In this webinar episode on web guiding fundamentals, we delve into the accuracy of web guides, discussing various factors that affect their performance. We explore how steady state and transient errors can influence guiding accuracy and highlight the importance of machine quality, material properties, and proper installation. Additionally, we cover the design requirements necessary for achieving optimal web guide performance, emphasizing the need to understand conditions like web speed, thickness, and tension.
00:00 Introduction to Web Guide Accuracy
00:19 Factors Affecting Steady State Error
00:51 Challenges with Transient Errors
01:33 Impact of Wrinkles and Other Issues
02:30 Design Requirements for Optimal Performance
03:00 Conclusion and Summary
Transcript
Show full transcript (491 words)
[Music] So the final question here is that you have a web guide and we talked about all these different things. What is the accuracy or how accurately can you guide a web? It actually depends. Like I mentioned, there are lots of different parameters that are going to affect the accuracy of the web guide.
If we are just dealing with a steady state error, we can expect plus or minus 0.25 mm. If you have a good machine in a perfect material, this is what you can expect. Higher accuracies are possible. Like in printed electronics, you can get much higher accuracy.
But if we're dealing with steady state errors, you have a good edge and all those kind of things, this is possible. But the problem is that most web guides are going to come into transient errors. These are either disturbances or material properties that are going to affect the disturbance in the web guide. Now, if you're trying to correct a transient error, it really depends upon what is the magnitude of the error, what is the frequency of the error and so on.
And another important thing that we need to consider is that these transient errors can actually propagate downstream of the sensor and these are called what are called as wave generation. Even though you correct it at the sensor, you don't really know the angle at which the web is approaching and that can cause weaves downstream. You won't have good guiding performance if you have wrinkles. I mean, if the web is wrinkling, that is going to cause the edge to move back and forth.
There's no way you can have good guiding performance with that. Or edge curl, flutter, or sometimes plane change can also have that effect. If you have large magnitude error and your stroke of the actuator is limited or the correction that the webgate can provide is limited then you can expect good grading performance whenever the actuator tops out on either side of its stroke. If you use a lower bandwidth actuator and you have a higher frequency error, you can expect good guiding performances and sensor.
If you don't have a good sensor or if it has gain changes then you can expect a good guiding performance and then improper installation can actually amplify the error. So that's another thing that we can expect. Anyway, so just to summarize the factors affecting we talked about a machine related, process related, material related and the web guide related which is like the stroke deadband actuator backlash correction stroke limit and things like that. So in terms of design requirements uh a good knowledge of the the the conditions like web speed location thickness stiffness environment tension side correction all of these are important for us to have a welldesigned web guide.
If you have a good understanding of all of these, we will do well. [Music]