Method for decontaminating the inner surface of a preform

Abstract

The present invention relates to a method for decontaminating the inner surface (26) of the neck (18) of a thermoplastic preform (12) passing sequentially along a production path (34) in a container manufacturing facility (10), each preform (12) being held by a separate holding member (58, 66), the decontamination method comprising: at least one treatment step (E1) including, within a first treatment zone (56) of the production path (34), exposing at least the inner surface (26) of the neck (18) to a bactericidal jet (54) containing a bactericide; at least one bactericide activation step (E2) including, within a second activation zone (62) of the production path (34) located downstream of the treatment zone (56), directly exposing the inner surface (26) of the neck (18) thus covered with bactericide to ultraviolet radiation (61), the power of which is about 30 mW / cm², to decompose the bactericide into more oxidizing substances, such as free radicals.

Description

Technical Field

[0001] This invention relates to a method for decontaminating the inner surface of the neck of a preform made of thermoplastic material that passes sequentially along a production path in a container manufacturing facility. Background Technology

[0002] It is known to manufacture containers for thermoplastic materials, such as polyethylene terephthalate (PET), through a stretch blow molding process of preformed parts.

[0003] Typically, preforms are axisymmetric in shape. A preform includes a neck that already has its final shape, while the body of the preform is designed to deform during the molding process. The main axis of the preform passes through the center of the neck.

[0004] To allow for deformation of the preform's body, the body is heated above its glass transition temperature, which makes the body walls malleable and significantly reduces their elastic limit. Conversely, the neck is kept below its glass transition temperature to prevent deformation.

[0005] During container molding, compressed molding fluid is injected into the body of the preform at blow molding pressure to cause the body of the preform to "expand" until it reaches its final shape.

[0006] Examples of methods for decontaminating preforms of thermoplastic materials intended for processing into containers in manufacturing facilities are known in the prior art.

[0007] The existing technology is divided into two categories: one is a method for cleaning the inner surface of a preform, and the other is a method for cleaning the outer surface of a preform, especially a method for cleaning the neck of a preform.

[0008] Cleaning the inner surface of the neck is a particularly important operation. Thorough cleaning of the inner surface is a critical standard, especially for the manufacture of containers designed to hold food. However, the inner surface of the neck is difficult to reach.

[0009] Chemical decontamination is known by exposing preforms to bactericides such as hydrogen peroxide (H2O2) or peracetic acid. These chemicals are strong oxidizing agents, allowing for the elimination of some of the microorganisms (viruses, bacteria, spores, etc.) exposed to them.

[0010] However, it has been confirmed that this chemical cleaning method is insufficient to adequately remove contaminants from preforms, especially when the preforms are intended for food or pharmaceutical use.

[0011] To improve the efficiency of bactericides, it is known that heating the bactericide, especially by exposing it to infrared radiation, can significantly enhance its effect. In effect, this heating breaks down the bactericide into more oxidizing substances, such as free radicals. At this point, the bactericide is said to be "activated."

[0012] However, the inability to heat the neck of the preform to activate the bactericide poses a challenge for those skilled in the art.

[0013] As an alternative to chemical cleaning, ultraviolet radiation is known to be used to remove stains instead of activated chemical cleaning agents.

[0014] The thermoplastic materials constituting preforms are typically opaque to ultraviolet (UV) radiation. Cleaning of the outer surface of the neck using UV radiation is limited by its surface properties; UV radiation cannot penetrate deep into the surface. Therefore, the surface to be cleaned must be directly exposed to UV radiation. This means that the surface to be treated must be accessible. For cleaning the inner surface of the preform neck, this means that cleaning is particularly difficult when the preform is held by a mandrel inserted into its neck.

[0015] However, irradiating the surface of preforms with ultraviolet radiation is less effective against certain types of microorganisms, such as mold, than chemical cleaning with bactericides, such as hydrogen peroxide (H2O2).

[0016] Typically, in most known solutions, ultraviolet treatment and chemical treatment are mutually exclusive.

[0017] Some have proposed using ultraviolet radiation instead of infrared radiation to activate bactericides.

[0018] Therefore, the preform is passed through hydrogen peroxide mist before being exposed to ultraviolet radiation. This achieves better cleaning results than ultraviolet irradiation alone.

[0019] However, this method decontaminates the preform as a whole as it passes through the feeding device of the manufacturing facility, rather than specifically targeting the inner surface of the neck.

[0020] The function of this feeding device is to organize and align preforms supplied in bulk. After alignment and straightening, the preforms are typically housed in an accumulation column between guide rails, where they can slide freely and come into contact with each other. The movement of the preforms is uncontrolled, and they can swing freely between the guide rails, especially due to the impact of collisions between them.

[0021] However, the inner surface of the neck of the preform was not uniformly covered by the bactericide, and hydrogen peroxide mist was deposited on the surface in the form of multiple droplets, but there were still uncovered areas between the droplets, especially on the inner surface of the neck where it was still difficult to be passively exposed to hydrogen peroxide mist.

[0022] Furthermore, in this decontamination method, the mist tends to escape and deposit on the surrounding components of the facility. However, because the disinfectant is highly corrosive, it needs to be diluted significantly to avoid prematurely corroding the exposed surrounding components. This further reduces the effectiveness of this decontamination method.

[0023] Furthermore, exposing preforms to ultraviolet radiation in such a feeding device has many drawbacks. In fact, the duration of preform exposure to ultraviolet radiation is uncontrolled and cannot be repeated.

[0024] In addition, the preforms need to be exposed to ultraviolet radiation for a very long time, which is not suitable for current production capacity.

[0025] In practice, it has been observed that the speed at which preforms pass through in sequence varies depending on the operating conditions of the downstream manufacturing facility. In cases of preform blockage or deceleration, these preforms may be exposed to UV radiation for extended periods, causing the thermoplastic material to crystallize, rendering them unusable for forming acceptable containers.

[0026] Furthermore, because the preforms are not individually held, some preforms may wobble or tilt when exposed to ultraviolet radiation. Consequently, a certain area on the inner surface of the neck may be underexposed.

[0027] US2019 / 176385 describes a method and apparatus for decontaminating preforms, which reduces the amount of residual hydrogen peroxide during preform sterilization. A sterilizing agent consisting of at least 30% or less hydrogen peroxide and a solvent with a boiling point of 85°C or lower is vaporized, and this sterilizing agent gas is sprayed onto the preform. The preform, after being sprayed with the sterilizing agent, is then heated to a temperature suitable for molding, regardless of whether hot air is sprayed onto the preform. Furthermore, after irradiating the preform with ultraviolet light, the sterilizing agent gas is sprayed onto the preform, and the preform is heated to a temperature suitable for molding.

[0028] However, a drawback of this method is that it does not provide sufficient cleaning effect, especially for the neck of the preform.

[0029] Generally speaking, there is a continuous pursuit of improved decontamination, especially for agricultural product packaging. Furthermore, decontamination must be suitable for very high production speeds, such as at least 60,000 preforms per hour.

[0030] Therefore, new solutions are sought to improve the degree of decontamination achieved and the types of microorganisms eliminated during decontamination operations on the outer surfaces of preforms (especially the inner surfaces of the neck of preforms). Summary of the Invention

[0031] This invention proposes a decontamination method for removing contamination from the inner surface of the neck of thermoplastic preforms passing in a line along a production path in a container manufacturing facility, each preform being held by a separate holding member, the decontamination method comprising at least the following steps:

[0032] - The processing step involves exposing at least the inner surface of the neck to a bactericidal jet containing a bactericide within a first processing zone of the production path;

[0033] - The activation step of the bactericide involves directly exposing the inner surface of the neck, which is thus covered with the bactericide, to ultraviolet radiation in a second activation zone in the production path located downstream of the first processing zone. The generated ultraviolet radiation has a power of approximately 30 mW / cm², so that the bactericide decomposes into more oxidizing substances, such as free radicals.

[0034] According to another feature of the method implemented in accordance with the teachings of this invention, the spectrum of ultraviolet radiation has an emission peak of about 254 nm.

[0035] Alternatively, the spectrum of ultraviolet radiation is between 265 and 275 nm.

[0036] According to another feature of the method implemented in accordance with the teachings of the present invention, during the activation step, the preform continuously moves along the production path.

[0037] According to another feature of the method implemented in accordance with the teachings of the present invention, the preform continuously moves along the production path during the processing steps.

[0038] According to another feature of the method implemented in accordance with the teachings of the present invention, during the processing step, the bactericidal jet is specifically directed toward the interior of the preform to be processed.

[0039] According to another feature of the method implemented in accordance with the teachings of the present invention, the bactericidal jet is sprayed from a nozzle that moves together with the preform to be treated in the first treatment zone.

[0040] According to another feature of the method implemented in accordance with the teachings of the present invention, ultraviolet radiation is generated by at least one light source fixedly arranged relative to the production path.

