阅读说明：本技术 处理玻璃壁容器的方法及相应的设备 (Method for treating glass-walled containers and corresponding apparatus ) 是由 克里斯多夫·德波伊 皮埃尔-卢克·埃切帕雷 张经维 于 2019-02-22 设计创作，主要内容包括：本发明涉及一种用于处理容器(1)的方法和相关设备,所述容器(1)包括限定用于容纳产品的容纳腔(3)的玻璃壁(2),所述玻璃壁(2)具有内面(4)和相对的外面(5),所述玻璃壁(2)设有第一涂层,所述第一涂层包括固体残留化合物,所述固体残留化合物由所述容器(1)先前已经经受的对所述玻璃壁(2)的所述内面(4)的表面附近的玻璃进行脱碱的步骤产生,所述方法包括用液体的液滴喷射所述玻璃壁(2)的表面的步骤,以从所述第一涂层开始在所述玻璃壁(2)上形成第二涂层,所述第二涂层包括所述残留化合物并且比所述第一涂层更透明和/或更均匀。-玻璃壁容器的处理。(The invention relates to a method and a related apparatus for handling containers (1), said containers (1) comprising a glass wall (2) defining a containing chamber (3) for containing a product, the glass wall (2) has an inner face (4) and an opposite outer face (5), the glass wall (2) is provided with a first coating comprising solid residual compounds, said solid residual compounds result from a step of dealkalizing the glass in the vicinity of the surface of the inner face (4) of the glass wall (2) to which the container (1) has previously been subjected, the method comprising the step of spraying the surface of the glass wall (2) with droplets of a liquid, to form, starting from the first coating, a second coating on the glass wall (2), said second coating comprising the residual compounds and being more transparent and/or more homogeneous than the first coating. Treatment of glass-walled containers.)

1. A method for handling containers (1), the containers (1) having a glass wall (2) defining a containing chamber (3) for a product, the glass wall (2) having an inner face (4) positioned facing the accommodation chamber (3) and an opposite outer face (5), the glass wall (2) being provided with a first coating comprising solid residual compounds resulting from a surface treatment step of the glass wall (2) to which the container (1) has previously been subjected, the surface treatment step is a step of dealkalizing the glass in the vicinity of the surface of the inner surface (4) of the glass wall (2), the method comprising the step of spraying droplets of a liquid onto the surface of the glass wall (2), to form a second coating on the glass wall (2) from the first coating, the second coating comprising the residual compounds and being more transparent and/or more homogeneous than the first coating.

2. The method according to the preceding claim, wherein the residual compound is in powder form.

3. The method according to any one of the preceding claims, wherein the dealkalizing step comprises treating the inner face (4) with a sulfur-containing substance, the solid residual compound preferably containing sodium sulfate.

4. The method according to any one of the preceding claims, wherein the spraying step is carried out on the container (1), the container (1) being at a temperature of from 0 to 100 ℃, and preferably at ambient temperature.

5. The method according to any one of the preceding claims, wherein the spraying step is carried out simultaneously on the surfaces of the inner face (4) and outer face (5) of the glass wall (2).

6. The method of any preceding claim, wherein the liquid is sprayed in the form of a mist.

7. The method according to the preceding claim, wherein at least 95% of the droplets have a diameter of 1 to 10 μ ι η, preferably 2 to 3 μ ι η.

8. The method according to any one of the preceding claims, wherein the liquid is a solvent for the solid residual compounds.

9. Method according to the preceding claim, wherein the solvent is water, preferably ultrapure water.

10. The method according to any one of the preceding claims, comprising, after the spraying step, a step of forced drying of the glass wall (2).

11. The method according to any one of the preceding claims, comprising, after the spraying step, an optical inspection step of the glass wall (2).

12. The method according to claims 10 and 11, wherein the optical inspection step is performed after the forced drying step.

13. A plant (14) for treating containers (1), said containers (1) having a glass wall (2) defining a containing cavity (3) for a product, said glass wall (2) having an inner face (4) positioned facing said containing cavity (3) and an opposite outer face (5), said plant (14) comprising a surface treatment station (15) of said glass wall (2) for subjecting said containers (1) to a surface treatment step of said glass wall (2) resulting in the formation of a first coating comprising solid residual compounds on said glass wall (2), said surface treatment station (15) being a station for dealkalizing glass in the vicinity of the surface of the inner face (4) of said glass wall (2), said plant (14) comprising a spraying station (16) for spraying droplets of a liquid onto the surface of said glass wall (2), the spraying station (16) is located downstream of the surface treatment station (15).

