Bonding material that holds DVD Blanks together (DVD Disc Spliting)

[pjay]

I can't believe this hasn't been talked about alot on this board. Starting back in 2005 when I started burning DVD-R's I was using Fujifilm DVD-R 8x (ProdiscF01) and a few months after I burned it, the disc started to split apart. This happen on about 15 other DVD-R from the same spindle. Nothing was on them that couldn't be replaced, but I stopped buying Fujifilm disc after that. This has also happen on a few Memorex, TDK DVD-R, Philips DVD+R DL's I had but not to the extent that the Fujifilm blanks split. My question is what kind of bonding material (glue) do companies use on there DVD blank media, and how does it vary from company to company (the real makers of the disc, not the brand name)

[admin]

It's mentioned here and there. But you're right, there's not a dedicated article.
I'll add that to the to-do list: http://www.digitalFAQ.com/forum/show...-web-2468.html

Most of that data is located in white papers and patent documents.
For example, http://www.sinoimpex.com/araldite/DV...gCoreRange.pdf (also attached to this post)
Or http://www.xenoncorp.com/Literature/PDF/DVD_Bro.pdf (also attached to this post)

The various materials are purchased by manufacturers and then used for their production lines (or their production lines as overseen by third parties).

It always comes back to the quality of materials. Cheap discs are well known for flaws like this. However, better media will use better materials. That is not to say that good discs will sometimes not be hampered by bad product. That's where real "bad batches" (tens of thousands of discs) come from. Even Taiyo Yuden and Mitsubishi have had to deal with this in the past. I'm not surprised that Prodisc had an issue, even with them being one of the better manufacturers.

Remember that end-user storage and handling can play into this, too. If you have a lot of issues, I'd question your humidity/location, as well as the cases used for the discs. Pressure from crappy cases are known to both crack media and stress the bonding enough to split discs. That includes "name brand" cases like AlphaPak, too!

[pjay]

Well usually I store them back in the cake boxes they came in. yes I know I probably shouldn't store them that way but it works great for me, no cracks or degrading on the inner ring at all. I also need to do it because space is a big issue for me. I understand about what you mean about the stress put on the disc from the inside ring out. However my spliting problem starts from the outside in. So I know that the storage wasn't the problem. I live in Florida so maybe that's it. It's not that big of a problem, I just mentioned it as something to look out for.

[admin]

Pressure on the hub can still cause the outer edges to buckle from pressure. In fact, that's more likely that the inner hub splitting, as the exterior portion of the disc is the weakest (as per basic physics).

It does not sound like storage is the likely issue, although it's still potential. Over the life of a disc, it can be hard to recall all cases, handling and even in-player use that may have led to its demise.

Florida does have temperatures and humidity that could affect optical media, depending on exactly where and how it has been stored for its entire lifespan.

[lordsmurf]

Here's another white paper on the topic...
This one specifically address the issue of longevity, with test results shown: