19 replies to this topic

[KarrieC]

We co pack a dry product for our customer.  A couple times a day the metal detectors will kick off a finished package.  When we separate the product from the packaging 99% of the time it is the packaging.  In the past we have just thrown the packaging away. I was told that was a normal occurrence due to the way the cardboard is made and since it is not the product no further investigation is needed. I have to admit writing up several foreign material investigations each day is time consuming especially when its the same outcome. Is there justification for not investigating the cardboard; other than determining it is the source for the kickoff?

[SQFconsultant]

What is the recuring issue with the packaging?

[Charles.C]

We co pack a dry product for our customer.  A couple times a day the metal detectors will kick off a finished package.  When we separate the product from the packaging 99% of the time it is the packaging.  In the past we have just thrown the packaging away. I was told that was a normal occurrence due to the way the cardboard is made and since it is not the product no further investigation is needed. I have to admit writing up several foreign material investigations each day is time consuming especially when its the same outcome. Is there justification for not investigating the cardboard; other than determining it is the source for the kickoff?

 

You need to determine why you are (apparently) getting false positives, eg incorrect/inappropriate MD setting.

[KarrieC]

What is the recuring issue with the packaging?

Small pieces of metal are embeded in some of the cartons (happens when they are made).  This causes kickoffs on our packaging line.  Since the consumer is not going to eat the outer carton and we do check the product we pack separately to confirm there is no metal in it; do we really need to do a complete investigation of the packaging?  We don't ship any cartons that kick off.  We do through them away.

[KarrieC]

You need to determine why you are (apparently) getting false positives, eg incorrect/inappropriate MD setting.

the kick off are real; not a false positive.  The product we pack is not causing the detector to kick off it's the packaging it goes into.  cardboard boxes.

[Scampi]

My concern would be all that metal "floating" around in your plant, Have you actually found the metal pieces in the cardboard, or are you just assuming, that since you're product is clean that is must be the cardboard?

 

I would 

A) push hard on the cardboard vendor, the metal shouldn't be there and perhaps they are not aware??   If nothing else, an employee could get hurt no?

 

B) Add this issue to the deviations section of the procedure with clear instruction of what to do ( follow the steps you've been doing)

 

Once you have a written deviation procedure for metal in the packing cartons, you just need to follow that---so you could alter the requirements in this case that DO NOT include a full blown investigation

 

OR-change the metal detection step so it's after product contact packaging, but before packing cases

[KarrieC]

My concern would be all that metal "floating" around in your plant, Have you actually found the metal pieces in the cardboard, or are you just assuming, that since you're product is clean that is must be the cardboard?

 

I would 

A) push hard on the cardboard vendor, the metal shouldn't be there and perhaps they are not aware??   If nothing else, an employee could get hurt no?

 

B) Add this issue to the deviations section of the procedure with clear instruction of what to do ( follow the steps you've been doing)

 

Once you have a written deviation procedure for metal in the packing cartons, you just need to follow that---so you could alter the requirements in this case that DO NOT include a full blown investigation

 

OR-change the metal detection step so it's after product contact packaging, but before packing cases

We co-pack product not produced in our facility.  Our Customer/ manufacturer supplies us with all the needed items...WIP product, retail cartons, outer case, etc. we have no contact with the paper company.   It a dry ambient stored product.  The Customer/ manufacturer does put the WIP through a metal detector before sending it to us.  However we need to be watching for metal that may come from our equipment. unfortunately the way the line was designed the cartons are filled and sealed before they get to the metal detector.   This is a section of the procedure I've written ...

