Six challenges of lightweighting

The trend for smaller and lightweight products is driven by benefits such as improved product design/performance, reduced manufacturing costs and reduced environmental impact.

Lightweighting can be achieved through replacing traditional fixing methods with an adhesive tape, by replacing substrates with lighter materials and by designing parts to use less material.

Lightweighting through replacing traditional heavy-duty substrates raises challenges in terms of substrate assembly, performance and aesthetics. Here we discuss these challenges and a solution for each.

1. Adhesion to lighter substrates
Introducing a lightweight substrate, for example replacing steel with aluminium, aluminium with plastic or engineering plastic with PE or PP plastic can present new bonding challenges due to their significantly diffferent surface and mechanical properties. Generally, with each decrease in substrate weight, adhesion to the lighter substrate becomes more difficult. Low surface energy (LSE) plastics, for example, can be particularly difficult to bond to, however, not impossible.

Lighter substrates such as aluminium, engineering plastics and various polyolefins are better suited to fabrication and assembly by adhesive bonding rather than traditional fixings from both a weight saving and mechanical performance perspective.

We offer a range of bonding materials suited to even the most difficult to bond to substrates, including plastics, metals, powder coated metals and foams. Our experienced Advisors can guide you in selecting and testing the products best suited to your unique requirements.

2. Attaching dissimilar substrates
Joining dissimilar materials can be challenging due to the differences in their chemical properties, for example if steel and aluminum are directly attached an electrochemical reaction will occur and cause corrosion of the metals. Differences in the coefficients of expansion can also be problematic.

We offer a range of products with flexibility and durability for any mismatch in coefficients of thermal expansion, as well as providing a reliable barrier between different surfaces to bond and separate dissimilar substrates.

3. Lighter weight substrates can be noisier
Lighter weight substrates are often noisier as they can produce more vibration, which creates noise of greater frequency (i.e., more vibrations per second) and of a higher pitch. As a result, the perception of lower quality or decreased safety may be created. This can be avoided by using lightweight aluminium sound damping tapes, or high performance foam tape, such as 3M™ VHB™ products, which absorb energy, as well as relaxing internal stresses.

4. Weaker/more flexible substrates
Lighter weight substrates can be more flexible but also weaker. As such, they may need reinforcement to increase their strength. There are a range of products available that provide this strength, which are also lightweight, helping to maintain a net reduction in product weight. Protective films and other materials are available for effective and easy strengthening of weaker and more flexible substrates, in a range of applications such as electronic devices and signage.

5. Differences in heat and flame susceptibility
When replacing substrates with lighter weight materials, consideration must be given to any requirement for heat and flame resistance. Whether a product requires overall heat resistance or one time protection from a flame event at the end of product life, a foil tape can be used to provide high performance protection where necessary. We offer a range of options for protection of a variety of substrates.

6. Visual appearance of lighter substrates
Introducing lighter weight substrates can have a significant effect on the appearance of products and their perceived quality. This can be addressed by adding veneers to new substrates to enhance their aesthetics, such as making plastic surfaces appear to be metal.