In the second installment of our \u201cSound Management\u201d special edition we will look at \u201cPassive\u201d solutions*1<\/sup> via high-performance materials. As the world of material development technologies continues to evolve, the \u201cSound Management\u201d approaches inherent in Asahi Kasei\u2019s material solutions have been drawing considerable attention. Some of our signature products are the nonwoven fabric \u201cPrecis\u00e9\u2122 \u201d \u2013 a super thin tri-layered fabric \u2013\u00a0and \u201cSunforce\u2122(AM)\u201d \u2013 a polyamide resin made into a foam. Looking onward to 2024, automotive exterior noise regulations are becoming stricter and high-level material contributions are being sought in this realm that Precis\u00e9\u2122 and Sunforce\u2122(AM) can provide. Let\u2019s turn to the representatives of our business divisions to learn more. Click here to contact us<\/a> about Asahi Kasei\u2019s products and usage examples.<\/p>\n \u25b2<Sunforce\u2122(AM) Team> Asahi Kasei Corporation, R&D HQ\/High-performance Polymer Technology Development Center, Polymer Base Technology Development Team: Tetsuo Nakamoto (second from left), Performance Products SBU\/Polymer Technology Development Management Dept.-Foam Technology Development Team: Shoji Imai (second from right) The product name \u201cPrecis\u00e9\u2122\u201d derives from the French word \u201cpr\u00e9cise.” This ultra-thin fabric is weaved into the top part of fabric sheets with Asahi Kasei\u2019s original technique, and is being implemented in a wide variety of materials for daily life and engineering purposes. How can this amazing technology help contribute to sound management solutions and benefit the automotive industry? Let\u2019s look to Mr. Yasuhito Takahashi and Mr. Katsuya Takahashi from our Spunbond Team for the answer.<\/p>\n Yasuhito Takahashi: \u201cOur team is in charge of a type of nonwoven called \u2018spunbond\u2019 that lays within Asahi Kasei\u2019s wide range of fabric products. There are many different types of nonwoven spunbonds, but sound absorption properties (the ability to absorb vibrations in the air and dampen them) are an extremely unique feature that only Precis\u00e9\u2122 holds. Traditional nonwoven spunbonds are comprised of a single-layer, and can be used for things like cosmetics masks. However, Precis\u00e9\u2122 has a tri-layered structure that sandwiches an ultra-fine fabric layer between two traditional nonwoven spunbond layers. This ultra-fine fabric layer plays an extremely significant role to enhance sound absorption performance. Using polyester as a base material, Asahi Kasei is the only company in the world that can manufacture this one-of-a-kind product.\u201d<\/p>\n Katsuya Takahashi: \u201cBy affixing Precis\u00e9\u2122 to the surface of the material, the base material\u2019s sound absorption performance can be improved while reducing the total amount of material used.\u201d<\/p>\n \u25b2Measurement result of sound absorption rate via Vertical Incidence method. For example, in order to increase the rate of sound absorption (red dotted line) of a 10 mm-thick single-layer felt fabric, it was once necessary to increase the thickness of the felt used. However, Precis\u00e9\u2122 is applied to the surface material (red solid line), sound absorption is dramatically increased even when compared to doubling the thickness of the material (blue dotted line). Yasuhito Takahashi: \u201cThe graph above shows one example of the effect of Precis\u00e9\u2122 when felt is used as a base material. Affixing just a 0.25 mm-thick layer of Precis\u00e9\u2122 to\u00a0a 10 mm layer of felt\u00a0provides a better sound absorption effect at 1,000 Hz or higher frequencies than even a felt layer of twice the thickness. Being significantly thinner, the overall weight of the fabric is also reduced, in turn improving the performance of the vehicle. So, if Precis\u00e9\u2122 is used to reduce the total amount of fabric in the vehicle, the total cost of the fabric can also be reduced depending on the price of the base material.<\/p>\n There is also an effect when replacing felt with urethane, so Precis\u00e9\u2122 can be used regardless of the base material as a sound absorptive surface \u2018skin.