Spinning globe

Conversion of Polyethylene to Plastic Bags (Continued)

Copyright, Welex, 1996

Polyethylene pellets are melted in an extruder, as seen on the here. They are melted as they are pushed through the machinery with a screw-like mechanism. Once the pellets are melted, they are pushed between parallel plates to make a flat sheet. The flat sheet is then drawn out as a falling film and cooled.

Copyright, Thong Fook Plastic Industries, 1996

In the case of trash bags we are interested in a cylindrically shaped product. This picture shows that when polyethylene is extruded in this shape it forms a large bubble.The bubble is cooled, and then can be cut and sealed on the bottom to result in the trash bags we all use.

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