GB2141092A - Form fill seal packaging machine - Google Patents

Abstract

A horizontal form fill seal packaging machine produces a succession of individually wrapped sealed product-containing packages each of which incorporates a reclosable fin seal running along rather than across the final package. In the machine, the male and female halves of a reclosable strip of known kind are drawn initially from separate reels 19, sealed respectively to the opposite longitudinal edge regions of the package film web 11 whilst the web is travelling in its substantially flat state, the web is then entubed around the products to bring the reclosable strip halves into mating closed engagement, and the tube is then fin-sealed longitudinally with the reclosable strip in its closed state. Cross-sealing and cutting the web completes the formation of each individual package. <IMAGE>

Description

SPECIFICATION Form fill seal packaging machine The Invention relates to Form Fill Seal Packaging Machines.

In such machines, packaging film is drawn from a reel in an initially flat elongate web; entubed, and sealed longitudinally, around a succession of products fed into the web; and then the longitudinally sealed tube is cross sealed and cut to discharge a succession of individually wrapped sealed products containing packages from the machine.

It is known to apply a two-part male-female reclosable strip to the sealed edges of the tube, so that the resulting packages can be each opened and closed to give repeated access to their contents.

U K Patent specification No 1 546433 (Roeder) describes and illustrates various methods of applying these reclosure strips.

U K Patent specification No 2087828 (Auto Wrappers) describes and illustrates a vertical flow form fill seal packaging machine in which such reclosure strips are incorporated into the longitudinal film seal which projects in a fin from the tube surface. In use, the reclosable sealed fin forms one end of the final package.

In a mchine embodying the present invention, a reclosable strip is incorporated into the longitudinal fin seal of the film tube; but the machine operates as a horizontal form fill seal packaging machine; and the sealed fin incorporating the reclosure strip runs along, not across, the final package.

In one machine embodying the invention, described and illustrated in this specification, a reclosure strip is incorporated into each package by drawing the male and female closure strip halves initially from separate reels; sealing them respectively to the opposite longitudinal edge regions of the film web whilst the web is travelling in its substantially flat state (when measured across the web); entubing the web around the products in a way which brings the closure strip halves into mating engagement; and sealing the tube longitudinally with the closure strip in that closed state.

This machine will now be described with reference to the accompanying drawings. It is currently the best way known to the applicants of putting the invention into practice.

In the drawings; Figure 1 shows diagramatically the respective flows of closure strip halves and film web through the machine; Figure 1 a shows in enlarged perspective one of several rollers guiding each closure strip half; Figure 1 b shows diagramatically the arrangement by which the closure strip halves are tensioned as they are drawn from their respective reel; Figure 2 shows in perspective the flow of the film web through the sealing and cutting stations; Figure 2a shows an enlarged cross section the way the film web is initially turned to entube it before it enters the sealing rollers; and Figure 3 shows in cross section the form of the final product containing package.

In Figure 1, the web 11 is drawn from a reel 1 2 and over successive tensioning rollers 1 3 to 1 7 to travel in the direction indicated by arrows and enter a station, referenced generally 18, at which the male and female reclosure strip halves are applied to the opposite longitudinal edges of the web by methods in accordance with the UK Patent specification No. 1 546433 previously referred to. The closure strip halves themselves are drawn from respectively separate but co-axial reels, one of which is illustrated and is referenced 1 9. They travel through a succession of tensioning and guiding rollers, none of which is individually referenced, to enter the station 18.

The reclosure strip halves are applied by a combination of heat sealing and adhesive bonding to the opposite longitudinal edges of the web 11. A glueing head 21 is shown diagramatically in Figure 1. Specific details of the process which takes place at station 1 8 can be obtained and selected from the disclosure of specification No. 546433.

The web, with closure strip halves applied to it, then travels down through a twin roller referenced generally 22 and into a folding and forming station 23 where it begins to be entubed around a succession of products each of which arrives in a direction indicated by arrow A. The products are delivered into the web by means such as a chain conveyor which are not described and illustrated and which the skilled reader can sellect from known alternatives.

As the web is entubed around the products, the reclosure stri;p halves on its opposite longitudinal edges are brought into mating engagement to form a fin projecting at right angles from beneath the tube. This fin travels through a succession of three pairs of contrarotating rollers. The rollers grip the fin, and crimp-heat-seal it. These rollers, which are illustrated in detail in Figure 2 but not shown in Figure 1, are the sole means of pulling the web and the reclosure strip halves from their respective reels and through the stations 18, 22 and 23.

The web travels through the machine at a constant and relatively high speed. The speed is limited by the nature of the web itself.

In this particular embodyment the web is a flexible laminated film of known construction.

It has a metalic coated outer surface over a clear plastic inner surface and is of relatively heavy gauge.