 

1. Corrective actions:
   1. Product was kicked off during production.
      1. Open the carton, place the food product into the clear container and run it through the metal detector without the outside cardboard packaging.
         1. If the product is not kicked off;  it is cleared.  It may be thrown into the garbage since it was exposed.
         2. If the product is kicked off; 
            1. Is there a visible piece of metal in the container?
               1. If so, try to determine if it came from our equipment.
               2. If it did not come from our equipment notify the manufacturers of the findings.  Retain the item until notified by the manufacturers.   Send them a copy of the foreign material investigation form.
               3. Remove the visible piece of metal and run the product through the detector again. (repeat step 1.)
            2. If there is no visible piece of metal in the product; place it in a new zip lock baggy and send to the manufacture so they can determine were the contamination occurred.  Send them a copy of the foreign material investigation form.
      2. Run the empty packaging through the detector.
         1. If the carton is not kicked off;  it is cleared.  It may be thrown into the garbage since it is used.
         2. If the carton is kicked off;  notify the manufacturer they will determine our next steps.
      3. Document the finding using the foreign material investigation form.

sorry that pasted funny.  The pieces of metal that are causing the problem are not visible.  tiny pieces imbedded- if its in the product we send it back to the customer so they can perform an investigation- we have no way of embedding any metal into their dry (hard) product.  I guess what I'm wondering is if there is a way to state "  the carton was the source an no further action is needed (investigation) just throw away the package."

[Scampi]

As long as you're sure your metal detector is calibrated properly for product in cartons?

 

Generally speaking, metal detectors don't work the best in your scenario.....are you adjusting settings when you run full cartons vs packaged product?  The company you bought it from can assist if you don't already have different settings

[KarrieC]

As long as you're sure your metal detector is calibrated properly for product in cartons?

 

Generally speaking, metal detectors don't work the best in your scenario.....are you adjusting settings when you run full cartons vs packaged product?  The company you bought it from can assist if you don't already have different settings

our test pieces are attached to full cartons in order to best represent the actual product.

[Ryan M.]

What a lot of people don't realize is A LOT of carboard is from recycled material and this is where the metal comes from.  The recycling process and it being recycled over and over and over you end up with embedded metal in the cardboard.

 

If you can work with the vendor to somehow limit the amount of recycled cardboard that may do the trick.  If you can't then you will need to do something with your metal detection process.  If it is possible to put a metal detector prior to the cardboard step that would be ideal.  This way you can get a true representation of any potential metal in the product and not in your secondary / tertiary packaging.

[Charles.C]

Hi Karrie,

 

As I understand, the kick-outs are invariably(?)  false positives with respect to the food.

 

(1) What size of (Ferrous, non-Ferrous, SS) test pieces are used ? (curious as to degree of sensitivity setting)

 

(2) Please clarify the "carton" which passes through the MD. Is this a retail box, eg 250g, or a master/outer carton with many retail boxes inside, eg 10kg. Or ?

 

(3) What % level of "cartons" are being kicked out daily ? eg 1%, 10%,  more than 10% ?

 

(4) I see you also re-scan the "carton" of kicked out items. What level % register (ie confirm initial result) as positive by the MD?

 

(5) Do any "cartons" give positive result before use but  no kick-out with product inside ? (relates to MD consistency/sensitivity)

 

(My experience is with frozen product sealed into  plastic bags which are MD scanned then packed into retail cardboard boxes and the latter into master cartons. Never encountered yr specific problem).

.

Edited by Charles.C, 25 May 2021 - 04:52 PM.
edited

[Scampi]

You'll probably want a technician to come in and add a program to run the product without the carton.

 

The sensitivity will need to be adjusted based on the individual packages (assuming your using the same machine to check the kickoffs).  Sometimes the actual aperture needs lowered and/or speed of conveyor reduced. Best to check with MD company

 

Then and only then would I change the process to what you had proposed.....the way you've written it seems absolutely fine to me

[dgt39]

You need to get the cardboard cartons back to the board manufacturer. They will be able to analyse the metal and see if it came from their process. The board mills we have dealt with welcome this feedback.

[liberator]

We have/had the same issue with our cartons and as Ryan noted, cartons contain a lot of recycled content ~50%+, and from that comes the metal contaminants. The only way around this is to have cartons that are made from virgin materials and no recycled content whatsoever. That's fine if you want to add 50%+ to the price of your cartons.

 

Our operators follow the same process that Karrie has posed. A kickoff, product is removed from carton and ran through the MD, if OK its put aside for rework. Empty carton is run through the MD and if kicked off it confirms metal. Sometimes the ops tear down the carton and keep putting it through the MD until they can narrow down to the exact piece of carton that has the metal.

 

We've pulled cartons down and found small pieces of aluminium foil, small fine wire and other pieces of metal. These cannot be eliminated from your carton unless you switch to virgin materials used to make the cartons. We can go months without any rejects and then can have weeks of rejects. It all comes down to the quality of the recycled material the carton manufacturer gets to make the cartons.

 

We used to raise NC's against the vendor for metal in the carton but received the same responses, part of the process, cannot be eliminated due to recycled content and if you don't want cartons using recycled just use virgin materials in the cartons then $$$$. I've visited a material recovery facility and see the junk that's mixed in with the cardboard. Household Recycling bins have, plastic, cardboard, glass and aluminium. They cannot completely separate out all the mixed materials and have a clean recycle stream, hence contamination. 

 

Nowadays the ops still follow the process to confirm product is not contaminated, just the carton and note it on the log sheets. No full investigations, unless the product shows a positive rejection.

[Charles.C]

We have/had the same issue with our cartons and as Ryan noted, cartons contain a lot of recycled content ~50%+, and from that comes the metal contaminants. The only way around this is to have cartons that are made from virgin materials and no recycled content whatsoever. That's fine if you want to add 50%+ to the price of your cartons.

 

Our operators follow the same process that Karrie has posed. A kickoff, product is removed from carton and ran through the MD, if OK its put aside for rework. Empty carton is run through the MD and if kicked off it confirms metal. Sometimes the ops tear down the carton and keep putting it through the MD until they can narrow down to the exact piece of carton that has the metal.

 

We've pulled cartons down and found small pieces of aluminium foil, small fine wire and other pieces of metal. These cannot be eliminated from your carton unless you switch to virgin materials used to make the cartons. We can go months without any rejects and then can have weeks of rejects. It all comes down to the quality of the recycled material the carton manufacturer gets to make the cartons.

 

We used to raise NC's against the vendor for metal in the carton but received the same responses, part of the process, cannot be eliminated due to recycled content and if you don't want cartons using recycled just use virgin materials in the cartons then $$$$. I've visited a material recovery facility and see the junk that's mixed in with the cardboard. Household Recycling bins have, plastic, cardboard, glass and aluminium. They cannot completely separate out all the mixed materials and have a clean recycle stream, hence contamination. 

 

Nowadays the ops still follow the process to confirm product is not contaminated, just the carton and note it on the log sheets. No full investigations, unless the product shows a positive rejection.

 

Hi Liberator,

 

Thks yr input.

 

Not exactly a plaudit with respect to the "carton" manufacturing business. And supplier approval ?

 

Is yr product (??) in direct contact with carton ?

 

I would initially ask you questions (1,2,4,5)  as my post 11. Still waiting for the OP's responses.

 

What did yr MD supplier suggest, eg see Post 12.  Pay 50% more ? (may also relate to Qu 2.3/Post 11)(eg labour costs vs 50%)

[liberator]

Hi Charles,

yes, not a good look, but this is the same across all carton/paperboard manufacturers, all of them are using recycled content, (cost and sustainability) which can get as high at 60%. Cartons do not have direct product contact. The inner layer of the cartons (the corrugated section) is made from the recycled papers. The inner and outer layers are made from a more premium paper, the outside - the artwork face, is premium glossy paper and fully virgin.

 

The inside that has indirect contact (product is in a polymer bag) is also a virgin material. So, the recycled cardboard is sandwiched between two "good" layers and very low to no risk of penetration. All the board manufacturers will use recycled content in cartons unless premium or virgin materials are required and that costs. It would not matter which board manufacturer we went to; we would still see the same issues due to recycled content. The recycling process can pull out metals with magnets but non-ferrous will still get through. They cannot filter through screens easily either as this could break up the cellulose fibres.

 

With a much larger focus on sustainability and recycling being driven by the consumer, along with a drive to reduce manufacturing costs the amount of recycling content in packaging materials is forever increasing.

 

We are seeing a strong drive, most notably in the plastics packaging now. We are seeing a higher demand for recycled plastics and it is something the company is driving to meet our sustainability requirements. Unlike board, recycled plastics cost more than virgin materials so there is an added cost of including recycled plastics in our packaging. But plastics can be better refined and cleaned up before being used for direct food contact.

 

It is a fine balance to be sustainable and reduce costs at the same time.

 

Re your questions for our site,

 

(1) What size of (Ferrous, non-Ferrous, SS) test pieces are used ? (curious as to degree of sensitivity setting)

 

Our detection limits are 4.5mm 316 Stainless Steel (SS), 3.0mm Non-Ferrous (Non-Fe), 2.0mm Ferrous (Fe). Is possible we could reduce the detector aperture to try and not capture the carton but the risk?

 

(2) Please clarify the "carton" which passes through the MD. Is this a retail box, eg 250g, or a master/outer carton with many retail boxes inside, eg 10kg. Or ?

 

These cartons are our “inners” 2kg product is packed (hot filled) into a plastic pouch and then into the inner which helps product retain shape – this is what passes over the MD. The inners are then packed into an outer, 6x2kg.So we cannot fill the pouch, then detect, then carton, very fluid product and needs the carton at filling,

 

(4) I see you also re-scan the "carton" of kicked out items. What level % register (ie confirm initial result) as positive by the MD?

 

Every metal rejection we have had on the line has been the result of the carton and confirmed following checks, nothing found in product.

 

(5) Do any "cartons" give positive result before use but  no kick-out with product inside ? (relates to MD consistency/sensitivity)

 

We do not MD the cartons prior to filling due to the process, cartons are formed and filled in one operation. The level of rejects due to metal are very very small so we manage the minor inconvenience. I have not been made aware of any issues of late – but they still could be occurring, they are just not communicating this to me.

[Charles.C]

 

Hi Charles,

 

yes, not a good look, but this is the same across all carton/paperboard manufacturers, all of them are using recycled content, (cost and sustainability) which can get as high at 60%. Cartons do not have direct product contact. The inner layer of the cartons (the corrugated section) is made from the recycled papers. The inner and outer layers are made from a more premium paper, the outside - the artwork face, is premium glossy paper and fully virgin.

 

The inside that has indirect contact (product is in a polymer bag) is also a virgin material. So, the recycled cardboard is sandwiched between two "good" layers and very low to no risk of penetration. All the board manufacturers will use recycled content in cartons unless premium or virgin materials are required and that costs. It would not matter which board manufacturer we went to; we would still see the same issues due to recycled content. The recycling process can pull out metals with magnets but non-ferrous will still get through. They cannot filter through screens easily either as this could break up the cellulose fibres.

 

With a much larger focus on sustainability and recycling being driven by the consumer, along with a drive to reduce manufacturing costs the amount of recycling content in packaging materials is forever increasing.

 

We are seeing a strong drive, most notably in the plastics packaging now. We are seeing a higher demand for recycled plastics and it is something the company is driving to meet our sustainability requirements. Unlike board, recycled plastics cost more than virgin materials so there is an added cost of including recycled plastics in our packaging. But plastics can be better refined and cleaned up before being used for direct food contact.

 

It is a fine balance to be sustainable and reduce costs at the same time.

 

Re your questions for our site,

 

(1) What size of (Ferrous, non-Ferrous, SS) test pieces are used ? (curious as to degree of sensitivity setting)

 

Our detection limits are 4.5mm 316 Stainless Steel (SS), 3.0mm Non-Ferrous (Non-Fe), 2.0mm Ferrous (Fe). Is possible we could reduce the detector aperture to try and not capture the carton but the risk?