14. Plant (14) according to the preceding claim, wherein said spraying station (16) is designed and configured to spray droplets of said liquid simultaneously onto the surfaces of said inner face (4) and outer face (5) of said glass wall (2).

15. Plant (14) according to any one of claims 13 and 14, wherein said spraying station (16) comprises a spraying device (17) and means for adjusting the distance between said spraying device (17) and said glass wall (2) and the angle (θ) of the spraying cone of said spraying device (17), wherein said angle (θ) is preferably comprised between 20 ° and 100 °.

16. The plant (14) according to any of claims 13 to 15, wherein the spraying station (16) is designed and configured to spray the liquid droplets in the form of a mist.

17. The plant (14) according to the preceding claim, wherein the droplets have an average diameter of 1 to 10 μm, preferably 2 to 3 μm.

18. Plant (14) according to any one of claims 13 to 17, comprising a forced drying station (18) of the glass wall (2) downstream of the spraying station (16).

19. Plant (14) according to any one of claims 13 to 18, comprising an optical inspection station (19) of the glass wall (2) downstream of the spraying station (16).

20. Plant (14) according to claims 18 and 19, wherein said optical inspection station (19) is located downstream of said forced drying station (18).

Technical Field

The present invention relates to the general field of methods and apparatus for treating glass-walled containers.

The invention relates more particularly to a method for treating a container having a glass wall delimiting a cavity for containing a product, said glass wall having an inner face positioned facing said containing cavity and an opposite outer face, said glass wall being provided with a first coating comprising solid residual compounds resulting from a surface treatment step of said glass wall to which said container has been previously subjected.

The invention also relates to a plant for treating containers having a glass wall defining a cavity for containing a product, said glass wall having an inner face positioned facing said containing cavity and an opposite outer face, said plant comprising a station for surface treating said glass wall, for subjecting said containers to a step of surface treatment of said glass wall, resulting in the formation of a first coating comprising solid residual compounds on said glass wall.

Background

In the field of pharmaceutical glass primary packaging, it is sought to propose containers, in particular of the vial type, having excellent chemical compatibility with the products or formulations they are intended to contain. In fact, the aim is to prevent any harmful interaction between the substances coming from the glass forming the container and the product contained in said container.

In this context, the pharmacopoeia identifies three very different types of glass containers which are acceptable for pharmaceutical use, depending on the nature of the formulation under consideration. These containers are classified according to their level of resistance to hydrolysis, i.e. according to the resistance that the glass forming them shows to the transfer of water-soluble inorganic substances under determined contact conditions between the surface of the glass container under consideration and water. A distinction is made between borosilicate glass containers which themselves have excellent resistance to hydrolysis and are therefore suitable for most pharmaceutical formulations, i.e. "type I", and conventional soda-lime-silica glass containers, i.e. "type III", which have far less favorable resistance to hydrolysis. Thus, the use of these "type III" containers is limited to non-aqueous carrier formulations for parenteral use, powders for parenteral use (other than lyophilized formulations), and formulations for non-parenteral use. A distinction is also made between so-called "type II" glass containers, which are conventional soda-lime-silica glass containers, like the type III glass containers, but which have a specific surface treatment on the inside to significantly improve their resistance to hydrolysis. Thus, type II glass containers exhibit excellent resistance to hydrolysis, which makes them suitable for packaging most acidic and neutral aqueous formulations.

A method is known, in particular for the surface treatment of type III glass containers to obtain type II glass containers, which essentially consists in extracting, at a depth of a few tens of nanometers, sodium present near the surface of the inner face of the soda-lime-silica glass container. Then, referring to the glass dealkalization treatment, it is generally carried out on-line by the container manufacturer, i.e. using a device directly integrated into the glassware line.

As is known, such surface treatment methods can provide sulfur compounds such as ammonium sulfate (NH), particularly in the form of crystalline powders₄)₂SO₄Injection into the containers to be treated while the containers are still at an elevated temperature after leaving the molding machine. Under the action of heat, the ammonium sulfate crystals sublime and form a gas which reacts with the sodium contained in the glass immediately adjacent to the inner surface of the treated vessel. Then, the sodium thus extracted from the glass was replaced with sodium sulfate Na₂SO₄The residual powdery compound of (a) settles on the surface of the inner face of the container in the form of a more or less pronounced bloom. Due to its milky or whitish appearance, this bloom often does not form uniformly on the surface of the container, making some areas of the container surface locally less transparent than others. Small spots, more particularly on the container wall, can also be observedIs a marked spot.

