A bedding or seating product comprising a spring core including upper and lower border wires. In the process that entails at least one diphenol, phosgene, at least one chain terminator, and optionally branching agents and is carried out in the presence of a catalyst the improvement comprising maintaining the concentration of the catalyst at a level of at least 0. An impulse reaches an impact location on the surface of the unfinished object under an inclination angle between the laser beam direction of the impulse and the surface to be formed. A transmission line connects each plate to a different conductor of the microstrip feed.