BAG FILLING PROCESS

Abstract: A process and apparatus for filling a bag with a powdered or granular material wherein a measured quantity of said material is subjected to a vacuum to compact the material prior to its being dispensed into the bag.

Description: Bag Filling Process The present invention relates to a process for filling a bag with a measured quantity of powdered or granular material , for example powdered cement . It has long been known to fill a bag with powdered material such as cement by dispensing measured quantities of the material into the bag from a hopper. However, using a conventional filling process, the packing density of the powdered material within a filled bag is typically very low, which has a number of disadvantages. Firstly, the loosely packed material within the bag will make the bag difficult to manipulate. Secondly, when the bag is opened, for example by hitting the bag with the blade of a shovel, a large amount of the powdered material may be dispersed into the surrounding atmosphere, thereby giving rise to a potential health hazard. Thirdly, a loosely packed bag, if sealed, will be more likely to burst when subjected to external pressure, for example when the bag is stored in a stack. We have now devised a process for filling a bag with powdered material which overcomes the limitations of existing processes . According to a first aspect of the present invention, there is provided a process for filling a bag with a powdered or granular material wherein a measured quantity of said material is subjected to a vacuum to compact the material prior to its being dispensed into the bag. It will be appreciated that by increasing the density of the powdered or granular material, the volume of air within the filled bag will be minimised. Preferably the material is compacted within a chamber and is dispensed by positioning the chamber within the bag, such that the base of the chamber extends substantially to the base of the bag, and then releasing the compacted material from the base of the chamber whilst simultaneously separating the base of the chamber from the base of the bag. The compacted material will thus remain relatively undisturbed as it is dispensed and therefore will maintain its high packing density. Preferably, having been evacuated to compact the powdered or granular material, the top of the chamber is pressurised to encourage the release of the compacted material into the bag. The chamber may be positioned within the bag by lowering the chamber into bag and/or by raising bag to envelop the chamber . The base of the chamber may be separated from the base of the bag by raising the chamber and/or by lowering bag. Once filled, the volume of air within the bag may be further reduced by inserting a suction device into the material contained in the bag, via the mouth of the bag, and applying suction via the suction device. The volume of air within the bag may also or otherwise be further reduced by forming a partial seal across the mouth of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from the interior of the bag through its partially sealed mouth. Preferably the partial seal is formed by series of joins extending across the mouth of the bag. Once the bag has been compressed and/or subjected to a vaccuum, the mouth of the bag may then be fully sealed or, where the partial seal is formed by a series of joins extending across the mouth of the bag, a second series of joins may be formed in parallel with the first series of joins. In the latter case, the joins of the first and second series are preferably staggered to form a series of convoluted passages across the mouth of the bag. Alternatively, once filled, the volume of air within the bag may be further reduced by fully sealing the mouth of the bag, forming a small puncture hole in the side of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from the interior of the bag through the puncture hole . Once the bag has been compressed and/or subjected to a vaccuum, the puncture hole is preferably closed, for example by a weld or by applying an adhesive patch to the bag to cover the hole. Prior to forming the small puncture hole, the fully sealed bag may be vibrated and/or compressed to cause air within the bag to collect adjacent the point at which the puncture hole is to be formed. According to a second aspect of the present invention, there is provided a process for filling a bag with powdered or granular material wherein a measured quantity of said material is compacted within a chamber and is dispensed by positioning the chamber within the bag, such that the base of the chamber extends substantially to the base of the bag, and then releasing the compacted material from the base of the chamber whilst simultaneously separating the base of the chamber from the base of the bag. The material may be compacted by compressing the material or, more preferably, by evacuating the chamber. According to a third aspect of the present invention, there is provided a process for reducing the volume of air within a bag filled with a measured quantity of powdered or granular material comprising the steps of forming a partial seal across the mouth of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from its interior through the partially sealed mouth. Preferably the partial seal is formed by series of joins extending across the mouth of the bag. Once the bag has been compressed and/or subjected to a vaccuum, the mouth of the bag may be fully sealed or, where the partial seal is