China VI Emission Standards greatly promotes the demand of automotive plastics

The upgraded China VI Emission Standards is about to be implemented. In the process of lightweighting upgrade, many plastic products are used for additional effects. The transformation of the automotive industry is accelerating, and new energy vehicles will be the focus of the next stage.

If dealing with the upgrading of the China VI Emission Standards was still not so urgent to many automobile manufacturers a few years ago, this has become not the case since last year.

Compared with the version V, version VI was upgraded in many directions, such as more scientific test cycle, increasing strict evaporative emission control requirements, and higher low temperature test requirements.

In the new round of product changes, products such as plastic front end frames, plastic tailgates and plastic intake manifolds have also become key development targets.

Round of groundbreaking changes

As the upgraded China VI Emission Standards is coming soon, the technology upgrade in lightweight automobiles has developed rapidly in the last one or two years. The use of plastic bumpers, fenders, wheel covers, and other accessories in interior and exterior trims has become the norm.

New energy vehicles have a great demand for resins such as nylon, polypropylene, polyurethane, and other engineering plastics, which account for over 30% of the total market demand for resins. Meanwhile, the demand for polyvinyl butyral accounts for over 85% of the total demand.

In the new round of product changes, products such as plastic front end frames, plastic tailgates and plastic intake manifolds have also become key development targets. This round of changes was also groundbreaking, because some plastic auto parts not only provide lightweight improvement, but also achieve unexpected results.

Let"s take plastic intake manifold as an example. Due to the complex shape of the manifold, aluminum alloy casting will inevitably increase the roughness of the inner wall, which will increase the air resistance and lead to problems such as high noise, incomplete combustion and more exhaust emissions.

In recent years, thanks to the development of vibration welding technology, the welding technology for large-size glass fiber reinforced PA66 has become increasingly mature. For this reason, the manifold can be made by injection molding into two manifold parts and integrating the two parts by vibration welding. The advantage of this treatment process is that the roughness of the inner wall can be greatly reduced, and the above problems can be alleviated, making a contribution to energy conservation and emission reduction.

Unexpected effects are also found in plastic seat frames. Hanwha Advanced Materials’ very fashionable GMT-PP automobile seat frame is made of glass fiber mat reinforced thermoplastic polypropylene (GMT-PP) composites. Compared with existing steel frames, the weight is reduced by 15%~20%, and 22% of the assemble components can also be reduced too. In addition, steel corrosion problems no longer exist, and the assembly cost is also reduced greatly because welding is not required.

Plastics widely accepted as the real solution

From the above, it can be seen that although manufacturers are worried about the low acceptance of plastics, facts have proved that plastics are the real solutions. Therefore, pioneering manufacturers continuously develop innovative solutions.

For example, the use of composite leaf spring is very innovative. The main materials of the composite include reinforcing fiber and base resin, which are then blended by the RTM process.

The total weight of the composite leaf spring (including the metal joint) is only half of a steel leaf spring. As the load distribution is more even, the damping property can speed up the vibration attenuation, the single spring structure can also reduce abnormal sounds, therefore improving the comfort.

The latest Volvo XC60 chassis suspension is made of this composite leaf spring which is processed with glass fiber (provided by Benteler) and polyurethane (provided by Henkel). Besides Volvo, some lightweight heavy trucks and buses in overseas have begun to adopt composite leaf spring structures. As the operating conditions of heavy trucks and buses are worse than those of passenger cars, it shows that the durability of composite leaf spring structures is not bad.

Besides, Tesla uses plastic on the upper fork arm of the front suspension of Model 3, and the connecting rod of the control arm of the new BMW 5-series rear suspension is also made of plastic. Although these are not as radical as the Volvo XC60, they are undoubtedly releasing a signal that plastics can also play an important role in structural components.


China VI Emission Standards ringing the alarm

From another point of view, China VI Emission Standards actually urges the manufacturers to shift to new energy vehicles production. Therefore, while upgrading traditional fueled vehicles, it is urgent for every enterprise to earn market share and accumulate technologies in the new energy vehicle market as soon as possible.

In the new energy powered battery structure, PPE, PC/ABS alloys, and flame retardant reinforced PA materials with flame retardancy are usually selected for the bracket, frame and end plate, in order to improve the lightweight performance.

In fact, in addition to the plastic parts mentioned above, the use of other plastic parts for new energy vehicles also has high potential. In 2018, the Chinese automobile market experienced its first annual decline since 1990, with the annual sales of 28.0806 million vehicles, representing a decrease of 2.76% year-on-year. However, the new energy vehicle market grew against this trend, with sales up 61.7% year-on-year to 1.256 million vehicles, exceeding the sales target of 1 million vehicles.