Although this residual blooming phenomenon is generally not particularly problematic for the packaging of the latter formulation, since the relevant glass containers are generally carefully cleaned before packaging, it can be particularly troublesome for certain operations of quality control at the outlet of the glassware line. First, this lack of frosted transparency can make optical inspection of glass defects difficult, thereby compromising container quality. Second, the presence of inhomogeneities, uneven appearance and stains of residual deposits on the surface of type II glass containers can be the cause of improper disposal (erroneous disposal). In fact, depending on the contrast and sensitivity adjustments of the optical inspection system used, significant stains at the surface of the containers are liable to be interpreted as glass defects, for example, and to cause an unreasonable handling of the relevant containers and therefore a loss of revenue for the container manufacturer.

Of course, it is conceivable to remove the type II glass container from residual bloom prior to inspection, for example by washing. In practice, this solution is not generally adopted by glass container manufacturers, since it would involve the implementation of expensive and complex complementary devices, which are generally not compatible with conventional industrial glass container production lines. Also, in the field of pharmaceutical glass primary packaging and in the eyes of pharmaceutical formulation packaging participants, the presence of such white bloom at the surface of glass containers often constitutes a unique feature of type II glass containers, which visually distinguishes them in particular from type III glass containers, which are less resistant to hydrolysis.

Disclosure of Invention

The object of the present invention is therefore to remedy the different drawbacks mentioned above and to propose a new treatment method and a corresponding installation that allow to facilitate the optical inspection of the glass walls of containers on the surface of which solid residual compounds have been deposited.

Another object of the invention is to propose a new process which is easy and inexpensive to implement and which requires only simple and standard industrial means for its implementation, while being particularly efficient.

Another object of the invention is to propose a new method that is particularly reliable, robust and repeatable, while achieving safety.

Another object of the invention is to propose a new process which can be implemented on-line and which allows a high processing rate.

Another object of the invention is to propose a new installation which allows an efficient, safe and rapid handling of glass-walled containers.

Another object of the invention is to propose a new installation which is particularly simple and cost-effective to design and implement.

Another object of the invention is to propose a new installation that is particularly robust and reliable.

The object of the invention is achieved by a method for treating a container having a glass wall delimiting a cavity for containing a product, said glass wall having an inner face positioned facing said containing cavity and an opposite outer face, said glass wall being provided with a first coating comprising solid residual compounds resulting from a surface treatment step of said glass wall to which said container has been previously subjected, said surface treatment step being a step of dealkalizing the glass in the vicinity of the surface of said inner face of said glass wall, said method comprising a step of spraying droplets of a liquid onto the surface of said glass wall to form a second coating on said glass wall from said first coating, said second coating comprising said residual compounds and being more transparent and/or more homogeneous than said first coating.

The object of the invention is also achieved by a plant for treating containers having a glass wall delimiting a cavity for containing a product, said glass wall having an inner face positioned facing said containing cavity and an opposite outer face, said plant comprising a station for surface treating said glass wall, a step of surface treatment of said glass wall being carried out on said containers, resulting in the formation of a first coating comprising solid residual compounds on said glass wall, said surface treatment station being a station for dealkalizing glass in the vicinity of the surface of the inner face of said glass wall, said plant comprising a station for spraying droplets of a liquid onto the surface of said glass wall, said spraying station being located downstream of said surface treatment station.

Drawings

Other objects and advantages of the present invention will appear in more detail on reading the following description, with reference to the accompanying drawings, given purely by way of illustrative and non-limiting example, in which:

figure 1 shows a container of the vial type, the glass walls of which are provided with a first coating comprising solid residual compounds resulting from a step of surface treatment of the glass walls (here a step of dealkalization of the glass in the vicinity of the surface of the inner face of the glass walls) to which the container has been previously subjected. Enlarging the area of the glass wall of these containers to highlight the non-uniform and not completely transparent character of the first coating in question;

fig. 2 shows a container obtained by subjecting the container of fig. 1 to a treatment method according to the invention. Enlarging the area of the glass wall of the containers to highlight the more uniform and transparent features of the second coating formed at the surface of the glass wall;

