Today’s question:
“A local printing house demonstrated to us a CDR packaging process that used in plastic shrink wrapping for the CD cases. The finished product looks nice, but the process exposes the CDR inside to moderately high heat for a short amount of time. The machine used runs the CD through on a belt. During the time that the CD is inside the machine, it is subjected to a temperature of 250 degrees F. The CD case emerges less than 10 seconds after entering, warm (but not painful) to the touch. Now, my obvious question: Is this heat exposure harmful to the audio recorded on the disk?”
In a word, no, not at this level. The temperature of the laser beam that burns the CDR is thousands of degrees hotter than that oven. The data burned on to the disc will not be affected. The only risk of exposing discs to this kind of temperature is one of potentially warping the disc (leave one on the dashboard of your car in summer sometime). With such a limited time of exposure, warping does not have time to occur at that temperature. We heat shrink CD media around here on a regular basis and have never observed any heat related problems.