Wang Chuanfu, the chairman and president of BYD which is one of the biggest new energy vehicles manufacturers, said he conservatively estimated that the market share of new energy vehicles would reach 30% in 2025, and would be a new blue ocean.

Analyzing the development situation, many traditional enterprises have introduced their own all-electric platforms since the past one or two years. With the introduction of all-electric platforms, many traditional technical barriers will be broken, which will be conducive to the use of plastic parts.

We have discussed the preference for plastic parts in new energy power batteries, but the application of plastic parts is not limited to this. For example, the charging port is made of plastic and plastic + metal. As far as high-voltage electricity is concerned, some metal shells are made by plastics instead of steel when there is no need to consider the shielding problem.

During this year"s Milan Design Week, design studio Mandalaki and Estrima jointly launched a concept car Estrima, which is positioned as a 4-wheel all-electric city car. Recycled plastics account for 80% of the car (the other 20% is mainly PVC), and it is expected to be sold in July this year.

Plastics for new energy vehicles

As for the selection of plastic materials, LFT modified plastic, i.e., long fiber reinforced thermoplastic, has become very hot. LFT"s reinforcing fibers include glass fiber, carbon fiber, aromatic polyamide fiber, stainless steel fiber, etc., of which glass fiber is the main fiber used. The base material is mainly polypropylene (PP), others include PA, PPA, PBT, etc. As a new lightweight material in the field of fiber reinforced polymers, LFT has good dimension stability, excellent impact resistance, and chemical stability.

LFT modified plastics are applied to many vehicle body parts, and can be used to make structural and semi-structural parts, such as front-end modules, bumper beams, instrument panel frames, battery brackets, spare tire compartments, seat frames, foot pedals, engine covers, luggage racks, panoramic windows and others.

Apart from the use of LFT modified plastics, the fire safety of new energy vehicles is another hot topic. Many vehicle parts, including connectors, connecting pieces, switches and other charging connection elements, the charging pile shell, power module shell, charger shell and other shell components, require good electrical insulation, flame retardancy (UL94 V0) and high heat resistance.

At present, there is no standardized voltage for electric vehicles around the world, and the voltages used by major new energy automobile enterprises are different. Take BYD as an example, its new energy vehicle has a high voltage of 690V and an instantaneous pulse of 800V or more. If flame retardant materials are not used, accidents such as electric leakage or spontaneous combustion of the whole vehicle will happen once the voltage breaks down or the temperature is too high. Therefore, it is urgent to improve the technology of flame retardant materials.

In this regard, modified plastics have become a hot spot. The role and position of modified plastics in the automobile industry are becoming more and more obvious. Such plastics as PP, PA, PC, POM, PPO, PBT, and ABS have been widely used in automobiles.

Take the battery case as an example. Currently, most of the battery cases are made of high-strength steel and light metals, and few of them are trying to replace metal with SMC. Modified PPO material is one of the ideal materials for lithium battery protective cases, because it has the advantages of good chemical resistance, strong flame retardancy, low temperature resistance, impact resistance, and good corrosion resistance to materials such as lithium cobaltate and lithium manganate.

Conclusion

With the implementation of China VI Emission Standards, the reform of the whole automotive industry is accelerating, and new energy will be the key direction in the next stage. After the manufacturers understand the highly promising market potential and get rid of the confusions, the lightweight technology for new energy vehicles will develop very rapidly.

However, this is not a small challenge to the technological development. Firstly, plastic materials will be increasingly used in structural components or semi-structural components (such as the upper fork arm of the front suspension of Tesla Model 3). Secondly, how to solve the problem of spontaneous combustion of new energy vehicles is an unavoidable question.

In fact, these are not the only concerns. Judging from last year"s Audi carcinogenic incident, the control of VOCs in vehicles will become more crucial in future. In other words, greater efforts should be put on the sustainability of automotive plastics.

Of course, opportunities come along with challenges. The improvements of lightweighting by plastic parts are massive, and plastic parts will become more important as big breakthroughs in the structural optimization of traditional automobiles will not be likely.

Moreover, the use of plastic parts also indirectly promotes the development of the welding technology. Compared with other welding methods, plastic laser welding technology has many advantages, such as non-contact, no water leakage, great welding speed, high precision, high weld strength, no flash, minimum thermal stress, easy control, good flexibility, good adaptability, etc.

The connection of automotive plastics is a key in its wide applications. The level of plastic welding technology will be one of the indicators to measure the advancement of the automotive production technology and the development of new materials.

In conclusion, the implementation of China VI Emission Standards is a trigger. In the future, automotive plastics will definitely have wider applications. There is still a lot of room to explore in this market. 

source : https://www.adsalecprj.com/Publicity/MarketNews/lang-eng/article-67032950/NewsArticle.aspx?lang=eng&article=67032950

edit : handelr