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Old February 12th, 2009, 11:24 AM   #1
jim767
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Tire cord splice sensor

Anyone know of a low cost fabric splice sensor I can use to detect a point of which a splice passes prior to being calendered. I can run this to a discrete input on the CLX IO.
Would be nice to have a sensor that is single sided. Your help is appreciated.
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Old February 12th, 2009, 01:10 PM   #2
Terry Woods
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Damn...

Depending on the situation, it seems you might only be asking for something as simple as the human eye! But then... you want to do this on the cheap...

I'm sure that the cord is traveling really, really fast. I'm not even gonna try to guess how fast.

So, how fast is the cord traveling?

Does the cord get fatter at the splice? If so, how much fatter?

Does the cord pass in the same exact place at all times?
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Old February 12th, 2009, 01:28 PM   #3
Terry Woods
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Another question...

How often do the splices occur?
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Old February 12th, 2009, 01:28 PM   #4
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The cord travels between 100 to 300 fpm.

The cord necks down at the splice and runs down the middle of the line all the time but has differing widths.

I would like to automate a sequence that is needed when a splice comes through. Right now it is dependent on the operator (human eye) to touch a pushbutton when they see it at a given location. Sometimes they may not see it in time for proper timing.

The spliced region is much denser then the remainder.
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Old February 12th, 2009, 01:31 PM   #5
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The spliced region only occurs once every few hours.
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Old February 12th, 2009, 01:41 PM   #6
Terry Woods
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Like I said... Damn!

"The cord necks down at the splice and runs down the middle of the line all the time but has differing widths."

Well, that throws most of my ideas out the window. I had a couple ideas that depended on the cord being a consistent size except at the point of splice, where the splice would be fatter.

The killer is that the widths differ in size... damn.

Questions:
Is the cord really a cord? That is, round like a tube...?

Does the cord vary in size during a given run? For example, does the cord maintain 1/4" during a particular run (except for the splice), or does the cord vary in size during any(all) part(s) of the run?
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Old February 12th, 2009, 01:51 PM   #7
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Cord is a fabric which varies in width from 50" to 60" which has individual strands spaced 1/16" apart and held together with a strand which goes back and forth laterally. You can actually see through the fabric as it is running on the line. The area of the splice would be more dense since you have overlapped two pieces.
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Old February 12th, 2009, 01:51 PM   #8
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Another question...

How long is the splice?
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Old February 12th, 2009, 01:54 PM   #9
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Damn...

Just realized from your response we are talking about a cord fabric...
...which is, of course, what you said in your first post.

Still thinking... tic-tock, tic-tock...
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Old February 12th, 2009, 01:55 PM   #10
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The splice is narrower crossways than the width of the fabric (50" to 60") and in the direction of the movement of the fabric is 6" to 12"
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Old February 12th, 2009, 01:55 PM   #11
Steve Bailey
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Try RKB

http://www.rkbopto.com/

I have used their products for splice detection in a paper application. I can't remember the exact model, except that it was a capacitive sensor and the sensitivity had to be adjusted regularly to compensate for variations in humidity.
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Old February 12th, 2009, 01:57 PM   #12
Terry Woods
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OK...

How about an infrared source and an analog detector. One unit is above the fabric and one is below. The setup can be placed in the middle of the fabric so that the width doesn't matter.
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Old February 12th, 2009, 02:14 PM   #13
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Any mfr suggestions for a IR source and analog detector before I go searching.

I looked at RKO but don't need high tech or expensive. I'll keep looking at what other stuff they have.

Thanks
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Old February 12th, 2009, 02:20 PM   #14
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The idea is that during the normal part of the fabric there would be relatively large amount of infrared making it from the source to the analog detector. Then, when a splice occurred, the signal would drop a relatively large amount.

So you would need to use an analog input on the PLC. The code would not be looking for a particular value. Rather, it would look for a radical downward change in the signal. At that time a digital output signal would do whatever it is that the operator is trying to accomplish... unless of course the push button is an input to the PLC. In that case the code detecting the analog signal would simply pass a flag to whatever code the push button applies.

Now, once the splice occurs, you want the code to send only one instance of the "push button" signal to the other code. The concern here is that there might be some "bounce" in the analog signal during the splice.

So, that means that you want to disable the analog detector code for a particular length of time. That time could be calculated (on the fly, or by recipe) relative to the linespeed and then loaded into a timer.
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Old February 12th, 2009, 02:23 PM   #15
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Banner, Red Lion(?)
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