CONTINUOUS TREATMENT WITH PLASMA

Abstract

The present invention relates to a continuous method for producing products with molecules or macromolecules attached thereto and apparatus for carrying out this method. The method comprises the steps of: (a) placing the object on or in the proximity of a surface; (b) controlling the electrical potential of the surface with respect to its surroundings; (c) activating the object by exposing it to an electrical discharge; (d) contacting the object with the molecule or macromolecule to be attached. Such macromolecules include bacteriophage. Thus products of methods of the invention are for prevention and amelioration of bacterial contamination of the product of methods of the invention or materials in contact with said products.

Claims

1-17. (canceled)

18. A continuous method for attaching bacteriophage to an object comprising the steps of: placing the object on or in the proximity of a moving surface; controlling the electrical potential of the surface with respect to its surroundings; activating the object by exposing it to an electrical discharge; and contacting the object with the bacteriophage to be attached.

19. A method for attaching bacteriophage to an object according to claim 18, wherein the moving surface is conducting.

20. A method for attaching bacteriophage to an object according to claim 18, wherein the electrical potential of the moving surface is controlled by grounding the platform.

21. A method for attaching bacteriophage to an object according to claim 18, wherein the electrical potential of the surface is controlled by generation of an electrostatic potential from an electrode.

22. A method for attaching bacteriophage to an object according to claim 18, wherein the moving surface is a conveyor belt.

23. A method for attaching bacteriophage to an object according to claim 18, wherein the electrical discharge is a corona discharge.

24. A method for attaching bacteriophage to an object according to claim 18, wherein the object is a particle of less than or equal to 2 mm in diameter.

25. A method for attaching bacteriophage to an object according to claim 18, wherein the object is a particle of less than 1 mm in diameter.

26. A method for attaching bacteriophage to an object according to claim 18, wherein the object is 1 mm-20 mm in diameter.

27. A method for attaching bacteriophage to an object according to claim 18, wherein the particle is a food or feed pellet.

28. A method for attaching bacteriophage to an object according to claim 18, wherein the surface comprises indentations for accommodating objects.

29. An apparatus for treating an object by attaching bacteriophage thereto by a continuous process comprising: a moving surface for supporting the object being treated; an electrical discharge device capable of generating an electrical discharge positioned to activate the object being treated comprising a first electrode for generating an electrical discharge and a second electrode for controlling the electrical potential of the moving surface with respect to its surroundings; and means for contacting the object being treated with the bacteriophage.

30. An apparatus according to claim 29, wherein the moving surface comprises indentations for accommodating objects.

31. An apparatus according to claim 29, wherein the moving surface is conducting.

32. An apparatus according to claim 29, wherein the moving surface is electrically grounded.

33. An apparatus according to claim 29, wherein the moving surface is located between the first and second electrodes.

34. An electrode assembly for exposing an object supported on a moving surface to an electrical discharge comprising: an electrical discharge device capable of generating an electrical discharge, further comprising an electrode having an electrical discharge generating surface capable of generating an electrical discharge originating from an active portion of the surface, wherein the surface is movable in order to allow generation of an electrical discharge from a different portion of the surface; a barrier located in closely spaced separation to an inactive area of the electrode wherein the barrier separates the active portion of the electrode from an inactive portion of the electrode; and means for cooling the inactive portion of the electrode.

35. An electrode assembly according to claim 34, wherein the electrical discharge is generated continuously while the electrical discharge generating surface moves.

36. An electrode assembly according to claim 34, wherein the means for cooling the inactive portion of the electrode is forced air cooling.

37. An apparatus for carrying out the method of claim 18, wherein the apparatus for treating an object by attaching bacteriophage thereto by a continuous process comprises: a moving surface for supporting the object being treated; an electrical discharge device capable of generating an electrical discharge positioned to activate the object being treated comprising a first electrode for generating an electrical discharge and a second electrode for controlling the electrical potential of the moving surface with respect to its surroundings; and means for contacting the object being treated with the bacteriophage.

Description

EXAMPLES AND DESCRIPTION OF THE DRAWINGS

[0068] The invention is now illustrated in the following specific embodiments with reference to the accompanying drawing:

[0069] FIG. 1 shows a schematic diagram of an apparatus 100 as described herein in the process of treating fine particles to attach infectious bacteriophage thereto, as is also described herein.

[0070] FIG. 2 shows an isometric diagram of an apparatus 200 as described herein for treating fine particles to attach infectious bacteriophage thereto, as is also described herein.

[0071] FIG. 3 shows a cross sectional diagram of an apparatus 200 as described herein for treating fine particles to attach infectious bacteriophage thereto, as is also described herein.