[0041] The present invention also proposes an apparatus for manufacturing containers from preforms made of thermoplastic materials, the apparatus implementing the method taught according to the present invention, the apparatus including at least one conveying device for conveying preforms in rows along a production path, the conveying device including holding members for individually holding the preforms during movement, the apparatus comprising:

[0042] - A preform processing area through which the production path passes, the processing area including at least one nozzle for spraying a bactericidal jet containing a bactericide, the bactericidal jet being intended to be directed directly toward the inner surface of the neck of the preform passing through the processing area;

[0043] - An activation zone for the bactericide, comprising at least one ultraviolet radiation source, the ultraviolet radiation being directed directly toward the inner surface of the neck of the preform passing through the activation zone, the activation zone being located downstream of the treatment zone, the ultraviolet radiation generated by the ultraviolet radiation source having a power of approximately 30 mW / cm², to decompose the bactericide into more oxidizing substances, such as free radicals.

[0044] According to another feature of the facility implemented in accordance with the teachings of this invention, the spectrum of ultraviolet radiation from the ultraviolet radiation source has an emission peak of about 254 nm.

[0045] Alternatively, the ultraviolet radiation source consists of one or more light-emitting diodes (LEDs) whose ultraviolet radiation spectrum has a wavelength between 265 and 275 nm.

[0046] According to another feature of the facility implemented in accordance with the teachings of the present invention, the facility includes a first conveying device within a processing area, the first conveying device having associated retaining members that move along a closed loop, each retaining member being associated with a nozzle for spraying the sterilizing jet, the nozzle moving together with the retaining member along the closed loop.

[0047] According to another feature of the facility implemented in accordance with the teachings of the present invention, the facility includes a second conveying device within the activation zone, the second conveying device having an associated holding member that moves along a closed loop, and at least one ultraviolet radiation source is fixedly arranged within the activation zone such that the holding member passes sequentially at a position directly opposite the light source.

[0048] According to another feature of the facility implemented in accordance with the teachings of the present invention, the facility includes a preform heat conditioning unit, with an activation zone arranged upstream of the heat conditioning unit.

[0049] According to another feature of the facility implemented in accordance with the teachings of the present invention, the facility includes a preform heat conditioning unit, with an activation zone arranged downstream of the heat conditioning unit.

[0050] According to another feature of the facility implemented in accordance with the teachings of the present invention, the first conveying device is formed of a wheel, with holding components arranged around the periphery of the wheel.

[0051] According to another feature of the facility implemented in accordance with the teachings of the present invention, the second conveying device is formed of a wheel, with holding components arranged around the periphery of the wheel.

[0052] According to another feature of the facility implemented in accordance with the teachings of the present invention, the retaining member is formed by a groove. Attached Figure Description

[0053] Other features and advantages of the invention will become apparent upon reading the following detailed description, with reference to the briefly described drawings for ease of understanding, in which:

[0054] [ Figure 1 [This is a schematic top view showing a container manufacturing facility implemented according to the teachings of the present invention;]

[0055] [ Figure 2 ] is an illustration of the method according to the present invention in [ Figure 1 Side view of a preform intended for decontamination within the facility;

[0056] [ Figure 3 ] is shown [ Figure 1 A top view of the facility's first processing area;

[0057] [ Figure 4 ] is along [ Figure 3 A sectional view taken from plane 4-4 shows a preform undergoing its first processing step in the facility's processing area.

[0058] [ Figure 5 ] is shown in detail [ Figure 1 A top view of the facility's second activation zone;

[0059] [ Figure 6 ] is along [ Figure 5 A sectional view taken from plane 6-6 shows a preform undergoing a second activation step in the facility activation zone. Detailed Implementation

[0060] In the following description, elements with the same structure or similar function will be referred to by the same reference numerals.

[0061] In the following description, the terms "upstream" and "downstream" will be used with reference to the direction of movement of the preform along its transport path.

[0062] [ Figure 1 The diagram schematically illustrates a facility 10 for manufacturing a container 11 based on a thermoplastic material, particularly PET (polyethylene terephthalate) preform 12.

[0063] like[ Figure 2 As shown, each preform 12 includes a cylindrical body 14 having an axis of "X". The body 14 includes sidewalls 16 defining an internal volume. The sidewalls 16 are in a rotational shape about the axis "X".

