CONTAINER FILLING SYSTEM

Abstract: A container filling system on an indexing, forming, filling and sealing machine, wherein each successive container (34) is progressively filled with variable volumes of a fluid, such as milk, in a manner which minimizes the foam build-up therein, thereby enhancing leak-proof top sealing characteristics during high production operations. The containers (34) are filled in accordance with the following filling sequence formula: wherein: V t = total container volume V i = volume delivered at i station i = station number N = number of stations

Description: TECHNICAL FIELD This invention relates generally to filling systems for containers and, more particularly, to variable volume progressive filling systems. BACKGROUND ART Heretofore, on constant speed indexing machines, it has been customary to progressively fill larger size containers with equal partial volumes of fluid at each of a number of stations, e.g., four fills of 16 ounces at each of four successive stations for a 64 ounce container. Such a process has resulted in the presence of an excessive volume of foam in the headspace of the container after the last station, requiring a separate defoaming apparatus after the last filling step before successful top sealing can be accomplished. DISCLOSURE OF THE INVENTION A general object of the invention is to provide an improved container filling system wherein the volume of resulting foam is minimal. Another object of the invention is to provide a progressive container filling system wherein variable volumes of a fluid, such as milk, are dispensed into a container to better control the amount of resultant foam when the container is filled. A further eject of the invention is to provide a progressive container filling system wherein partial volumes of fluid are dispensed into the container at each of a predetermined number of stations substantially in accordance with an ideal distribution formula. These and other objects and advantages of the invention will become more apparent when reference is made to the following description and accompanying drawings. According to one aspect of the present invention, there is provided a method of filling liquid-carrying containers prior to sealing thereof, wherein predetermined volumes of liquid are dispensed into the containers at respective stations of a plurality of stations, characterized in that progressively larger volumes of liquid are dispensed into each container at said respective stations to fill each container with a resultant minimal amount of foam in the headspace thereof. According to another aspect of the present invention, there is provided a filling system comprising a forming, filling and sealing machine for liquid-carrying containers, including a plurality of liquid-dispensing stations respective stations of which dispense predetermined volumes of liquid into each container, characterized in that said respective stations are arranged to dispense progressively larger volumes of liquid into each container. BRIEF DESCRIPTION OF THE DRAWINGS The figure is a side elevational view of a container filling machine embodying the invention. BEST MODE OF CARRYING OUT THE INVENTION Referring now to the drawing in greater detail, there is illustrated a forming, filling and sealing machine 10 of the liquid packaging type, including a base frame 12 and a vertical support keel 14. A magazine 16 for holding a plurality of paperboard blanks 18 is mounted on one end of the keel 14. A loading mechanism 20 is mounted on the keel just below the magazine 16 and adapted to withdraw one blank at a time from the magazine while opening same into a four-sided tube 22 and then to load the individual tube onto one of six mandrels 24 of an indexable turret mechanism 26 in approximately the 4:00 o'clock position. An adjustable stop member 25 is operatively connected to each mandrel 24 to accommodate the forming of containers having the same cross-section but different heights. As the mandrel indexes counterclockwise, each tube 22 passes by a prebreaker unit 28, a heater 30, and a closing and sealing unit 32, to an unloading 6:00 o'clock position. At the latter position, each bottom-sealed container, represented at 34, is stripped from the mandrel 24 by a stripping unit 36, and placed on a stationary rail 38 adjacent a pair of parallel endless conveyors 40 whose indexing sequence is coordinated with that of the turret mechanism 26 through suitable control panel means, represented at 41. A transfer pusher 42 moves each open-topped container 34 from the rail 38 into suitable pockets (not shown) on the conveyor 40. After a predetermined number of indexes of the conveyor, each successive container 34 is typically positioned beneath a top pre-breaker unit 44. Each container 34 is thereafter progressively indexed at a constant indexing speed into position beneath four filling units 46, 48, 50 and 52 in series, each of which feeds a measured volume of a particular liquid, such as milk, from a source 54 into each successive container. After passing by the last filler unit 52, the container tops are folded, heated, and sealed by respective folding, heating, and sealing units 56, 58 and 60. The filling units 46, 48, 50 and 52 may contain either four respective different sized pistons, all with the same stroke length, or constant piston size with different stroke lengths, so as to dispense variable volumes of the fluid into each container 34 being indexed therepast, in accordance with the following formula: V i = V t 2N² [N + 2i - 1] wherein: V t = total carton volume V i = volume delivered at i station i = station number N = number of stations For example, to fill a 1.89 litre (64 ounce) container over four successive stations, in lieu of dispensing 0.47 litre (16 ounces) at each station 46, 48, 50 and 52, as has heretofore been the customary approach, the application of the above filling sequence formula would produce the following result: In situations where the formula produces individual station volumes in other than whole numbers, such results may generally be rounded off to the nearest whole number for facilitating the designing or selecting of the individual cylinders and their pistons. For example, to fill a 0.95 litre (32 ounce) container over three successive stations, such as beneath the filler units 46, 48 and 50 only, the application of the filling sequence formula would produce the following result: Tests have shown that containers filled in accordance with the above filling sequence formula have reduced the final foam volume substantially, eliminating the need for a defoaming operation between the last filler unit 52 and the top sealing unit 60. INDUSTRIAL APPLICABILITY It should be apparent that the invention provides a container filling system wherein foam is reduced to the point that there is minimal foam interference in the headspace of each container, such that the top sealing operation may be effectively and thoroughly completed in a manner which prevents subsequent leakage from occurring. It should also be apparent that, rather than varying the piston and cylinder diameter for constant stroke length, it would be possible to maintain a constant piston and cylinder diameter and vary the stroke length thereof to produce the above described progressively variable volumes at the respective stations of a constant speed indexing machine, when applying the recommended filling formula. It should be further apparent that there may be more filling units on a particular machine than the four shown in the drawing, in conformance to the above described filling sequence formula, or that fewer than the four filling units included may be used for particular container sizes. While but one general embodiment has been shown and described, other modifications thereof are possible within the scope of the following claims.