[0072] FIG. 4 shows a side view diagram of an apparatus 200 as described herein for treating fine particles to attach infectious bacteriophage thereto, as is also described herein

EXAMPLE 1

[0073] An apparatus 100 for treating fine particles to attach infectious bacteriophage thereto is shown in FIG. 1.

[0074] The following components of the apparatus are shown in FIG. 1: [0075] 101—Hopper containing fine particles, which are deposited on the belt; [0076] 102—Moving belt which is made of conducting material, or is made to have conducting properties by the addition of a second electrode. This grounds the particles, thus greatly reducing or eliminating the issues with static build up; [0077] 103—Barrier across belt ensures that a fine (monolayer) of fine particles enter the corona area; [0078] 104—Rotating ceramic electrode which generates a corona to activate the material. The rotating electrode allows cooling of the top surface via channelled air flow; [0079] 105—Air is channelled over the top of the electrode to allow cooling; [0080] 106—Silicon polymer blades isolate feed from the air flow and scrape the electrode surface of any particles which attach; [0081] 107—Barrier to prevent liquid coming into contact with the corona; [0082] 108—Device to spray phage suspension onto activated feed with reservoir for same; [0083] 109—Hopper to collect phage-immobilised feed.

[0084] Thus in operation the moving (conveyor) belt 102 has fine particles deposited on it from a hopper 101. The particles are of less than or equal to 2 mm such that static electric effects might cause them to be moved at spread or dispersed in an uncontrolled manner. The particles deposited on the belt travel beneath a barrier 103 running transversely across the belt 102 in order to shape and flatten the mass of particles on the belt 102 and into a monolayer in preparation for bulk treatment of the particles.

[0085] The conveyor surface is made of a conducting material or its electrical potential is manipulated by way of using a second electrode. This serves to earth or ground the particles in order to eliminate static electricity and thus the movement of fine particles on the conveyor due to static electricity. Such effects are particularly pronounced when the particles are formed into a monolayer.

[0086] The monolayer of particles travelling on the conveyor then pass through a corona discharge 110 which causes activation of the surface of the particles. Activation is the generation of reactive free radicals on the surface of the particles.

[0087] The electrode that produces the corona discharge 104 is preferably ceramic, because the conveyor belt is conducting and thus a ceramic electrode is preferred for compatibility. In addition, the ceramic electrode 104 is cylindrical and rotates while producing the corona discharge 110. The lowest part of the curved surface of the cylindrical electrode 104 is arranged transversely to the direction of movement of the conveyor belt and faces the particles travelling on the conveyor belt 102. The electrode produces the corona discharge from this lowest portion of its surface that faces the conveyor belt.

[0088] Concomitant rotation of the cylindrical electrode 104 while producing the corona discharge means that the active portion of the electrode is constantly changing as a previously inactive portion of the electrode is brought into use as the electrode surface rotates. Production of corona discharge produces heat and causes the temperature of the active portion of the electrode to rise. Rotation of the electrode means that the previously active portion of the electrode 104 can be rotated into a cooling area 105 wherein air is channelled over the inactive, upper, portion of the electrode 104 in order to cool it before that section of the electrode becomes active once more.

[0089] In addition, silicone polymer blades 106 are arranged in close and parallel separation along the length of the curved cylindrical surface of the ceramic electrode. The presence of these silicone polymer blades 106 allows the separation of the atmosphere on the “active” side of the electrode from the atmosphere on the “inactive” side of the electrode. In this way the effectiveness of the cooling system by which air is passed over the “inactive” side of the electrode is improved and the passage of cooling air on the “inactive” side is prevented from blowing on or affecting affect the fragile monolayer of fine particles born on the conveyor belt facing the “active” side of the electrode. In addition, the arrangement of the blades 106 to be in close and parallel separation with these curved surface of the electrode 104 means that particles that may have adhered to the surface of the electrode because of a static charge or for other reasons are scraped off the electrode it rotates during the treatment process.

[0090] The activated particles on the conveyor then pass through an aperture in a screen 107 into a spraying area wherein a suspension of bacteriophage in a carrier liquid is sprayed from a reservoir 108 onto the activated particles. Spraying the bacteriophage onto the activated particles means that the surface of the bacteriophage reacts with the free radicals present on the surface of the activated particles in order to covalently link the bacteriophage to the particles. The bacteriophage attached in this way can retain infectivity and are significantly less susceptible to dehydration, chemical activation or predation. The suspension contains 1×10.sup.4 between and 1×10.sup.12 bacteriophage per ml. The suspension is applied by way of passing the suspension through a spray nozzle to form a spray formed of droplets with an average diameter of Y μm. A pump is used to apply the suspension at a flow rate of Y ml per second. The spray nozzle is located Y mm from the activated phage whilst the bacteriophage-containing spray is applied.