[0064] The upper end of the body 14 extends through a neck 18, which has an opening 19 radially defined by a bottle neck 21. The neck 18 has the final shape of the neck of the container 11 to be obtained. Therefore, the neck 18 must not undergo any deformation during the manufacture of the container 11. The body 14 includes a bottom 20 that is closed at its lower end, and the bottom 20 is generally hemispherical in shape. The neck 18 includes a flange 22 disposed at its connection with the body 14. The lower surface of the flange 22 is designed to form a support surface to allow support of the preform 12 during molding and / or conveying.

[0065] The neck 18 is defined by an outer surface 24 and an inner surface 26. The inner surface 26 has a cylindrical shape with an axis of "X".

[0066] At the end of the injection molding process, the preform 12 is cooled to allow the thermoplastic material to remain in an amorphous state. Therefore, by heating it above the glass transition temperature, the thermoplastic material can be made malleable again.

[0067] See again [ Figure 1 The manufacturing facility 10 includes a heat conditioning unit 30 and a molding unit 32.

[0068] The preforms 12 move in a row along the production path 34, which passes through the heat treatment unit 30 and the forming unit 32. The direction of movement of the preforms 12 is... Figure 1 The arrow "F1" indicates this. During normal operation of manufacturing facility 10, preform 12 continuously moves along production path 34.

[0069] Manufacturing facility 10 includes a conveying device for conveying preforms 12 in rows along production path 34. The conveying device includes holding members 58, 66 for individually holding the preforms 12 during movement, as will be described in more detail below. Thus, the preforms 12 are continuously held individually throughout the production path 34.

[0070] Manufacturing facility 10 typically supplies preforms 12 that have been sorted and aligned into a row by a feeding device (not shown).

[0071] Production path 34 begins at the moment when the preforms 12 are so straightened and aligned in a row, and held individually by individual holding members of the conveying equipment of manufacturing facility 10. The starting point of production path 34 is indicated here by point P0.

[0072] The function of the heat treatment unit 30 is to heat the body 14 of the preform 12 to a temperature higher than or equal to the glass transition temperature of the constituent material, for example, to a temperature higher than 70°C when the material is PET. The heat treatment unit 30 includes a conveyor 36 (shown schematically) for conveying the preform 12 and causing it to rotate.

[0073] The conveyor 36 typically includes a mandrel (not shown) axially embedded in the neck 18 to convey the preform 12. The mandrel closes the opening 19 of the neck 18. Therefore, the inner surface 26 of the neck 18 is completely inaccessible as the preform 12 moves along the heat conditioning unit 30. The mandrel moves along a closed loop. The mandrel is carried, for example, by links of a chain or by a separate shuttle moving along a guide rail.

[0074] The heat conditioning unit 30 also includes a heating device 40 for heating the preform 12. For example, the heat conditioning unit is a lamp or laser source that emits heating electromagnetic radiation toward the reflector, in this case, infrared radiation in the near-infrared range.

[0075] The preform 12 enters the heat treatment unit 30 when carried solely by the mandrel of the conveyor 36, entering through the entry point indicated by point P1. The conveyor 36 transports the thermoformed part along the U-shaped section of its production path 34, passing through the heating zone 42. The body 14 of the thermoformed part is heated by the heating device 40 as it passes through, which is positioned as needed on either side of the preform 12 relative to its direction of movement.

[0076] Conversely, the neck 18 of the preform 12 is kept at a temperature well below the glass transition temperature. For this purpose, the neck 18 is protected from infrared radiation.

[0077] After passing through the heating zone 42, the preform 12 is removed from the heat conditioning unit 30 at the exit point P2. The preform is then transferred to the mold of the molding unit 32 via a conveying device 44, such as a transfer wheel, arranged between the heat conditioning unit 30 and the molding unit 32.

[0078] The transfer wheel here includes an arm (not shown, but known in itself) that sequentially grasps the preform 12 at its neck 18 as it leaves the heat conditioning unit 30, so as to sequentially introduce the preform into the mold 46 of the molding unit 32. The molding unit 32 includes a turntable 48, around which a plurality of blow molding stations 50 with molds 46 are arranged.

[0079] Each thermoformed preform 12 exiting the heat treatment unit 30 is introduced into the mold 46 of the blow molding station 50, where it is blow-molded and transformed into a container 11 by the deformation of its body 14. Once completed, the container 11 is removed from the blow molding station 50 via the second conveyor 52. Importantly, the inner surface 26 of the neck 18 of the preform 12 is thoroughly cleaned before it reaches the blow molding unit 32.

[0080] To this end, the present invention proposes a method for cleaning the inner surface 26 of the neck 18, which is particularly effective even at very high production rates (greater than or equal to 66,000 containers per hour).

