Metal Detectable Plastics

I was going to suggest using a metal loaded plastic, but as the metal will be small particles I'm not sure if a metal detector would pick it up?

John.

John is right.

To detect small amount to distributed metal particles or chunk or small metal, very high sensitivity equipment is required to detect and and object need to pass through the metal detector. This is done for small metal detection in food items such as Chocolates and Biscuits and perhaps Bread where small metal chips can get in the automated process.

I have seen such equipments placed in Cadbury India Chocolate manufacturing plants.

You can detect plain plastic with a capacitive proximity sensor and I know Keyence produce a range of laser sensors which can sense different types of plastic of the same colour by the amount of light that is reflected back to the sensor. Expensive but very effective

Al

Even if you compounded micron size iron particles into your plastic the loading would have to be above ~25% to be noticeable by many "affordable" metal detectors, and at this loading you would have issues as to embrittlement and wetting.

I know of research being done as to this but I haven't heard of any products on the market yet...

I cnant understand.

plastic material containning metal particle?why? and detect it by metal detector?

what do you od? seve it as tag or count it for statistic?

if you hope to delet the matel particle, you can add a magnetic field. if you hope to detect the particle, you can use metal detector.

...??

Will this plastic be in direct contact with food? If so, then your choice is extremely limited due to the Food and Drug requirements. http://www.cfsan.fda.gov/~lrd/foodadd.html This presumes you are in a country governed by these requirements.

What is the purpose for this detection? Counting? Proximity? Density? There are other methods for these purposes. I could ask another couple of dozen questions but the easiest is for you to contact SABIC (used to be GE Plastics): http://www.geplastics.com/gep/en/Home/Home/home.html

Good luck

I'm going to guess that the machine in question is some sort of food packaging automation or a piece that mixes a food product; and that he is considering substituting a part that is currently made of metal, with one that is made of plastic. His peers may have brought up objections to using plastic because if a part breaks off and gets mixed in with the food product, it will not be detectable prior to packaging, the way that a metal part would be detectable. Am I correct in this assumption? This is in fact one of the major reasons why metal (SS) is typically used in the food processing industry.

As was mentioned, the metallic content of any plastic you'd want to use would need to be fairly high in order for it to register on a detector. And to make sure a non-metal-containing fragment did not break off into the mix, the metal would have to be very well dispersed within the plastic. This would involve a metal powder of some sort. And metal powder being used in a food processing environment would raise considerable red flags!

Ahhh! You may have guessed it! Bauer1 should tell us for sure.

Let's say that you are correct, well, the loading does not usually migrate to a resin rich outer skin and therefore, if a part would break-off, chip, etc., then no matter if the loading is detectable, this part may sneak past the detectors. In addition, depending if you use fibers there will be a difference in the part's matrix transverse to the flow as compared to parallel to the flow and this could lead to non or lesser filled metallic sections as well. Oh well, now I know why some of my cereals are crunchy.

Terry Larson Business Dev. Manager

Panduit Corp.

Terl@Panduit.com

708-532-1800 ext 1724

Manufacturers of Metal Detectable Plastic Products.

February 09, 2009

FDA Compliance of Panduit Metal Detectable Polypropylene (-186) and Nylon (-86)

Panduit Corp. manufactures wire management products made of metal detectable polypropylene and nyon material. These products are intended for use in the proximity of food processing, handling, and packaging operations. In addition, these products are used for managing wiring on food processing and packaging equipment, and inside electrical control panels found in food processing and packaging operations.

Panduit Corp. declares that the materials that comprise Panduit metal detectable polypropylene comply with the following sections of US FDA regulation 21 CFR and may be used in indirect food contact applications per:

Section 184 – Direct Food Substances Affirmed as Generally Recognized as Safe (GRAS)

170.39 – Threshold of Regulation for Substances Used in Food-Contact Articles

178.3297 – Indirect Food Additives – Colorants for Polymers

177.1520 – Indirect Food Additives – Olefin Polymers

This statement applies to articles supplied by Panduit Corp. and without any further modification. Since conditions of use are outside of Panduit Corp.'s control, Panduit Corp. makes no warranties, express or implied, and assumes no liability in connection with any use of this information.

For an understanding of the U.S. FDA 21 CFR regulations, please go to the FDA's website at:

http://www.cfsan.fda.gov

We appreciate your interest and use of Panduit metal detectable products.

Sincerely,

Terry Larson

Business Development Manager, Wiring Components

I have used plastics with stainless steel fibers in them. They are produced in bundles that are wrapped in a plastic sheath, cut into small lengths, and mixed with conventional plastics. I believe that both RTP and LNP (division of Sabic Plastics) can supply the materials, specs, and perhaps samples. They are slightly more difficult to mold than glass fiber filled plastics, and you can't use magnets in the molding machine hopper (commonly used to screen out metals) for obvious reasons.