Foreign Object Detection

[ryan1988]

Hi All,

I am wondering if there is technology currently available that is able to detect foreign objects within a box of fresh cut leaves (baby leaf spinach, lettuce etc...)
The foreign objects in particular are frogs, mice, moths and other small animals.

I have seen sorting machines currently available within food processing industry to perform this task however all product is required to pass the detection equipment in a single layer for efficient detection and foreign object removal.

Our requirement is for a whole box of product to be scanned and identify whether or not foreign objects are present in the box.

Any information would be greatly appreciated!

Regards.

 

[VEBill]

Not sure about the moth, but perhaps measure the precise CO2 levels to see if any frogs or mice have been exhaling within the more-or-less sealed box. This assumes that they wee beasty is still alive.

 

[Compositepro]

I think your most robust solution would be to run your leaves through an air separation step. If you are trying to find animals that have gotten into the boxes after you have processed the leaves, that will be a losing battle. You have to keep vermin out. What will you do when the detector finds something?

 

[IRstuff]

Also, you need to consider what your lower detection limit requirements are. The US FDA has specific rules for how much of an animal or insect are allowed in a given volume of food.

Trying to find this type of contamination AFTER the fact is a losing proposition. As with product defects, the earlier you can weed out the contamination, the cheaper it is to do. Throwing away or reprocessing an entire crate is much more expensive than throwing out or reprocessing a few leaves.

TTFN
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[ryan1988]

Thanks for the feedback everyone.

We would like this scan to be the first step after harvest before the product enters the processing factory.
In our current setup, the product is mechanically harvested and travels up a short conveyor before filling 84L plastic crates (approx 560mmx495mmx360mm). These crates are stacked on pallets before the cool chain and then sent onto the processors.

If it were possible to detect the object in one of these crates, we would simply manually remove the crate before its stacked and search for the foreign material.
the other option is to try to scan the product as it is travelling up the conveyor, as the product thickness would be 4-5 leaves at worst.
Our current detection is visual. As you can imagine it is easy for a couple of leaves to hide a small animal underneath.

Would an IR camera be a suitable option?

 

[dicksewerrat]

Frogs and toads I think are ambient temp/ A mouse would be seen by IR.

Richard A. Cornelius, P.E.

http://WWW.amlinereast.com

 

[Comcokid]

There are some detection systems used in grain and food processing that incorporate a RF network analyzer connected to two microwave horns (or other antennas) to measure the transmission path loss. Path loss is influenced on the bulk moisture content which affects the bulk dielectric constant. Such a system might be able to do detection provided the produce wasn't too wet. I'm just aware that such systems exist, but who uses them, who makes them, or who designs them, I don't have a clue.

Some years ago I attended a large RF and microwave conference. Among the many highly technical papers being presented on the newest semiconductor physics and THz microwave techniques was one where the title was something like: "The dielectric properties of rice weevils". Your post reminds me of that. Always struck me as a humorous subject to present a paper on.

 

[itsmoked]

Modern gesture sensor sensing could probably detect the anomalies too.

THz imagining would certainly be able to do it as would X-raying, both possibly a bit extreme though.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[Compositepro]

A conveyor in the field can easily be retrofitted with an air separator. A half Hp blower may be all you need to blow the leaves up to packaging while denser object fall out the bottom. Sure there is some detailed design required, but a lot less than some high tech sensor, and it will be cheaper and more productive. There is very likely already commercial equipment to do this.

 

[jraef]

I have no constructive suggestions, but this makes me laugh a little because it is the basis for my argument when, on at least a yearly basis at family holiday dinners, I confront a family member who is a militant vegan. She gets downright rude with everyone about how we are all "murdering" animals for our gustatory hedonistic pleasure, while she lauds over us that she is eating "Tofurky" or some other equally boring vegan dish-du-jour. I like to point out the hypocrisy in her stance, because there are PLENTY of little tiny beasties that are slaughtered in the process of harvesting plant based foods as well, but we basically waste their protoplasm or at best, recycle it as fertilizer. I also call her a "speciesist" because she is in fact also consuming animals as defined as "living things that are not plants" in that there are countless microbes and small critters in plant foods as well that are going directly into her "acid murder chamber" of a stomach. But because she cannot see them, she discounts them for the convenience of her high and mighty position.


"You measure the size of the accomplishment by the obstacles you had to overcome to reach your goals" -- Booker T. Washington

 

[IRstuff]

OK, that's just being mean ;-)

TTFN
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[racookpe1978]

If animals (mammals!) then an IR scan of shallow layers would help ID hot-spots caused by the animal. But! The act of laying out the vegetation would tend to scar the animlas - either into the food processing plant, or (sometimes) back out of the food process facility. Insects though are cold-blooded - and much, much smaller.

Maybe if the scanning trays or conveyor belts were sloped uphill? Would critters run "up" away from "danger" into the facility, or down (away) from danger and outside?
Add high-intensity IR and UV lights right above the scanning trays to scare light-phobic insects back outside (into the darker, lower points?) before the IR scanner looking for rats and mice?
Put your HP water-wash sprays there as well (aimed down and out-of-facility) to "encourage" the critters to leave the conveyor belts, which would cool the veggies off (before the IR scanners) with water that could be separated and recycled - since it is not your final sterile "rinse" before processing.

 

[zappedagain]

Keith, that's THz imaging, not 'Thz imagining'. THz is finally going mainstream.

http://advancedphotonix.com/thzsolutions/

Z

 

[MacGyverS2000]

I can tell you slope of the conveyer belt won't cause most creatures to stir... Frogs will typically hide under the vegetation already on the belt, many insects are as likely to fly off of the belt (at any angle) as they are to ride it to the end, etc.

I think you'll first need to define what your problem children/animals actually are...

Dan - Owner

http://www.Hi-TecDesigns.com