[0081] This decontamination method is applied to the preform 12 as it moves along the production path 34. Importantly, each preform 12 is held by individual retaining members 58 and 66 for this method to be effective.

[0082] This stain removal method includes at least the following two steps in sequence.

[0083] The first processing step “E1” includes, within the first processing zone 56 of the production path 34, exposing at least the inner surface 26 of the neck 18 to a bactericidal jet 54 containing a bactericide.

[0084] An embodiment of the first processing step “E1” is specifically shown in Figure 3 and Figure 4 .

[0085] The first processing zone 56 is located upstream of the thermal conditioning unit 30.

[0086] Bactericides such as hydrogen peroxide (H2O2) are examples.

[0087] The disinfectant can be diluted in a diluent, such as water. For example, the disinfectant is a disinfectant solution diluted to at least 10%, such as a disinfectant solution diluted to 20% or 25%. The disinfectant jet 54 can be formed by mixing the atomized solution with a pressurized gas called a "carrier gas" to allow the propulsion of the disinfectant jet 54. The carrier gas is formed, for example, by compressed air.

[0088] The first processing step “E1” is achieved by guiding at least one sterilizing jet 54 toward the interior of the preform 12 via the opening 19 while the preform is held by a separate holding member 58. The sterilizing jet 54 is more specifically guided directly toward the inner surface 26 of the neck 18 of the preform 12.

[0089] The bactericidal jet 54 is configured to allow complete and uniform coverage of the inner surface 26 of the neck 18.

[0090] Each sterilizing jet 54 is axially emitted from a nozzle 60 onto the neck 18, the nozzle being positioned directly opposite the opening 19 of the preform 12. This advantageously allows for the very precise deposition of a uniform layer of sterilizing agent on the entire inner surface 26 of the neck 18 of the preform 12, as the preform 12 is held in position relative to the nozzle 60.

[0091] During the first processing step “E1”, the preform 12 moves continuously within the first processing area 56.

[0092] Preferably, each nozzle 60 is movably mounted together with its associated retaining member 58. In this way, the sterilizing jet 54 is ejected from the nozzle 60, which moves together with the preform 12 to be treated in the first treatment zone 56.

[0093] Therefore, during the first processing step “E1”, the sterilizing jet 54 is specifically directed toward the interior of the preform 12 to be processed and enters through the opening 19.

[0094] Preferably, during processing step “E1”, the sterilizing jet 54 is guided only toward the interior of the preform 12 to be processed.

[0095] Therefore, as the preform moves along the treatment zone 56, the sterilizing jet 54 can be aimed only at the inner surface 26 of the neck 18 of the preform 12. This, in particular, allows for the use of only the sterilizing dose necessary to treat the inner surface of the neck 18 without loss.

[0096] In a variant of the invention (not shown), the treatment zone includes a nozzle rail fixed relative to the ground, such that each preform passes sequentially beneath each nozzle of the nozzle rail as it moves along the treatment zone. In this variant, the outer surface of the neck is also exposed to the bactericidal jet.

[0097] The method includes a second activation step "E2" for the bactericide, which is performed after the first treatment step "E1". The second activation step "E2" involves directly exposing the inner surface 26 of the neck 18, thus coated with the bactericide, to ultraviolet radiation 61 (UV) within a second activation zone 62 located downstream of the treatment zone 56. An embodiment of the second activation step "E2" is particularly shown in... Figure 5 and Figure 6 .

[0098] The term "direct" means that ultraviolet radiation 61 reaches the inner surface 26 locally without passing through the walls of the preform 12. As mentioned in the introduction, in practice, the preform 12 is typically made of a material that does not allow ultraviolet radiation to pass through easily.

[0099] The second activation region 62 is located upstream of the thermal regulation unit 30. In a variant, the second activation region may be located downstream of the thermal regulation unit 30.

[0100] For example, UVc type ultraviolet radiation 61 with wavelengths between 100 nm and 280 nm. Preferably, the spectrum of ultraviolet radiation 61 has an emission peak of about 254 nm.

[0101] The power of the generated ultraviolet radiation 61 is, for example, about 30 mW / cm².

[0102] The ultraviolet radiation 61 is generated by a light source, such as an amalgam lamp or a light-emitting diode (LED). In this respect, the ultraviolet radiation 61 can advantageously be generated by one or more LEDs with wavelengths between 265 and 275 nm, and the power of the generated ultraviolet radiation 61 is about 30 mW / cm².

