tapered side 15 corresponds to angular taper of taper 13 of plastic bag 12 so that lower section 3 of funnel 14 can be sealingly engaged in the throat of neck 20 as shown in fig1 and 5 the slightly outward flaring of tapered side 17 provides a convenient catchment for more securely holding funnel 14 in the hand not shown of user crease 22a also assists in the assembly of disposable bag 10 by providing a stop against which fold 22 is brought into contact during assembly a closure 38 is formed as an extension of one of the sidewalls of funnel 14 and is adapted to be folded at fold 32 across the open mouth 34 of funnel 14 into contact with the other side of side elements 30 an adhesive strip under overlay 37 seals closure 38 across funnel 14 edges 39 of closure 38 are tapered inwardly in a taper that corresponds angularly with the taper of tapered sides 17 historically most plastic bags are configured with a tubular construction meaning that the sidewalls are parallel along the length of the bag plastic bag 12 is unique in that it has a convergent taper 13 oriented upwardly toward mouth 24 when mouth 24 and the adjoining neck 20 is inverted into plastic bag 12 neck 20 becomes a funnel extension 20a fig3 that diverges away from the adjacent sidewalls to create a.