Method and apparatus for packaging a liquid food product

Abstract

An apparatus for forming a thermoplastic container from a cylindrical preform and for delivering a predetermined volume of a beverage component into the container. The apparatus includes: a mold defining a shape of the container; a member configured to inject at least one beverage component into a recess in the preform so as to promote expansion of the preform inside the mold into the shape of the container, the member being further configured to inject the at least one beverage component in a first volume intentionally greater than the predetermined volume; and the member also being configured to remove a fraction of the first volume of the beverage component until a second volume of beverage component remaining in the container is equal to the predetermined volume.

Claims

1. An apparatus for forming a thermoplastic container from a heated cylindrical preform and for delivering a predetermined volume of a beverage component into the container, the apparatus comprising: a mold defining a shape of the container; an injection device configured to inject at least one beverage component into a recess in the preform so as to promote expansion of the preform inside the mold into the shape of the container, the injection device being further configured to inject the at least one beverage component in a first volume intentionally greater than the predetermined volume; the injection device including a nozzle coupled to an actuator configured to pressurize and provide the beverage component; and a suction device independent of the actuator, the suction device being coupled to the nozzle and configured to withdrawal and remove a fraction of the first volume of the beverage component until a second volume of beverage component remaining in the container is equal to the predetermined volume.

2. The apparatus according to claim 1, wherein the suction device is a suction pump.

3. The apparatus according to claim 1, wherein the actuator includes a filling cylinder and piston.

4. The apparatus according to claim 1, wherein the suction device is a suction pump.

5. The apparatus according to claim 1, further comprising a stretch rod coupled to and extending through the nozzle, the stretch rod being moveable between extended and retracted positions.

6. The apparatus according to claim 5, wherein the stretch rod is hollow.

7. The apparatus according to claim 6, further comprising a suction device configured to withdrawal the fraction of the first volume of the beverage component through the stretch rod.

8. The apparatus according to claim 7, wherein the suction device is a suction pump.

9. The apparatus according to claim 5, wherein the stretch rod is coupled to an actuator configured to pressurize and provide the beverage component through the stretch rod.

10. The apparatus according to claim 9, wherein the actuator includes a filling cylinder and piston.

11. The apparatus according to claim 6, wherein the stretch rod has an internal profile configured to minimize turbulence of the beverage component during injection through the stretch rod.

12. The apparatus according to claim 6, wherein a first injection path for the beverage component is defined through the stretch rod and a second injection path is defined about the stretch rod, the second injection path being for one of the beverage component or a second beverage component.

13. The apparatus according to claim 5, wherein an injection path for the beverage component is defined about the stretch rod and the stretch rod has an external profile configured to minimize turbulence of the beverage component during injection of the beverage component.

14. An apparatus for forming a thermoplastic container from a heated cylindrical preform and for delivering a predetermined volume of a beverage component into the container, the apparatus comprising: a mold defining a shape of the container; a nozzle coupled to an injection device configured to inject at least one beverage component into a recess in the preform so as to promote expansion of the preform inside the mold into the shape of the container, the nozzle and injection device being further configured to inject the at least one beverage component in a first volume intentionally greater than the predetermined volume; and the nozzle also coupled to a suction device, distinct from the injection device, configured to remove a fraction of the first volume of the beverage component until a second volume of beverage component remaining in the container is equal to the predetermined volume.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be described in detail with reference to the appended figures, which relate to exemplary embodiments.

(2) FIG. 1 shows a general diagram of an installation suitable for operating with the invention.

(3) FIG. 2 is a schematic diagram of another installation embodying the principles of the present invention.

(4) FIG. 3 shows a bell-shaped nozzle end-piece used within the context of the invention.

(5) FIG. 4 shows the monitoring of the formation of a mineral water bottle according to one example of the use of the invention.

DETAILED DESCRIPTION

(6) The embodiment given here by way of example relates to a process for manufacturing PET mineral water bottles from a heated preform. The preform has the shape of a cylindrical tube closed at its lower end. The open head of the preform corresponds to the throat or neck of the bottle, onto which a closure cap is screwed.

(7) Referring to FIG. 1, a stretch rod 10 is inserted into a compressed-air actuator 15. The stretch rod 10 is generally controlled by an air actuator associated with a cam, which gives it a longitudinal movement (represented by an arrow). It is also possible to use a stretch motor.

(8) The compressed-air actuator 15 comprises a control cylinder 17 controlling an injection head 18, through which the stretch rod 10 passes. The injection head 18 is connected to the neck 20 of a PET preform placed in a mold (not shown), which preform, after being expanded, takes on the shape of a mineral water bottle, this shape being determined by the wall of the mold.

(9) The actuator 15 comprises three chambers, the upper two chambers 15a and 15b being filled with compressed air. Between these upper two chambers 15a, 15b, a piston wall 19 slides in a direction parallel to the stretch rod (the 30 displacement being represented by an arrow). The stretch rod 10 passes through the center of this wall 19.

(10) The compressed-air actuator also includes a lateral inlet 30 for the beverage, here mineral water, connected to a third chamber 15c of the actuator, this being the bottom chamber. The beverage is fed in via a line 32.

(11) An external mineral water inlet feeds the liquid via the remote end of this line 32 into a first valve 34, which is connected to the opening of a single-chamber filling cylinder 40 comprising a piston 42 controlled by a filling motor (movement of which is represented by an arrow). This motor imparts a longitudinal movement on the piston in the single chamber of the filling cylinder 40.

(12) On the line 32 there is a second valve 36, which is in series behind the first valve 34 and the opening of the filling cylinder 40. The line 32 then runs into the bottom chamber 15c of the compressed-air actuator 15.