[0103] During the second activation step “E2”, the preform 12 continues to move along the production path.

[0104] Ultraviolet radiation 61 is generated here by at least one light source 64 fixedly arranged relative to the production path 34.

[0105] The preform 12 is held by a separate holding member 66 during its passage through the second activation zone 62. This allows for full exposure of the inner surface 26 of the neck 18 and is repeatable and controllable for all preforms 12.

[0106] The second activation zone 62 includes a plurality of ultraviolet radiation sources 64 fixed relative to the ground, such that each preform 12 passes under each light source 64 in sequence as it moves along the second activation zone 62, such that ultraviolet radiation 61 enters the preform 12 through its opening 19 and then directly reaches the inner surface 26 of the neck 18.

[0107] In a variant of the invention not shown, each light source and its associated holding member 66 are movably mounted together. Therefore, ultraviolet radiation is generated by the light source that moves together with the preform to be activated in the activation zone.

[0108] The fact that the preform 12 is held by a separate retaining member 66 during its passage through the second activation zone 62 allows the inner surface 26 of the neck 18 to be fully exposed within a controlled time.

[0109] By exposing the disinfectant covering the inner surface 26 of the neck 18 to ultraviolet radiation, the disinfectant breaks down into more oxidizing substances, such as free radicals. At this point, the disinfectant is said to be "activated".

[0110] The method implemented according to the teachings of this invention achieves a highly effective decontamination effect, reducing the number of microorganisms present on the inner surface 26 of the neck 18 to one in 100,000 before the application of the decontamination method. In other words, the method according to the teachings of this invention can reduce contaminants present on the inner surface 26 of the neck 18 by at least 5-log. This method is excellent because this level of decontamination is achieved by exposing the inner surface of the neck 18 to ultraviolet radiation for an extremely short time, much less than one second, for example, between 500 ms and 3 s. This makes the method particularly suitable for very high container production rates, such as 66,000 containers per hour or more.

[0111] To implement this method, the facility 10 for manufacturing container 11 from preforms 12 made of thermoplastic material includes a conveying device for conveying the preforms 12 in rows along production path 34.

[0112] Facility 10 also includes a preform 12 processing area 56 through which a production path 34 passes, the processing area also including at least one nozzle 60 for spraying a stream of disinfectant in the form of a disinfectant jet 54 containing disinfectant intended to be directed directly toward the inner surface 26 of the neck 18 of the preform 12 passing through the processing area 56.

[0113] Facility 10 also includes a bactericide activation zone 62, which includes at least one light source 64 for generating ultraviolet radiation 61, which is intended to be directed directly toward the inner surface 26 of the neck 18 of the preform 12 passing through the activation zone 62.

[0114] The bactericide activation zone 62 is located downstream of the treatment zone 56. The activation zone 62 is separate from the treatment zone 56 so that the bactericide is not exposed to ultraviolet radiation 61 before being deposited onto the inner surface 26 of the neck 18 of the preform 12.

[0115] The conveying devices include retaining members 58, 66 for individually holding the preform 12 during movement. At least some of these conveying devices include individual retaining members 58, 66 for gripping the preform 12 from the outside. This allows the retaining opening 19 to remain open, thereby keeping the inner surface 26 of the neck 18 accessible from the outside to allow the inner surface to be sequentially exposed to the sterilizing jet 54 and ultraviolet radiation 61.

[0116] Therefore, the mandrel described above is not applicable because the mandrel is inserted into the neck 18 to grip the preform 12 from the inside. This is why the first processing area 56 and the second activation area 62 are arranged upstream or downstream of the heat conditioning unit 30. However, if the preform is gripped in the heat conditioning unit by a holding member that allows its inner surface of the neck to remain accessible, the first processing area and the second activation area can be located inside the heat conditioning unit.

[0117] This conveying device includes a first conveying device 68 within the first processing area 56. The first conveying device 68 has an associated holding member 58 that moves along a closed loop.

[0118] Here, each retaining member 58 is associated with a nozzle 60 for spraying the sterilizing jet 54, the nozzle moving together with the retaining member 58 along a closed loop. The nozzle 60 is controlled to spray the sterilizing jet 54 when it is within the first treatment zone 56.

[0119] Advantageously, the sterilization jet 54 is stopped outside the first processing zone 56. This allows the sterilizer to be prevented from spreading beyond the preform 12. Therefore, sterilizer is advantageously saved. Furthermore, since sterilizers are generally highly corrosive, this allows the generation of a corrosive atmosphere that could damage certain components of facility 10 to be avoided.