[0091] In once the bacteriophage have been covalently attached to particles the conveyor takes the particles to a storage hopper 109

EXAMPLE 2

[0092] An apparatus 200 for treating fine particles to attach infectious bacteriophage thereto is shown in FIGS. 2 and 3.

[0093] The following components of the apparatus are shown in FIGS. 2 and 3: [0094] 202—Moving belt whose electrical potential and the electrical potential of items borne thereon is controlled via the second/counter electrode 210. This grounds the particles, thus greatly reducing or eliminating the issues with static build up; [0095] 204—Rotating ceramic electrode which generates a corona to activate the material. The rotating electrode allows cooling of the top surface via channelled air flow; [0096] 205—Cooling pipe that supplies/channels air over the top of the electrode to allow cooling; [0097] 206—Silicon polymer blade to isolate feed from the air flow and scrape the electrode surface of any particles which attach thereto; [0098] 207—Barrier to prevent liquid coming into contact with the corona; [0099] 210—Counter electrode; and [0100] 212—High voltage (HV) cable.

[0101] Thus in operation the moving (conveyor) belt 202 has fine particles deposited on it from a hopper or other container (not shown). The particles are of a size such that static electric effects might cause them to be moved at spread or dispersed in an uncontrolled manner. The particles deposited on the belt travel beneath a barrier (not shown) running transversely across the belt 202 in order to shape and flatten the mass of particles on the belt 202 and into a monolayer in preparation for bulk treatment of the particles.

[0102] The electrical potential of the conveyor surface is manipulated by way of using a second electrode that acts as a counter electrode. This serves to control static electric charges borne by the particles and thus control or prevent the movement of fine particles on the conveyor due to static electricity. Such effects are particularly pronounced when the particles are formed into a monolayer.

[0103] The monolayer of particles travelling on the conveyor then pass through a corona discharge which causes activation of the surface of the particles. Activation is the generation of reactive free radicals on the surface of the particles.

[0104] The electrode that produces the corona discharge 204 is ceramic. In addition, the ceramic electrode 204 is cylindrical and rotates while producing the corona discharge. The lowest part of the curved surface of the cylindrical electrode 204 is arranged transversely to the direction of movement of the conveyor belt and faces the particles travelling on the conveyor belt 202. The electrode produces the corona discharge from this lowest portion of its surface that faces the conveyor belt. The electrical energy for generating the corona discharge is supplied via a high-voltage (HV) cable 212. The HV cable is held a safety distance of 60 mm from other conductive material.

[0105] Concomitant rotation of the cylindrical electrode 204 while producing the corona discharge means that the active portion of the electrode is constantly changing as a previously inactive portion of the electrode is brought into use as the electrode surface rotates. Production of corona discharge produces heat and causes the temperature of the active portion of the electrode to rise. Rotation of the electrode means that the previously active portion of the electrode 204 can be rotated into the vicinity of a cooling pipe 205 wherein air is channelled over the inactive, upper, portion of the electrode 204 in order to cool it before that section of the electrode becomes active once more.

[0106] In addition, silicone polymer blades 206 are arranged in close and parallel separation along the length of the curved cylindrical surface of the ceramic electrode. The presence of these silicone polymer blades 206 allows the separation of the atmosphere on the “active” side of the electrode from the atmosphere on the “inactive” side of the electrode. In this way the effectiveness of the cooling system by which air is passed over the “inactive” side of the electrode is improved and the passage of cooling air on the “inactive” side is prevented from blowing on or affecting affect the fragile monolayer of fine particles born on the conveyor belt facing the “active” side of the electrode. In addition, the arrangement of the blades 206 to be in close and parallel separation with these curved surface of the electrode 204 means that particles that may have adhered to the surface of the electrode because of a static charge or for other reasons are scraped off the electrode it rotates during the treatment process.

[0107] The activated particles on the conveyor then pass through an aperture in a screen (not shown) into a spraying area wherein a suspension of bacteriophage in a carrier liquid is sprayed from a reservoir (not shown) onto the activated particles. Spraying the bacteriophage onto the activated particles means that the surface of the bacteriophage reacts with the free radicals present on the surface of the activated particles in order to covalently link the bacteriophage to the particles. The bacteriophage attached in this way can retain infectivity and are significantly less susceptible to dehydration, chemical activation or predation. The suspension contains 1×10.sup.4 to 1×10.sup.12 bacteriophage per ml. The suspension is applied by way of passing the suspension through a spray nozzle to form a spray formed of droplets.

[0108] In once the bacteriophage have been covalently attached to particles the conveyor takes the particles to a storage hopper (not shown)

[0109] The invention thus provides methods and apparatus for treating substrates in order to attach substances thereto, uses of the apparatus and products provided by applying a method of the invention using the apparatus.

REFERENCES

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