(13) The bottom chamber 15c of the compressed-air actuator is penetrated by the control cylinder 17, which controls the filling head 18, the internal volume of which emerges through the lower outlet of the compressed-air actuator 15 and through the filling head 18. The control cylinder has a lateral opening 25 allowing the beverage to circulate between the bottom chamber 15c of the actuator 15 and the inside of the control cylinder 17.

(14) The stretch rod 10 itself passes through the control cylinder 17 as far as the filling head 18 and the neck 20 of the bottle preform.

(15) Referring to FIG. 2, showing an alternative embodiment, a pressurizing actuator 100 increases the pressure of the beverage in the beverage feed line 110. A volumetric sensor 120 allows the volume injected through the line 110 to be monitored. The beverage is introduced into the nozzle 130 through the line 110.

(16) The stretch rod 140 is introduced along the axis of the nozzle 130.

(17) A suction pump 150 is attached to a line 170 connected via a volumetric sensor 160 to the nozzle 130.

(18) The nozzle 130 is positioned facing the mold (not shown) in which the PET preform, to be expanded and filled with beverage, here mineral water, is positioned. After the expansion phase, a PET water bottle 180 is formed.

(19) Referring to FIG. 3, a bell-shaped nozzle end-piece 500 according to a preferred embodiment is shown. The internal and external pressures on either side of the circumference of the neck of the preform (i.e. on the external surfaces 510 of the neck and on the internal surfaces 520 of the neck) are identical, owing to the presence of a passage 505 connecting the volumes on either side of the circumference, inside the nozzle. During filling, sealing is provided by the flange 530 on the preform. Thanks to this device, there is no risk of the neck of the preform deforming while a pressurized fluid is being injected by the nozzle.

(20) According to another embodiment, a nozzle end-piece holds the external surfaces 510 of the neck of the preform in such a way that when a pressurized fluid is injected via the top of the nozzle into the recess of the preform, the pressure exerted on the internal walls 520 of the neck of the preform by the fluid is compensated for by the holding by the walls of the bell-shaped nozzle end-piece. The neck of the preform therefore does not deform, despite the high pressure.

(21) FIG. 4 shows the variation over time of the position 101 of the stretch rod and the position 102 of the filling actuator controlling the inflow of the mineral water into the expanded preform.

(22) The horizontal axis represents the time, the left-hand vertical axis represents the position of the stretch rod and the right-hand vertical axis represents the volume of water introduced into the expanded preform, this being proportional to the position of the filling actuator.

(23) During a first part of the process, from 0 to 250 ms, the stretch rod advances at an essentially constant rate, according to a preferred embodiment. However, according to another embodiment, during a first phase 110 of the process, in particular from 0 to 150 ms, the stretch rod advances at an increasing speed due to a positive acceleration. During a second phase 115 of the process, from 150 ms to 250 ms, the stretch rod advances with a negative acceleration, the speed decreasing until it becomes zero at 250 ms. However, it will be understood that the changes in speed must be sufficiently gentle to ensure regular and reliable stretching of the thermoplastic.

(24) 250 ms after the start of the process (reference 103), the stretch rod has reached its final position P.sub.f, from which it no longer moves.

(25) At the same instant, the filling actuator has introduced a volume V.sub.1 of mineral water into the expanded preform. The volume introduced from the start of the process (therefore between 0 ms and 250 ms) has progressively increased, with a progressive increase in the flow rate (filling actuator displacement acceleration).

(26) During the moments that follow, which constitute a third phase 120 of the process, up to 320 ms, the total volume of water introduced is constant, the flow rate being invariant. Next, the volume suddenly decreases by a small fraction (around 4%) over a period of 40 ms.

(27) From this instant on, the total volume introduced stabilizes around the value V2, which is finally reached after a few oscillations, the flow rate of liquid being introduced being zero.

(28) A few instants later, starting from 450 ms after the start of the process (reference 104), the filling actuator has reached a final position, from which it no longer moves. At this moment, it has introduced a volume V2 of mineral water into the expanded preform. The volume V2 is greater than V.sub.1, but less than twice the volume V.sub.1.

(29) During the method of using the device described, the temperature of the preform is brought beforehand to a value between 50 C. and 130 C., or even between 75 C. and 100 C. In the preferred embodiment, this value is 95 C., the plastic used being PET.

(30) The rod has a speed of between 0.5 and 3.0 m/s.sup.1, or even between 1.0 and 5 m/s.sup.1. In the preferred embodiment, this value is 1.6 m/s.sup.1.

(31) The temperature of the beverage is brought beforehand to a value 25 between 1 C. and 120 C., preferably between 10 C. and 90 C. In the preferred embodiment, this value is 30 C.

(32) The longitudinal stretch ratio of the thermoplastic is between 2 and 5 or even between 2.5 and 4. In the preferred embodiment, this value is 3.5.

(33) The radial stretch ratio of the thermoplastic is between 2 and 7, or even between 3 and 4.5. In the preferred embodiment, this value is 4.

(34) The thermoplastic is chosen from the group consisting of polyethylene terephthalates, polypropylenes, polyethylenes, polycarbonates, polystyrenes, polylactic acids, polyvinyl chlorides and combinations thereof. In the preferred embodiment, it is PET.

(35) The temperature of the mold is at least 50 C. below the melting point of the thermoplastic, which in the case of PET is 230 C. Preferably, this 5 temperature is maintained below 100 C. In the preferred embodiment, the temperature of the mold is equal to the ambient temperature.

(36) Of course, the invention is not limited to the embodiments described and illustrated by the appended drawings; rather it extends to all variants that can be envisaged by a person skilled in the art within the scope of the claims.