[0120] The first conveying device 68 is formed by a conveyor wheel, with retaining members 58 arranged around its periphery. For example, it is a conveyor wheel mounted to rotate relative to the ground about a vertical axis "Z1". The closed loop is therefore circular. In this particular embodiment, the first processing zone 56 has an angle arc between 5 and 30 degrees, preferably 15 degrees, such that a sufficient amount of bactericide is sprayed onto the inner surface 26 of the neck 18 of the preform 12 passing through the processing zone 56.

[0121] In a variant of the invention not shown, the retaining member is carried by an independent shuttle that moves along the guide rail.

[0122] The retaining member 58 is formed, for example, by a groove, and the lower surface of the flange 22 abuts against the periphery of the groove, such as... Figure 4 As shown.

[0123] In a variant not shown, the retaining member may be formed below and / or above the flange by a clamp that grips the preform from the outside.

[0124] The first conveying device 68 is located upstream of the thermal conditioning unit 30 and the inlet point P0 of the facility 10.

[0125] In the embodiment shown in the accompanying drawings, the conveying device for conveying the preform 12 in the second activation zone 62 includes a second conveying device 70, which includes an associated holding member 66 that moves along a closed loop. The second conveying device 70 is separate from the first conveying device 68.

[0126] In a variant of the invention not shown, the retaining member is carried by an independent shuttle that moves along the guide rail.

[0127] In a variant of the present invention not shown, the first activation zone and the second processing zone are arranged on the same conveying device.

[0128] The second conveying device 70 is formed by a conveyor wheel, with retaining members 66 arranged around its periphery. For example, it is a conveyor wheel mounted so that it can rotate relative to the ground about a vertical axis "Z2". The closed loop is therefore circular.

[0129] The retaining member 66 is formed, for example, by a groove, and the lower surface of the flange 22 abuts against the periphery of the groove.

[0130] In a variant not shown, the retaining member may be formed below and / or above the flange by a clamp that grips the preform from the outside.

[0131] The second conveying device 70 is located upstream of the heat conditioning unit 30 and downstream of the first conveying device 68.

[0132] In a variant of the invention not shown, the second conveying device is arranged downstream of the heat conditioning unit. Preferably, the second conveying device is arranged upstream of the forming unit.

[0133] exist Figure 5 and Figure 6 In the embodiment shown, the activation zone 62 includes a plurality of ultraviolet radiation sources 64 fixed relative to the ground, the radiation sources being distributed along an angular arc between 65 and 130 degrees, preferably along an angular arc of 92.5 degrees, such that all bactericides sprayed onto the inner surface 26 of the neck 18 of the preform 12 as it passes through the treatment zone 56 are activated upon leaving the activation zone 62.

[0134] Therefore, the holding member 66 of the second conveying device 70 moves directly opposite the light source 64 within the second activation zone 62. Thus, when the preform 12 passes axially directly opposite these light sources, the neck 18 faces the light source 64. Therefore, ultraviolet radiation 61 enters axially into the interior of the preform 12 through the opening 19.

[0135] The light source 64 is, for example, an amalgam lamp associated with a reflector 72, which allows ultraviolet radiation 61 to be directed directly toward the inner surface 26 of the neck 18 of the preform 12 and enters through the opening 19.

[0136] This invention is specifically applied to the decontamination of the inner surface of the neck. However, the inner surface of the body can benefit in the same way as the inner surface of the neck, as it is also exposed to a portion of the bactericidal jet and ultraviolet radiation reaches the entire inner surface of the body.

[0137] The decontamination method implemented according to the teachings of this invention can therefore achieve a very effective decontamination effect on preforms even at very high production speeds. This method also allows for the protection of neck integrity by preventing the neck 18 of the preform 12 from being exposed to infrared radiation.

[0138] A significant advantage is that the fact that the preforms are kept separate at each step of the process allows for very precise control of the exposure time to the sterilizing jet and the exposure time to ultraviolet radiation. Therefore, the sterilizing dose applied to each preform and the radiation dose received by each preform can be controlled very precisely.

Claims

1. A decontamination method for decontaminating the inner surface (26) of the neck (18) of thermoplastic preforms (12) passing in a production path (34) in a container manufacturing facility (10), each preform (12) being held by a separate holding member (58, 66), the decontamination method comprising at least the following steps: - Processing step (E1) involves exposing at least the inner surface (26) of the neck (18) to a bactericidal jet (54) containing a bactericide in the first processing zone (56) of the production path (34). - The activation step (E2) of the bactericide involves exposing the inner surface (26) of the neck (18) thus covered with the bactericide to ultraviolet radiation (61) in a second activation zone (62) located downstream of the first processing zone (56) in the production path (34). The generated ultraviolet radiation (61) has a power of about 30 mW / cm², so as to decompose the bactericide into more oxidizing substances, such as free radicals.

