Mold opening-closing mechanism optimization through modeFRONTIER

Ostorero Marcello - Bottero (Italy)



Bottero, company operating worldwide in the glass machinery field, has recently introduced on the market the EMOC, a family of molds opening and closing (MOC) mechanisms for hollow glass industry, based on a completely new concept. Here we present the way a number of (a) dynamic and (b) thermal issues have been faced and resolved with the help of modeFRONTIER. (a) The space constraints of the mechanism are very strong, especially for the blow side one, since it must be "top mounted" (assembled on the top of the section box) and "retrofittable" on existing machines. This leads to a very complex three dimensional kinematic chain, impossible to be tuned in an analytical way. A high performance level is required to this mechanism, particularly regarding clamping forces in closed position, force available at the beginning of the molds stroke, reduced closing time, absence of vibrations during movement, robustness with respect to irregularities in air supply.
To tune this system, an optimization approach based on modeFRONTIER has been used: using this methodology, all requirements were met. (b) The central aspect of a hollow glass production is the heat exchange, controlled by the MOC cooling system: it must be managed with high accuracy, to ensure the correct formability of the molten glass. The EMOC cooling system is based on a completely new concept, since the air is coming from the arm and enters in the mold at middle height: this ensures a wide range of advantages regarding the cooling system, which can be used on the complete machine cycle, and the mold air path, which can be customized to ensure the temperature profile most appropriate for a particular production. With respect to traditional concepts, it conjugates the "power heat extraction" of the axial cooling (usable only in closed molds position) with the flexibility and precision of the radial one (usable only in open molds position).
In the EMOC the air path shape changes with the arm position: in particular the closed position duct is completely different from the opened one.
To ensure the same air massflow at the two or three molds that can be assembled on the arm, a deflector was introduced, designed trough optimization based on modeFRONTIER. This method is currently used in Bottero to ensure the correct air repartition of each designed mechanism version.