* Pre-Blow Pressure Too Early and/or Too High: As the stretch rod descends, pressure lower than the final blow pressure
is activated to prevent the preform from collapsing and to impart a desired wall thickness to various regions of the bottle.
Other processing parameters, namely the magnitude of the blow pressure
, the timing of the blow relative to the stretch rod motion, and stretch rod speed, were also studied to improve the simulation predictions of the bottle wall thickness.
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.
Although smaller radii can be machined into a mold, the resultant radii formed on the blow molded article will probably be about 0.25 to 0.30 mm (0.01 to 0.012 in.), depending on the processing conditions, such as blow pressure
, melt temperature, mold temperature, etc.
and humidity had only a small effect on shrinkage.
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.
When the rod reaches the bottom wall of the container, a high blow pressure
is applied inside the preform to reach the final container shape and maximize cooling efficiency.
Loramendi's Advanced Blow System allows for a low blow pressure
, which results in reduced air consumption, less tooling wear and improved core density.
The results for Group X show that both a higher blow pressure
and a higher mold temperature produced higher gloss.
Engineers have hooked up compressors to conduct cooling and 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.