System for complete dispensing of flowable materials from a bulk shipping container

A method of fully dispensing liquid or semi-liquid material from a plastic liquid bag having a middle and corners contained in a bulk container, the method comprising the steps of:

• attaching a plastic air bag to the plastic liquid bag wherein the plastic air bag includes a plurality of sides an air inlet port formed at one end and an obstruction region defined by a weld line formed on an opposite end thereof;
• and
• connecting the air inlet port to a source of pressurized air for inflating the plastic air bag wherein inflating the plastic air bag reaches a level at which the pressurized air in the air bag counteracts a liquid pressure within the liquid bag and as the inflating of the air bag continues up to the weld line, the air being forced around the sides of the air bag causing the air bag to push into the corners of the liquid bag which in turn forces the liquid material in the liquid bag from the corners toward the middle of the liquid bag and then as the liquid material gets down low enough, the air in the air bag then forces underneath of the liquid material in the liquid bag and lift the liquid material in the middle so that all the remaining liquid material can be drained out from the liquid bag.