Why are there Circles on Blu-ray Discs?!

[andyn1080]

So recently I’ve noticed that the back of my Blu-ray Discs have these “circles” on them, they look like how a fingerprint would look if someone touched the back of the disc, they wipe off easy like a fingerprint would but they are circles and like that shape of the holder where the discs sit. What are these from? Anyone else experience this? I’ve looked all over online and can’t find anyone even talking about this. When I get home I’ll take a picture of them. Even happens on someone my video game Discs aswell. All my Blu-Rays/Discs are stored in a cool temperature room.

[andyn1080]

Sorry there’s a few typos but the edit option won’t work for some reason. I’m also using my iPhone to do this so that might be why.

*even happens on some of my video game discs aswell

[Zarak]

I assume that they're from these machines:

[Vilya]

While I have not seen the images of your affected discs, sometimes residue from the plastic disc cases themselves can transfer to the disc surface. This is a result of poor quality control in the injection molding of the plastic cases. In my personal experience, the white translucent cases do this more often than the blue or black cases.

The good news is that this residue will come off with a simple cleaning, but it may also return if you continue to use the original case. If the residue returns, or if you just don't want to potentially deal with this issue again, you can buy high quality replacement cases such as those made by Viva Elite. You can buy them at multiple online sites, including ebay.

[andyn1080]

Originally Posted by Zarak

I assume that they're from these machines:

Yes that’s exactly how big they are but here’s the head scratcher....when I buy new movies/games and look at the back of the disc they aren’t there/present, but months/years later there they are....how does that happen??

[HD Goofnut]

Originally Posted by andyn1080

Yes that’s exactly how big they are but here’s the head scratcher....when I buy new movies/games and look at the back of the disc they aren’t there/present, but months/years later there they are....how does that happen??

My first guess would be added moisture in your home.

[andyn1080]

Originally Posted by Vilya

While I have not seen the images of your affected discs, sometimes residue from the plastic disc cases themselves can transfer to the disc surface. This is a result of poor quality control in the injection molding of the plastic cases. In my personal experience, the white translucent cases do this more often than the blue or black cases.

The good news is that this residue will come off with a simple cleaning, but it may also return if you continue to use the original case. If the residue returns, or if you just don't want to potentially deal with this issue again, you can buy high quality replacement cases such as those made by Viva Elite. You can buy them at multiple online sites, including ebay.

Ah ok this comment alongside the top image is starting to add up now. So basically the circles are from the manufactureing process, it’s just so odd that when I buy them new there aren’t any but months/years later they are present on the back of the disc. I guess that’s what’s throwing me off. But yeah they clean off and don’t seem to affect the disc in any way. At first I though disc rot and got all freaked out. Lol I have crds from the late 90s early 2000s that still look and work flawlessly. I may have a few GameCube games with disc rot due to the person I bought them from not taking care of them and probably leaving them in extreme weather (ugh some people). Also always though disc rot could transfer to other discs....god I hope that’s not a thing lol

[Zarak]

Maybe the machines leave behind a faint residue that collects dust after a while? I've noticed the rings on some of my discs before too, and they rub off with a soft cloth.

[andyn1080]

Yeah true, I was just super worried it might be some kinda rot or deteriorating happening. Being a physical media collector things like this get me all worried I’ll lose parts of my collection. Only thing digital has on us collectors lol

[Leeon0]

Originally Posted by Vilya

While I have not seen the images of your affected discs, sometimes residue from the plastic disc cases themselves can transfer to the disc surface. This is a result of poor quality control in the injection molding of the plastic cases. In my personal experience, the white translucent cases do this more often than the blue or black cases.

The good news is that this residue will come off with a simple cleaning, but it may also return if you continue to use the original case. If the residue returns, or if you just don't want to potentially deal with this issue again, you can buy high quality replacement cases such as those made by Viva Elite. You can buy them at multiple online sites, including ebay.

Strange that you should say that because to me Viva Elite and "high quality" can no longer appear in the same sentence. The "Elites" are virtually eco thin, they have plenty of residue, and the center hubs are a disaster.

What's more, the appearance of residue can't be correlated with poor quality control. Slip agents are added to the plastic (I assume in the molten state) during the manufacturing process to prevent the plastic sheets from binding. Since the additive is integrated into plastic, the residue appears to perpetually ooze out even after it's cleaned off. The good news is the more you clean it over time the less of it you see reappearing. Denatured alcohol has worked well for me.

