TABLE OF CONTENTS Note: these procedures represent good practice. In an actual production environment, always follow the procedures for that particular plant.
During the start-up of a blow moulding machine, precautions should be taken, for example: noone must stand in front of the die or nozzle and that the hopper should be firmly in place so the screw cannot be accessed. Start-up is the most hazardous time in the process because material left in the barrel from the last run can overheat and degrade, spewing hot gases and degraded plastic from the nozzle or die at high pressure. Another potential hazard is that many steps must be taken, and often quickly.
An understanding of the settings is needed before starting up a blow moulding machine. Obtain advice from someone who is very familiar with the equipment, or better yet, consult the written procedures. A general procedure is:
Turn on the main power switches and then select or set the temperatures.
Ensure that the cooling water is on and check to see that it is flowing through the feed throat.
Preheat the hydraulic oil to its correct operating temperature. This may be done either by pumping the oil back into the tank or by using a preheater fitted for this purpose.
Once the machine has reached the required temperature, it should be allowed to settle down before any material is introduced into the barrel. The settling-in (equilibration) time, sometimes called soak time, is the time needed...
