{"id":12832,"date":"2022-02-23T06:05:40","date_gmt":"2022-02-23T12:05:40","guid":{"rendered":"https:\/\/www.ulprospector.com\/knowledge\/?p=12832"},"modified":"2022-04-05T10:28:25","modified_gmt":"2022-04-05T16:28:25","slug":"pe-automotive-plastics-progress-and-progression","status":"publish","type":"post","link":"https:\/\/ulprospector.ul.com\/12832\/pe-automotive-plastics-progress-and-progression\/","title":{"rendered":"Automotive Plastics \u2013 Progress and Progression"},"content":{"rendered":"
\"Matrix
Fig 1 Automotive matrix lights molded with precision (courtesy: Sumitomo)<\/figcaption><\/figure>\n

Over the last 40 years or so, plastics have revolutionized the way that cars are made. While a car from the 1950s had almost no plastic, the typical automobile today has more than 120kg of plastic. The global market for lightweight automotive materials expects to reach $91.3 billion, with a CAGR of 11.4%. Plastics now make up approximately 50% of the volume of a new vehicle but less than 10% of its weight. Currently, there are about 30,000 parts in a vehicle, out of which a third are made of plastic. Every 10% drop in vehicle weight equals a 5 to 7% decrease in fuel usage.<\/p>\n

Yet while the typical car includes many different plastics, three types \u2013 polypropylene<\/a>, polyurethane<\/a> and PVC<\/a> \u2013 are the most common. More than 70% of the plastic used in automobiles comes from these three.<\/p>\n

What are the likely challenges for the future?<\/strong><\/h2>\n

Overall, the consumption of polymers in the automotive sector continues to grow. Traditionally, carmakers were reluctant to reduce the weight of the car unless cost-savings could be made as well. This led to ingenious ways of consolidating parts: wholly integrated single-piece units offering significant cost savings for the manufacturer.<\/p>\n

But this is changing, as the move to net-zero pushes up the priority of saving further weight. Electric vehicles are limited by range, so the more the weight of the car can be reduced, the further it can travel without the need to recharge.<\/p>\n

The application of polymer components within engine transmission will become more common, as high-temperature performance is not a requirement for electric battery components, the fuel systems or other required ICE parts. The entire structure of the battery pack offers opportunities for polymers and composites.<\/p>\n

The growth of some plastics (PP<\/a>, PA<\/a>, PC<\/a> and PE<\/a>) is expected to increase, while the consumption of high-temperature engineering plastics is expected to slow down. Polycarbonate (PC) is expected to grow at a particularly fast rate, as it will be used in sensors and LEDs.<\/p>\n

On the other hand, the consumption of engineered polymers will be countered by smaller and lighter components.<\/p>\n

Some recent advances<\/strong><\/h2>\n

(a) 3D woven textile composite sheets<\/em><\/strong><\/h3>\n

A new material that is as stiff as metal but flexible enough to withstand strong vibrations could transform the car manufacturing industry, say experts from the University of Surrey.<\/p>\n

In a paper published in Scientific Reports by Nature, scientists from Surrey joined forces with Johns Hopkins University in Baltimore and the University of California to develop a material that has high stiffness and damping.<\/p>\n

The team achieved this by using 3D woven technical textile composite sheets with selected unbonded fibers, allowing the inside of the material to move and absorb vibrations while the surrounding material remains rigid.<\/p>\n

(b) Precision optics<\/em><\/strong><\/h3>\n

Matrix LED automotive lights are an application where significant growth is forecast. The adaptive headlight segment is expected to grow at the fastest rate between now and 2023, driven by high demand in Europe and Asia Pacific.<\/p>\n

Adaptive headlights are a highly sophisticated technology comprising complex optical surfaces, where light is guided through the micro-milled polished surfaces. Connected to a camera control system, individual LEDs are switched on and off to ensure road users aren’t blinded by a full-beam or to highlight a particular road obstacle. Right now, the technology is confined to premium vehicles, but it’s anticipated that these headlights could become more mainstream in the near future.<\/p>\n

Liquid silicone rubber (LSR<\/a>) is replacing glass and traditional polymers in more technically demanding industrial optical applications, such as thick-walled optical fibers, prisms or lenses. LSR is a good material for automotive optics. It enables manufacturers to achieve component geometries and technical features not previously possible, such as molding complex optical surfaces onto a light guide for a matrix headlight.<\/p>\n

Due to its liquidity, it is especially well suited for injection molding. But optical function can be compromised if the contours are inaccurate. Significant developments are happening in optical injection molding.<\/p>\n

To achieve the extremely precise shot control needed and to handle the low-viscosity material, Sumitomo (SHI) Demag has launched a fully-integrated precision IntElect LSR injection molding package. Units feature a specially designed screw, a modified plasticizing unit, a shut-off system specifically designed for LSR and a spring-loaded non-return valve. These achieve high processing consistency and avoid uncontrolled backflow of material.<\/p>\n

(c) Carbon fiber reinforced SMC <\/em><\/strong><\/h4>\n

The sheet molding compound (SMC) process has proven to be one of the most versatile production methods for composite components. It combines low waste production and high-volume capability with design freedom and integration of functions.<\/p>\n

But the growth of CF-SMC technology in the automotive industry has been slow, often because the system cost was prohibitive.<\/p>\n

“In recent years, novel SMC materials based on carbon fiber have become commercially available and are now applied at full industrial scale to produce ultra-light structural parts that outperform their equivalents in aluminum and steel,” explains Ron Verleg, Senior R&D Scientist at AOC. \u201cSeveral thermosetting resin systems can be used with the SMC process, with each one having its specific advantages and disadvantages.\u201d<\/p>\n

\u201cAOC has developed a unique SMC technology that enables chopped CF molded parts with the mechanical performance of Epoxy Resin CF-SMC to be manufactured with the ease of UPR and VER SMC,” says Luuk Groenewoud, Strategic Projects Manager at AOC. “This breakthrough technology is based on AOC’s Daron polyurethane hybrid technology.”<\/p>\n

Combining Daron with carbon fibers in SMC enables reliable manufacture of components with mechanical strength, low density, E-coat capability and low emissions while maintaining the design flexibility typical for composites. In the U.K.-government-funded research project, called TUCANA, this new CF-SMC has enabled the development of structural automotive parts. Led by Jaguar Land Rover, TUCANA brings together a consortium of academic and industry partners with the aim of delivering stiffer and lighter vehicle structures to boost the performance of electrified vehicles whilst enabling cost-effective, scalable carbon fiber composites to be manufactured.<\/p>\n

Table 1 Characteristics of leading automotive polymers and their applications<\/strong><\/h3>\n

Polypropylene<\/strong><\/a><\/p>\n