Author: Radomskyi Maksym VasyliovychIts no secret that the noise level inside the car and outside it largely depends on the presence and nature of the vibrations of the body and various structural elements. As the requirements for the level of acoustic tuning increase, the demand from manufacturers and characteristics of materials also increases. In this case, two main tasks must be solved. First, the reduction of structure-borne noise on metal plates with a thickness of more than 2.0 mm in the most noise and vibration-loaded areas. Secondly, this effect must be achieved without significantly increasing the vehicle weight. Few people know that the protective kit can add up to 30-50 kg. excess weight. It is in this direction that numerous scientific and research developments are carried out.
Distinctive features of BiMast products
One of the worlds leading manufacturers of insulating materials in many parameters managed to combine a large number of components that increase the consumer properties of products. Among the advantages of innovative developments are the following:
- Increasing the rigidity of the structure G. For example, when installing BiMast Super on a 1.0 mm plate. the stiffness modulus of the "Metal-Vibration Absorber" system will be equal to the stiffness modulus of a 1.2 mm thick plate. At the same time, the susceptibility of the plate to vibration is significantly reduced and leads to a decrease in the number of resonances.
- The mechanical loss factor (LF) of BiMast materials reaches 0.4 (Bimast Bomb).
- Materials of the Bimast series have a vibration-damping effect on metal with a thickness of 2 - 4 mm. This is due to the high CMF of these materials and the ability to have the effect of increasing rigidity.
- When working with BiMast materials, it is enough to process 40-60 percent of the surface of vibration-loaded areas of the car (depending on the grade of material).
- Reducing the effect of mounting vibration absorbers on vehicle weight. This does not affect the vibration-absorbing properties in any way. An unnecessary increase in mass without an increase in the CMF leads to an increase in the number of resonances and, as a result, to the absence of a noise reduction effect.
- Anti-corrosion effect. The presence of a self-adhesive mastic layer allows the material to be hermetically mounted on the metal surface and to consider the BiMast layer as a means of preventing corrosion processes. The materials are not hygroscopic and therefore reliably protect the body from moisture penetration and metal corrosion.
- Ease of installation. The high elasticity of BiMast series materials allows them to be mounted without using a heat gun. Only when machining surfaces with radii less than 30 mm. the use of a heat gun is recommended. This may seem inconvenient in comparison with the installation of the Vibroplast material, but this method allows you to achieve a complete repetition of the contour of the part. In general, it can be said that BiMast materials are easier to install than mastic and easier than bituminous materials.
Sound insulation materials of the Vibroton series
Vibroton (Vibroton) - a series of new generation soundproofing materials based on modified polyethylene foam. It was specially designed to isolate noise over a wide frequency range. These materials are ideal for soundproofing the floor of the car interior, as well as the engine compartment from the passenger compartment.
The material has a multi-layer structure. The bottom layer, based on gray polyethylene foam, 8 ... 10 mm thick. , has sound-absorbing and sound-reflecting properties. The upper face layer is black, 2mm thick, has sound-reflecting properties. The top layer is embossed with a decorative front layer with logos.
The material is mounted with a sound-absorbing layer to the vehicle’s noise source. The lack of an adhesive layer is associated with an increase in the sound insulation properties of the material. For ease of installation, the material can be partially fixed with Gerbent mastic tapes. With the help of a thermal gun, the cut parts are given a surface shape and the parts are connected to each other by means of strips of fused bitumen material.
Sound Cover Kits
Sound Cover (Sound Cover) - sets of floor noise insulation for cars. These kits are intended both for use with standard (factory) sound insulation, and without it. Made on the basis of Vibroton series materials. The kits have all the properties and characteristics of these materials listed above. The simplicity and ease of installation of the kits is their main difference. The absence of the need to paint materials significantly saves time. The cuts, grooves and indentations on the parts allow them to be ideally mounted on the floors of the car.
Recent studies have shown that the use of the Sound Cover kit in the mid-segment subcompact cabin results in a significant reduction in noise. Comparisons were made between a vehicle with a factory floor kit and a vehicle with a Sound Cover kit.
Floor-standing soundproofing kit (based on Vibrotone) has a number of significant advantages in comparison with standard soundproofing:
- improved acoustic, thermal insulation characteristics
- does not absorb water, does not decompose
- resistance to mechanical damage
- frost resistance
- durability
- reduction of installation time, in comparison with serial noise insulation materials
- attractive, for the consumer, appearance.
When combined with BiMast materials with Vibroton materials or Sound Cover kits, the maximum effect of reducing noise in the car interior is achieved
Barrier Soundproofing Materials
Barrier is a soundproofing material made on the basis of polyethylene foam. The closed cellular structure allows for low thermal conductivity (high degree of thermal insulation) and excellent sound insulation characteristics. The area of application is similar to the well - known Splen material , but at the same time the Barrier is offered at a lower price. The material has an adhesive mounting layer, which greatly facilitates its installation. The material is offered for implementation, both with a front coating of metallized lavsan and without it. Possesses a high degree of sound insulation in the mid-frequency range. The best indicators are observed in the range 1000..3000Hz and are 17… 25dB. Used for secondary elimination of structure-borne noise and airborne sound insulation. Elasticity and low specific weight (less than 1 kg / m2 at a thickness of 10.0 mm) allow the material to be mounted in the most inaccessible places.
Acoustic sound-absorbing material Accent
These protective equipment have shown particular effectiveness in the fight against airborne noise. Its correct application can “remove” up to 70-90% of the energy of sound vibrations in the low frequency range. In addition, it can be considered both a seal and a thermal insulator. In this regard, the spectrum of its involvement in the process of protection from external undesirable factors is quite wide. He gained special respect among motorists when equipping audio systems. Setting the accent in tandem with a vibration absorber under the interior trim panels helps prevent them from vibrating when interacting with acoustic waves emanating from the speakers, which prevents distortion and extraneous inclusion in the sound range.
