Krauss-Maffei will show a new mould temperature control technology at MediaTech 2003 next month that it claims will enable DVD discs to be produced on cycle times of less than three seconds.The technology uses two separate mould cooling circuits to overcome the traditional balance between keeping the mould surface temperature high enough to achieve the correct DVD microstructure, while avoiding unnecessarily extension of the cycle time.
In the new KM moulding system, one cooling circuit is used to maintain mould surface temperature during injection of the polymer at a level sufficiently high enough to achieve the required surface microstructure. Once injection is complete, cooling switches to the second, much cooler circuit that rapidly draws thermal energy from the mould.
According to KM, the system will allow sub-three second cycle times without sacrificing production yield and with no harmful effect on DVD dishing and tilt values. The system's ability to rapidly adjust mould temperatures is also claimed to provide faster changeover times.
The system will be demonstrated on KM's stand at Mediatech 2003, which runs from 13-15 May in Las Vegas.
Source: Kraus-Maffei
