eggshell inspection


Thread Starter

Alex van Dalen

Our customer ask me if it's possible to detect eggshell on a egg, after the shell is peeled off. Has somebody ever did some testing with it.

mschumacher - Ajax Magnethermic

Banner has some nice photo electric sensors that can detect slight variations in color. The more contrast the better maybe dye the egg.

Curt Wuollet

I'd try an ultrasonic sensor. There should be a major difference in reflection from the hard shell bits and the soft membrane/protein. Regards cww
I had the same question. Raw or hard boiled? I have no experience with this, but I imagine that you could use a food dye on the shell before peeling. Then use a spectrophotometer after peeling to detect the spectral signature of the dye. It could be possible without the dye, but if it is hard boiled, you might have trouble distinguishing between the egg white and the shell. Of course, introducing dye into the process faces many hurdles (effect on product quality, additional cost, regulatory issues). Dustin Beebe

Robert D. Wagner, P.E.

I love a yolk(joke) on Friday afternoon. Wasn't the original poster trying to detect whether or not a shell was present. I assumed that this would preclude the contents from being in a fluid (raw) state, as shell absence in the raw state should be self evident. For a boiled egg, I would think using an optical sensor to monitor reflectivity should provide sufficient distinction to detect the difference between a textured egg shell and a shiny boiled egg white. Robert D. Wagner, P.E.

Crucius, Wesley

How about an analog photo-electric proximity device, looking at reflectivity? Seems like there would be a big difference from peel to un-peeled...
While this isn't my field at all, please accept an outsiders comment. Just as 'inspecting more' doesn't lead to higher quality, 'measuring more' may not be the magic answer. Is it not possible to design a process so it would be impossible for shell to be present? Run the egg through something that would break the shell, but not damage the egg. Wash and jumble the eggs together to peel the shells off. Rinse them so thoroughly that no shell could possibly remain. Just as more instrumentation is not the silver bullet for safer plants (my specialty), I wonder what benefit instrumentation would really provide for this application. Granted, the original post did not ask *why* the customer wanted to do this. Hey, it's Friday, and I'm bored... Paul Gruhn, P.E., C.F.S.E. Siemens, Houston, TX

Robin Schlinger

For several years, I was involved in the installation and testing of vision systems for a consumer product. Even if the process is supposed to remove something (or not have a defect), all systems are not perfect. Vision systems can serve two purposes: 1 - Act as feedback that something is wrong with the previous process. We installed a vision system that at first showed we had a less than 0.1% defect rate, but it lead to complaints in the field (and lost sales). By installing the vision system, we were able to reduce this defect rate to less than 0.01% (and reduce complaints by over 99%). At first we had a high rejection rate, but by using the feedback from the vision system, we were able to fine tune our machinery to lower the defect rate. This was NOT POSSIBLE prior to the vision system, since our production rate was so high and the defect rate was so low. 2 - If the original process cannot be designed to eliminate defects, the vision system can be used to trigger a reject. It is better to reject the eggshell right when it is detected, with little other product loss, than to let the eggshell contamination ruin a whole batch of product. This is a similar use to a vision system we used to reject contamination from a product stream. It is a common application in the food industry. Robin Schlinger [email protected]

Alex van Dalen

Tanks for the reply. A Vision system will not be the way. There are little pieces of the shell in the egg. With a vision system you can only see the upper surface. I also tried a x-ray scanner as camera. But this becomes too expensive and the egg is too small for the system. We also not know which egg contains the shell pieces. We have successfully used it to count the hole in cheese (I'm from Holland). Instead of the signal of a camera we used a standard bag inspection system , like the one on the airports. With the x-ray system we can look trough the cheese en the Vision system counts the hole. We have used this for quality inspection, before our system the cut the cheese in half.
Maybe an audio frequency could be aimed at the egg, received on the other side (or reflected), subtract the excitation signal, and FFT the result. Might bits of egg shell show up as spikes on a frequency distribution? -- Ken Irving <[email protected]>
Dear Sir, Please send me details about automation that could be used for poultry application. An detail case study would be beneficial. Jateen Dave

Lunnon, Robert

On the lighter side ....

&lt;Joke mode on>

We've had
X ray
Ultrasonic Vision systems

I suggest we give the egg a cat scan.....
(Only problem is to stop the cat from eating the egg...)

&lt;Joke mode off>

May be you can try this simple solution out...Measure the reflected light intensity from
1. The Egg shell
2. The membrane...There certainly would be a difference...the membrane reflecting more light and the shell dispersing more light...Let me know if this works.
You could use an infrared camera and a small blast of hot air. The shell and egg will retain and emit heat at different rates. This will readily show up with an IR camera. I could supply you with contacts of persons doing reasearch with this concept. I can be contacted at [email protected]
Dear Alex van Dalen,
Can you kindly give me some details as which kind of X-ray Imagery you used? I mean the brand and its costs. Is there any brand specifically
designed for the kind of work you do? As I am also interested in it.
Best regards.