[James Luckard]

[andyn1080]

Originally Posted by James Luckard

Hahaha funny part is that this is all that would show up on google when I typed in circles on Blu-ray Discs lol crop circles

[Vilya]

Originally Posted by Leeon0

Strange that you should say that because to me Viva Elite and "high quality" can no longer appear in the same sentence. The "Elites" are virtually eco thin, they have plenty of residue, and the center hubs are a disaster.

What's more, the appearance of residue can't be correlated with poor quality control. Slip agents are added to the plastic (I assume in the molten state) during the manufacturing process to prevent the plastic sheets from binding. Since the additive is integrated into plastic, the residue appears to perpetually ooze out even after it's cleaned off. The good news is the more you clean it over time the less of it you see reappearing. Denatured alcohol has worked well for me.

I mentioned Viva Elite because they were recommended to me and I have not experienced the issues that you apparently have. Other brands of cases are certainly available.

Blu-ray disc cases are made with a plastic called Polypropylene (PP), specifically polypropylene homopolymer. DVD cases are made with Polystyrene (PS) also known as Plastic #6.

https://omnexus.specialchem.com/sele...ene-pp-plastic

Most plastics "outgas" and at different rates under different conditions.

"Most plastics contain volatile organic compounds (VOCs). These are poisonous, carbon-containing chemicals that are volatile enough to evaporate even at room temperature."

"For example, a shower curtain made with PVC can outgas for a month or longer and high temperature and humidity tend to speed up the process."

New shower curtains often reek!

https://www.directplastics.co.uk/abo...hould-you-care

Improper venting during the injection molding of plastics can exacerbate outgassing.

"Proper venting is essential to molding a defect-free part. Without it, air and gas are trapped in the mold, which compress and heat as the cavity fills. Trapped gas is one of the most common causes of part burns, and it can also lead to short shots and voids, blemishes and discernible knit lines that weaken the part.

Moreover, trapped gas can cause residue buildup in vented pins, which then necessitates frequent production interruptions to clean the tool. It can even cause corrosion of the tool steel, thereby increasing tool-maintenance costs."

https://www.ptonline.com/articles/ho...ection-molding

"When a Blu-ray case has been wiped clean inside, snapped shut, and tucked away inside a cabinet, none of those contaminants are present. Yet after several months or so, the residue will reappear inside the case. That's evidence of outgassing."

https://forum.blu-ray.com/showpost.p...2&postcount=22

Slip and other agents added to the process can certainly cause problems, too, if not done correctly. All of these are quality control concerns.

I once worked in a factory that did injection molding and those machines were quite persnickety. Defective parts were common if these machines were not meticulously maintained. I worked in a neighboring department where adhesives were mixed; I made different kinds of glue all day. Nasty job that I was happy to leave after just two years.

[Vilya]

The good news is that I have ALWAYS been able to clean affected discs no matter how long they have been so affected. I had discovered that some of my discs had turned foggy, or milky white, that I had not accessed in many, many years, yet I was able to clean them all and they work fine.

I used 91% isopropyl alcohol to clean them with great results. I have also read that the use of distilled white vinegar also works really well, but I have not personally tried this method.

[Leeon0]

Originally Posted by Vilya

Blu-ray disc cases are made with a plastic called Polypropylene (PP), specifically polypropylene homopolymer. DVD cases are made with Polystyrene (PS) also known as Plastic #6.

Ah, if only BD cases were made out of the same plastic as DVD cases are . . . I would have saved countless hours wiping off all that messy residue inside the Blu-ray cases. Bummer.

[Phillip c. Niethe]

... Aliens....they didn't want to stop with just the crops...just noticed James beat me to the punch line, should have read the comments before I posted. Kudos to the excellent post of the Signs Poster

[Leonidas King]

I've never seen those circles under any BD's.

[Vilya]

The Polypropylene cases are the bigger offenders for outgassing by far. I do not think I have had any cases of noticeable outgassing residue with my Polystyrene dvd cases.

Kinda ironic that the better format gets the lesser quality case.

The clear slim line cases are Polypropylene whereas the solid black ones are Polystyrene and the former can often be found in multiple disc sets of either format.

[andyn1080]

Well this is my luck, i go home and can’t find any disc with it on it because I prob wiped it all off BUT I noticed it’s also on the trays of the cases. It was hard to get a good pic but here’s 2. These circles are usually on the back of the discs aswell. 29994250-C9EE-4E3A-A07C-1E38E33A86C6.jpg

B273977B-BE4C-4867-B589-0BA1B4ABABC5.jpg

[andyn1080]

I went under a red lamp to see if that would be easier to see on camera. Little better lol B161A845-F3F3-4370-80E3-B1103B2D1626.jpg