Lightweight construction and the absence of engine noise in electric vehicles make tire rolling noise more noticeable inside the cabin. Especially the so-called cavity noise peak at the tire resonance frequency is significantly more intrusive and unpleasant compared to combustion vehicles. Hence, modern electric vehicles are increasingly equipped with tires that have an acoustic polyurethane (PU) foam lining on the inside. These so-called "Silent Tires" significantly reduce noise emissions both inside the vehicle and in the surrounding environment, ensuring an improved driving experience.

This simple solution concept presents tire manufacturers with a complex and demanding task: a second logistics line must be integrated into tire factories to transport the lightweight but high-volume foam to the "tire wedding" at the end of the production line. This requires substantial space for logistics handling and multiple stages of intermediate storage for the foam. Numerous additional manual or semi-automatic steps are required for logistics, cutting, adding adhesives and inserting the foam into the tire. And finally, for each tire produced, the appropriate foam must be provided "just-in-sequence". As a result, the manufacturing costs of a tire increase by up to 25% and it is often impossible to integrate the technology into existing tire plants. In addition, there are significant volumes of waste generated from the off cuts of the polyurethane foam pieces.

In the innovative LASER-FIT process, a tailor-made acoustic foam is produced directly inside the tire from liquid starting materials. Many of the disadvantages of the conventional process can be avoided. This direct foam process, which has long been established in other industries and applications, is made possible by the patented foam activation using a laser after the foam has been applied. In the activation process a powerful laser system removes part of the air-impermeable foam skin, that any foam system forms during generation and that prevents from noise absorption.

This LASER-FIT (short for “Laser Foam-in-Tire) method not only eliminates the just-in-sequence complexity, time-consuming logistics and manual process steps. It also gives the tire manufacturer greater freedom in adapting geometry and volume of the foam to the tire type. It significantly reduces footprint, CAPEX and inventories. Moreover, it minimizes waste generation and carbon footprint, and in many cases, it is the only sensible way to introduce Foam-in Tire technology in brownfield plants.

We build fascinating laser-equipment.

However, chemistry and a secure international supply-chain for foam precursors are not our business. That is why we have partnered with Henkel, the world leader for technical adhesives and PU foams in the automotive industry. Henkels’ Loctite® LASER-FIT α-Methyl-PU foam and 4JET’s LASER-FIT Line are co-developed systems, tailor made to suit the mutual requirements for the best possible Silent Tire solution. And that is why we have no doubts that we will be able to serve the international tire industry with a consistent and reliable quality for Simply Silent Tires!