මෝටර් රථ ධ්වනි ද්‍රව්‍ය කැබින් සුවපහසුව වැඩි දියුණු කරන ආකාරය | NVH මාර්ගෝපදේශය

How Automotive Acoustic Materials Improve Cabin Comfort

For automotive OEM and Tier 1 engineers, cabin comfort is not simply about reducing a few decibels.

Effective automotive acoustic engineering starts with three fundamental questions:

• ශබ්දය පැමිණෙන්නේ කොහෙන්ද?
• How does it travel into the cabin?
• Which material or structural solution is best suited to control it?

In automotive NVH engineering, noise generally reaches the passenger compartment through two primary paths:

• වාතයේ ශබ්දය
• Structure-borne noise

Understanding the difference between these two transmission paths is essential when selecting automotive acoustic absorbers, insulation materials, damping layers, decouplers, and multilayer acoustic systems.

ඉක්මන් පිළිතුර

Automotive acoustic materials improve cabin comfort by controlling sound and vibration through several different mechanisms.

Porous fiber materials are mainly used to absorb airborne sound.

Damping materials help reduce panel vibration.

Barrier layers reduce sound transmission.

Decoupling materials help limit vibration transfer between structures.

In real vehicle applications, these functions are often combined into an integrated acoustic package rather than relying on a single material to solve every NVH problem.

1. What Is Automotive NVH?

NVH stands for:

• ශබ්දය
• කම්පන
• රළු බව

Together, these factors strongly influence how drivers and passengers perceive vehicle comfort and quality.

ශබ්දය

Noise refers to the sound heard by vehicle occupants.

Typical automotive noise sources include:

• Tire and road noise
• සුළං ශබ්දය
• එන්ජින් ශබ්දය
• Electric motor noise
• Gear whine
• HVAC noise
• Cooling system noise
• Body-panel radiation

Different frequency ranges create very different subjective impressions.

Low-frequency noise may be perceived as:

• වේගයෙන් වර්ධනය වේ
• හ umb නඟයි
• droning

Higher-frequency noise may be perceived as:

• හිනාවෙනවා
• හෙසින්ග්
• sharp tonal noise
• electric motor high-frequency noise

This is why overall sound pressure level alone cannot fully describe cabin acoustic quality.

කම්පන

Vibration originates from mechanical excitation.

සාමාන්‍ය මූලාශ්‍රවලට ඇතුළත් වන්නේ:

• Tire-road interaction
• Suspension movement
• Powertrain excitation
• විදුලි මෝටර
• ගියර් පද්ධති
• Structural resonance

These vibrations can travel through:

• අත්හිටුවීමේ සංරචක
• උපරාමු
• චැසි
• ශරීර පුවරු
• Seat rails
• සුක්කානම් පද්ධති

Some vibrations are directly perceived by occupants.

Others excite body panels, which then radiate sound into the cabin.

රළු බව

Harshness refers more to the subjective perception of vehicle vibration and sound quality than to a single physical parameter.

උදාහරණ:

• Strong impact when driving over road irregularities
• Excessive low-frequency vibration
• Cabin booming at specific vehicle speeds
• Unpleasant structural resonance

The objective of good NVH engineering is therefore not to eliminate every sound.

It is to control undesirable acoustic and vibration energy.

2. How Does Noise Enter the Vehicle Cabin?

From a transmission-path perspective, automotive cabin noise can generally be divided into two major categories:

Airborne Noise

සහ

ව්‍යුහයෙන් බෝවන ශබ්දය

These two mechanisms require different control strategies.

3. What Is Airborne Noise?

Airborne noise is sound energy that primarily travels through the air before reaching the passenger compartment.

For example, tire-road interaction generates acoustic energy around the wheel area.

Part of that sound travels through air and can enter the vehicle through the floor, wheel arch, doors, or other body structures.

Similarly, HVAC blowers generate sound that travels directly through air ducts and the cabin.

Typical airborne noise sources include:

• සුළං ශබ්දය
• Tire radiation noise
• HVAC noise
• Cooling fan noise
• Exterior traffic noise
• Some electric motor noise
• Some powertrain noise

Once airborne sound enters the cabin, it can also reflect repeatedly from interior surfaces.

If the vehicle interior has insufficient sound absorption, sound energy may continue reflecting from areas such as:

• වහලය
• හෙඩ්ලයිනර්
• දොරවල්
• උපකරණ පුවරුව
• මහල
• කඳ

This increases the acoustic energy perceived by occupants.

That is why sound-absorbing materials are widely used throughout the vehicle interior.

4. How Do Fibrous Automotive Acoustic Materials Absorb Sound?

PP/PET fibrous acoustic materials are typical porous sound absorbers.

When a sound wave enters the fiber network, air particles move through a complex porous structure.

During this process, acoustic energy is reduced through mechanisms such as:

• Friction between air and fibers
• Viscous losses
• Thermal exchange
• Energy dissipation caused by airflow through the porous network

A small portion of the acoustic energy is ultimately converted into heat.

As a result, less sound energy is reflected back into the cabin.

This is the basic principle behind fibrous automotive acoustic absorbers.

5. Why Is Thickness Alone Not Enough?

A common assumption is that thicker acoustic material always performs better.

In reality, automotive sound absorption depends on many parameters, including:

• ඝනකම
• මූලික බර
• ඝනත්වය
• තන්තු විෂ්කම්භය
• Fiber structure
• පෝරෝසිටි
• වායු ප්‍රවාහ ප්‍රතිරෝධය
• සම්පීඩන අනුපාතය
• ස්ථාපන තත්ත්වය
• Target frequency range

One of the most important parameters is airflow resistance.

If a material is too open, sound can pass through easily, but interaction between the moving air and the fiber network may be insufficient.

If a material is too dense, too much sound may be reflected at the surface instead of entering the porous structure.

High-performance acoustic materials therefore require an appropriate balance between:

Porosity, fiber structure, and airflow resistance.

6. What Is Structure-Borne Noise?

Structure-borne noise begins as mechanical vibration transmitted through the vehicle structure.

සාමාන්‍ය උදාහරණයක් වන්නේ:

Road excitation

↓

ටයර් කම්පනය

↓

අත්හිටුවීම

↓

උප රාමුව

↓

Vehicle body

↓

Body-panel vibration

↓

Sound radiation into the cabin

The final sound may still be heard through the air, but the original transmission path was structural.

This is the key difference between structure-borne and airborne noise.

7. Why Can Acoustic Fiber Not Solve All Structure-Borne Noise?

This is one of the most important distinctions in automotive acoustic engineering.

Porous acoustic fiber is mainly designed to absorb airborne sound energy.

If the main problem is strong vibration of a door panel, floor panel, wheelhouse, or another structural component, adding more acoustic fiber alone will not eliminate the root cause.

Structure-borne noise typically requires a combination of several control methods.

තෙත් කිරීමේ ද්රව්ය

Damping layers are used to reduce vibration amplitude in metal or composite panels.

සාමාන්‍ය යෙදුම් ක්ෂේත්‍රවලට ඇතුළත් වන්නේ:

• Door outer panels
• බිම් පුවරු
• Wheelhouse areas
• Trunk panels
• Body sheet metal

Decoupling Materials

Decoupling layers help reduce mechanical coupling between structures.

They are also important in multilayer acoustic systems where a compliant layer is required between a barrier and the vehicle body.

බාධක ද්‍රව්‍ය

Barrier layers are used to reduce sound transmission.

They typically rely on higher surface mass or multilayer construction to improve transmission loss.

Absorbing Materials

Absorbing layers reduce airborne sound energy once that energy reaches the cabin or acoustic package.

In practical vehicle design, these functions are often combined as:

Damping + Decoupling + Barrier + Absorption

8. Airborne and Structure-Borne Noise Are Often Coupled

In real vehicle NVH problems, airborne and structure-borne mechanisms are not completely independent.

උදාහරණයක් වශයෙන්:

Road excitation first generates mechanical vibration.

That vibration travels through the suspension and body structure.

The body panel is then excited.

The vibrating panel radiates sound into the cabin air.

The full path may therefore be:

Road Excitation

↓

Structure-Borne Vibration

↓

Body-Panel Vibration

↓

Airborne Sound Radiation

↓

Passenger Perception

For this reason, OEM NVH engineers do not simply ask whether a problem is airborne or structure-borne.

