Automotive – LASD (Liquid-Applied Sound Deadener)

As vehicle manufacturers(VMs) strive to lower manufacturing costs and simultaneously reduce weight, increase performance, and use environmentally friendly materials, a new generation of low VOC coatings has been developed and used for various applications in auto factories’ body and paint shops. One of these ‘green’ technologies focuses on the sound damping of vehicle body structures to reduce noise in the passenger compartment.
Our tailor-made, high-quality water-based pure acrylic polymer emulsion that was specifically developed for this application help formulate highly efficient aqueous sound damping masses. For instance, in order to meet a Korea-based global VM’s needs to go ‘green,’ our R&D Institute developed water-based acrylic dispersion that has been provided for the VM’s local tier-1 exclusive supplier (formulator) of water-based liquid-applied sound deadener(LASD) because water-based LASD has the lowest applied cost and because it is the most feasible replacement to die-cut asphalt melt sheets(AMS) the VM adopted.
These sheet-type materials are manually installed in the listed locations, and bond to the sheet metal on exposure to heat in the sealer oven. This is difficult, time-consuming, and labor-intensive. Up to 15 of these die-cut pads have to be applied, often introducing dirt and contaminants and causing dustiness in the paint shop, which can contribute to paint finish defects.
In contrast, water-based LASD is a bakeable thick-film coating that is designed to replace melt-on (heat-fusible), manually-applied asphalt damping pads used on various areas of a vehicle's body structure – namely floor pans, tunnel, dash panel, inner door skins, roof panel, and trunk floor – to damp sheet metal resonance, allowing for automated, robotic application. This reduces labor costs, process variation, and multiple inventory part numbers, as associated with asphalt pads. Robotic application enables VMs to obtain optimal geometry, location, and thickness of the coating, even as running changes are made.
Water-based LASD offers significantly better acoustical performance than asphalt pads of equal thickness/weight. Thus, the weight of the sound-damping package is reduced without compromising acoustical performance. The reduced costs associated with economies of scale in terms of labor, inventory holding costs, application costs, wastage, and other factors, are the main force promoting use of this emulsion technology.
Application benefits of water-based LASD, from a technical standpoint, are summarized as follows: