Are "acid-free" backing boards truly acid-free? Part 2

[BCW Supplies]

Once again we would like to thank mschmidt for his thought provoking study which you can find here; http://boards.collectors-society.com/ubbthreads.php?ubb=showflat&Number=4534727&fpart=1

 

Based on Mike's data and conclusions we decided to have the products that are represented in his experiment tested at an independent laboratory. Mike had concluded "that [sBS] boards will actively contribute, on a molecular level, to the decay of your comic book from the moment they're placed inside the bag" based on the results of his testing using a pHydrion pH pencil. Mike stated that the calcium carbonate coating of the SBS board was absorbing only the acid from the board itself and that over time the SBS board would become completely acidic. However, we at BCW stated that we believe Mike's conclusion is in error. We suggested that the fact that the coated side of the BCW board became more acidic with use over a two year period indicates that some of the residual acid from the comic book is being absorbed by the calcium carbonate coating on the board. Further, we suggested that the fact that the uncoated side of the BCW board did not change in pH over a period of two years of use meant that acid was not migrating from the SBS board to the comic book. As you will see, the data below supports our position.

 

We submitted samples to Chicago Paper Testing Laboratories, Inc. on 20 July 2011 and I was present in the laboratory on Tuesday 2 August 2011 for some of the testing. We had the lab perform TAPPI T-435 (pH) on a comic book (Marvel Comics Presents #61), E. Gerber Half-Back, BCW Comic Backing Board, Bill Cole Thin X-Tender, Miller Hobby Comic Backing Board, and an Ultra Pro Comic Backing Board. We also had them perform ASTM D-4988 (Alkaline Reserve) on an E. Gerber Half-Back, BCW Comic Backing Board, Bill Cole Thin X-Tender, Miller Hobby Comic Backing Board, and an Ultra Pro Comic Backing Board. In addition, we had them perform TAPPI T-401 (Fiber Analysis) on an E. Gerber Half-Back, BCW Comic Backing Board, and Bill Cole Thin X-Tender. And finally, we had the laboratory perform ASTM D-776 (Artificial Ageing) on a comic book (Marvel Comics Presents #61) and backing boards from both E. Gerber and BCW for 10 and 20 years.

 

Let's look at the results of TAPPI T-435 (pH) from the samples submitted;

 

Comic Book pH 5.4

E. Gerber Half-Back pH 8.52

BCW Comic Backing Board pH 8.47

Bill Cole Thin X-Tender pH 8.57

Miller Hobby Comic Backing Board pH 9.36

Ultra Pro Comic Backing Board pH 7.94

 

As you can see, the comic book is acidic as expected. The boards all have relatively the same pH with Miller Hobby at the top of the scale and Ultra Pro at the bottom.

 

Now let's look at the results of ASTM D-4988 (Alkaline Reserve);

 

E. Gerber Half-Back 7.69%

BCW Comic Backing Board 3.64%

Bill Cole Thin X-Tender 6.57%

Miller Hobby Comic Backing Board 4.45%

Ultra Pro Comic Backing Board 4.72%

 

From the data we can see that the E. Gerber Half-Backs and Bill Cole Thin X-Tenders actually have more than twice the Alkaline Reserve as advertised. The SBS boards all have about the same Alkaline Reserve with Ultra Pro at the top of the scale and BCW Supplies on the bottom.

 

Let's take a look at the results of ASTM D-776 (Artificial Ageing);

 

Aged 10 years

 

Comic Book pH 5.45

E Gerber Half-Back pH 8.07

 

Comic Book pH 5.44

BCW Comic Backing Board pH 7.62

 

Aged 20 years

 

Comic Book pH 5.27

E Gerber Half-Back pH 8.07

 

Comic Book pH 5.26

BCW Comic Backing Board pH 7.34

 

From the data we can see that the E. Gerber Half-Back's pH level does not change over a 10 year period which suggests that the E. Gerber Half-Back does not absorb any residual acid from the comic book. This is the conclusion that we drew from Mike's data originally, and it is also the position of E. Gerber that their product does not absorb any residual acid from a comic book. It only acts as a stiffener. As the BCW Comic Backing Board absorbs some of the phenolic acid that migrates from the pages of a comic book the pH level of the board naturally decreases as the buffer reaches the saturation point (which is why we recommend that you change your boards every 3 to 5 years). Phenolic acid is released as lignin breaks down in the pages of a comic book and exhibits itself as the yellow residue that you see on a comic backing board after several years of use.

 

Please note that ASTM D-776 does not allow for the micro-environment that is created when sealing a comic book in a bag with a backing board. Therefore, we were not able to confirm our hypothesis that a comic book will deteriorate more quickly if the phenolic acid is not absorbed.

 

Now let's look at the results of TAPPI T-401 (Fiber Analysis);

 

E. Gerber Half-Back

 

Bleached Kraft Softwood 12.1%

Bleached Kraft Hardwood 55.9%

Groundwood 32%

Unbleached Kraft Hardwood 0%

 

BCW Comic Backing Board

 

Bleached Kraft Softwood 9.6%

Bleached Kraft Hardwood 90.4%

Groundwood 0%

Unbleached Kraft Hardwood Trace

 

Bill Cole Thin X-Tender

 

Bleached Kraft Softwood 17.2%

Bleached Kraft Hardwood 61.1%

Groundwood 21.7%

Unbleached Kraft Hardwood 0%

 

SBS is stabilized paper board, meaning that it is made using a chemical process (also known as bleaching) where the lignin is removed from the pulp. This process does leave some residual acid in the SBS from bleaching and a buffer of calcium carbonate is added to stabilize the sheet. The paper mills have a target pH level of between 6.5 and 7.2 which means that the lower the buffer the less residual acid that remains in the paper. Bill Cole Thin X-Tenders and E. Gerber Half-Backs and Full-Backs are made of VAT board which has a coating on both sides that is bleached, but the core of the VAT board is made using mechanical pulp and contains lignin. The reason that this is important is that the lignin will eventually break down and the board could become acidic depending on how much calcium carbonate is in the board and how much phenolic acid is released.

 

There is between 32% and 21.7% Groundwood in the E. Gerber Half-Backs and Bill Cole Thin X-Tenders respectively. Because Groundwood contains lignin, the VAT board requires a greater Alkaline Reserve to remain stable. Note that the Alkaline Reserve of the E. Gerber Half-Back is greater than that of the Bill Cole Thin X-Tenders. This is because there is more Groundwood in the E. Gerber Half-Back and therefore requires more calcium carbonate to achieve roughly the same pH level as the Bill Cole Thin X-Tender.

 

Attached are copies of the documentation that we received from the laboratory for your reference.

114681.pdf

114682.pdf

[BCW Supplies]

We at BCW would like to give each of you the opportunity to try our product for yourself. So, for the next week we will send a free pack of BCW Comic Backing Boards to anyone who sends us a PM here on the forum with your name, address, and phone number. Also, please indicate whether you would like to receive Current, Silver Age, or Golden Age BCW Comic Backing Boards. Please note that this offer is only valid for residents of the United States and for members whose forum account was registered prior to this post.

[namisgr]

From the data we can see that the E. Gerber Half-Back's pH level does not change over a 10 year period which suggests that the E. Gerber Half-Back does not absorb any residual acid from the comic book.

 

You've blown the interpretation of the data once again.

 

As any chemist or biologist worth their salt can tell you, a relatively strong buffer like an excellent backing board with a high buffering capacity/alkaline reserve will not change pH as appreciably as a less effective backing board with a lesser buffering capacity. Your board is dropping in pH in the 'aging' test to a much greater degree than the Gerber half-back because it has a smaller buffering capacity (i.e., is able to absorb less acid given off by a comic book).

 

Finally, what exactly is the point of running controlled comparative tests of comic book archival products when you are incapable of interpreting the results properly?

[DeadOne]

free

[jeBailey]

The boards should be pH neutral and is as follows.

 

Chemical solution that is neither acidic nor alkaline (has a pH of 7.0), such as pure water.

 

As you can see from the results the the half backs are as close to neutral as they can be.

 

John B.

[Designer Toast]

Thanks for the info. My only question is why would an independent lab allow you to be present during testing? I haven't read the report yet, and I found that odd.

 

Thanks for posting and welcome to the boards.

[sckao]

The boards should be pH neutral and is as follows.

 

Chemical solution that is neither acidic nor alkaline (has a pH of 7.0), such as pure water.

 

As you can see from the results the the half backs are as close to neutral as they can be.

 

John B.

 

I fail to see how you arrived at this conclusion.

 

 

[bababooey]

From the data we can see that the E. Gerber Half-Back's pH level does not change over a 10 year period which suggests that the E. Gerber Half-Back does not absorb any residual acid from the comic book.

 

You've blown the interpretation of the data once again.

 

As any chemist or biologist worth their salt can tell you, a relatively strong buffer like an excellent backing board with a high buffering capacity/alkaline reserve will not change pH as appreciably as a less effective backing board with a lesser buffering capacity. Your board is dropping in pH in the 'aging' test to a much greater degree than the Gerber half-back because it has a smaller buffering capacity (i.e., is able to absorb less acid given off by a comic book).

 

Finally, what exactly is the point of running controlled comparative tests of comic book archival products when you are incapable of interpreting the results properly?

Namisgr, so the PH level of the E. Gerber doesn't change which is a "good" thing not a sign that it is lacking the ability to absorb - is that your point?

The numbers certainly seem far different from the first mschmidt experiment.

bababooey - not worth salt nor pepper

[electricprune]

How did the pH of the book actually go up slightly in the 10 year test? I can see staying the same or going down slightly. Is alkaline residue from the boards remaining on the books giving it a false reading?

[mschmidt]

Let's take a look at the results of ASTM D-776 (Artificial Ageing);

 

Aged 10 years

 

Comic Book pH 5.45

E Gerber Half-Back pH 8.07

 

Comic Book pH 5.44

BCW Comic Backing Board pH 7.62

 

Aged 20 years

 

Comic Book pH 5.27

E Gerber Half-Back pH 8.07

 

Comic Book pH 5.26

BCW Comic Backing Board pH 7.34

 

From the data we can see that the E. Gerber Half-Back's pH level does not change over a 10 year period which suggests that the E. Gerber Half-Back does not absorb any residual acid from the comic book. This is the conclusion that we drew from Mike's data originally, and it is also the position of E. Gerber that their product does not absorb any residual acid from a comic book. It only acts as a stiffener.

No.

 

As Bob says, you're once again misinterpreting the data you're getting back.

 

The fact that the pH value of the Gerber Half-Back doesn't change noticeably over a 10-20 period is a very good thing - this is solid proof that the alkaline buffer throughout the board is keeping the board stabilized & non-acidic. This is how you want a backing board to behave.

 

Whether Gerber markets these boards as "acid-absorbing" or not is utterly irrelevant - the board has an alkaline buffer throughout, which means that it will absorb residual acid from the comic book as the book ages; whether you like it or not, that's a scientific fact.

 

 

As the BCW Comic Backing Board absorbs some of the phenolic acid that migrates from the pages of a comic book the pH level of the board naturally decreases as the buffer reaches the saturation point (which is why we recommend that you change your boards every 3 to 5 years). Phenolic acid is released as lignin breaks down in the pages of a comic book and exhibits itself as the yellow residue that you see on a comic backing board after several years of use.

 

Please note that ASTM D-776 does not allow for the micro-environment that is created when sealing a comic book in a bag with a backing board. Therefore, we were not able to confirm our hypothesis that a comic book will deteriorate more quickly if the phenolic acid is not absorbed.

And, no.

 

The pH value of the BCW backing board is dropping because the thin alkaline spray-coating you guys put on one side of the board is being saturated by the acidic core of the board itself.

[RockMyAmadeus]

I love vinegar.

[lizards2]

I love vinegar.

essential for making pickles

[RockMyAmadeus]

I love vinegar.

essential for making pickles

 

Mmmm....pickles.....

 

 

[mschmidt]

Namisgr, so the PH level of the E. Gerber doesn't change which is a "good" thing not a sign that it is lacking the ability to absorb - is that your point?

The numbers certainly seem far different from the first mschmidt experiment.

bababooey - not worth salt nor pepper

 

The whole point of an archival-safe backing board is that the pH value remains stable - that the board doesn't become acidic over time.

 

The BCW rep's claim of "the pH value [of the Gerber board] isn't changing, so the board doesn't absorb any residual acid" which he has put forth a couple of times is pure speculation on his side - because it's a scientific fact that an alkaline reserve will absorb residual acid up until said reserve has been saturated whether you advertise this as a selling point or not.

 

And, as Bob says, the larger the alkaline reserve, the more residual acid it can absorb before the board itself starts turning acidic.

 

The big difference between the ASTM D-776 test presented above and my (less scientific) test is that ASTM D-776 ("Standard Test Method for Determination of Dry Heat on Properties of Paper and Board") measures what happens when the backing board is exposed to dry heat inside an oven (to simulate accelerated aging) - it doesn't actually measure what happens to the board when it's been in a semi-sealed environment inside a comic book bag with a comic book for a while.

 

From both tests, it's obvious that the BCW board is "acid-free at time of manufacture" due to the alkaline spray-coating they use on one side of the board. The BCW board, however, has the smallest alkaline reserve of any of the boards tested, which is why you see the pH value dropping over time even without the introduction of any other element to the environment.

 

What my test showed was once a comic book was introduced into the mix, the pH value of the BCW board dropped rapidly (whereas the true acid-free boards basically stayed the same) - which, again, is congruent with the results in the test above. The only logical explanation for this is that the small alkaline reserve of the BCW board is no match for the acidic core of the BCW board itself & the residual acids released by the comic book - and when this reserve becomes fully saturated, the board becomes acidic.

[marvelcollector]

It's odd BCW commented that E Gerber and Bill Cole have "almost double the alkaline reserve as advertised."

 

Because that's a good thing in their favor...

[RockMyAmadeus]

This whole thread is SUPER nerdy.

 

Almost Big Bang nerdy, but not quite.

 

Nerds arguing about residual acidity and alkaline buffers...

 

[Transplant]

The only thing better would be a nerd pointing out nerdy the nerds are.

[KolmarAvenue]

Once again we would like to thank mschmidt for his thought provoking study which you can find here; http://boards.collectors-society.com/ubbthreads.php?ubb=showflat&Number=4534727&fpart=1

 

Based on Mike's data and conclusions we decided to have the products that are represented in his experiment tested at an independent laboratory. Mike had concluded...

 

fyi, mschmidt prefers to be called "michael", "miguel" or "el jefe"; but never mike.

[BCW Supplies]

..what exactly is the point of running controlled comparative tests of comic book archival products when you are incapable of interpreting the results properly?

This is an open discussion. Please feel free to give us your interpretation of the results.

 

The whole point of an archival-safe backing board is that the pH value remains stable - that the board doesn't become acidic over time.

I agree with this statement in part. But, there is acid in the VAT board. There is residual acid from bleaching in the white outer layers of the board. Also, the core of the board is made from mechanical pulp and it contains lignin. Lignin breaks down over time and releases phenolic acid. Whether or not the VAT board will eventually become acidic or not depends on whether there is enough calcium carbonate to absorb the phenolic acid. This is why the Alkaline Reserve is such a large percentage.

 

The BCW rep's claim of "the pH value [of the Gerber board] isn't changing, so the board doesn't absorb any residual acid" which he has put forth a couple of times is pure speculation on his side - because it's a scientific fact that an alkaline reserve will absorb residual acid up until said reserve has been saturated whether you advertise this as a selling point or not.

It seems that one thing everyone can agree on is that calcium carbonate absorbs acid. The reason that I am saying that the VAT board doesn't absorb any residual acid is that the acceleration test shows that there is no measurable change in the pH after 20 years. This is a good thing, but the core of the board still contains Groundwood. Grounwood contains lignin. When lignin breaks down it releases phenolic acid. So, neither SBS or VAT board is truly acid free. This also means that VAT board is not archival because it hasn't been stabilized (i.e. the lignin is not removed).

 

[quote=Guidelines for Information

About Preservation Products]archival quality. A nontechnical term that suggests that a material or product is permanent, durable, or chemically stable, and that it can therefore be used safely for preservation purposes. The phrase is not quantifiable; at this writing, no standards exist that describe how long “archival” or “archivally sound” material will last.

SBS has no lignin and therefore more closely resembles the definition of "acid free" than VAT board does.

 

[quote=Guidelines for Information

About Preservation Products]acid free. In chemistry, materials that have a pH of 7.0 or higher. Sometimes used incorrectly as a synonym for alkaline. Acid-free materials may be produced from virtually any cellulose fiber source (cotton and wood, among others), if measures are taken during manufacture to eliminate active acid from the pulp. However free of acid a paper or board may be immediately after manufacture, over time the presence of residual chlorine from bleaching, aluminum sulfate from sizing, or pollutants in the atmosphere may lead to the formation of acid unless an alkaline substance is added to the paper or board.

 

It's odd BCW commented that E Gerber and Bill Cole have "almost double the alkaline reserve as advertised."

 

Because that's a good thing in their favor...

I promised to post the results no matter what they were, and that's what I did. However, a high Alkaline Reserve is not really a good thing. As I stated in the original post of this thread, paper mills have a target pH in the range of 6.5 to 7.2 pH. The more acid that's in the paper the greater the Alkaline Reserve that is required to render the paper neutral.

[Designer Toast]