\u2019\u201d<\/p>\n Yasuhito Takahashi: \u201cThe area that has seen the most advancementin development for automobilesisin the engine vicinity. Having excellent heat-resistance, flame-retardance and water-repellency, Precis\u00e9\u2122 is perfect for vehicle parts that experience high temperatures, such as the engine hood, dashboard insulator, engine compartment, and so on. We also recommend Precis\u00e9\u2122 for sound absorption as the surface material of parts where porous materials are applied or when multiple sheet panels are bonded together as a base. The ultra-fine layerfabricsthat have been used on surface materials in the past were not strong andwould quickly show signs of wear like becoming fuzzy when grazed, but Precis\u00e9\u2122 protects the ultra-fine layer sandwiched within its tri-layer structure, so it is resistant to abrasion.\u201d<\/p>\n Katsuya Takahashi: \u201cAdditionally, Precis\u00e9\u2122 is easy to use also due to its \u2018conformability\u2019 as it can conform to the shape of even parts of the car with complex wiring. Because of these great features, I think this is a brilliant idea that I\u2019d like to recommend to all customers.\u201d<\/p>\n Yasuhito Takahashi: \u201cWe use one word to describe Precis\u00e9\u2122, though it has many different types andits thickness or design can also be changed. The density of the ultra-fine fabric layer in the middle can also be adjusted to perfectly control the air that flows through sound,as well as control the level of sound absorption and which frequency is removed. Thus, we can present Precis\u00e9\u2122 to our customers as a standalone product or propose it as a product to be combined with a base material. As Precis\u00e9\u2122 is one of our products that can bring out excellent sound absorption performance when bonded with various base materials, we have just started moving forward with a prototype together with Asahi Kasei\u2019s own Sunforce\u2122(AM).\u201d<\/p>\n Learn more about Precis\u00e9\u2122 at the link below: Sunforce\u2122(AM) is a polyamide foam resin and a new breakthrough material that is capable of sound absorption. Now we will ask Tetsuo Nakamoto of Asahi Kasei\u2019s R&D headquarters, who developed a way to make the previously impossible possible, and Shoji Imai of our Polymer Technology Development Headquarters about the characteristics and what types of contributions we can expect from the product.<\/p>\n Nakamoto: \u201cSunforce \u2122(AM) is a foam EP (engineering plastics are high-performance resins) that was developed as a new grade under the Sunforce\u2122(AM) series*2<\/sup>. It is a bead-like material made from a foaming polyamide-based resin \u2013 the same as nylon \u2013 that can be molded into various shapes. Since polyamide resin has high heat-resistance as well as oil-resistance and chemical-resistance, it has been traditionally used as an EP for automotive applications, but Sunforce\u2122(AM) has a combination of the excellent properties pertaining to polyamide resin as well as the extremely light weight benefits of foam. The density of Sunforce\u2122(AM) is about 1\/5 that of polyamide resin (5.5 times expansion ratio). Furthermore, with technology we are currently developing it will be possible to achieve up to 1\/7 or 1\/8 the density (7 to 8 times expansion ratio).\u201d Nakamoto: \u201cPolyamide is a difficult resin make into a foam, so until now a polyamide-based foam with a high expansion ratio did not exist. However, a few years ago we established a goal of developing a polyamide foam and through continued basic research on the foaming process we finally succeeded in making it a reality. At the same time, in addition to light-weighting functionality for automotive use, we considered the needs for NVH (Noise, Vibration, Harshness), which were drawing attention from stricter automotive noise regulations (such as UN-ECE R51-03, the United Nations Regulation on the Noise from Four-wheel Vehicles), and began technological development for a revelation in sound absorbing properties. Conventional hard resin foams (like Styrofoam) do not have sound absorbing properties, but we were able to make the foam particles in a specific form and thus the only polyamide foam with sound absorbing properties, Sunforce\u2122(AM), was born.<\/p>\n We found a way to produce Sunforce\u2122(AM) in a special bead-like shape using our newly developed foam bead manufacturing and foam molding technology. By creating a porous bead foam with tiny millimeter-sized holes, we succeeded in giving it sound absorbing properties. The sound waves enter these holes and then it is dampened.