Materials experts stay ahead of the game: making the right material choices for consumer products

density-thumbnailConsumer product development is distinguished from other manufacturing sectors by high turnaround, with many products having a typical lifespan of no more than two to five years. Whether household appliances, electronic devices, or even cars, the market has a constant appetite for new products and its attention is fickle. Tastes evolve—a product that was the epitome of good design five years ago may now look dated. Even the most cutting-edge devices may only secure demand for so long before market share is lost to competitors or newer technology. Manufacturers have a limited horizon in which to capitalize on the success of their new products and generate profit, and they need to get it right. But how?

Making material choices in a fast-changing world

Relatively rapid development cycles and constant innovation place considerable pressure on materials specialists in this sector—and it’s not just product development that requires the selection of new and replacement materials. In-house cost-saving initiatives may seek to increase margins by using fewer or cheaper materials, or by consolidating suppliers. Unforeseen supply disruption due to events such as natural disasters or factory closures may place severe restrictions on manufacturers that must be managed by finding suitable substitute materials as quickly as possible.

There are many factors to consider when choosing materials for consumer products. And without the luxury of time for extensive testing, it’s not surprising that it sometimes goes wrong. Indeed, Smithers Rapra, an independent authority on rubber, plastics, and composite materials, report that around 70% of plastic products fail prematurely, and 45% of these failures are due to poor material selection or substitution. That’s almost a third of all plastic products that are compromised by sub-optimal material choices.

Getting it right first time means looking at the big picture

In light of these challenges, more and more manufacturers of consumer projects are adopting a systematic approach to material selection and substitution[1]. In doing this, they consider the  complete range of material properties and process choices—including mechanical properties, manufacturing requirements and limitations, longevity of supply, end-user requirements and preferences, aesthetics, environmental considerations including restricted substances, packaging, shipping challenges, and other factors specific to each product.

These criteria can become either “constraints” (restricting the selection to those materials that meet, for example, the specific mechanical requirements) or “objectives” (factors to maximize or minimize while being traded-off against one another). A structured, repeatable process is then used to find materials that optimize performance against the objectives for a particular function. Graphical tools such as Granta’s CES Selector are increasingly being used to make and present these decisions. This helps engineering design teams focus on likely candidates and study trade-offs, for example, between cost and engineering performance.

Responding rapidly by building on generic material properties

Using CES Selector to support materials decisions

Tecumseh’s materials experts used graphical and systematic materials selection methods to make decisions which have already saved 2 million euros.

In the Smithers Rapra findings, the majority of failure modes are due to embrittlement caused by various medium- to long-term degradation mechanisms.  Sometimes, even finding this materials information can be challenging, complicated by the number of material types and grades available from a wealth of different suppliers. These key material properties may not be quoted by suppliers, making failure difficult to predict at the design stages. It is often not applying what you know that is the problem, but finding all the information that you need.

To avoid working with incomplete information, leading material experts often employ a two-stage process. First, they perform their material selections using comprehensive information on generic materials—encompassing the full range of material property information without any gaps. Only then, having identified a short list of the best material choices, do they go on to interrogate supplier datasheets and other reference data sources, and move on to simulations and prototyping. Such approaches save both time and money: Tecumseh recently reported that they had saved 2 million Euros in this way. As Sophie Colmek explained, “having first carried out the rational selection, engineers could concentrate more advanced simulations on just a few likely candidate materials.”

Putting material choices in the hands of the experts

These strategies come into play both at the design stage and when rapidly responding to issues encountered during production.  By looking at the big picture, building on relevant generic material properties, and applying a rational selection process, consumer product manufactures are putting the material choices back in the hands of those who really understand both the materials and their applications—their engineers. Tecumseh are not alone in this. A growing number of consumer product manufactures are finding that such systematic selection approaches are reducing development time, helping them to quickly overcome problems, reduce cost, react to legislative changes, and increase productivity.

[1] This approach is well documented in engineering textbooks such as, “Materials Selection in Mechanical Design” (4th edition) by M.F. Ashby, Butterworth Heinemann, 2011. Some of the key concepts are also described here:

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