GB2030539A - Process for packaging powdery or granular products in flexible packages and installation for implementing this process - Google Patents

Abstract

The process consists essentially in introducing, into a flexible package of a given capacity, a quantity of product whose volume is slightly less than the capacity of said package, in closing the thus filled package, in dividing this latter into two substantially equal parts connected by an intermediate zone devoid of product, by means of vibrations and simultaneous tilting in opposite directions of the two halves of the package, and in carrying out, in this intermediate zone, a sealing operation associated with an operation for separating the thus defined divided packages. The two halves of the filled package are tilted about a ramp 13 which is vibrated. Devices 5, 11 also vibrate the package conveyors 5, 8. <IMAGE>

Description

SPECIFICATION Process for packaging powdery or granular products in flexible packages and installation for implementing this process The present invention relates to a process for packaging in an economical way powdery or granular products in flexible packages. It relates also to an installation for implementing this process.

It is known that powdery products, such as for example plaster and cement, are generally packaged in 50 kg sacks made from kraft paper, a plastic material or other appropriate materials.

Now, at the present time users would like to have at their disposal lighter packages, in particular of 25 kg. Unfortunately, the cost of packaging is thus considerably increased, this increase being due, on the one hand to the cost of manufacturing two sacks instead of one and, on the other hand, to the extra time required for filling and handling these two sacks.

The principal aim then of the present invention is to remedy these disadvantages and, for this, it provides a packaging process which is characterized in that it consists essentially in introducing, into a flexible package of a given capacity, a quantity of product whose volume is slightly less than the capacity of the package, in closing the package thus filled, in dividing this latter into two substantially equal parts connected by an intermediate zone devoid of product, by means of vibrations and through the simultaneous tilting in opposite directions of the two halves of the package and in carrying out, in this intermediate zone, a sealing operation associated with an operation for separating the thus defined and divided packages.

The packaging process of the invention enables then, in short, two distinct packages to be very easily obtained each containing a fraction of the product introduced at the outset into the package. In practice, these two fractions will of course be equal.

It is thus possible to reduce very easily by half the charges contained in present-day sacks, and in particular to package products such a plaster or cement in 25 kg sacks instead of the 50 kg sacks usually used, without for all that doubling the packaging cost. It is in fact sufficient simply to provide a starting sack slightly larger than the normal 50 kg sack. Furthermore, this sack could be less strong, so more economical, since finally it will only have to support a charge reduced by a half.

According to one characteristic of the invention, the separation operation may consist in making a cut in the intermediate zone and the sealing operation may consist in forming at least one closure line along the lip of each of the thus separated packages.

As a variation however, the separating operation may consist in forming two substantially parallel closure lines in the intermediate zone and the sealing operation may consist in making a cut in the intermediate zone between these two closure lines.

An installation for implementing this process is characterized in that it comprises a first plane and inclined conveyor assembly followed by a second plane and substantially horizontal conveyor assembly, situated in the extension of the first, the second conveyor assembly at least being caused to vibrate; a central ramp, provided vibrating, which is disposed along the median longitudinal axis of the two conveyor assemblies so as to extend horizontally, from the top of the first conveyor assembly over a certain length thereof, to become substantially parallel thereto over the remaining length and to be again horizontal from the bottom of the first conveyor assembly, along two successive sections, connected by an inclined ramp segment, the downstream section being lower than the upstream section, the ramp being provided, from the beginning of the downstream section, with two lateral parallel arms which form a fork and comprising, substantially from this same point, two downwardly sloping deflectors; two fixed flanges for maintaining the packages laterally in position, disposed laterally on the edges of the two conveyor assemblies, from the top of the first to substantially the fixing point of the two side arms to the ramp; a device for sealing the divided packages and a device for separating these latter.

It will be readily understood that with such an installation, the packaging process of the invention may be effected completely automatically as the sack advances, previously filled, over the two conveyor assemblies.

According to a preferred embodiment of the installation, the two conveyor assemblies are each constituted by two parallel conveyor belts, and the vibrating ramp is disposed longitudinally between the two belts of each assembly. By using these conveyor belts, a very high rate of obtaining the finished product can be provided.