formed by a series of joins extending across the mouth of the bag, a second series of joins may be formed in parallel with the first series of joins. In the latter case, the joins of the first and second series are preferably staggered to form a series of convoluted passages across the mouth of the bag. According to a fourth aspect of the present invention, there is provided a process for partially sealing a bag by forming at least one series of joins across the mouth of the bag. Preferably at least two series of joins are formed in parallel across the mouth of the bag, with the joins of adjacent series being staggered to form a series of convoluted passages across the mouth of the bag. According to a fifth aspect of the present invention, there is provided a process for reducing the volume of air within a bag filled with a measured quantity of powdered or granular material comprising the steps of fully sealing the mouth of the bag, forming a small puncture hole in the side of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from the interior of the bag through the puncture hole. Once the bag has been compressed and/or subjected to a vaccuum, the puncture hole is preferably closed, for example by a weld or by applying an adhesive patch to the bag to cover the hole. Prior to forming the small puncture hole, the fully sealed bag may be vibrated and/or compressed to cause air within the bag to collect adjacent the point at which the puncture hole is to be formed. According to a sixth aspect of the present invention, there is provided a process for reducing the volume of air within a bag filled with a measured quantity of powdered or granular material comprising inserting a suction device into the material contained in the bag, via the mouth of the bag, and applying suction via the suction device. Embodiments of the present invention will now be described by way of examples only and with reference to the accompanying drawing which is a schematic illustration of an in-line bag packing process in accordance with the present invention. Referring to the drawing, a hopper 2 is shown, from which powdered material is fed by an screw 4 to a weighing chamber 6. Once the desired weight of material has accumulated in the weighing chamber, the material is discharged into a conditioning chamber 8, within which the material is compacted by evacuating air from the chamber. The compacted material is then released from the base of the conditioning chamber 8 into a plastics bag 10 which is positioned such that it envelops the conditioning chamber, with the base of the chamber extending substantially to the base of the bag. As the compacted material is being released, the plastics bag 10 is gradually lowered away from the conditioning chamber 8, thereby minimising any disturbance which might loosen the compacted material. To assist in the release of material from the conditioning chamber, a pressure differential is preferably established by re-introducing air into the top of the chamber . The filled bag is then transported to a possing station where the mouth of the bag is held open as its contents are subjected to a low frequency jog, for example by repeatedly raising and dropping the bag or by subjecting the bag to a series of blows . The filled bag may pass through a series of possing stations according to the rate at which filled bags are delivered from the conditioning chamber and the level of de- aeration required. A suction device (not shown) is then inserted into the material contained in the bag, via the mouth of the bag, and suction applied via the suction device to further compact the material. The apparatus is preferably arranged such that, between successive suction operations, air is blown through the suction device to dislodge any residual material therefrom, which might otherwise reduce the suction capability of the device. The bag is then partially sealed by forming a series of welds 12 across its mouth and then compressed between a pair of opposed plates 14 to expel excess air from its interior through the partially sealed mouth. A pair of opposed rollers 16 run across the top of the bag 10 as it is compressed to expel any remaining air from the ullage region of the bag. Excess air may also or otherwise be expelled from the interior of the partially sealed bag by subjecting the bag to a vaccuum, for example by placing the partially sealed bag in a vaccuum chamber which is then evacuated. A second series of welds 18 is finally formed across the top of the bag 10, in parallel with the first series of welds 12, with the two series of welds being staggered to provide a series of convoluted channels which allow further air to escape from the bag, for example if the bag is compressed within a stack, but which also inhibit the release of the powdered or granular material from, or the ingress of moisture into, the bag. In an alternative embodiment, the mouth of the bag is fully sealed and the bag transported on its side along a vibrating conveyor belt, causing any remaining air to accumulate against the upper surface of the bag. The fully sealed bag may also or otherwise be compressed, before the uppermost side of the bag is punctured and the bag compressed and/or subjected to a vaccuum, e.g. within a vaccuum chamber, to expel the accumulated air. Finally, the puncture hole is sealed by a weld or by applying an adhesive patch over the hole. The processes thus described result in a tightly packed bag of powdered material which contains a minimal volume of air.

