Method of making a precisely partitioned bulbous-shape container

A method of making a bulbous-shape open-top container of unitary construction of thermoplastic material which container is precisely partitioned by a longitudinally extending internal bulkhead of predetermined size, shape and orientation, said method comprising:

• providing a longitudinally partitioned preform of said thermoplastic material which preform comprises a tubular exterior wall and said internal bulkhead, said step of providing a preform comprising cutting a predetermined length from an endless longitudinally partitioned tubular extrusion comprising said tubular exterior wall and an integral longitudinally extending said internal bulkhead;
• heating the body of said preform to a sufficiently high temperature equal to or greater than the thermoplastic temperature of said thermoplastic material to enable pinching one end of said preform closed and to enable blow molding said exterior wall to said bulbous-shape of said container;
• pinching said one end of said preform closed prior to said blow molding;
• and
• converting said preform into said container by blow molding said exterior wall of said preform to said bulbous-shape while constraining said bulkhead along its faces and edges, during said heating, said pinching, and said blow molding, to virtually obviate changing its size, shape, or orientation during said blow molding.