DEFINED STRETCH POSITION FOR PRE AND MAIN BLOW ACTIVATION DURING BLOWING

Nowdays PLC or microprocessors are used for Blowing system which are time based. The process delay time is set by operator based on his experience. The time is also the function of pneumatic cylinders friction and maintenance done by operator. Therefore it is observed that older machine have more bottle quality problem and can not be set by operator. The usage of various grade preform and its dimension has vary the stretch delay time. Stretching of preform is also the function of its temperature therefore the lower temperature of preform required more time delay and vise versa. The operator is not capable to understand this engineering and he continue by trial and error resulting inconsistent quality of bottles and the rejection.

To dispense with this problem, Technopet has devised, the stretch position, based instate of time base system for activation of valve for pre and main blow. Operator simply feed the position points of the stretch rod in the mold at which the blow valve is to activate. Since the blow valve position with respect to bottle height is fixed the bottle quality variation occurred due to change in functional parameter are eliminated. No need of operator intervention in continuous blowing process.