Advanced polymers enable handheld device designers greater freedom

New advanced polymers have enabled handheld device designers greater freedom so they can continue to refresh the look, feel and upgrade performance, while delivering a better environmental footprint, according to Handheld Segment Leader Mark Hazel of DuPont Performance Polymers. Hazel identifies the polymer material as DuPont™ Zytel® RS HTN high performance polyamide a renewably sourced polymer that has seen a four times growth rate since its introduction just four years ago. Stiffness, strength, low warpage and low moisture pickup combine to help ensure thinner walls for sleek, light designs that improve performance. Derived from sebacic acid, the material affords environmental benefits by replacing petroleum sources with non-food renewable sources. In handheld electronics applications one of the major characteristics required in a material is its Radio Frequency Interference (RFI) compatibility. If the material picks up moisture, it changes its RFI characteristics and detunes itself. This means that the battery has to supply more power to the antenna and the battery life suffers as a result. At DuPont we have developed enhanced materials, which are less prone to moisture absorption. Handheld devices dominate the consumer electronics market and make up a significant share of the commercial market too. Within this subset, which also includes laptops, ultrabooks, game controllers and hand held meters, mobile phones account for a staggering volume of sales. Multiple reports – although not agreeing on the total figure – put shipments in the first quarter of 2013 at over 370 million handsets. Mobile phones, along with other handheld devices, have undergone significant design changes over the last decade, with both functional and aesthetic features appearing and then disappearing as trends and technology change. Hazel explains the design evolution of the mobile phone, which has also been mirrored in the development of many other devices including gaming hardware, tablets and laptops: "In the early days many phones used to comprise a stiff plastic chassis with decorative and sometimes removable front and back covers. This chassis gave the phone its strength and provided the mounting frame for all of the internal electronics. However, as they evolved, with larger screens and more powerful electronics, this chassis concept became less attractive functionally, as users wanted the screen size but without the body bulk. Many OEMs therefore steadily reverted to a design where the screen and rear cover act as significant parts of the structure, freeing up much more internal space for the enhanced electronics." Zytel® HTN is a high-performance polyamide resin that can be used to make thinner, lighter and more durable handheld device housings while making them longer-lasting and easier to produce. From a processing perspective, Zytel® HTN grades can also save energy, cost and time thanks to its excellent flow and dimensional stability. A halogen-free, flame-retardant grade is also available for compliance with recycling programs for discarded electronic products. Specific grades are also available that can withstand high-temperature circuit assembly methods, including those using lead-free solder. Aesthetically, both grades deliver very good surface quality and appearance and are easily coloured.