Claims: Claims . 1) A process for filling a bag with a powdered or granular material wherein a measured quantity of said material is subjected to a vacuum to compact the material prior to its being dispensed into the bag. 2) A process as claimed in Claim 1, wherein the powdered or granular material is compacted within a chamber and is dispensed by positioning the chamber within the bag, such that the base of the chamber extends substantially to the base of the bag, and then releasing the compacted material from the base of the chamber whilst simultaneously separating the base of the chamber from the base of the bag. 3) A process as claimed in Claim 2, wherein, once the chamber has been evacuated to compact the powdered or granular material, the top of the chamber is then pressurised to encourage the release of the compacted material into the bag. 4) A process as claimed in Claim 2 or Claim 3, wherein the chamber is positioned within the bag by lowering the chamber into bag. 5) A process as claimed in Claim 2 or Claim 3, wherein the chamber is positioned within the bag by raising the bag to envelop the chamber. 6) A process as claimed in any of Claims 2 to 5, wherein the base of the chamber is separated from the base of the bag by raising the chamber. 7) A process as claimed in any of Claims 2 to 5, wherein the base of the chamber is separated from the base of the bag by lowering the bag. 8) A process as claimed in any preceding claim, wherein, once the bag has been filled, the volume of air within the bag is then further reduced by forming a partial seal across the mouth of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from the interior of the bag through its partially sealed mouth. 9) A process as claimed in Claim 8, wherein the partial seal is formed by series of joins extending across the mouth of the bag. 10) A process as claimed in Claim 8 or Claim 9, wherein, once the bag has been compressed and/or subjected to a vaccuum, the mouth of the bag is then fully sealed. 11) A process as claimed in Claim 9, wherein, once the bag has been compressed and/or subjected to a vaccuum, a second series of joins is then formed in parallel with the first series of joins. 12) A process as claimed in Claim 11, wherein the joins of the first and second series are staggered to form a series of convoluted passages across the mouth of the bag. 13) A process as claimed in any of Claims 1 to 7, wherein, once the bag has been filled, the volume of air within the bag is then further reduced by fully sealing the mouth of the bag, forming a small puncture hole in the side of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from the interior of the bag through the puncture hole. 14) A process as claimed in Claim 13, wherein, once the bag has been compressed and/or subjected to a vaccuum, the puncture hole is then closed. 15) A process as claimed in Claim 14, wherein the puncture hole is closed by a weld. 16) A process as claimed in Claim 14, wherein the puncture hole is closed by applying an adhesive patch to the bag to cover the hole . 17) A process for filling a bag with powdered or granular material wherein a measured quantity of said material is compacted within a chamber and is dispensed by positioning the chamber within the bag, such that the base of the chamber extends substantially to the base of the bag, and then releasing the compacted material from the base of the chamber whilst simultaneously separating the base of the chamber from the base of the bag. 18) A process as claimed in Claim 17, wherein the powdered or granular material is compacted by compressing the material. 19) A process as claimed in Claim 17, wherein the powdered or granular material is compacted by evacuating the chamber. 20) A process as claimed in Claim 19, wherein, having been evacuated to compact the powdered or granular material, the top of the chamber is then pressurised to encourage the release of the compacted material into the bag. 21) A process as claimed in any of Claims 17 to 20, wherein the chamber is positioned within the bag by lowering the chamber into bag. 22) A process as claimed in any of Claims 17 to 20, wherein the chamber is positioned within the bag by raising the bag to envelop the chamber. 23) A process as claimed in any of Claims 17 to 22, wherein the base of the chamber is separated from the base of the bag by raising the chamber. 24) A process as claimed in any of Claims 17 to 22, wherein the base of the chamber is separated from the base of the bag by lowering the bag. 25) A process for reducing the volume of air within a bag filled with a measured quantity of powdered or granular material comprising the steps of forming a partial seal across the mouth of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from the interior of the bag through the partially sealed mouth. 26) A process as claimed in Claim 25, wherein the partial seal is formed by series of joins extending across the mouth of the bag. 27) A process as claimed in Claim 25 or Claim 26, wherein, once the bag has been compressed and/or subjected to a vaccuum, the mouth of the bag is then fully sealed. 28) A process as claimed in Claim 26, wherein, once the bag has been compressed and/or subjected to a vaccuum, a second series of joins is then formed in parallel with the first series of joins. 29) A process as claimed in Claim 28, wherein the joins of the first and second series are staggered to form a series of convoluted passages across the mouth of the bag. 30) A process for partially sealing a bag by forming at least one series of joins across the mouth of the bag. 31) A process as claimed in Claim 30, wherein at least two series of joins are formed in parallel across the mouth of the bag, with the joins of adjacent series being staggered to form a series of convoluted passages across the mouth of the bag. 32) A process for reducing the volume of air within a bag filled with a measured quantity of powdered or granular material comprising the steps of fully sealing the mouth of the bag, forming a small puncture hole in the side of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from the interior of the bag through the puncture hole . 33) A process as claimed in Claim 32, wherein, once the bag has been compressed and/or subjected to a vaccuum, the puncture hole is then closed. 34) A process as claimed in Claim 33, wherein the puncture hole is closed by a weld. 35) A process as claimed in Claim 33, wherein the puncture hole is closed by applying an adhesive patch to the bag to cover the hole . 36) An apparatus arranged to fill a bag with a powdered or granular material by subjecting a measured quantity of said material to a vacuum to compact the material and dispensing the compacted material into the bag. 37) An apparatus as claimed in Claim 36, wherein the powdered or granular material is compacted within a chamber and is dispensed by positioning the chamber within the bag, such that the base of the chamber extends substantially to the base of the bag, and releasing the compacted material from the base of the chamber whilst simultaneously separating the base of the chamber from the base of the bag. 38) An apparatus as claimed in Claim 37, wherein, once the chamber has been evacuated to compact the powdered or granular material, the top of the chamber is then pressurised to encourage the release of the compacted material into the bag. 39) An apparatus as claimed in Claim 37 or Claim 38, wherein the chamber is positioned within the bag by lowering the chamber into bag. 40) An apparatus as claimed in Claim 37 or Claim 38, wherein the chamber is positioned within the bag by raising the bag to envelop the chamber. 41) An apparatus as claimed in any of Claims 37 to 40, wherein the base of the chamber is separated from the base of the bag by raising the chamber. 42) An apparatus as claimed in any of Claims 37 to 40, wherein the base of the chamber is separated from the base of the bag by lowering the bag. 43) An apparatus as claimed in any of Claims 36 to 42, wherein, once the bag has been filled, the volume of air within the bag is then further reduced by forming a partial seal across the mouth of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from the interior of the bag through its partially sealed mouth. 44) An apparatus as claimed in Claim 43, wherein the partial seal is formed by series of joins extending across the mouth of the bag. 45) An apparatus as claimed in Claim 43 or Claim 44, wherein, once the bag has been compressed and/or subjected to a vaccuum, the mouth of the bag is then fully sealed. 46) An apparatus as claimed in Claim 44, wherein, once the bag has been compressed and/or subjected to a vaccuum, a second series of joins is then formed in parallel with the first series of joins. 47) An apparatus as claimed in Claim 46, wherein the joins of the first and second series are staggered to form a series of convoluted passages across the mouth of the bag. 48) An apparatus as claimed in any of Claims 36 to 42, wherein, once the bag has been filled, the volume of air within the bag is then further reduced by fully sealing the mouth of the bag, forming a small puncture hole in the side of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from the interior of the bag through the puncture hole . 49) An apparatus as claimed in Claim 48, wherein, once the bag has been compressed and/or subjected to a vaccuum, the puncture hole is then closed. 50) An apparatus as claimed in Claim 49, wherein the puncture hole is closed by a weld. 51) An apparatus as claimed in Claim 49, wherein the puncture hole is closed by applying an adhesive patch to the bag to cover the hole. 52) An apparatus arranged to fill a bag with powdered or granular material by compacting a measured quantity of said material within a chamber and dispensing the compacted material by positioning the chamber within the bag, such that the base of the chamber extends substantially to the base of the bag, and then releasing the compacted material from the base of the chamber whilst simultaneously separating the base of the chamber from the base of the bag. 53) An apparatus as claimed in Claim 52, wherein the powdered or granular material is compacted by compressing the material . 54) An apparatus as claimed in Claim 52, wherein the powdered or granular material is compacted by evacuating the chamber. 55) An apparatus as claimed in Claim 54, wherein, having been evacuated to compact the powdered or granular material, the top of the chamber is then pressurised to encourage the release of the compacted material into the bag. 56) An apparatus as claimed in any of Claims 52 to 55, wherein the chamber is positioned within the bag by lowering the chamber into bag. 57) An apparatus as claimed in any of Claims 52 to 55, wherein the chamber is positioned within the bag by raising the bag to envelop the chamber. 58) An apparatus as claimed in any of Claims 52 to 57, wherein the base of the chamber is separated from the base of the bag by raising the chamber. 59) An apparatus as claimed in any of Claims 52 to 57, wherein the base of the chamber is separated from the base of the bag by lowering the bag. 60) An apparatus arranged to reduce the volume of air within a bag filled with a measured quantity of powdered or granular material by forming a partial seal across the mouth of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from the interior of the bag through the partially sealed mouth. 61) An apparatus as claimed in Claim 60, wherein the partial seal is formed by series of joins extending across the mouth of the bag. 62) An apparatus as claimed in Claim 60 or Claim 61, wherein, once the bag has been compressed and/or subjected to a vaccuum, the mouth of the bag is then fully sealed. 63) An apparatus as claimed in Claim 61, wherein, once the bag has been compressed and/or subjected to a vaccuum, a second series of joins is then formed in parallel with the first series of joins. 64) An apparatus as claimed in Claim 63, wherein the joins of the first and second series are staggered to form a series of convoluted passages across the mouth of the bag. 65) An apparatus arranged to partially seal a bag by forming at least one series of joins across the mouth of the bag. 66) An apparatus as claimed in Claim 65, wherein at least two series of joins are formed in parallel across the mouth of the bag, with the joins of adjacent series being staggered to form a series of convoluted passages across the mouth of the bag. 67) An apparatus arranged to reduce the volume of air within a bag filled with a measured quantity of powdered or granular material by fully sealing the mouth of the bag, forming a small puncture hole in the side of the bag and then compressing the bag and/or subjecting the bag to a vaccuum, to expel air from the interior of the bag through the puncture hole. 68) An apparatus as claimed in Claim 67, wherein, once the bag has been compressed and/or subjected to a vaccuum, the puncture hole is then closed. 69) An apparatus as claimed in Claim 68, wherein the puncture hole is closed by a weld. 70) An apparatus as claimed in Claim 68, wherein the puncture hole is closed by applying an adhesive patch to the bag to cover the hole . 71) A process as claimed in Claim 13 or Claim 32, wherein prior to forming the small puncture hole, the fully sealed bag is compressed and/or vibrated to cause air within the bag to collect adjacent the point at which the puncture hole is to be formed. 72) An apparatus as claimed in Claim 48 or Claim 67, wherein prior to forming the small puncture hole, the fully sealed bag is compressed and/or vibrated to cause air within the bag to collect adjacent the point at which the puncture hole is to be formed. 73) A process for reducing the volume of air within a bag filled with a measured quantity of powdered or granular material comprising inserting a suction device into the material contained in the bag, via the mouth of the bag, and applying suction via the suction device. 74) An apparatus arranged to reduce the volume of air within a bag filled with a measured quantity of powdered or granular material by inserting a suction device into the material contained in the bag, via the mouth of the bag, and applying suction via the suction device .

Inventors: BALDRY RICHARD HUGH, HEGARTY TIMOTH JOHN MICHAEL, BALDRY, RICHARD, HUGH, HEGARTY, TIMOTH, JOHN, MICHAEL
Applicants: BALDRY RICHARD HUGH, GRT LTD, HEGARTY TIMOTH JOHN MICHAEL, BALDRY, RICHARD, HUGH, GRT LIMITED, HEGARTY, TIMOTH, JOHN, MICHAEL
Application year: 2001
Main classification: B65B63
IPC codes: B65B1