Can DVDs have laser rot?
Laserdiscs are subject to what’s commonly called laser rot: the deterioration of the aluminum layer due to oxidation. This was mostly due to the use of insufficiently pure aluminum during replication. The large size of laserdiscs makes them flexible, so that movement along the bond between sides can break the seal. Like laserdiscs, DVDs are made of two platters glued together, but DVDs are more rigid and use newer adhesives. Also, DVDs are molded from polycarbonate, which absorbs about ten times less moisture than the PMMA used for laserdiscs. It’s too early to know for sure, but DVDs will probably have few laser rot problems. There have been reports of a few discs going bad, possibly due to poor adhesive, chemical reactions, or oxidation of the aluminum layer. See http://www.mindspring.com/~yerington/.
Laserdiscs are subject to what’s commonly called laser rot: the deterioration of the aluminum layer due to oxidation. The large size of laserdiscs makes them flexible, so that movement along the bond between sides can break the seal. Like laserdiscs, DVDs are made of two platters glued together, but DVDs are more rigid and use newer adhesives. Also, DVDs are molded from polycarbonate, which absorbs about ten times less moisture than the PMMA used for laserdiscs. It’s too early to know for sure, but DVD’s will probably have few or no laser rot problems.
Laser rot is a colloquial term referring to various defects or deteriorations of optical discs. There are rare cases of problems with DVDs, but these have largely disappeared as manufacturing processes have improved. The result of deterioration is that a disc which played perfectly when it was new develops problems later, such as skipping, freezing, or picture breakup. If a disc seems to go bad, make sure it’s not dirty, scratched, or warped (see 1.39). Try cleaning it and try playing it in other players. If the disc consistently has problems, it may have deteriorated. If so, there’s nothing you can do to fix it, so you should try to get a replacement from the supplier. Before DVDs there were laserdiscs (see 2.6), which were occasionally subject to what was commonly called laser rot: the deterioration of the aluminum layer due to oxidation or other chemical change. This usually results from the use of insufficiently pure metal for the reflective coating created during replication, but
Laserdiscs were subject to what’s commonly called laser rot: the deterioration of the aluminum layer due to oxidation or other chemical change. This often results from the use of insufficiently pure metal for the reflective coating created during replication, but can be exacerbated by mechanical shear stress due to bending, warping or thermal cycles (the large size of laserdiscs makes them flexible, so that movement along the bond between layers can break the seal — this is called delamination). Deterioration of the data layer can be caused by chemical contaminants or gasses in the glue, or by moisture that penetrates the plastic substrate. Like laserdiscs, DVDs are made of two platters glued together, but DVDs are more rigid and use newer adhesives. DVDs are molded from polycarbonate, which absorbs about ten times less moisture than the slightly hygroscopic acrylic (PMMA) used for laserdiscs. DVDs can have delamination problems, partly because some cases and some players hold too tig
Laserdiscs are subject to what’s commonly called laser rot: the deterioration of the aluminum layer due to oxidation or other chemical change. This often results from the use of insufficiently pure aluminum during replication, but can be exacerbated by mechanical shear stress due to bending, warping or thermal cycles (the large size of laserdiscs makes them flexible, so that movement along the bond between layers can break the seal). Deterioration of the data layer can be caused by chemical contaminants or gasses in the glue, or by moisture that penetrates the acrylic substrates. Like laserdiscs, DVDs are made of two platters glued together, but DVDs are more rigid and use newer adhesives. DVDs are molded from polycarbonate, which absorbs about ten times less moisture than the slightly hygroscopic acrylic (PMMA) used for laserdiscs. It’s too early to know for sure, but DVDs will probably have few laser rot problems. There have been reports of a few discs going bad, possibly due to poor
