As is widely recognized, acoustic treatment is critically important to high-end audio systems and cinema environments. In large public theaters and concert halls, acoustic treatment is found throughout. The extensive use of acoustic damping materials, acoustic testing and quantitative measurements helps ensure listening quality within the sound field and the best possible sound experience for audiences in every seating location. In the past, limitations in knowledge and technology often led people to overlook sound insulation during the early stages of creating an audiovisual environment. In practice, sound insulation in spaces requiring acoustic treatment can prevent sound leakage. It preserves the intended acoustic performance and allows audiences to enjoy an undisturbed music or audiovisual experience, while also preventing sound generated inside from disturbing the outside environment. For this issue, I visited Bonderra Industries Co.,Ltd. in Zhongshan, Guangdong, to learn about its insights and experience in the research and development of sound insulation materials. Below, I introduce the company and its latest developments in acoustic materials.
A Focus on Developing Polymer Materials for Vibration Damping, Noise Reduction and Sound Insulation
Bonderra Industries Co.,Ltd. (hereinafter referred to as Bonderra) was established in 1988 as a technology enterprise integrating design and development, manufacturing and sales. The company currently supplies polymer-based products and materials for vibration damping, noise reduction, sound insulation, sealing, thermal insulation and moisture protection. In 2009, it was recognized as a “National High-Tech Enterprise” and a “Guangdong Private Technology Enterprise.” In particular, Bonderra has long maintained a leading position in overall capabilities within the specialized market for vibration damping materials for air conditioners. Its “Bonderra” trademark was recognized as a “Guangdong Famous Trademark” in 2011.
For more than twenty years, Bonderra has been committed to creating comfortable and quiet living environments. Its butyl rubber vibration damping products have a wide range of applications. These include vibration damping and sound insulation materials for vibrating machinery, such as air conditioners, dishwashers and washing machines; composite vibration damping and sound insulation materials for automobiles; and self-adhesive butyl rubber moisture-barrier membranes, used primarily in building basements, bathrooms and other environments requiring high-performance moisture protection. In this field, the company’s equipment and facilities for new-materials research and development have reached a leading level in China. For example, its laboratory has equipment for measuring damping performance using the cantilever-beam resonance method, which is currently available at only a small number of major specialized testing institutions in China. The company has a municipal engineering R&D center and a municipal enterprise technology center, together with advanced research equipment and experienced professional engineering personnel. Drawing on its research resources accumulated over many years, Bonderra has continued to pursue exploratory research in vibration damping, sound insulation and noise reduction.
New Developments: Professional Acoustic Materials
With more than twenty years of accumulated research into vibration damping materials, Bonderra has a solid research foundation in polymer materials for vibration damping, noise reduction and sound insulation. In recent years, in response to widespread demand for professional sound insulation materials across relevant fields, the company has developed an environmentally friendly range of vibration damping and sound insulation products based entirely on butyl rubber. Its starting point has been comprehensive solutions, particularly for the more challenging problem of low-frequency sound insulation. Bonderra now has a relatively complete line of environmentally friendly butyl rubber sound insulation materials under the BON-PLUS brand. The range includes composite sound insulation panels, wall isolation mounts, ceiling isolation hangers, spring-and-rubber vibration isolators, solid sound insulation sheets, semi-solid sound insulation sheets and sound-insulating sealing strips.