Claims: A method of filling liquid-carrying containers (34) prior to sealing thereof, wherein predetermined volumes of liquid are dispensed into the containers (34) at respective stations (46-52) of a plurality of stations (46-52), characterized in that progressively larger volumes of liquid are dispensed into each container (34) at said respective stations (46-52) to fill each container (34) with a resultant minimal amount of foam in the headspace thereof. A method as claimed in claim 1, wherein the filling occurs in accordance with the following formula: V i = V t 2N² [N + 2i -1] wherein: V t = total container volume V i = volume delivered at i station i = station number N = number of stations A method as claimed in claim 1 or 2, wherein the containers (34) are conveyed from one station (46) to the next (48) at a constant indexing speed. A method as claimed in claim 1, 2 or 3, wherein the respective stations (46-52) comprise respective piston-and-cylinder devices (46-52) which vary in piston and cylinder width while all are actuated through the same stroke length. A method as claimed in claim 1, 2 or 3 wherein the respective stations (46-52) comprise respective piston-and-cylinder devices (46-52) which are of substantially the same cylinder and piston width, but vary in the lengths of their respective dispensing strokes. A method as claimed in any preceding claim, and further comprising, for particular applications involving different container sizes, changing the number of said respective stations (46-52) through which dispensing occurs. A filling system comprising a forming, filling and sealing machine (10) for liquid-carrying containers (34), including a plurality of liquid-dispensing stations (46-52) respective stations (46-52) of which dispense predetermined volumes of liquid into each container (34), characterized in that said respective stations (46-52) are arranged to dispense progressively larger volumes of liquid into each container (34). A machine as claimed in claim 7, wherein said respective stations (46-52) are arranged to fill in accordance with the formula: V i = V t 2N² [N + 2i - 1] wherein: V t = total container volume V i = volume delivered at i station i = station number N = number of stations A machine as claimed in claim 7 or 8, wherein the respective stations (46-52) comprise respective piston-and-cylinder devices (46-52) which vary in piston and cylinder width while all are actuated through the same stroke length. A machine as claimed in claim 7 or 8, wherein the respective stations (46-52) comprise respective piston-and-cylinder devices (46-52) which are of substantially the same cylinder and piston width, but vary in the lengths of their respective dispensing strokes.

Inventors: MCDONALD, KENNETH PAUL, RANGWALA, BADRUDDIN KALIMUDDIN
Applicants: ELOPAK SYSTEMS AG
Application year: 1989
Main classification: B65B3
IPC codes: B65B9, B65B3