These applications help you eliminate the need for a printed line. Eliminating the printed line saves the cost of ink to print the line and the web material where the line would be printed.
Converting applications will typically require some type of guiding. It can be in the form of terminal or intermediate web guides, each with the peculiar conditions required to provide an effective placement of the web guide. However, all these applications are used in environments subject to atmospheric conditions. One of the most challenging web guiding applications deals with vacuum web guiding.
The line has to be of the same width and color in order for the sensor to track it. Any variation and the sensor will not recognize it. The same thing happens when using the negative space as guiding feature.
In a previous post we presented the concept of negative space web guiding as an option to line guiding. We are talking about using the negative spaces between printed features, such as the separation between labels. This application does come with its challenges.
It requires the printing of a line on a web. It's purpose is to provide a feature that a sensor can track to determine the web position. The typical use is in web converting where guiding on the edge might not be a precise parameter in printing labels. However, printing a line is an additional cost. After all, it is additional ink. If the line is printed outside of the main printed features of the web, it could be leaving money in the converting floor in the form of excess trim on the edges of the web.
Contrast sensing relies on detecting a feature on the surface of the web. This feature can be printed, laminated or embossed. This is a great application when the printed, laminated or embossed features are relevant to the positioning of the web instead of the edge of the web.
Web guiding is that component of a converting line that no one thinks about until it affects the converting operation.
In some cases, we believe that a problem in a converting line is due to guiding issues when it really isn't. That is why it is important to understand web guiding, and why we invest time in creating this series in web guiding fundamentals. First, the best way to prevent issues with web guiding is to understand how it works, how to best select and install a system, and what we should consider when trouble shooting.
We have reviewed all the major components of a web guiding system, sensor, web guide mechanism, actuator and controller. However, the question still remains what is a good web guiding system? For this we have to address web guiding performance
Speaking of web guiding performance, how accurately can you guide a web? Well, it depends...
Web guiding accuracy depends on many parameters that affect such accuracy.