In loudspeaker manufacturing, adhesives play a very important role and the potential solutions we offer to increase the productivity of the manufacturing process are not yet fully understood.
In loudspeaker manufacturing, adhesives play a very important role and the potential solutions we offer to increase the productivity of the manufacturing process are not yet fully understood. A typical loudspeaker is bonded in at least 7 places. Using the right adhesive can help the manufacturer to produce a high quality and reliable product.
High adhesion strength and good sealing ability are two of the most important properties of adhesives, but it is also important to note that sound quality is also affected by adhesives. Sound quality can be improved by adjusting the flexibility of the adhesive to eliminate vibrations affecting the moving parts of the loudspeaker. Good flexibility and adhesion are necessary to protect the loudspeaker from the effects of impact, shock or strong vibration. Finally, most components need to withstand long-term changes in temperature, vibration, and humidity, so it is also important that the adhesive does not degrade over time.
The link that connects the spider and the voice coil, known as the Bobbin, is typically made of polyimide-coated paper or fabric and wrapped around copper wire. The spider serves to keep the voice coil moving up and down in the center of the magnetic gap, causing the speaker cone to vibrate and thus create sound waves. Cyanoacrylates (also known as CA glue or fast-drying glue) are still widely used in this case. The fast-drying properties of the glue can help create a strong bond in a short time and meet the needs of manufacturers for increased productivity. Rubber toughened Modified CA glue provides flexibility for the bond. Some manufacturers of this type of adhesive are: MXBon, 3M, Henkel, … High performance gasket adhesives are cured by the evaporation of solvent materials. These adhesives also provide a flexible bond between the Voice coil and Spider. Some speaker manufacturers also apply reinforcing materials to the bonding area to ensure the longevity of the bond. There are some manufacturers of solvent based adhesives are: 3M, Henkel, … published
Speaker manufacturers can significantly increase the efficiency of the manufacturing process by using UV irradiation systems and UV adhesives in the process. These adhesives will cure within seconds when exposed to high energy light. In the case of Spider, the strong light-resistant poly cotton material makes this process more difficult, but by using a high-intensity focused lamp, the high-intensity light can penetrate the fabric, allowing the adhesive to achieve its best adhesion strength in just 10 seconds. In addition, acrylates-based adhesives have been researched and developed to be able to operate stably at 150 degrees Celsius. Such temperatures arise from the energy of the voice coil and are a major obstacle that is difficult for standard adhesives and CA adhesives to overcome. The loudspeaker is created in a custom-made and quite complex manufacturing process. However, optimization can still be achieved, especially with the use of UV adhesives. The properties of these adhesives can be adjusted to meet acoustic requirements, and the addition of fluorescence can facilitate in-line quality control. With UV light-cured adhesives, manufacturers can significantly increase labor productivity and thus gain a competitive advantage.
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