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For the application of NVH (Noise, Vibration, and Harshness) pads in the automotive industry, Hot Melt PSA (Pressure Sensitive Adhesives) plays a critical role in ensuring long-term performance under extreme conditions.

Here is the English translation of the technical characteristics and requirements.

1. Key Characteristics

• Initial Tack: The adhesive must provide immediate bonding with light pressure to ensure efficiency during the fast-paced assembly process.

• Broad Substrate Compatibility: It must adhere reliably to various materials, ranging from Low Surface Energy (LSE) plastics like PP (Polypropylene) and ABS to metal frames.

• Operational Efficiency: As a 100% solid system (solvent-free), it is eco-friendly and eliminates the need for drying time, significantly increasing production speed.

2. Essential Requirements

Due to the dynamic and harsh environments vehicles encounter, the following stringent properties are required:

① Thermal Resistance (Heat & Cold)

Vehicle interiors can reach over 80°C in summer and drop below -30°C in winter.

• High-Temperature Cohesion: The adhesive must maintain high cohesion and a proper softening point to prevent sliding or detachment at high temperatures.

• Low-Temperature Flexibility: It must remain flexible at sub-zero temperatures to prevent "glass transition," where the adhesive layer becomes brittle and cracks.

② Low Odor & Low VOCs

To maintain air quality within the sealed cabin, the emission of Volatile Organic Compounds (VOCs) must be minimized.

• Strict Chemical Regulation: It must meet global automotive standards (such as Hyundai/Kia's MS specifications) regarding formaldehyde, benzene, and other harmful substances.

③ Vibration Damping & Durability

Since the primary purpose of NVH pads is to suppress vibration, the adhesive must possess high fatigue resistance to prevent delamination during continuous mechanical stress.

④ Moisture & Chemical Resistance

Adhesives used near door trims or floor mats are often exposed to humidity and contaminants. The bond must remain stable and not degrade when exposed to moisture.

3. Duzone PSA (Pressure Sensitive Adhesives)