FIG. 3 schematically shows a flask-type container for carrying out a preferred embodiment of the step of ejecting liquid droplets of the treatment method according to the invention;

fig. 4 and 5 highlight pictures taken by Scanning Electron Microscope (SEM) of the glass wall surfaces of two glass-walled containers according to the invention, the first container not being subjected to the method according to the invention (fig. 4), in contrast to the second container (fig. 5). Fig. 6 schematically shows the change in particle morphology of the residual compounds of the coating provided on the wall of the container according to the invention, caused by the method according to the invention;

fig. 7 schematically shows an experimental fixture for evaluating the uniformity of the second coating obtained at the end of the method according to the invention. FIG. 8 shows in a graph the results obtained during a test for evaluating the uniformity by means of the fixture of FIG. 7;

fig. 9 schematically shows a particularly advantageous embodiment of the installation according to the invention.

Detailed Description

According to a first aspect, the invention relates to a method for handling containers 1, said containers 1 comprising a glass wall 2 defining a cavity 3 for containing a product (or substance), said glass wall 2 having an inner face 4 positioned facing said containing cavity 3 and preferably intended to be in direct contact with said product, and an opposite outer face 5. The container 1 in question is therefore preferably a hollow glass container. Preferably, the product is advantageously fluid, i.e. easily flowable, like for example a liquid, a paste (e.g. a liquid with high viscosity) or a powder substance. Preferably, the container 1 forms a container designed to contain a product or substance with pharmaceutical properties, such as a drug potentially for administration by parenteral route (systemic or local area) or ingestion or absorption by a patient, or a diagnostic substance, such as a chemical or biological agent. By extension, the container 1 can be designed to contain biological substances (or body fluids), such as blood, blood products or by-products, urine, etc. Even if preferred for applications in the pharmaceutical and diagnostic field, the invention is not, however, limited to containers for pharmaceutical and diagnostic use, and as an alternative variant, it also relates to a container designed to contain a liquid, paste or powder substance for industrial (storage of chemical products, etc.), veterinary, food or also cosmetic use.

The container 1 in question may have any shape suitable for its function, for example the shape of a vial or bottle. In this case, the glass wall 2 is advantageously formed by a glass bottom 6, a glass side wall 7 rising from and at the periphery of the bottom 6, and a neck 8 provided with a ring 9, the ring 9 closing the container 1 while forming a filling/dispensing opening 10 communicating the cavity 3 with the outside. Said opening 10 is advantageously designed to be able to be closed by a stopper or a removable or pierceable membrane seal). However, it is fully conceivable that the container 1 takes any other shape, in particular a non-neck shape, depending on the intended use, such as a can, a tube, a vial, a syringe or others. Such glass-walled containers 1, in particular glass-walled containers 1 in the shape of vials, can be obtained by any conventional glassware method (moulded glass, blown glass, drawn glass, Vello or Danner method, etc.).

The term "glass" is preferably understood here in its conventional meaning and therefore denotes mineral glass. Preferably, the glass constituting the wall 2 of the container 1 is transparent (or at least translucent) itself, to allow visual inspection of said container 1 using conventional optical means, in order to look for potential glass defects present in particular in the thickness of said wall 2 or at the inner face 4 thereof. Furthermore, the transparent (or at least translucent) nature of glass may prove necessary in the case of pharmaceutical products to allow visual inspection of the product once it is packaged in the container. Still preferably, the glass constituting the walls of the container is colourless (white glass), but may still be coloured, for example by means of a metal oxide, to protect the fluid substance contained in the container from light, in particular in a certain wavelength range (UV, etc.).

More specifically, the method of the invention relates to a container 1 whose glass wall 2 is provided with a first coating comprising solid residual compounds resulting from a step of surface treatment of said glass wall 2 to which said container 1 has been previously (preferably automatically) subjected. Advantageously, said residual compounds are solid substances which are formed as said first coating and are deposited onto the surface of the glass wall 2 of the container 1 as a result of a surface treatment step to which said container 1, in particular the glass wall 2 of the container 1, has been subjected before the implementation of the method according to the invention. Preferably, the residual compound is powdered, granular.

