Bulk packaging multi-wall sack and apparatus for manufacturing the sack
An as-manufactured multi-wall sack that comprises an inner pouch 5 and an outer bag 7 is disclosed. The sack has a top end that (a) is open in the as-manufactured form of the sack so that the sack can be filled with product via the open end and (b) is formed so that it can be closed to form a top block end. The as-manufactured form of the sack comprises pressure adhesive that connects together the inner pouch and the outer bag at the open top end of the sack. The as-manufactured form of the sack also comprises heat-activated adhesive on sections of the outer bag that adhere to other sections of the outer bag as part of the sequence of steps to close the outer bag. An apparatus and a method for closing the as-manufactured sack are also disclosed.
1. An as-manufactured multi-wall sack that comprises an inner pouch made from a polymeric material and an outer bag made from a paper-based material, with the sack having a top end that (a) is open in the as-manufactured form of the sack so that the sack can be filled with product via the open end and (b) is formed so that it can be closed to form a top block end, and wherein, in the as-manufactured form of the sack, the sack comprises pressure adhesive that connects together the inner pouch and the outer bag at the open top end of the sack, and wherein the amount and/or the type of pressure adhesive is selected so that the adhesion of the inner pouch to the outer bag is greater on one of a front or a rear side of the sack than on the opposite side of the sack so that, as part of a sequence of steps to close the outer bag after a step of heat sealing the inner pouch closed, the front and rear sides of the outer bag can each be folded outwardly in opposite directions with the sealed inner pouch being selectively detached from one of the sides of the outer bag and being retained by the other side and folding outwardly with that other side.
2. The sack defined in claim 1 wherein, in the as-manufactured form of the sack, the sack comprises heat-activated adhesive on sections of the outer bag that adhere to other sections of the outer bag as part of the sequence of steps to close the outer bag.
3. The sack defined in claim 2 wherein, in the as-manufactured form of the sack, the positions of the sections of the outer bag that carry heat-activated adhesive are selected so that the sequence of steps to close the outer bag where possible positions the heat-activated adhesive sections so that the sections do not overlie the inner pouch.
4. The sack defined in claim 1 , wherein said sack further comprises an “easy” open feature on the outer bag that facilitates opening the outer bag after it has been closed.
5. A filled and sealed bulk packaging sack formed by filling and closing the as-manufactured multi-wall sack defined in claim 1 whereby the filled and sealed sack has a top block end with the front and rear sides of the outer bad folded outwardly in opposite directions with the sealed inner pouch detached from one of the sides of the outer bag and retained by the other side and folded outwardly with that other side.
6. The bulk packaging sack defined in claim 5 , wherein said bulk packaging sack further comprises a vent seal to allow air to escape from the inner pouch after the inner pouch has been closed.
7. The bulk packaging sack defined in claim 6 , wherein the vent seal defines a tortuous flow path for air to escape from the closed inner pouch.
8. The bulk packaging sack defined in claim 5 , wherein said bulk packaging sack further comprises product identification coding applied to the inner pouch after filling the as-manufactured multi-wall sack with product and prior to closing the outer bag.
9. The bulk packaging sack defined in claim 8 , wherein said bulk packaging sack further comprises product identification coding on the outer bag.