Solutions Current Issues > Jan.Feb.Mar_2009 > PRODUCT PROFILE
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FROM METAL TO PLASTIC
Understanding the "Whys" and "Why Nots" of Converting
Brackets, containers, complex assemblies — when you upgrade from metal to plastic, you open up an almost unlimited range of possibilities.
Why? From inexpensive commodity resins like polyethylene and polypropylene to high-end engineering materials like polyetheretherketone (PEEK), plastics move beyond the limitations of metals to provide:
- More design options
- Electrical and thermal insulation
- Corrosion resistance
- Reduced weight
- Vibration and sound isolation
- Reduced parts count
- Damage-free impact recovery
- Lower cost
More than any other material, plastics offer “net shape” production opportunities, often with minimum or no additional machining, assembly, or finishing steps.
Why Not? With all these advantages, why would a designer choose metal over plastic?
- Thickness for thickness, metal is stiffe
- Metal is electrically and thermally conductive
- Inherent RF (radio frequency) shielding
- Better resistance to high temperatures
Is It That Simple? No, not really. It wouldn’t make sense to replace a simple stamped metal bracket with an identical plastic one, because there may be no cost saving at all and the bracket probably won’t perform as well. It also wouldn’t make sense to use plastic where high temperatures would require the use of exotic engineering materials — unless there were other factors, such as parts consolidation, that made it cost-effective.
At RL Hudson, we understand that not every component is a candidate for the upgrade from metal to plastic, just as we understand that a successful conversion can yield a wide range of benefits. Over the next several months, watch for an expanded discussion of materials, methods, and designs here in Solutions and on our website, at rlhudson.com.
Design Assistance It’s always tempting to approach the upgrade from metal to plastic as if it were a simple drop-in replacement, but a successful conversion requires a thorough, from-the-basics analysis of how the part is used, along with a careful study of the costs of each alternative. RL Hudson’s design engineers and materials specialists can help, bringing broad knowledge and years of experience to your project. Call us when you’re ready to make the switch.