Herein, the term "residual compounds" preferably refers to products or by-products of the surface treatment step which are not particularly desired. In other words, although the formation of the first coating comprising said solid residual compounds at the surface of the glass wall 2 is a potentially known and foreseeable result of said surface treatment step, it preferably does not constitute a phenomenon specifically and automatically sought, and said residual compounds are preferably not intended to be preserved at the surface of the glass wall 2 of the container 1 in normal use of the container 1. Preferably, the residual compound is a substance susceptible to providing the first coating with optically observable properties, preferably in the visible range. Preferably, the first coating takes the form of a whitish or coloured bloom, which is preferably non-uniform, non-uniform and/or has some opacity in the visible domain. The first coating does not have to be continuous and does not have to cover the entire surface of the glass wall 2.

In the context of the present invention, the term "surface treatment" preferably refers to an operation aimed at modifying the physical and/or chemical properties of the glass at or in the immediate vicinity of the surface of the glass wall 2 of the container 1.

More preferably, said glass wall 2 of the container 1 is made of a glass containing at least one oxide of an alkali metal or of an alkaline earth metal (such as, preferably, soda-lime-silica glass) and the surface treatment step to which the container referred to according to the method of the invention has been previously subjected is a step of dealkalizing the glass in the vicinity of the surface of the inner face 4 of the glass wall 2 of the container 1. Potentially, as will be seen hereinafter, the dealkalization step may also affect to some extent the glass near the surface of the outer face 5 of the glass wall 2 of the container 1. In other words, the surface treatment step may comprise the consumption of alkali metal ions (for example sodium ions) in the glass forming the wall 2 of the container 1, at the surface of the inner face 4 of the glass wall 2 (and possibly at the surface of the outer face 5 of the glass wall 2), and preferably at a depth of some tens of nanometers. The container 1 referred to in the method according to the invention can therefore advantageously be a type II glass container, obtained from a type III glass container (conventional soda-lime-silica glass) which has been subjected to a dealkalization step. However, it could potentially be a type I glass container (borosilicate glass) or an aluminosilicate glass container that has been subjected to a dealkalization step, since they are in fact glasses containing at least one alkali or alkaline earth metal oxide.

Preferably, the dealkalization step comprises treating the inner face 4 with a sulfur-containing substance, which is preferably introduced into the housing chamber 3 of the container 1, while the housing chamber 3 of the container 1 is at an elevated temperature (typically about 500 to 650 ℃), for example at the end of the step of forming the container 1, or after such a step of forming the container 1, the container 1 is subjected to an annealing step. Still more preferably, the substance is ammonium sulfate (NH) in the form of a crystalline powder₄)₂SO₄. Thus, the solid residual compound contains sodium sulfate Na in powder form₂SO₄Which can be deposited in a particularly uneven manner on the surface of the inner face 4 of said glass wall 2 (and possibly also on the surface of the outer face 5 of said glass wall 2) of the container 1, as shown in figure 1. Alternatively, the substance may be sulfur dioxide, SO₂Or sulfur trioxide SO₃Or alternatively a sulfur or fluorine-containing substance, under certain conditions, which may also form a coating with a desired homogeneity at the surface of the glass wall 2.

According to the invention, the method for treating a glass-walled container 1 comprises a step of spraying droplets of liquid against the surface of the glass wall 2 (or at least a portion thereof) to form a second coating on the glass wall 2 from the first coating, the second coating advantageously being more transparent and/or more uniform than the first coating, as will be explained hereinafter.

According to the invention, the second coating thus formed comprises said residual compounds. In fact, the liquid spraying step of the method according to the invention differs from the step of washing the glass wall 2 in that, at the end of the spraying step, residual compounds are still present at the surface of the glass wall 2. Thus, although the first coating of the glass wall 2 comprises a first mass of residual compounds before the spraying step of the method according to the invention, the second coating formed at the end of said spraying step advantageously comprises a second mass of said residual compounds substantially equal to (or possibly very slightly lower than) said first mass. At the end of the method according to the invention, the presence of residual compounds in the second coating formed at the surface of the glass wall 2 will advantageously be visually observable (presence of blooming or visible flaws (tromubles)) and in any case will be able to be verified by observation by means of more advanced optical analysis means, for example by means of a microscope.

The invention is therefore based on the idea of spraying droplets of liquid (i.e. fine droplets) onto said first coating previously formed at the surface of the glass wall 2 of the container 1, so as to advantageously form a layer (or pad) of distinct droplets, spaced apart on the surface of said glass wall 2 on which said first coating comprising solid residual compounds has been formed. In particular, the latter preferably has been formed at least on the surface of the inner face 4 of the glass wall 2 of the container 1, said spraying step consisting in spraying said droplets at least on the surface of said inner face 4, more particularly on the side wall 7 of said container 1.

