In systems for processing paper or vinyl webs, many process steps run inline and at a constant speed. Reliable sensor technology is crucial, especially when punching hole patterns: On the one hand, it must be ensured that the web is present at all, and on the other hand, the inserted punches must be checked.
These two tasks were to be combined in a special machine – simple presence check of the strip goods and simultaneous measurement of cut-outs along the entire strip width.
Before the die-cutter works, it must be clearly recognized whether the paper or vinyl web is in the process. If the material is missing, tools would come to nothing, which can lead to damage or rejects.
The challenge lies in the nature of the belt fabric. It is a very thin material with a thickness of less than one millimeter. In this case, a lateral query would not be process-reliable, as the material edge is hardly detectable and position fluctuations can occur.
Instead, the track is monitored from above. A compact, energetic probe is aligned at a 90° angle to the track and checks whether there is a bright surface in the detection area. The energetic measuring principle is particularly suitable here, as the strip fabric is light or white and clearly distinguishes itself from the background. This creates a simple, reliable signal: there is a track or not.
In addition to pure material detection, the hole pattern should also be checked. Different hole diameters in the range of about three to five millimeters are inserted along the running paper web. These must be recognized and measured in the process.
That’s where 2D/3D displacement sensors come in. They project a laser line across the bandwidth and continuously record the height profile of the surface. Recesses such as holes or punches appear in the profile as significant indentations. In this way, the diameter, position and course of the cut-outs along the web can be evaluated – during ongoing production.
The special advantage of this concept lies in the combination of both applications within one system. A cost-efficient, compact sensor ensures easy presence checking. For the precise geometry detection of the hole patterns, 2D/3D profile sensors take over the task.
Since both classic sensor technology and profile-based measuring systems come from the portfolio of one supplier, an integrated solution for different requirements is created within the same machine. This facilitates integration, parameterization and subsequent adjustments.
Such applications can be found wherever strip material is processed, for example in the paper, packaging or film industries. In-line measurements during the running process enable continuous quality monitoring without additional inspection steps.
The combination of simple presence detection and profile-based hole measurement shows how different sensor technologies complement each other in a targeted manner. While an energetic probe ensures process reliability through material recognition, profile sensors provide detailed geometry data of the cut-outs
This results in continuous inline control of the strip goods – from the presence of the material to the precise monitoring of the hole pattern.
Job title