The outstanding acoustic and noise reduction performance of aluminum-plastic co-extruded profiles is the result of its principle and the series of measures taken by manufacturers. The following is a detailed explanation:

- Principle of sound insulation and noise reduction

    - Multi-layer structure blocking: Aluminum-plastic co-extruded profile is a multi-layer composite structure, the outer layer of the aluminum alloy is hard and dense, which can effectively block the spread of high-frequency sound. High-frequency sound energy is relatively concentrated, when encountering the aluminum alloy layer, most of the energy will be reflected back, and cannot penetrate the profile into the room. The plastic part of the inner layer, especially the foam plastic, has a porous and loose structure. When the sound passes through the aluminum alloy layer and enters the plastic layer, it will be reflected and refracted in these pores, and the sound energy is gradually consumed in the process, thus achieving further attenuation of the sound.

    - Resonance absorption: Sound is a kind of vibration, and different frequencies of sound correspond to different vibration frequencies. The plastic part of aluminum-plastic co-extruded profiles, due to its material characteristics and internal structure, will resonate when stimulated by a specific frequency of sound. In the resonance process, the mechanical energy of the sound will be converted into other forms of energy such as heat energy, and thus achieve the effect of absorbing sound and reducing noise. For example, when certain frequencies of traffic noise coming from outside are close to the intrinsic frequency of the plastic layer, the plastic layer will resonate, effectively weakening the noise of these frequencies.

- Liaoning MOHAN's profile structure design measures

    - Optimized Cavity Structure: MOHAN Liaoning designs its co-extruded profiles with a multi-chamber structure. These chambers are independent of each other and work in tandem, so that when sound enters the profile, it is reflected and interfered with many times in each chamber. Different chambers have different reflection and absorption characteristics for different frequencies of sound, and by reasonably designing the number, size and shape of the chambers, it is possible to realize effective noise blocking for a wide range of frequencies. For example, larger cavities have a better buffering effect on low-frequency sounds, while smaller cavities can handle high-frequency sounds more effectively.

    - Sealing structure design: The joints and gaps of the profiles are the weak points where noise can easily enter. Liaoning MOHAN adopts precise sealing design in the profile structure design. For example, during the installation of windows and doors, the profiles are tightly fitted with each other through special sealing adhesive strips to form a tight sealing defense. This sealing structure not only prevents air leakage, but also effectively blocks the spread of sound, greatly improving the sound insulation effect.

- Liaoning MOHAN material selection measures

    - High-quality aluminum alloy: Liaoning MOHAN uses aluminum alloy with high density and strength, which makes it more reflective of high-frequency sound. At the same time, the aluminum alloy has good stability, in the process of long-term use, will not be reduced due to environmental factors, and can always maintain good sound blocking effect.

    - High-performance foamed plastic: In the plastic part, Liaoning MOHAN adopts high-performance foamed plastic as the inner layer material. This kind of foam is characterized by high closed cell ratio and fine and uniform bubble holes. The high porosity means that it is difficult for sound to penetrate through the holes, while the fine and uniform structure of the bubble holes can more effectively convert the sound energy into thermal energy and enhance the absorption capacity of sound, thus bringing ideal sound insulation and noise reduction performance to the profile.