Production systems, such as injection molding systems, which are employed to create production materials such as optical disks, usually include more than one production component, such as injection molding machines. The injection molding machines form clear substrates employed in the manufacture of optical disks, such as DVDs, CDs or other plastic media. In a system where two or more injection molders are employed, it is sometimes difficult to shut parts of the system down when other parts are producing rejectable product.
In DVD replication lines, two or more injection molding machines, one metalizer-bonding machine and one scanner may be integrated. The injection molding machines have a drop limit condition (the condition is fixed by software), such that when the quality of a disk as measured by the scanner is inadequate, the injection molding machines are shut down. One major disadvantage is that with the drop limit, it is not possible to run lower than 20 shots (discs) per injection molding machine. This is the minimal number of shots before the line can be shut down. Therefore, with every downstream interruption of production, at least twenty clear substrates are wasted by each injection molding machine.
In addition, in prior art production systems, completely shutting down the production components causes startup delays when trying to restart the production system. Also, if one injection molding machine stops the other machines are unaware of the shut down and continue running and making clear discs which will be wasted.