Method and apparatus for manufacturing a double bag

Abstract

A method and apparatus for manufacturing a double bag (20) are disclosed. The method comprises placing an inner bag (30) in an outer bag (40) through an open top end (42), inserting a gas feeding tube (50) between through the open top end (42), feeding a head space (44) between the inner bag (30) and the outer bag (40) with an inert gas through the gas feeding tube (50), extracting the gas feeding tube (50), and sealing the top end (42). A gas box (80) surrounds the open top end (42) to reduce the risk of oxygen entering the head space (44).

Claims

1. Method for manufacturing a double bag having an inner bag in an outer bag with an open top end, the method comprising: inserting a gas feeding tube through the open top end; placing a gas box over the open top end; feeding a head space between the inner bag and the outer bag with an inert gas through the gas feeding tube; enclosing the double bag with a chamber and thereby controlling the amount of the inert gas in the head space; extracting the gas feeding tube; and sealing the outer bag.

2. The method of claim 1, wherein placing the gas box comprises closing an upper box and a lower box.

3. The method of claim 1, wherein the inert gas is nitrogen.

4. The method of claim 1, wherein the gas box is flushed with nitrogen prior to feeding the head space.

5. The method of claim 1, further comprising evacuating substantially all the air from the head space prior to feeding the head space with the inert gas.

6. The method of claim 1, wherein the feeding of the head space with the inert gas comprises feeding the head space with the inert gas a first time, followed by evacuation of the head space and subsequently feeding the head space with an inert gas a second time.

7. The method of claim 1, further comprises at least partially sealing the top end prior to feeding the head space with the inert gas.

8. The method of claim 1, wherein inner bag comprises at least one of a liquid or a powder.

9. The method of claim 1, further comprising asserting a defined pressure about a lower part of the outer bag.

10. An apparatus for the manufacture of a double bag comprising: a placement device for placing an inner bag in an outer bag in a bag sealing machine; a gas box for enclosing an open top end of the outer bag; a welding device for sealing top edges of the outer bag; a gas feeding device for filing a head space between the inner bag and the outer bag with an inert gas; and a chamber for enclosing the double bag.

11. The apparatus of claim 10, wherein the gas box comprises an upper box and a lower box.

12. The apparatus of claim 10, wherein the gas feeding device comprises a removable tube adapted to be removed after filling the head space with the inert gas.

13. The apparatus of claim 10, further comprising a vacuum device for evacuating the head space.

14. The apparatus of claim 10, further comprising a chamber for enclosing a bottom of the outer bag.

15. The apparatus of claim 14, wherein the chamber maintains a constant pressure about the outer bag.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) For a more complete understanding of the present invention and the advantages thereof, reference is now made to the following description and the accompanying drawings, in which:

(2) FIG. 1 shows an example of a manufacturing apparatus according to one aspect of this invention.

(3) FIG. 2 shows a double bag.

(4) FIG. 3 illustrates the method of manufacture of the double bag.

(5) FIGS. 4A-4C show various stages of the method of manufacture.

(6) FIG. 5 shows a box about the outer bag.

DETAILED DESCRIPTION OF THE INVENTION

(7) FIG. 1 shows a perspective view of an example of a manufacturing apparatus 10 for a double bag 20 according to one aspect of this invention and FIG. 2 shows an example of the double bag 20. The double bag 20 has an inner bag 30 and an outer bag 40. The inner bag 30 has at least one port 32, and commonly two ports, and is filled in one or more chambers with contents 35, e.g. a pharmaceutical product, such as but not limited to a saline solution, or a biological product, such as but not limited to blood products. The contents 35 can be in powder or fluid form and could also contain a mixture of powders and fluids. It would also be possible for the inner bag 30 to contain nutritional or nutraceutical products. The inner bag 30 is manufactured in another apparatus and the contents 35 remain sealed within the inner bag 30 during the manufacture of the double bag 20.

(8) The outer bag 40 is placed about the inner bag 30 at a bag manufacturing position (not shown). The manufacturing apparatus 10 includes further an upper support 12u and a lower support 121 to hold the double bag 20 in position and a support 14 on which the double bag 20 is placed. In one aspect of the manufacturing apparatus, the support 14 is a transport belt on which the double bag 20 is placed and on which the double bag 20 is transported from the bag manufacturing position into the manufacturing apparatus 10. In another aspect, the support is a stationary support table 14 and the double bag 20 is placed onto the support table 14.

(9) The double bag 20 is shown in more detail in FIG. 2. It will be appreciated that this double bag 20 is merely exemplary and its design is not limiting of the invention. The inner bag 30 and the outer bag 40 are manufactured from polymer materials, such as but not limited to polypropylene, that can be heat sealed. The polymer materials have barrier properties to reduce the risk of oxygen passing through the materials and contaminating the contents 35.

(10) The manufacturing apparatus 10 is provided with a gas feeding tube 50 which can be inserted into an open top end 42 of the outer bag 40. The gas feeding tube 50 is connected to a gas supply 60 for supplying nitrogen gas (or another inert gas) into the outer bag 40. The gas feeding tube 50 can be inserted into and removed from the head space 44 between the inner bag 30 and the outer bag 40. The gas feeding tube 50 can also be connected to a vacuum pump 70 for removing gas from the head space 44. Alternatively, a separate tube could be connected to the vacuum pump 70. The manufacturing apparatus 10 includes two spreading arms 52 which can be used to open the top end 42 of the outer bag 40 to provide a smooth surface.

(11) The manufacturing apparatus 10 includes a gas box 80 which is constructed from an upper box 80u and a lower box 801. The upper box 80u and the lower box 801 can be moved together to form the gas box 80 such that the gas box 80 encloses the top end 42 of the outer bag 40, as is shown in FIGS. 4B and 4C. The manufacturing apparatus has also a heating element 90 formed of an upper heating element 90u and a lower heating element 901. The gas box 80 and the heating element 90 are shown in more detail in FIGS. 4A-4C. It will be seen from FIG. 4A that the top end 42 of the outer bag 40 has been inserted between the upper box 80u and the lower box 801.

(12) The top box 80u and the lower box 801 have each a sealing rim 82u and 821 which cooperate when the upper box 80u is closed onto the lower box 801 to form a nitrogen space 84 connected to a nitrogen feed line 86, as is shown in FIG. 4B. FIGS. 4A and 4B demonstrate that the open top end 42 is arranged, on closure of the upper box 80u and the lower box 801, such that the open top end 42 is located within the nitrogen space 84. The nitrogen space 84 is flushed with nitrogen gas through the nitrogen feed line 86.

(13) The upper heating element 90u and the lower heating element 901 can also be moved together to form a weld or seam in the outer bag 40, as can be seen in FIG. 4C.

(14) FIG. 3 shows a flow diagram for the manufacture of the double bag 20. In a first step 310 the double bag 20 with the inner bag 30 and the outer bag 40 is transported into the manufacturing machine 10. This is done by placing the double bag 20 on the support 14 in the form of the transport belt. The outer bag 40 is opened in step 313. The opening 313 is carried out by pulling apart the two sheets forming the outer bag 40, for example using suckers and then inserting the spreading arms 52 into the open top end 42 of the outer bag 40 to spread open the open top end 42 of the bag and smooths the open top end 42. The gas feeding tube 50 is then inserted through the open top end 42 in step 319.

(15) In step 320 the upper holding element 12u and the lower holding element 121 are moved together to hold the double bag 20 in the manufacturing apparatus, as is seen in FIG. 4A. In step 323 the upper box 80a and the lower box 80b are moved together to form the gas box 80 about the open top end 42. The gas box 80 is flushed with an inert gas—such as nitrogen—in step 326. In step 330 the head space 44 in the outer bag 40 can be evacuated and then filled in step 335 with an inert gas, such as nitrogen.

(16) After filling the head space 44 in step 335, the gas feeding tube 50 is extracted in step 340 and the top end 42 heat sealed in step 350. The sealed double bag 20 with the inner bag 30 and the outer bag 40 can be transported out of the manufacturing apparatus 10 on the support 14 in the form of the transport belt.

(17) The evacuation of the head space 44 in step 330 is optional. This evacuation removes as much air as possible before the head space 44 is filled with nitrogen. This minimises the amount of oxygen in the head space 44 before the outer bag 40 is sealed in step 350.

(18) In a further aspect of the invention, the head space 44 can be evacuated again after a first filling with nitrogen in step 335 and then refilled with nitrogen. The first filling with nitrogen effectively flushes out any remaining oxygen in the bag before the second filling with nitrogen. The flushing and refilling process can be repeated several times to remove any remaining residual oxygen.

(19) The gas box 80 encloses the top end 42 of the outer bag 40 in order to provide a controlled atmosphere and avoid leakage of atmospheric air containing oxygen from the atmosphere into the head space 44 of the outer bag 40.

(20) In a further aspect, the amount of the inert gas in the head space 44 can be controlled by enclosing the double bag 20 with the outer bag 40 and the inner bag 30 with a chamber 500 as shown in FIG. 5. The chamber 500 is connected to a gas supply 520 which supplies a gas, such as nitrogen or another inert gas or indeed air, and is moved toward the support 14 on which the double bag 20 is placed in the manufacturing apparatus 10. The chamber 500 has sealing lips 510, which are used to form a substantially gas tight connection and the gas is supplied to a pre-determined pressure within the chamber 500. The gas pressure in the chamber 500 balances the pressure of the nitrogen head space 44 and ensures that a substantially similar amount of nitrogen (or other inert gas) is in the head space 44. This can be important in meeting customer and regulatory requirements.

REFERENCE NUMERALS

(21) 10 Manufacturing apparatus 12u Upper support 12l Lower support 14 Support 20 Double bag 30 Inner bag 32 Port 35 Contents 40 Outer bag 42 Top end 44 Head Space 50 Gas feeding tube 52 Spreading arms 60 Gas supply 70 Vacuum pump 80 gas box 80u Upper box 80l Lower box 82u Sealing rim 82l Sealing rum 84 Nitrogen space 86 Nitrogen feed line 90u Upper support 90l Lower support 500 Chamber 510 Sealing lips 520 Gas supply