\u201d<\/p>\n Nakamoto: \u201cOne of the beneficial features of Sunforce\u2122(AM) is that it provides a high sound absorption rate between 1,000\uff5e3,000 Hz frequencies (Fig.1). This frequency range is actually equivalent to that of the sound for the vehicle engine motor, so it is optimal for sound absorption. Also, if Sunforce\u2122(AM) is bonded together with other materials, the sound absorption frequency range can be changed. For example, by stacking layers of nonwoven fabric on the surface of Sunforce\u2122(AM) where sound enters, the target frequency band can be lowered (Fig.2). By adding a combination of nonwoven fabric and acoustic insulator (i.e. resin film) in layers on the surface where sound enters, there will be a wider frequency range for sound absorption\u00a0(Fig. 3). Furthermore, we have proven that particularly strong sound absorption occurs by laminating a hard resin layer on the surface opposite to where the sound enters.\u201d<\/p>\n Nakamoto: \u201cBeing different from generic sound absorption material made of glass wool or felt fabric, Sunforce\u2122(AM) is a rigid foam in a stable shape, so one of the major benefits is excellent handleability. Furthermore, another great benefit is that it allows the use of traditional generic bead molding machines for a variety of components with complex shapes, such as sound insulator covers or piping structures. Sincecomplex shapes (uneven shapes) can be easily formed on the surface of the foam, arranging the uneven surfaces facing each other can leave spaces for heat to escape while improving sound absorption performance, as well as allow for more design freedom.\u201d<\/p>\n Nakamoto: \u201cSunforce\u2122(AM) is able to contribute to the reduction of in-cabin noise as well as external noise if embedded into various automotive components. For gasoline engine vehicles, the insulator and sound insulator cover near the engine compartment would be the primary applications. As EVs become more wide-spread, sound management of frequency ranges for sounds other than the engine, like road noise, inverter electromagnetic noise, and noise from the air conditioner intake\/exhaust is expected to be needed, so we are advancing development to contribute to this as well.\u201d<\/p>\n Imai: \u201cAs our Sunforce\u2122(AM) is not capable of creating sound by itself (like electronics can), we are trying to propose component designs (NVH designs) that could maximize the sound absorption\/cancellation performance of Sunforce\u2122(AM) using acoustic CAE, aiming to support customers\u2019 needs for component noise reduction. Since the automotive industry\u2019s mainstream development shifted the focus from gasoline engine vehicles to EVs, customers need support for a wider range of frequencies that Sunforce\u00ae\ufe0e AM alone cannot provide optimal performance (the lower frequency range of 1kHz or less and the higher frequency range of 10kHz or more). In order to support this change, we have started working on the proposal of complex designs\u00a0using fiber-based sound absorption\/cancellation materials (like resin film) as well as sound absorption component designs via panel vibration or resonance that make the best use of the strengths of Sunforce\u2122(AM), which includes great moldability for complex shapes. In response to customer needs for creating a \u201cquiet (comfortable) space in the car,\u201d we have recently started proposing not only Sunforce\u2122(AM) on its own, but collaborative functional proposals with Precis\u00e9\u2122 and \u2018Active Noise Cancellation\u2019 electronics.\u201d<\/p>\n Learn more about Sunforce\u2122(AM) at the link below: The greatest advantages of our high-performance materials for sound management (\u201cPassive\u201d solutions) like Precis\u00e9\u2122 and Sunforce\u2122(AM) are their ability to contribute to the noise cancelation of mid to high-range sounds while reducing weight and the amount of material used. As such, the benefits of reducing costs and burden on the environment are clear. At the same time, no individual product is almighty and there is a limit to what they can do on their own. In addition to the passive material collaborations that we introduced in this installment, we are also starting endeavors for \u201cactive\u201d approaches through electronics. As for Asahi Kasei\u2019s \u201cTotal\u201d solution and the individual ideas on the scene\u2026 We will continue in our 3rd<\/sup> installment.<\/p>\n Click here to contact us<\/a> about Asahi Kasei\u2019s products and usage examples.<\/p>\n
\n*1<\/sup>\u00a0\u201cPassive\u201d solutions absorb and control sounds. \u201cActive\u201d solutions produce sounds or vibrations to work against external factors.
