DESIGN
COMMENT
Michael Paloian, Integrated Design Systems, Inc.
Designing for Sustainability What is the most popular buzzword in the plastics industry today? The answer is sustainability. Everyone is jumping on the sustainability bandwagon. Some companies use the word for the sole purpose of promotion and marketing, while others genuinely believe they are saving the environment. Unfortunately, most people don’t truly understand the implications of the word and how to maximize the utility of plastics from the cradle to the grave genuinely. The remainder of this editorial will discuss this topic objectively. Plastic materials have revolutionized society since their commercial introduction a little more than 100 years ago. They have become an integral part of our economy, society, and way of life because of their unique properties. One of these properties is their corrosion resistance and ability to sustain decomposition for long periods, sometimes hundreds of years. Unfortunately, this same property is the biggest problem associated with plastics; you can’t easily get rid of them once they have been created. All you must do is check the internet for plastic pollution, and you’ll quickly see the exponential amount of plastic waste deposited into our environment every year. For example, 1.25 million tons of micro pellets are dumped into our environment this year vs. almost zero in 1950! Projects for the next 30 years could triple that annual amount unless policies are changed. The question is, what is being done and what can be done? Plastics like PET, PE, PS, and PP are collected, segregated, and reprocessed. Some companies like Ocean Plastics are gathering plastic waste from the ocean and recycling it into pellets for reuse. Other plastics are burned and used as fuel. How can designers truly design for sustainability? There are several considerations listed below: 1. Specify recycled materials – Surprisingly, recycled polyethylene is similar in cost to virgin polyethylene; the former is slightly higher than the latter. Designers must be aware of the property profile of recycled PE. Some applications are not well suited for recycled PE. Applications requiring stringent control of specific physical properties are not good candidates for recycled PE. 2. Cost – Cost-sensitive products are better suited to virgin PE than recycled materials, which are usually more expensive. 3. Regrind vs. Recycled – Can one claim a 5% use of regrind is equivalent to 100% recycled ocean plastics? Some companies claim their product is manufactured from recycled plastics because it contains a small amount of regrind, obviously deceptive. The industry should institute regulatory guidelines to prohibit this type of misrepresentation. 4. Design for Recycling – Ease of recycling is dependent on part
design. Ideally, product designs should be easily assembled and disassembled for recycling. Plastic parts that include large molded-in metal inserts, multilayer composition, and inseparable assemblies are difficult to recycle. 5. Availability – Designers should always consider material availability when specifying resins. If the resin supplier is not dependable and alternative sources don’t exist, it will pose a problem for maintaining long-term production commitments. Specifying recycled resins is sensible and beneficial when the application, market, and manufacturing requirements make sense. Designers should never assume the properties of the recycled resin are as good as virgin material since the former comprises a blend of various materials that have been degraded during an unknown period. Compliance certificates are recommended when recycled materials are specified to maintain quality and production consistency. I hope this brief discussion about sustainability has been informative. I look forward to hearing from you. Please feel free to contact me with your questions or comments by writing to me at paloian@idsys.com www.rotoworldmag.com 47
