Contour-Depending Temperature Control

New Temperature Control Technologies 2.4.9.1 Contour-Depending Temperature Control... 

Contour-dependent temperature control is very close to the ideal temperature control and develops high potential for optimization in terms of molded part quality and cycle time. Thus, the part quality and the efficiency of the part can be significantly increased. 

The temperature differences at the conventional temperature-controlled molded parts are usually over 10 °C. Significant reductions in cycle time (about 2% per 1 °C it results in 20% and more shorter cycle times) enables the contour-dependent temperature control because the hottest regions of the molded parts are cycle-time dependent. 

For contour-dependent temperature control, the disassembly of the mold insert into single-layer elements is required (Figure 2.97) and into which the temperature control channel is milled in. Later, these layer elements are connected together in a vacuum brazing technology and then result in a uniform temperature control system. Figure 2.98 shows the comparison between a conventional and a contour-dependent temperature control. 

FIGURE 2.98 Comparison between conventional (top) and contour-dependent (bottom) executed temperature controls (source Innova Engineering GmbH)... 

Exciplexes are complexes of the excited fluorophore molecule (which can be electron donor or acceptor) with the solvent molecule. Like many bimolecular processes, the formation of excimers and exciplexes are diffusion controlled processes. The fluorescence of these complexes is detected at relatively high concentrations of excited species, so a sufficient number of contacts should occur during the excited state lifetime and, hence, the characteristics of the dual emission depend strongly on the temperature and viscosity of solvents. A well-known example of exciplex is an excited state complex of anthracene and /V,/V-diethylaniline resulting from the transfer of an electron from an amine molecule to an excited anthracene. Molecules of anthracene in toluene fluoresce at 400 nm with contour having vibronic structure. An addition to the same solution of diethylaniline reveals quenching of anthracene accompanied by appearance of a broad, structureless fluorescence band of the exciplex near 500 nm (Fig. 2 )... 

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