They need to understand:

• Which source is dominant?
• Which transfer path contributes most?
• Which frequency range requires improvement?

9. Different Frequency Ranges Require Different NVH Strategies

No single material can effectively solve every noise problem across the entire frequency spectrum.

Different frequency ranges typically require different engineering strategies.

අඩු සංඛ්‍යාතය

Low-frequency problems are often related to:

• Body modes
• ව්‍යුහාත්මක කම්පනය
• පැනල් අනුනාදය
• Suspension excitation
• Powertrain excitation

Severe low-frequency issues usually cannot be solved by lightweight porous absorbers alone.

Typical solutions may include:

• ව්‍යුහාත්මක ප්‍රශස්තිකරණය
• කුණු කන්ද
• කම්පන හුදකලා කිරීම
• Mount optimization
• Body stiffness optimization

Mid Frequency

Mid-frequency noise often requires a combination of:

• කුණු කන්ද
• විසංයෝජනය කිරීම
• බාධක කාර්ය සාධනය
• ශබ්ද අවශෝෂණය

Mid-to-High Frequency

Fibrous porous absorbers are particularly useful in the mid-to-high-frequency range.

Their acoustic performance can be tuned by adjusting:

• ඝනකම
• මූලික බර
• Fiber structure
• වායු ප්‍රවාහ ප්‍රතිරෝධය

This is why automotive acoustic materials should not be evaluated by a single absorption value.

The full absorption curve across the relevant frequency range is far more meaningful.

10. Why Do Electric Vehicles Change Acoustic Material Requirements?

Electric vehicles do not make NVH engineering easier.

They change the noise spectrum.

In internal-combustion vehicles, engine noise creates a relatively strong background sound that can mask other noise sources.

In electric vehicles, this masking effect is reduced.

As a result, previously less noticeable sounds can become more prominent, including:

• ටයර් ශබ්දය
• මාර්ග ශබ්දය
• සුළං ශබ්දය
• විදුලි මෝටරයේ ශබ්දය
• ගියර් ශබ්දය
• Inverter tonal noise
• HVAC noise
• Cooling-system noise

EV acoustic design therefore places greater emphasis on:

• පුළුල් කලාප ශබ්ද අවශෝෂණය
• Mid-to-high-frequency noise control
• සැහැල්ලු කිරීම
• ද්‍රව්‍ය ඒකාබද්ධ කිරීම
• Local acoustic optimization

11. Why Are Lightweight Acoustic Materials Becoming More Important?

Adding more NVH material can improve acoustic performance.

However, additional material also increases vehicle mass.

This can directly affect:

• වාහන බර
• බලශක්ති පරිභෝජනය
• EV driving range
• නිෂ්පාදන පිරිවැය
• එකලස් කිරීමේ සංකීර්ණතාව

For this reason, the goal is not simply to add more material.

The objective is to achieve the required acoustic performance with lower weight and less installation space.

This is one of the main advantages of fibrous automotive acoustic materials.

සකස් කිරීමෙන්:

• තන්තු සංයුතිය
• මූලික බර
• ඝනකම
• ඝනත්වය
• ස්ථර ව්‍යුහය

the material can be optimized for different locations and vehicle platforms.

12. Where Are Automotive Acoustic Materials Used?

Different vehicle zones have different acoustic requirements.

Roof and Headliner

Typical concerns include:

• සුළං ශබ්දය
• Cabin reverberation
• Rain impact noise
• පුළුල් කලාප ශබ්ද අවශෝෂණය

Low weight is particularly important in this area.

දොරවල්

Door systems may be affected by:

• Exterior airborne noise
• Door-panel vibration
• Cavity resonance
• Speaker interaction

For this reason, door acoustic systems often require both absorption and structural vibration control.

Firewall and Dashboard Area

This is one of the most important NVH control zones.

Typical noise sources include:

• Powertrain noise
• මාර්ග ශබ්දය
• HVAC noise
• Structural radiation

Multilayer acoustic systems are commonly used here rather than a single absorber.

මහල

Typical concerns include:

• Tire-road excitation
• Suspension noise
• Underbody noise
• ව්‍යුහාත්මක කම්පනය

Common floor acoustic systems may include:

Absorber + Decoupler + Barrier

with localized damping where necessary.

Wheel Arch

The wheel area is one of the most important noise sources in the vehicle.

Acoustic materials used here may need to address:

• ටයර් ශබ්දය
• Road excitation
• Stone impact
• ජල නිරාවරණය
• දූෂණය

Therefore, material selection must also consider:

• තෙතමනය ප්රතිරෝධය
• කල්පැවැත්ම
• දූෂණයට ප්‍රතිරෝධය

කඳ

Rear-wheel and rear-body excitation can introduce significant acoustic energy into the trunk cavity.

Absorptive materials can reduce cavity reflection and help limit further sound propagation toward the passenger compartment.

Pillars and Body Cavities

Vehicle cavities can act as acoustic transmission paths.

Proper use of:

• Acoustic absorbers
• Cavity fillers
• මුද්රා තැබීමේ පද්ධති

can reduce sound transmission through these areas.

13. Which Material Parameters Should OEM Engineers Evaluate?

Automotive acoustic materials should not be evaluated only by whether they are “good at absorbing sound.”

A more complete evaluation should include the following parameters.

ධ්වනි කාර්ය සාධනය

• ශබ්ද අවශෝෂණ සංගුණකය
• Frequency-dependent absorption curve
• වායු ප්‍රවාහ ප්‍රතිරෝධය
• වායු ප්‍රවාහ ප්‍රතිරෝධය

භෞතික ගුණාංග

• ඝනකම
• මූලික බර
• ඝනත්වය
• සම්පීඩන ප්‍රතිසාධනය
• විචල්ය ස්ථායීතාව

පාරිසරික කාර්ය සාධනය

• තාප ප්රතිරෝධය
• තෙතමනය ප්රතිරෝධය
• වයස්ගත ප්රතිරෝධය

Automotive Requirements

• ලැව්බභාවය
• VOC performance
• සුවඳ
• මීදුම
• ද්රව්ය අනුකූලතාව

සැකසුම් කාර්ය සාධනය

• කපන්න
• තාප සැකසුම
• ලැමිෙන්ටේෂන්
• ස්වයං-ඇලවුම් පිටුබලය
• Aluminum foil lamination
• Complex-shape conversion

තිරසාර

• සැහැල්ලු කිරීම
• ප්‍රතිචක්‍රීකරණය
• Material simplification
• ප්‍රතිචක්‍රීකරණය කළ අන්තර්ගතය

14. Why Is Installation Condition as Important as Material Data?

The same acoustic material can perform very differently under different installation conditions.

වැදගත් සාධක අතරට:

• වායු හිඩැස
• සම්පීඩනය
• Backing surface
• ස්ථාපන ප්රදේශය
• ජ්යාමිතිය
• Edge leakage
• Adjacent materials
• බහු ස්ථර ඉදිකිරීම්

For example, a material with a free-state thickness of 20 mm may behave very differently if compressed to 8 mm after installation.

Compression can change:

• පෝරෝසිටි
• වායු ප්‍රවාහ ප්‍රතිරෝධය
• Effective thickness
• ධ්වනි කාර්ය සාධනය

This is why automotive acoustic materials should not be evaluated only from laboratory datasheets.

Final installed condition must also be considered.

15. Transulate™ Automotive Acoustic Materials

පරිවර්තනය කරන්න™ is a PP/PET bicomponent fiber material series developed by SINOYQX for automotive acoustic and thermal-management applications.

The material is designed for applications including:

• Automotive sound absorption
• තාප පරිවරණය
• Lightweight acoustic packages

සාමාන්‍ය යෙදුම් ක්ෂේත්‍රවලට ඇතුළත් වන්නේ:

• වහලය
• හෙඩ්ලයිනර්
• දොර
• උපකරණ පුවරුව
• ෆයර්වෝල්
• මහල
• කඳ
• ස්ථම්භය
• අභ්යන්තර ටිම්

Depending on the project, key material parameters can be customized, including:

• මූලික බර
• ඝනකම
• ඝනත්වය
• Fiber structure
• ලැමිෙන්ටේෂන් ව්‍යුහය

16. How to Select the Transulate™ Series

පරිවර්තනය කරන්න™ LT Series

Typical basis weight:

100-200 g/m²

සාමාන්‍ය ඝනකම:

10–20 මි.මී.