 

(2) Please clarify the "carton" which passes through the MD. Is this a retail box, eg 250g, or a master/outer carton with many retail boxes inside, eg 10kg. Or ?

 

These cartons are our “inners” 2kg product is packed (hot filled) into a plastic pouch and then into the inner which helps product retain shape – this is what passes over the MD. The inners are then packed into an outer, 6x2kg.So we cannot fill the pouch, then detect, then carton, very fluid product and needs the carton at filling,

 

(4) I see you also re-scan the "carton" of kicked out items. What level % register (ie confirm initial result) as positive by the MD?

 

Every metal rejection we have had on the line has been the result of the carton and confirmed following checks, nothing found in product.

 

(5) Do any "cartons" give positive result before use but  no kick-out with product inside ? (relates to MD consistency/sensitivity)

 

We do not MD the cartons prior to filling due to the process, cartons are formed and filled in one operation. The level of rejects due to metal are very very small so we manage the minor inconvenience. I have not been made aware of any issues of late – but they still could be occurring, they are just not communicating this to me.

 

 

Hi Liberator,

 

Many thanks yr detailed reply.

 

I guess you have a somewhat special case inasmuch as cannot scan plastic bag. Unlucky.

 

IMEX some customers require evidence that plastic is not recycled.  End of story.

 

Indirect contact afaik massively relaxes the FS requirements. Not 100% sure as to the OP's actual situation.

 

I'm a little confused as to why yr (I assume genuine) reject rate is very low if the recycling metal problem is actually significant from a contamination POV. Your  MD sensitivity is only slightly more generous than usual  IMO. Does the typical carton sandwich design make metal detection anyway more difficult in practice ?

Yr comment about supplier's raw material variations/yr reject level variability suggests that carton suppliers have poor or no control of their raw material.

 

Not my area of expertise but presumably the FS contaminant specification for cartons relates to Food Grade/direct/indirect contact ? How does this compare to the likelihood of MD detection (if known) ?

 

Hopefully the level of rejects is similarly low for the OP. Especially if "carton" is direct contact..

 

Thanks again.

 

PS - My inner boxes (up to 500g) have no corrugated section. Cardboard no detailed chemical spec.(no direct contact). OP again no idea.

[Scampi]

Let's also not confuse cardboard/cardstock with corrugated cardboard

 

Retail packaging is almost exclusively cardboard, without a corrugated layer (think cracker boxes)

 

Shipping cartons are corrugated cardboard, made from different sourced material and, at least here, made from 100% recycled materials

 

Cracker boxes and the like are all stamped (in Canada) made from recycled materials) these are NON product contacts containers, I've never actually looked at direct contact boxes to see what the difference is. if any

 

BTW, we DO NOT want anyone to cut down yet more trees to make boxes, that's ridiculous    We need our (the whole world I mean) recycling stream to be cleaner

 

Also note:  our customers are moving away from plastic packaging at a rapid pace, so while yes, our plastics are virgin material, the alternative will not be

[Ryan M.]

FYI...there is now push in the USA from politicians to mandate a percentage of recycled resin in plastic manufacturing including food and beverage.  Watch out because this is in conflict with FDA requirements of "virgin" resin for food contact materials.

 

It will be interesting to see how this plays out over the long run.  My hope is the FDA requirements win out because recycled resin would open a can of worms in terms of food safety risk in direct contact packaging materials. 

 

Oy vey...I guess one way to save the planet is to kill off some people?

[Scampi]

Here's an interesting read----it would seem the FDA may not have a leg to stand on (based on my quick perusal of the paper) as there are a lot of holes in the approach as it stands and food contact "approved" packaging may not be what we all thought it was

 

 

https://www.ncbi.nlm...les/PMC7053054/