The two reels 19 which carry each of the reclosure stip halves rotate independently about their common axis as the material is drawn from them. The rollers through which each reclosure strip passes are shaped as shown in Figure 1a, so that the strip halves are positively guided into the station 1 8 and will not ride off the edges of the rollers. Each of these guiding rollers rotates freely about its own pivot.

One of these rollers, reference 24, is carried on the end of a tensioning arm 25 and is illustrated with the arm 25 in Figure 1 b; the arm 25 is shaped as a bell crank and pivots at 26 about the main frame of the machine. Two optical sensors 27, 28 are also fixed to the main frame of the machine in positions such that the end 29 of the arm remote from the roller 24 moves between each of these sensors as the arm 25 moves about its pivot 26.

Each sensor 27, 28 respectively cuts off and initiates the drive from a geared motor unit 31 which moves the arm 25 in one direction (clockwise when viewed as in Figure about its pivot 26. When the arm 25 is driven down (i.e. clockwise) about its pivot 26, more material is automatically pulled off the reel 1 9 associated with it. When the end 29 of the arm 25 registers on the sensor 27, the drive is cut off automatically and the arm 25 then swings automatically anti-clockwise about its pivot 26 as the material is pulled through the station 1 8 by the succession of three pairs of contra-rotating rollers which follow the entubing station 23.

Eventually, the end 29 of arm 25 will register opposite the sensor 28. The drive unit 31 will then automatically be activated to swing the arm 25 clockwise about pivot 26 and so draw more material from reel 19.

Sensor 27 then cuts off the drive, and arm 25 returns automatically upwards (i.e. anticlockwise) about pivot 26 as the material is drawn through the machine until sensor 28 actuates the powered drive again.

The twin roller set 22 is shown in perspective at the left hand end of Figure 2. The first of these rollers is shouldered towards each of its opposite ends to guide the width of the web between the two shoulders. Both rollers are grooved to accommodate and guide the reclosure strip halves whilst allowing the web itself to seat flat against the rollers across its width.

After passing through the twin roller set 22 the web is entubed about a forming box 32.

A plate 33 constrains the web to run against and over the top of the box 32, and the opposite longitudinal edges of the web are brought towards one another and eventually together around the bottom edges of the box 32 to form a fin 34 projecting at right angles beneath the web tube.

As the fin 34 is formed, the reclosure strip halves come together in mating engagement.

The fin enters the three successive pairs of contra-rotating rollers 35, 36, 37. All are driven about a vertical axis of rotation, beneath the bedplate 38 along which the products are conveyed inside the web tube.

The first set of contra-rotating rollers 35 is grooved to accomodate the reclosure strip halves as the fin 34 passes through these rollers. The second rollers 36 are knurled and are heated, in known manner, to heat the fin 34. The third set of rollers 37 are again grooved, this time according to a pattern which will crimp seal the previously heated fin 34 without of course sealing together the reclosure strip halves.

Between the rollers 36 and 37, a knife 39 is stationed. The knife 39 moves intermittantly in and out to nick the fin 34 and so provide a start for the subsequent reopening of the finished package. When the nicked part of the fin 34 is eventually spread, the spread will travel along one of the crimp lines of the fin, and will free the sealed edges of the fin so that the reclosable strip can be opened. The knife 39 can be pneumatically or electromagnetically driven to perform its intermittant nicking function.

Another set of rollers 41 is interposed between rollers 37 and the final crimping and cross sealing station 42 of the machine. These rollers 41 turn the sealed fin 34 up against the underside of the web tube. As the tube travels through the cross sealing and cutting station 42 which is conventional in design; a gap in the middle region of the heat crimping heads 43 prevents the fin from inadvertantly being sealed to the cross seal.

The speed of the rollers 35, 36, 37 and of the final cross sealing and cutting rollers 42 is matched to the speed of the web. The web could be made of so-called cold seal material in which case none of the rollers 35 onwards need be heated. Although the machine described and illustrated is a continuous flow machine the invention is equally applicable to an intermittant flow machine. Ultrasonic means of sealing could also be incorporated at or after the final cross seal and cut.

Claims (4)

1. A horizontal form fill seal packaging machine adapted to produce a succession of individual packages each incorporating a reclosable fin seal and with the seal running along rather than across the package.

2. A machine in accordance with Claim 1 and in which the package is produced by drawing male and female reclosable strip halves initially from separate reels; sealing them respectively to the opposite longitudinal edge regions of the package film web w hilst the web is travelling in its substantially flat state; entubing the web around the products which are to be packaged so as to bring the closure strip halves into mating engagement; sealing the tube longitudinally with the closure strip in that engaged closed state; and cross-sealing and cutting the web to discharge a succession of individually wrapped sealed product-containing packages from the machine.

3. A package produced by a machine in accordance with Claim 1 or Claim 2.

4. A horizontal form fill seal packaging machine substantially as described herein with reference to and as illustrated in the accompanying drawings.