Suitable for lightweight applications such as:

• වහලය
• හෙඩ්ලයිනර්
• දොර
• ස්ථම්භය
• අභ්යන්තර ටිම්

The key focus is low weight.

පරිවර්තනය කරන්න™ AP Series

Typical basis weight:

300-500 g/m²

සාමාන්‍ය ඝනකම:

20–30 මි.මී.

සුදුසු වන්නේ:

• ෆයර්වෝල්
• දොර
• මහල
• කඳ
• General acoustic packages

Transulate™ HP Series

Typical basis weight:

600-900 g/m²

සාමාන්‍ය ඝනකම:

30–50 මි.මී.

Suitable for applications requiring higher sound absorption and where more installation space is available.

17. What Additional Processing Options Are Available?

Depending on OEM and Tier 1 project requirements, Transulate™ can be supplied or converted as:

• රෝල්ස්
• ෂීට්
• ඩයි-කට් කොටස්
• Self-adhesive parts
• Aluminum-foil laminated products
• Nonwoven-faced products
• Multilayer composites
• අභිරුචිකරණය කළ ඝණකම
• Customized basis weight

The final acoustic structure should be selected according to:

Target Frequency + Installation Location + Available Space + Weight Target

18. Automotive Acoustic Engineering Is Moving from Material Selection to System Design

The future of automotive NVH development is not simply about identifying which absorber has the highest sound absorption coefficient.

වඩාත් වැදගත් ප්‍රශ්න වන්නේ:

• Which noise source is dominant?
• Which transfer path is most important?
• Which frequency range needs improvement?
• Which material is best suited to the location?
• How can the target performance be achieved with less weight?

A more effective development process is:

Identify the Noise Source

↓

Analyze the Transfer Path

↓

Define the Target Frequency

↓

Select the Control Strategy

↓

ද්රව්යය ගලපන්න

↓

Validate at Component Level

↓

Validate at Vehicle Level

This is how material performance can be converted into real cabin comfort.

නිගමනය

Vehicle cabin comfort is not controlled by a single material.

Airborne noise is mainly managed through:

Sound absorption and sound insulation.

Structure-borne noise generally requires:

Damping, vibration isolation, decoupling, and structural optimization.

Fibrous automotive acoustic materials play an important role in reducing airborne sound energy, limiting cabin reflections, and improving mid-to-high-frequency acoustic performance.

This becomes even more important in electric vehicles, where reduced engine masking makes tire noise, wind noise, and electric-drive tonal noise more noticeable.

At the same time, vehicle manufacturers continue to reduce weight.

For this reason, the next generation of automotive acoustic systems is not about adding more material.

එය ගැන:

Using the right material, in the right location, for the right frequency range.

Transulate™ automotive acoustic materials can be customized according to OEM and Tier 1 requirements, including application location, target frequency, thickness, basis weight, lamination structure, and annual demand.

නිතර අසන ප්රශ්න

What is the difference between airborne noise and structure-borne noise in a vehicle?

Airborne noise travels primarily through air, such as wind noise, HVAC noise, and some tire noise.

Structure-borne noise begins as mechanical vibration transmitted through the suspension, body, or other structural components before being radiated as sound.

Can automotive acoustic fiber directly reduce structure-borne noise?

සම්පූර්ණයෙන්ම නොවේ.

Porous fibrous materials primarily absorb airborne sound.

If the main problem is structural panel vibration, additional damping, isolation, decoupling, or structural optimization is usually required.

What are the most important parameters for automotive sound absorbers?

Important parameters include thickness, basis weight, fiber structure, airflow resistance, absorption performance across frequency, compression condition, installation gap, and target frequency range.

Why are lightweight acoustic materials important for electric vehicles?

Electric vehicles have less engine masking noise, so tire noise, wind noise, electric motor noise, and other high-frequency sounds become more noticeable.

At the same time, lower vehicle mass helps improve energy efficiency and driving range.

Where can Transulate™ automotive acoustic materials be used?

Typical applications include roof, headliner, doors, firewall, dashboard, floor, trunk, pillars, and interior trim.

The final material specification should be selected according to installation space, target frequency, basis weight, and thickness requirements.