A poorly blown core or one blown with low blow pressure
has more space between the sand grain and longer bridges.
depending on the processing conditions, such as blow pressure
, melt temperature, mold temperature, etc.
The authors (17) also studied the effect of ISBM process parameters and preform design on the bottle properties; the process parameters comprising the blow pressure
, the timing of the blow pressure
activation relative to the stretch rod motion was studied to improve the simulation predictions of bottle wall thickness (18), (19).
The optimal conditions are rear temperature of 320 (degrees)F, front temperature of 300 (degrees)F, block temperature of 300 (degrees)F, injection pressure of 1000 psi, blow pressure
of 60 psi, mold temperature of 120 (degrees)F, and mold close time of 60 seconds.
Some newer developments include improved infrared heating techniques for reheat blow molding; very high speed rotary extrusion presses, particularly for the milk container industry; mold indexing on shuttle presses to allow for offset spout formation; multilayer continuous extrusion blow molding for barrier containers; and the continuous production of heat-set PET bottles by carefully controlling orientation crystallization and thermal crystallization, preform and mold temperature, and blow pressure
and residence time in the mold.
utilized is a function of part size and parison wall thickness.
Engineers have hooked up compressors to conduct cooling and blow pressure
Therefore the preblow pressure is applied shortly after the end of preform stretching quickly followed by the final blow pressure
, since there is no risk for the rod to contact the preform wall in that situation.
Loramendi's Advanced Blow System allows for a low blow pressure
, which results in reduced air consumption, less tooling wear and improved core density.
4) Two groups of tests were conducted--one to analyze the factors in a hot start process, the other to analyze factors and process at constant blow pressure
A less-than-optimum venting pattern was used so that a highly flowable sand would fill the box at a given blow pressure
, but a less flowable sand would not.
ext] is an external force corresponding to the blow pressure