Method and apparatus for smoothing of bag making material in form, fill and seal machines

A device for assuring substantial smoothness in bags formed on a form, fill and seal machine comprising structure engageable with a closure along one edge of flattened bag making material below a forming and filling tube, and cooperating members operating cyclically from a position at the stabilizer in a flattening stroke across the material. The flattening members are desirably rollers which may be heated to effect a flatness retaining seal across the flattened material.

BACKGROUND OF THE INVENTION 
This invention relates to improvements in smoothing of bag making material 
in form, fill and seal machines wherein bag making film material is formed 
into bags filled with product after descending from a form, fill tubular 
nozzle toward bag sealing means. 
Examples of form, fill and seal bag making and filling machines especially 
relevant to the present invention are disclosed in U.S. Pat. Nos. 
4,355,494 and 4,829,745, which to any extent necessary are incorporated 
herein by reference so that the present invention may be more succinctly 
disclosed herein. 
The problem to which the present invention is directed is elaborately 
described in the aforesaid U.S. Pat. No. 4,829,745, namely that wrinkles 
tend to form along the edge seal lines of the bags produced as a result of 
the operation of the form, fill and seal machines wherein the tube of bag 
making material is, after it descends below the discharge end of the form 
and fill tube, sealed thereacross by sealing form means to form one side 
of a bag and then filled and sealed across to form the opposite side of 
the bag. As disclosed in that patent, gripper means at one side of the 
flattened tube and a swinging arm inside the tube cooperate to maintain a 
flat configuration of the bag making material relative to the sealing jaw 
means. That arrangement, while reasonably effective, requires mechanism 
functioning within the filling area of the form and fill tubular nozzle, 
and the present invention aims to avoid that complication. 
SUMMARY OF THE PRESENT INVENTION 
An important object of the present invention is to provide a new and 
improved device and method for assuring substantially smooth bags formed 
on a form, fill and seal machine. 
Another object of the present invention is to provide new and improved 
means and method for assuring substantial smoothness in the bags produced 
during operation of a form, fill and seal machine. 
Still another object of the invention is to provide means which functions 
at the outside of bag making material for assuring smoothness in the bags 
produced in a form, fill and seal machine. 
Yet another object of the present invention is to provide new and improved 
means and method for concurrently smoothing and sealing flattened bag 
making material below the discharge end of a form, fill and seal machine 
tubular forming and filling nozzle member.

DETAILED DESCRIPTION 
A device 5 (FIG. 1) embodying the present invention is disclosed in 
association with the discharge end of a tubular forming and filling chute 
or nozzle 7 about which bag making material 8 is in free tubular embrace 
having been formed up about the tube 7 in the usual fashion wherein the 
material is fed to the tube 7 in sheet form and edges of the sheet are 
brought together in a closure 9. Whereas the closure 9 may be simply in 
the form of a sealed fin, it may also be a reclosable plastic zipper 
wherein complementary zipper profiles are reclosably interlocked. In any 
event, the fin 9 becomes the closure for the mouth ends of the bags to be 
formed from the bag making material 8. 
At the discharge end of the tube 7, means are provided for shaping the bag 
making material 8 into substantially flattened form to facilitate the bag 
making process. To this end, the lower extremity of the tube 7 has aligned 
spreaders 10 and 11 which are desirably substantially similar oppositely 
extending spreader fins. The spreader fin 10 guides the portion of the 
material 8 having the closure 9 laterally into one edge of the flattened 
material 8, while the spreader fin 11 guides the opposite portion of the 
material 8 into an opposite edge of the flattened material. 
Cooperating with the spreader fin 10 is a bifurcated stabilizer bar 12 
which, as best seen in FIGS. 2 and 4 has a fin receiving guide slot 13 
complementary to the fin 10 and the closure 9. A frame member 14 supports 
the bar 12 in operative position by means of a supporting arm 15. 
Means comprising rollers 17 are provided cooperative with the spreader fins 
10 and 11 and the stabilizer 12 for smoothing the flattened material 8. To 
this end, the rollers 17 are carried rotatably on the ends of 
reciprocatable rod arms 18 bracketing the stabilizer 12 therebetween and 
guided by means of a guide block 19 which may be supported on the arm 15 
immediately adjacently in back of the stabilizer 12. Reciprocation of the 
arms 18 is effected by means comprising a piston rod 20 operable by means 
of a fluid operated actuator 21 desirably fixedly mounted on the frame 14. 
The arrangement is such that the roller arms 18 are adapted to be 
cyclically driven between a starting position of the rollers 17 resting in 
clearance relation on the stabilizer 12 as shown in FIG. 1, to a fully 
extended position as shown in FIGS. 3 and 4, and returned to the starting 
position in a cycle of operation stroke coordinated in operation with the 
associated machine, and more particularly the discharge of product into 
the immediately trailing bag after the filled lead bag has been sealed and 
cut off from the trailing bag, in the conventional manner. In each 
operating stroke of the rollers 17 from the retracted position at the 
stabilizer 12, into the fully extended position at the edge of the 
flattened material 8 opposite to the closure edge 9, the rollers function 
to smooth the flattened material 8 and thus assure that the bags as formed 
will be substantially smooth, that is, the walls of the bags will be 
substantially free from wrinkle tucks or pleats or other distortions that 
may result from puffing or stretching of the bag material during filling 
of the bag. 
Desirably, not only do the rollers 17 effect smoothing of the flattened 
material 8, but also effect an at least preliminary sealing 22 across the 
flattened material 8. Such sealing is desirably effected across that 
portion of the flattened material 8 that provides for the final side seal 
of the lead bag and the adjacent side seal of the following bag, thereby 
holding the desirably flattened condition of the material until 
conventional sealing bars may effect final sealing of the material. To 
enable the rollers to effect the sealing they are adapted to be heated as 
by having the actuating rods 18 or at least axles 18a for the rollers or 
the rollers themselves provided with heating means of conventional form. 
Thus, it is apparent that the present invention provides a simple, 
efficient, easily accessible device for smoothing the flattened bag making 
material below the forming and filling tube of the associated form, fill 
and seal machine. 
It will be understood that variations and modifications may be effected 
without departing from the spirit and scope of the novel concepts of the 
present invention.