2. The stain removal method according to claim 1, characterized in that, The spectrum of the ultraviolet radiation (61) has an emission peak of about 254 nm.

3. The stain removal method according to claim 1, characterized in that, The spectrum of the ultraviolet radiation (61) is between 265 nm and 275 nm.

4. The stain removal method according to any one of claims 1 to 3, characterized in that, During the activation step (E2), the preform (12) moves continuously along the production path (34).

5. The stain removal method according to any one of claims 1 to 4, characterized in that, During the processing step (E1), the preform (12) moves continuously along the production path (34).

6. The stain removal method according to any one of claims 1 to 5, characterized in that, During the processing step (E1), the sterilizing jet (54) is specifically directed toward the interior of the preform (12) to be processed.

7. The stain removal method according to claim 6, characterized in that, The sterilizing jet (54) is sprayed from a nozzle (60), which moves together with the preform (12) to be treated in the first treatment zone (56).

8. The decontamination method according to any one of claims 1 to 7, characterized in that, The ultraviolet radiation (61) is generated by at least one light source (64) fixedly arranged relative to the production path (34).

9. A facility (10) for manufacturing a container (11) from a preform (12) of a thermoplastic material, the facility implementing a decontamination method according to any one of claims 1 to 8, the facility (10) comprising at least one conveying device (68, 70) for conveying the preforms (12) in a row along a production path (34), the conveying device including retaining members (58, 66) for individually holding the preforms (12) during movement, the facility (10) comprising: - A processing area (56) of a preform (12), through which the production path (34) passes, the processing area including at least one nozzle (60) for spraying a bactericidal jet (54) containing a bactericide, the bactericidal jet being intended to be directed directly toward the inner surface (26) of the neck (18) of the preform (12) passing through the processing area (56). - An activation zone (62) for the bactericide, comprising at least one ultraviolet radiation (61) source (64) intended to be directed directly toward the inner surface (26) of the neck (18) of the preform (12) passing through the activation zone (62), the activation zone (62) being downstream of the treatment zone (56), the ultraviolet radiation (61) generated by the ultraviolet radiation source (64) having a power of approximately 30 mW / cm², to decompose the bactericide into more oxidizing substances, such as free radicals.

10. The facility (10) according to claim 9, characterized in that, The ultraviolet radiation (61) spectrum of the ultraviolet radiation source (64) has an emission peak of about 254 nm.

11. The facility (10) according to claim 9, characterized in that, The ultraviolet radiation source (64) consists of one or more light-emitting diodes (LEDs) whose ultraviolet radiation (61) has a wavelength between 265 nm and 275 nm.

12. The facility (10) according to any one of claims 9 to 11, characterized in that, The facility includes a first conveying device (68) within the processing area (56), the first conveying device having associated retaining members (58) that move along a closed loop, each of the retaining members (58) being associated with a nozzle (60) for spraying the sterilizing jet (54), the nozzle moving together with the retaining member (58) along the closed loop.

13. The facility (10) according to any one of claims 9 to 12, characterized in that, The facility includes a second conveying device (70) within the activation zone (62), the second conveying device having an associated holding member (66) that moves along a closed loop, and at least one of the ultraviolet radiation sources (64) is fixedly arranged within the activation zone (62) such that the holding member (66) moves in a position directly opposite the ultraviolet radiation source (64).

14. The facility (10) according to any one of claims 9 to 12, characterized in that, The facility includes a heat conditioning unit (30) for a preform (12), and the activation zone (62) is arranged upstream of the heat conditioning unit (30).

15. The facility (10) according to any one of claims 9 to 12, characterized in that, The facility includes a heat conditioning unit (30) for a preform (12), and the activation zone (62) is arranged downstream of the heat conditioning unit (30).

16. The facility (10) according to claim 12, characterized in that, The first conveying device (68) is formed of a wheel, and the retaining member (58) is arranged around the periphery of the wheel.

17. The facility (10) according to claim 13, characterized in that, The second conveying device (70) is formed of a wheel, and the retaining member (66) is arranged around the periphery of the wheel.

18. The facility according to claim 16 or 17, characterized in that, The retaining members (58, 66) are formed by grooves.

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