\n(* For the previous article, please see Part 1<\/a>.)<\/p>\n![\"\"](\"https:\/\/asahi-kasei-mobility.com\/en\/wp-content\/uploads\/2021\/12\/soundmanagement_5_interview1-1024x683.jpg\")
<Precise\u2122 Team> Precise SBU\/Spunbond Dept.-Spunbond Material Sales Team: Yasuhito Takahashi (far left), Spunbond Dept.-Spunbond Technology Development Team: Katsuya Takahashi (far right)<\/p><\/div>\nThe world\u2019s only sound absorbing nonwoven fabric – \u201cPrecis\u00e9\u2122\u201d<\/span><\/h2>\n
![\"\"](\"https:\/\/asahi-kasei-mobility.com\/en\/wp-content\/uploads\/2021\/12\/soundmanagement_5_interview2-1024x683.jpg\")
<\/p>\nThe World\u2019s First! An ultra-fine polyester fiber layer sandwich<\/span><\/h2>\n
![\"\"](\"https:\/\/asahi-kasei-mobility.com\/en\/wp-content\/uploads\/2021\/12\/what_is_preciseen.png\")
<\/p>\nAttain thinner and lighter features while enhancing the base material\u2019s sound absorption performance<\/span><\/h2>\n
![\"\"](\"https:\/\/asahi-kasei-mobility.com\/en\/wp-content\/uploads\/2021\/12\/what_is_precise2en.png\")
<Source: Asahi Kasei\u2019s research><\/p><\/div>\n![\"\"](\"https:\/\/asahi-kasei-mobility.com\/en\/wp-content\/uploads\/2021\/12\/soundmanagement_5_interview5-1024x683.jpg\")
<\/h2>\nFrom engines to roof liners, Precis\u00e9\u2122 can be used on a wide range of parts<\/span><\/h2>\n
![\"\"](\"https:\/\/asahi-kasei-mobility.com\/en\/wp-content\/uploads\/2021\/12\/soundmanagement_5_interview6-1024x683.jpg\")
<\/h2>\nPrecis\u00e9\u2122 is so diverse \u2013 are you considering any product collaborations?<\/span><\/h2>\n
\nhttps:\/\/www.asahi-kasei.co.jp\/fibers\/en\/precise\/index.html<\/a><\/p>\nNew invention!\u00a0Sunforce\u2122(AM), the foam engineering plastic (EP), with sound absorption capabilities<\/span><\/h2>\n
![\"\"](\"https:\/\/asahi-kasei-mobility.com\/en\/wp-content\/uploads\/2021\/12\/soundmanagement_5_interview7-1024x683.jpg\")
<\/h3>\nEP for automotive application at 1\/5 or less weight?!<\/span><\/h2>\n
\n*2<\/sup> Sunforce\u2122 was also discussed in special theme vol.03: Cruising distance.
\nhttps:\/\/asahi-kasei-mobility.com\/en\/interview\/going_the_distance\/<\/a><\/p>\nOne step ahead of the market needs for noise restrictions<\/span><\/h2>\n
![\"\"](\"https:\/\/asahi-kasei-mobility.com\/en\/wp-content\/uploads\/2021\/12\/3-EN-1024x732.png\")
<\/p>\nGood at sound absorption\/cancellation of mid to high frequency noise at 1,000\u301c3,000 Hz<\/span><\/h2>\n
![\"\"](\"https:\/\/asahi-kasei-mobility.com\/en\/wp-content\/uploads\/2021\/12\/4-\uff15-EN-1024x670.png\")
<\/p>\n![\"\"](\"https:\/\/asahi-kasei-mobility.com\/en\/wp-content\/uploads\/2021\/12\/6-7-EN-1024x744.png\")
<\/p>\nExcellent handling and easily moldable into complex shapes<\/span><\/h2>\n
Cancel engine noise, road noise in EVs, and more<\/span><\/h2>\n
Proposals for component design and collaborative features for different materials as well<\/span><\/h2>\n
![\"\"](\"https:\/\/asahi-kasei-mobility.com\/en\/wp-content\/uploads\/2021\/12\/soundmanagement_5_interview11-1024x683.jpg\")
<\/p>\n
\nhttps:\/\/asahi-kasei-mobility.com\/en\/products\/sunforce_am\/<\/a>
\nhttps:\/\/www.asahi-kasei-plastics.com\/en\/technology\/sunforce_am\/<\/a><\/p>\nAiming for \u201cTotal\u201d solutions<\/span><\/h2>\n