wood and generate a large amount of waste products which are harmful to the environment. This brings a dilemma where an entirely sustainable and green material is converted to a non-environmentally friendly material”

(El Akban et. al, Green Chemistry, 2021).

For now, the point is that reconsidering classical synthetic polymers in the light of more natural and renewable materials may have an interesting future.

Modularity.  The ease of disassembly into “modules” is often listed as an eco-design practice that improves circularity, but the present author is skeptical about providing practical details.  More specific guidance requires each manufacturer to know how its products can be disassembled at their end of life and where such disassembly would lead in terms of reuse, remanufacturing, or material recovery.   In the context of plastics, a large plastic housing that can be easily disassembled into a single clean material is more likely to be sent to a recycler rather than reused as a “module” in other products.

It is unfortunate that software tools to make early design choices for disassembly began to be developed 25 years ago but have gone by the wayside since.   The author had personal experience with such a “Green Design Advisor” tool that modeled a product assembly from its raw materials and showed how disassembly into environmentally and economically viable recovery fractions could be optimized.

One example that is probably still true today is that an epoxy circuit board and its components would be a “module” to be submitted to size a reduction, separation, and metal recovery process.  Such a tool could also model the choice of a plastic housing vs. a metal alloy and the impacts of circular recovery of the material choices. Disassembly modeling tools for product designers is an area that needs significant development now, while software using artificial intelligence (AI) claims to be the answer. We shall see.

In conclusion, it must be recognized that most plastics were never designed for the environment in the first place. While there is currently no 100% perfect alternative, engineers do have options to improve the life cycle sustainability of tomorrow’s products.

• Select lower PCF plastics and avoid regulated additives.
• Reduce the amount of plastics if possible and keep larger parts free of different materials.
• Consider materials other than plastics.
• Be aware of new developments in both sources of plastic and end-of-life options.

Roger L. Franz / RogerLFranz@gmail.com   – Sept. 2024