In a first embodiment of the installation, the separating device is composed of a circular saw acting against the ramp which is interrupted slightly downstream of the saw so as to section the divided packages at the intermediate zone and the sealing device comprises two closure means situated on each side of the median longitudinal axis of the two conveyor assemblies, downstream of the circular saw and disposed so as to form at least one closure line on the open end of each of the thus separated divided packages, the two deflectors fixed to the ramp extending beyond the free end of this latter as far as the furthermost end of the second conveyor belt assembly.

In this case, there is provided a maintaining device for pressing, one against the other, the two lips of the opening of each of the separated packages, this maintaining device extending over the whole length separating the entrance of the circular saw from the furthermost end of the second conveyor belt assembly. This maintaining device will be preferably formed by mobile bands applied on both sides of the two lips of each of the divided packages. Thus the penetration of the lips of each of the separated packages into the closure means is grealy facilitated.

So as to attain this last objective, there is provided, as a variation, downstream of the circular saw, a device for crimping the two lips of the opening of each of the divided packages so as to bring them into contact with one another, the crimping device being, preferably, formed by two upper serrated wheels, mounted on the same driven shaft perpendicular to the ramp and meshing respectively with two lower serrated wheels carried by the same idler shaft parallel to the driven shaft, each of the upper wheels having a male-female serration complementary to that of the other one and each of the lower wheels having a male-female serration complementary to that of the corresponding upper wheel.

In a second embodiment of the installation, the sealing device is formed by a closure means for forming two closure lines in the intermediate zone of the package and the separating device is situated downstream of the closure means so as to form a separation line between the two closure lines. The sealing and separating operations may thus be easily and efficiently carried out.

According to a characteristic of this second embodiment, the separating device is formed by two rotary knives adapted for completely sectioning the package.

However, as a variation, the separating device may be formed by a perforating machine adapted to effect pre-cutting marks between the two closure lines in the intermediate zone, so that the divided packages may then be easily separated by hand from one another, as required.

Finally, each of the closure means of the two embodiments is formed by a stitching machine.

It goes, however, without saying that, in the case particularly of plastic packages, a thermowelding machine could be used.

Two embodiments of the present invention will be described hereafter, with reference to the accompanying drawings, given solely by way of example, in which: Figure 1 is a schematical side view of a first embodiment of the installation for implementing the process of the present invention, the lateral maintaining flanges having been omitted; Figure 2 is a schematical bottom view of the device of Figure 1 with its maintaining flanges; Figure 3 is an enlarged sectional view along line Ill-Ill of Figure 1; Figure 4 is an enlarged sectional view along line IV-IV of Figure 1; Figure 5 is an enlarged sectional view along line V-V of Figure 1; in which a sack has been shown; Figure 6 is an enlarged sectional view along line VI-VI of Figure 1; Figures 7 and 8 are respectively enlarged sectional views along lines VII-VII and VIII-VIII of Figure 1 showing the two closure means in which packages are engaged; Figure 9 is a partial sectional side view of a crimping device of the invention; Figure 10 is a sectional view along line X-X of Figure 9; Figure 7 7 is a view of the end part of a second embodiment of the device of the invention; Figure 12 is an enlarged sectional view along line XII-XII of Figure 11; Figure 13 is an enlarged sectional view along line XIII-XIII of Figure 11; Figure 14 is a top view of a package after closure by the device of Figure 12; Figure 15 is a top view of a package after separation by the device of Figure 13.

Referring to Figures 1 and 2, there can be seen a first embodiment of the installation of the invention which comprises first of all a conveyor belt designated generally by reference 1 and the purpose of which is simply to compact packages or sacks such as 2 formed for example by valve or open mouth sacks made from kraft paper or other appropriate material. These sacks come from a conventional bag-filling machine where they have been previously filled with any powdery or granular material, such for example as cement or plaster, then normally closed again.

For this purpose, conveyor belt 1 comprises, in a way known per se, a lower belt 3 and an upper belt 4 between which sacks 2 must pass. Moreover, the lower belt is fitted with vibrating means 5, so as to compact uniformly the product contained in the sacks.

After this first conveyor belt 1, there is disposed a first plane and inclined conveyor assembly which is here constituted by two inclined parallel and coplanar conveyor belts 6 and 7. In the extension of these latter is provided a second substiantially horizontal plane conveyor assembly, here constituted by two other parallel and coplanar conveyor belts 8 and 9, the driving side of which is supported, in its upper position, by means of rollers 10 and may be vibrated by means of vibrating elements 11.

A longitudinal ramp 12, provided vibrating, is mounted between the two belts of each assembly.

This vibrating ramp 12 is formed by a first horizontal part 13 which extends from the top of the inclined belt assembly 6 and 7 and which extends, from a point situated above this latter, through an inclined part 14 parallel to the inclined belts. From the bottom of these latter, ramp 12 is formed by two horizontal sections 15 and 16 connected by an inclined ramp segment 17. In the following description, sections 15 and 16 will be respectively called upstream section and downstream section. At the junction point of inclined segment 17 with downstream section 16, ramp 12 is provided with two horizontal arms 18 and 19 (Figure 2) coplanartherewith,which extend progressively outwards to become parallel to the ramp so as to form a fork. From this same junction point, two oppositely downwardly inclined deflectors 20 and 21 are fixed to the ramp over the whole of its downstream section 16. Finally, two flanges 22 and 23 (Figure 2) are mounted laterally at the edges of the two assemblies of conveyor belts. These flanges converge towards one another along the inclined conveyor belt assembly 6 and 7 to become substantially parallel, from the bottom of these latter to the point where arms 18 and 19 are fixed to ramp 12.

With such a structure of the installation, sack 2 which arrives at the end of the first belt 1 in the form shown in Figure 3, is carried along by the two inclined belts 6 and 7 whilst its middle part is progressively raised by ramp 12 which, at its part 13, is rising in relation to the inclined belts. Due to gravity and to the vibrations of the ramp, the packaged product is divided roughly, on each side of the ramp, into two half-sacks 24 and 25 connected by an intermediate zone 26 and maintained in position laterally between flanges 22 and 23. The sack then slides along the inclined part 14 of the ramp towards the two horizontal conveyor belts 8 and 9. Along the horizontal conveyor belts 8 and 9, the distribution of the product in the half-sacks is, in a first stage, improved along the upstream section 15 of the ramp (see Figure 4).Over this section, the height of the ramp 12 is such that the two half sacks 24,25, are substantially vertical. Along the inclined segment 17, the intermediate zone 26 of the sack is progressively separated from the ramp, the two half-sacks being held in place laterally by the two flanges 22 and 23.

Thus the part of the packaged product which might have remained in the intermediate zone following the previous distribution operations, may freely fall into the two half-sacks 24 and 25 (see Figure 5). The intermediate zone 26, thus totally devoid of product is then widened by means of the fork formed by arms 18 and 19, and by the downstream section 16 of ramp 12 (see Figure 6). During this operation, the two half-sacks 24 and 25 are held inwardly in place by deflectors 20 and 21.

It will be easily understood, that the two conveyor assemblies may also consist each in a plate submitted to directional vibrations which allow the sacks to advance all along the installation, these vibrations being of course also used to divide the packaged product into the two half-sacks. In this case, the ramp may be secured to the plate and may be caused to vibrate jointly with the latter. The two conveyor assemblies may also be made of a combination of a two conveyor belts assembly with a vibrating plate, so as each one is used either as the first inclined conveyor assembly or as the second substiantially horizontal conveyor assembly. There may also be provided two conveyor assemblies comprising each two vibrating plates or a vibrating plates assembly associated with a conveyor belts assembly.The two conveyor belt assemblies provide however a greater speed of movement of the sacks and so, a higher rate of obtaining the finished product.

The installation of the invention comprises also at the end part of the horizontal conveyor belts 8 and 9, a separating device associated with a device for sealing the divided sacks.

In the first embodiment shown in Figures 1 and 2, the separating device is formed by a circular saw 27.

Ramp 12 which extends as far as the exit of the circular saw 27 serves as a counter-blade therefor. It is provided to this end, just below the saw, with a slit 28. Thus, sack 2 may be entirely sectioned at its intermediate zone 26 to be separated into two open half-sacks. The two deflectors 20 and 21 associated with ramp 12 extend, over a lesser height, beyond the free end thereof so as to hold in place, as far as the end of the two belts 8 and 9, the two thus separated half sacks.

As for the sealing device, it is formed by two closure means 29 and 30 situated on each side of the median longitudinal axis of the two conveyor assemblies downstream of the circular saw 28.

