Why regular paper is ineffective for modern logistics – insight from Weber Etiketten

With modern warehouse logistics, the height of the racking systems often clashes with the optical reach of standard scanning systems. In a distance between 8 and 10 meters, diffuse reflection (the scattering of light) from normal paper labels becomes too weak to be accurately read. This phenomenon is dubbed “information shadow”, present in the upper levels of the warehouse, which forces specialists to pause the work flow. To understand how modern materials solve this engineering related situation, we spoke with Weber Etiketten Bulgaria, a company with years long experience in the production of specialized industrial labels and system for identification.

"In modern warehouses, height is an advantage for capacity, but it often becomes a nightmare for operators. When a pallet needs to be scanned at 10 m height, the standard label usually "disappears" for the terminal's laser. The result? The forklift operator wastes time maneuvering, gets off the machine or, worse, enters the codes manually, which leads to errors. The solution that logistics engineers are increasingly using are the so-called retroreflective labels," the company shared.

To understand how to achieve identification from a distance over 10 meters, we need to check the surface layer of the retroreflective label, which functions differently from standard materials. With normal paper one can spot diffuse reflection (scattering of light in random directions), which leads to a rapid weaking of the signal. Retroreflective technology, however, relies on a physical principle regarding the return of the ray.

"The microelements in the material's structure act as miniature lenses that focus the incoming laser beam and reflect it exactly along the path of its source," explain the experts from Weber Label Bulgaria. According to them, the refractive index is at the heart of the process. When the laser beam from the scanner hits the label, it passes through the front surface of embedded glass spheres or microprisms and is refracted towards the back wall, which is covered with a highly reflective metallized layer.

Photo source: Weber Etiketten Bulgaria, Weber Marking Systems