Sensor needed to fit application.

[powersoff]

I need a sensor that can detect if a bag filled with commodity(fruit) is sealed.
The bags will be moving at a rate of about 100 per minute on a conveyor.
Does anyone have any suggestions?

Thanks

 

[dV8r]

Check out the Banner iVue.

http://www.bannerengineering.com/en...Vision-Sensors/503/iVu-Series-TG-Image-Sensor

 

[jraef]

Define what constitutes a known seal. A sensor needs to detect something. Even a vision based system like the one above needs to be programmed to detect a difference in the scanned object compared to a previously set up criterion. We have no way of telling what your "seal" looks like. Does a sealed bag change shape? Does it hold air pressure, i.e. you can press on it expecting to detect resistance? Does the color or contrast of the sealed area change?


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376

 

[powersoff]

Thanks for the replies. I downloaded the manual from banner and will have to look at in more detail.


Jraef you hit the nail on the head with the "Does it hold air pressure".
If the bag has a hole in it the product would be damaged even if seal is ok.
The bag would be similar to a single serving bag of potato
chips.
The seal would have a different contrast.

 

[jraef]

Vision based systems like the one above or the Balluff Sharpshooter can be programmed to look for contrast, and there are specific contrast optical sensors available from people like Sick Sensor Intelligence.

You might also consider a simple limit switch that presses on the bag as it goes down a conveyor and if the bag has a hole, the pressure from the switch deflates it a little and triggers a reject. You could do it with a hinged plate that the bags pass under and a roller limit switch behind it. If you want analog sensing of that, there are analog output inductive sensors that could give you a relative plate deflection that you could track in the PLC from a 0-10VDC signal.



"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376

 

[HEC]

Why use a sensor? Why not run the bags along a channel with tapered sides and an open bottom. Size the channel such that only sealed bags will stay in the channel, un sealed or undersized bags will drop through.

Mark Hutton

 

[powersoff]

I do need to add a sensor to count the bags(only good product). I did not mention that in my original post.
If I can eliminate a sensor to test for bad bag that makes my life easier. I love the idea of the bad package dropping in a open channel.
If this is not acceptable to the powers that be, I like the idea of the hinge-limit switch combination.
This site amazes me the willingness of professionals to offer guidance to people they don't know in need of assistance.


Thanks again.

 

[jraef]

Most of us are "Solution Junkies". We just can't help ourselves...

We need a 12 step program I guess.


"If I had eight hours to chop down a tree, I'd spend six sharpening my axe." -- Abraham Lincoln
For the best use of Eng-Tips, please click here -> faq731-376

 

[itsmoked]

A rotating wheel with spokes but no outer rim. Each spoke is lightly spring loaded to operate a single switch if the spoke is depressed. The spokes walk over each passing bag synchronized with a particular location on the bag where a single light touch would reliably show resistance without damaging the chips.

I would be concerned that the clever chute method might crunch some chips at the required speed.

A non-contact method would be a pinpoint proximity sensor that looks at a location that has an air jet impinging on it. Correct bags would not depress as far as leaky bags.

Keith Cress
kcress -

http://www.flaminsystems.com