In the embodiment shown in Figures 7 and 8, these means are stitching machines adapted to form at least one line of stitching in the upper zone of each half-sack, thus ensuring the sealing thereof. But it is evident that, in the case particularly of sacks made from a plastic material, the two stitching machines could be replaced by two thermo-welding machines capable of effecting at least one sealing line bonding the two lips of each half-sack one against the other.

The two devices could even be used jointly.

In Figures 7 and 8, it can be seen that deflectors 20 and 21 are in sloping position at the level of the closure means which are situated one after the other. But deflectors could very well be used which pass progressively from a sloping position to a vertical position between the exit of the saw and the inlet of each of the closure means so as to present the sacks in a vertical position at the entrance to these latter which would then have to be positioned accordingly and could face each other.

The lips of each of the separated half-sacks 24 and 25 are introduced downstream of the circular saw 27 into a maintaining device. In the embodiment shown, this maintaining device is formed by at least two bands 31 and 32, which are driven by any suitable drive means over the whole length separating the entrance to the circular saw 27 from the end of the installation, while facing each other. The two bands 31 and 32 are disposed very close to one another, so that the two lips of each opening introduced between the bands are pressed one against the other, as is shown in Figures 7 and 8: that facilitates their penetration into the closure means 29 and 30. In the embodiment shown, the bands are inclined at the level of the closure means.But it is evident that in the case where the half-sacks are to be presented in a vertical position in front of the closure means, the bands will be twisted to pass progressively to a vertical position.

Still with a view to facilitating the penetration of the lips of the two half-sacks into the closure means, there may be used, instead of the bands, a crimping device (not shown in Figure 1), disposed upstream of circular saw 27 and adapted to form two crimping lines in the intermediate zone 26 of sack 2. Thus, the two lips of each half-sack are maintained temporarily in contact with one another before penetrating into the closure means. This crimping device, shown partially in Figures 9 and 10, is formed of two upper serrated wheels 33 and 34, mounted on a driven shaft (not shown) so as to be driven thereby and two lower serrated wheels 35 and 36 carried by an idler shaft (not shown), these two shafts being perpendicularto ramp 12. Each of the upper wheels is provided with a male-female serration 37 or 38 complementary to that of the other one and of the lower wheels comprises a male-female serration 39 or 40 complementary to that of the corresponding upper wheel. With this double complementarity of the serrations, on the one hand the indentation points of each crimping line are provided alternately on one face and on the other of the intermediate zone 26, thus ensuring an efficient crimping and, on the other hand, the lower wheels are reliably and efficiently driven by the upper wheels. It is evident that the cut will then be effected between the two crimping lines and that the closure line will be formed on the lips below the corresponding crimping line.

In Figure 11 there is shown the end part of a second embodiment of the installation according to the invention, the initial part of which is identical to that of the first embodiment. In this embodiment, the sealing device is formed by a closure means which is here a stitching machine 41 (see Figure 12) adapted to form a double line of stitching 42 in the intermedi ate zone 26 of sack 2, as shown in Figure 14. Ramp 12 is interrupted just in front of the stitching machine 41, the two deflectors 20 and 21 extending in the same way as in the preceding embodiment, except that it is not necessary to bring them, if required, to a vertical position. It is very evident that, as before, the stitching machine could be replaced by a thermowelding machine.

After the closure means there is disposed a separating device 43 formed here by rotary knives acting in the intermediate zone 26 of sack 2, between the two lines of stitching, as shown in Figure 13, so as to section the sack and separate it into two half-sacks 24 and 25, as shown in Figure 15.

The separating device 43 could, if need be, be formed by a simple perforating machine capable of forming the intermediate zone of the sack, between closure lines 42, pre-cutting marks. The two parts 24 and 25 of the sack would then remain connected to one another and could then be, if required, readily separated by hand according to the needs.

in the two embodiments described above, the cutting end of the two packages thus formed could be covered with an adhesive strip or similar so as to further improve the seal of the closure.

Moreover, conveyor belts 8 and 9 of the second assembly may be disposed slightly inclined so as to increase the rate for obtaining the finished product.

In addition to providing the advantage of packaging very easily charges reduced by half, without for all that doubling the cost of the packaging, the invention described in the present patent application enables the product to be packaged to be separated directly into two through the effect of gravity added to the effects of vibration.

That will be particularly useful for packaging products which are difficult to separate, but it is evident that the invention may serve for packaging all sorts of powdery or granular products without taking into account their separating power.