1. BON-PLUS Composite Sound Insulation Panels
The environmentally friendly butyl rubber composite sound insulation panel is a representative product in this category. Two grades are currently available: a three-layer composite structure and a five-layer composite structure. The former consists of facing panels and an environmentally friendly, semi-solid butyl rubber vibration-damping and sound-insulating compound, with a weighted airborne sound insulation rating of 35–40 dB(A). The latter consists of facing panels, steel sheet and the same type of environmentally friendly, semi-solid butyl rubber compound, with a weighted airborne sound insulation rating of 42–46 dB(A). Both have a B1 flame-retardancy classification. These composite panels eliminate the drawbacks of using toxic or harmful substances such as bitumen as damping materials, a practice previously widespread in the industry. Environmentally friendly and health-conscious, they can be widely used in theaters, recording studios, home theater rooms, karaoke venues, bars, upscale hotels and other buildings or spaces that require protection from unwanted sound. In addition to their environmental and health benefits, another advantage is their slender profile: BON-PLUS composite panels are very thin compared with solid walls providing equivalent sound insulation. This is undoubtedly an attractive choice in today’s buildings, where every bit of space is valuable. By using the BON-PLUS all-butyl-rubber range of sound insulation materials on all six interior surfaces of a room, sound disturbance between the interior and exterior can be greatly reduced while taking up relatively little building space.
2. BON-PLUS Wall Isolation Mounts
Wall isolation mounts are fittings for installing composite sound insulation panels on walls and are important components in BON-PLUS sound insulation projects. They play a significant role in interrupting sound transmission that causes mutual disturbance between indoor and outdoor environments. Each mount consists of a metal bracket and a vibration-isolating rubber element. The rubber element is made primarily of chlorobutyl rubber, which offers excellent vibration isolation and durability and can generally maintain good vibration isolation performance after more than twenty years of use. This is a patented product of Bonderra
3. BON-PLUS Ceiling Isolation Hangers
This product consists of a metal bracket, an isolation spring, a vibration-isolating chlorobutyl rubber element and a suspension rod. Its overall stiffness can be customized so that the effective vibration isolation frequency range of the product used in each project extends down to the lowest sub-bass frequency. Metal springs offer stable stiffness and a long service life. Combining metal springs with rubber elements provides good sound insulation at both low and high frequencies. The product must be designed and customized for each individual project.
Wall isolation mounts and ceiling isolation hangers are important fittings for installing composite sound insulation panels on walls and ceilings. Once the panels are installed with these fittings, the mounting structure is stabilized. More importantly, the fittings create an acoustic break between the sound-insulating layer and the structural slab, interrupting sound transmission through the structure and reducing losses in the sound insulation performance of the composite panels. This greatly improves the overall sound insulation of the treated space.
4. BON-PLUS Spring-and-Rubber Vibration Isolators
This product consists of isolation springs and vibration-isolating rubber elements. Its overall stiffness can be customized to ensure that its effective vibration isolation frequency range extends down to the lowest sub-bass frequency. The rubber elements are made primarily of chlorobutyl rubber, which offers excellent vibration isolation and durability and can generally maintain good vibration isolation performance after more than twenty years of use. Combining metal springs with rubber elements provides good sound insulation at both low and high frequencies. As important installation components in floating floors, these isolators primarily support the floor’s composite sound insulation panels and the conventional finished flooring above them. They effectively interrupt sound transmission between the structural floor slab and the sound-insulating layer, with particularly strong performance in blocking low-frequency sound transmission.
5. Bon-Plus Environmentally Friendly Solid Butyl Rubber Sound Insulation Sheets
This is an environmentally friendly vibration-damping and sound-insulating material made primarily from butyl rubber and other polymers. It offers good vibration damping and sound insulation performance, together with excellent resistance to aging. The material likewise contains no toxic or harmful ingredients such as bitumen and is environmentally friendly and health-conscious. Sheet thickness can be selected from 3 to 10 mm according to practical requirements. A pressure-sensitive adhesive layer can be applied to one or both sides for convenient direct-bond installation, and dimensions can also be customized. When used together with composite sound insulation panels, these environmentally friendly solid butyl rubber sound insulation sheets can further improve a building’s sound insulation without taking up building space.
Having contributed for decades to vibration damping, sound insulation and noise reduction for air conditioners and other vibrating equipment, Bonderra has, in recent years, introduced new sound insulation materials for the acoustics sector that can truly be described as helping to build the field. With its distinctive strengths, leading technology and experience, Bonderra will surely offer the market more choices and make an even greater contribution to society through its future work in acoustics.
Source: Shiting Fashaowang (WeChat)
Read the original article (in Chinese)
