Blow molding machinery is used to create hollow containers or parts made from plastic. In addition to overseeing operations during this process, the operator is responsible for keeping extrusion blow molding machines in optimal condition. As part of this, the machinery must be purged. This consists of cleaning the interior portion of the machine, which primarily focuses on ridding it of plastic residue.
Even when machinery is purchased from a reputable extrusion blow molding machine manufacturer, after so much use, it must be purged. There are several key benefits when using the appropriate pursing compound and going through the procedure correctly. These include reducing machine downtime, experiencing less material waste, having fewer container or part rejects, and facilitating color and material changeovers more quickly.
The purging compound used for extrusion blow molding machine is a specially made commercial-grade product. Typically, the compound is comprised of a base resin with various additives mixed in so that not only is the machine purged but also the die, screw, and barrel. However, a purging compound has other purposes. For instance, it cleans a hot runner mold and removes carbon and color deposits. It is important to note that depending on the type of compound, the dies and screws may not be left in place during the purging process.
For purging, safety is always the priority. Therefore, the operator must take the appropriate precautions according to company guidelines. To start purging, increase the temperature of the die between 35 and 55 degrees Fahrenheit, followed by extruding any remaining resin from the system. Next, the feed throat and hopper are cleaned. In the event that the extrusion machine is badly contaminated, be sure to remove the screen pack to prevent an issue with plugging and remove the die.
Slowly feed the purging compound into the hopper, initially using the lowest screw speed. When material comes out from the head, increase the speed to the maximum yet safe level. Periodically, stop the screw altogether so the compound can sit for several minutes. Then, simply set the screw speed back to maximum. Once all of the resin, color, and/or contamination is eliminated, set the extrusion machinery parameters to normal, make sure the die is in place, and add a new screen pack.
The outstanding performance of an extrusion machine begins with a well-manufactured product. PET All Manufacturing offers a full range of high-quality equipment for customers in the United States and Europe. To view the different types of machinery that we manufacture, please visit our website or call us to speak to a company representative.