Process And Apparatus For Pouch-Forming With Optimized Fill Accuracy And Headspace
This invention discloses a process for forming a pouch having an evacuated headspace containing a flowable material. The process relates to optimizing both, the evacuation of the headspace in the pouch and the accuracy of the flowable material filled in the pouch. Specifically, the present invention employs a process that includes a multiple-step or a continuous compression of the pouch headspace to accomplish the goals. Also disclosed is a vertical form-fill-seal apparatus for forming a pouch containing a flowable material and having an evacuated headspace.
1 . A vertical form-fill-seal apparatus for forming a pouch containing a flowable material and having an evacuated headspace, said apparatus comprising:
(A) a tube-forming section for forming a vertical continuous tube from a roll of film;
(B) a horizontal sealing section for forming a transverse seal across said vertical continuous tube;
(C) a filling station for supplying a predetermined amount of flowable material to said vertical continuous tube;
(D) pinchers for transversely pinching said vertical continuous tube to form a pinched portion of said continuous tube;
(E) an evacuating passage between said pinchers that opens onto said headspace between the predetermined amount of flowable material and the pinched portion; and
(F) a deflating apparatus for evacuating said headspace via the evacuating passage, wherein said deflating apparatus is programmed to actuate in multiple steps or continuously while the continuous film is indexing,
wherein the deflating apparatus includes a first set of deflators configured to transversely compress the vertical continuous tube at a first portion thereof and further includes a second set of deflators configured to transversely compress the vertical continuous tube at a second portion thereof spaced apart from the first portion.
2 . The vertical form fill-seal apparatus as recited in claim 1 , wherein said deflating apparatus is actuated in an asynchronous manner.
3 . The vertical form fill-seal apparatus of claim 1 , wherein the first deflators are spaced between the second deflators and the pinchers.
4 . The vertical form fill-seal apparatus of claim 1 , wherein the first set of deflators is configured to squeeze the predetermined amount of flowable material within the vertical continuous tube at the first portion, and the second set of deflators is configured to squeeze the vertical continuous tube at the second portion to move the predetermined amount of flowable material towards the first portion.
5 . The vertical form fill-seal apparatus of claim 2 , wherein the first set of deflators is actuated before the second set of deflators.
6 . The vertical form fill-seal apparatus of claim 5 , wherein the first and second sets of deflators are each configured to be actuated based on the indexing of the continuous film.
7 . The vertical form fill-seal apparatus of claim 1 , wherein the formed pouch is configured to have a headspace volume equal to or less than 2 percent by volume.