Claims (15)

1. A process for packaging powdery or granular products in flexible packages, characterized in that it consists essentially in introducing, into a flexible package of a given capacity, a quantity of product whose volume is slightly less than the capacity of said package, in closing the package thus filled, in dividing this latter into two substantially equal parts connected by an intermediate zone devoid of product, by means of vibration and with simultaneous tilting in opposite directions of the two halves of the package, and carrying out, in this intermediate zone, a sealing operation associated with an operation for separating the thus defined divided packages.

2. A process according to claim 1, characterized in that the separating operation consists in effecting a cut at the level of the intermediate zone and in that the sealing operation consists in forming at least one closure line on the lips of each of the thus separated packages.

3. A process according to claim 1, characterized in that the sealing operation consists in forming two substantially parallel closure lines in the intermediate zone and in that the associated separating operation then consists in effecting a cut in the intermediate zone between the two closure lines.

4. An installation for implementing the process according to claim 1, characterized in that it comprises a first plane and inclined conveyor assembly, followed by a second plane and substantially horizontal conveyor assembly, situated in the extension of the first, the second conveyor assembly at least being caused to vibrate; a central ramp, provided vibrating, which is disposed along the median longitudinal axis of the two conveyor assemblies so as to extend horizontally, from the top of the first conveyor assembly over a certain length thereof to become substantially parallel thereto over theremaining length and to be again horizontal, from the bottom of the first conveyor assembly along two successive sections, connected by an inclined ramp segment, the downstream section being lower than the upstream section, the ramp being provided, from the beginning of the downstream section, with two parallel lateral arms which form a fork and comprising, substantially from this same point, two downwardly inclined deflectors; two fixed flanges for maintaining the packages laterally in position, disposed laterally on the edges of the two conveyor assemblies, from the top of the first one to substantially the fixing point of the two side arms to the ramp; a device for sealing the divided packages and a device for separating these latter.

5. An installation according to claim 4, characterized in that the two conveyor assemblies are each constituted by two parallel conveyor belts and the vibrating ramp is disposed longitudinally between the two belts of each conveyor assembly.

6. An installation according to claim 4 or 5, characterized in that the separating device is formed by a circular saw acting against the ramp which is interrupted, slightly downstream of the saw, so as to section the divided packages at the intermediate zone and in that the sealing device comprises two closure means situated on each side of the median longitudinal axis of the two conveyor assemblies downstream of the circular saw and disposed so as to form at least one closure line on the open end of each of the divided packages thus separated, the two deflectors fixed to the ramp extending beyond the free end of the latter as far as the furthermost end of the second conveyor assembly.

7. An installation according to claim 6, characterized in that it is provided with a maintaining device intended to press the two lips of the opening of each of the separated packages one against the other, this maintaining device extending over the whole length separating the entrance to the circular saw from the furthermost end of the second conveyor belt assembly.

8. An installation according to claim 7, characterized in that the maintaining device is formed by mobile bands applied on both sides of the two lips of each of the divided packages.

9. An installation according to claim 6, characterized in that it comprises, downstream of the circular saw, a device for crimping the two lips of the opening of each of the divided packages so as to bring these latter into contact with one another.

10. An installation according to claim 9, characterized in that the crimping device is formed by two upper serrated wheels, mounted on the same driven shaft perpendicularto the ramp and meshing respectively with the two lower serrated wheels carried by the same idler shaft parallel to the driven shaft, each of the upper wheels having a malefemale serration complementary to that of the other one and each of the lower wheels having a malefemale serration complementary to that of the corresponding upper wheel.

11. An installation according to claim 4 or 5 characterized in that the sealing device is formed by a closure means for forming two closure lines in the intermediate zone of the package and in that the separating device is situated downstream of the closure means so as to form a separation line between these two closure lines.

12. An installation according to claim 11, characterized in that the separating device is formed by two rotary knives adapted to completely section the package.

13. An installation according to claim 11, characterized in that the separating device is formed by a perforating machine adapted to form pre-cutting marks between the two closure lines of the intermediate zone.

14. An installation according to any one of claims 6 to 13, characterized in that each of the closure means is formed by a stitching machine.

15. An installation according to any one of claims 6 to 13, characterized in that each of the closure means is formed by a thermo-welding machine.