Plastic injection molding and process

摘要

Plastic containers are described herein that are injection molded with an high density polyethylene (HDPE) blow molding grade resin having a density of about 0.960 to about 0.965 g/cc and a melt index of about 0.7 to about 1.0 g/10 min. at injection temperatures of about 570° F. to about 670° F. and mold cavity pressures of about 20,000 psig to about 27,000 psig. Relatively thin walled, rigid, containers, such as livestock feed containers, may be manufactured as described using about 20% to 50% less material while retaining strength and durability comparable to containers molded of HDPE injection molding grade resins.

主权项

1. A method of injection molding a thin walled injection molded container with a two-part mold, the method comprising:
injecting into the two-part mold defining all dimensions of said container using an injection molding machine a blow molding grade high density polyethylene (HDPE) resin in melt form having a melt index in a range of about 0.7 to about 1.0 g/10 min and a density in a range of about 0.958 to about 0.965 g/cc, such that a combination of said blow molding grade HDPE resin and injecting into said two-part mold using said injection molding machine provides the entire thin walled injection molded container having outer dimensions that include a diameter or width in a range of about 15.0 inches to about 25.0 inches, and a side wall having an overall height in a range of about 5.0 inches to about 25.0 inches, and a wall thickness in a range of about 0.070 inches to about 0.150 inches, and the side wall when injection molded is continuous with the base part.