Said droplets are thus locally in direct contact with the first coating layer comprising residual compounds and then interact with the latter to modify at least one of its characteristics, which has an effect on the optical properties of the coated glass wall 2.

In fact, it is very interesting to observe that the ejection of such droplets may advantageously allow to modify the conformation of the residual compounds at the surface of the glass wall 2. In particular, in the preferred case in which the residual compound is in the form of powder, granules, the ejection of the droplets advantageously allows the local dissociation of the clusters of granules and the redistribution of the granules in a more dispersed and homogeneous manner with respect to the surface of the glass wall 2.

The method according to the invention may therefore allow to obtain a second coating at the surface of the glass wall of the container 1 that is more uniform and homogeneous than the first coating initially present at the surface of the glass wall 2 of the container 1. This advantageously results in a reduction of the local variations in the amount of residual compounds at the surface of the wall 2, which tend to form areas that appear more opaque than others. Moreover, the effect of stains initially observable at the surface of the glass wall 2 is significantly attenuated, or even completely eliminated. This homogenizing effect is particularly visible in fig. 2, which shows, as an example, a container obtained at the end of the method according to the invention from a container having walls made of soda-lime-silica glass dealkalized with ammonium sulfate, as shown in fig. 1.

In practice, the uniform, homogeneous nature of the second coating layer formed at the end of the spraying step can be characterized as follows. The container 1 with the glass wall 2 treated according to the invention is placed vertically in front of a background of uniform colour (for example black) and the container 1 is illuminated by a lamp located below and opposite the bottom 6 of the container 1. A picture of the front of the container 1 and a uniformly colored background is then taken using a digital reflex camera or similar device. The captured picture is then converted into an 8-bit grayscale digital image by image processing software (e.g., "ImageJ" software developed by the national institutes of health). Still by means of the image processing software, a rectangular surface is selected, which preferably corresponds to a more or less extended area of the side wall 7 of the container 1, and a grey level curve is plotted over the whole selected rectangular surface. Finally, the gray level variance of the rectangular surface is calculated (e.g., by spreadsheet software) based on the data corresponding to the gray level curve. The variance thus calculated represents the uniformity of the shading of the selected surface area of the sidewall 7 and hence of the coating formed according to the invention. The lower the variance value, the more uniform the coating. The gain in terms of homogeneity provided by the method according to the invention can also be verified by comparing the respective variances obtained according to the method disclosed above from photographs of the same container taken before and after the method has been carried out on the same container. Of course, any other suitable method may be implemented to verify and quantify the homogenization achieved.

Advantageously, as mentioned above, the spraying step of the method according to the invention allows the formation of a second coating which, although still comprising said residual compounds, is more transparent than the first coating initially present at the surface of the glass wall 2 of the container 1. In fact, it has been observed that the ejection of the droplets may allow to increase, to a certain extent and according to the nature and quantity of the residual compounds deposited, the transparency of the coated glass wall 2 of the container 1. Whereas before the spraying step the glass wall 2 provided with the first coating has a first transparency level (i.e. it allows a certain amount of light to which it is exposed to pass through it), after the spraying step the wall 2 in fact advantageously has a second transparency level, which is higher than the first transparency level. A method of characterizing and verifying the transparency gain advantageously provided by the method according to the invention will be described hereinafter.

In some cases, as will be seen in the tests described hereinafter, the spraying step of the method according to the invention allows, in a particularly interesting and surprising way, to form, from the first coating, a second coating on the glass wall 2, which comprises the residual compounds and is not only more transparent than the first coating originally present at the surface of the glass wall 2 but also more homogeneous.

The method according to the invention therefore allows very convenient subsequent optical inspection of the relative container 1 to find glass defects at the glass wall of the container, without the need to previously clean the glass wall 2 of the container 1 of deposits of residual compounds. Here, although the second, more uniform coating still contains the residual compounds, its formation advantageously helps to better identify high contrast glass defects and reduces the risk of erroneous discarding. Obtaining a second, more transparent coating advantageously allows for ease of detection of most lower contrast glass defects (e.g., stains). Preferably, during the spraying step, the liquid is sprayed onto the surface of the glass wall 2 in the form of a mist, i.e. in the form of very fine droplets (liquid aerosol) suspended in the ambient air, typically having an average diameter of less than or even much less than 1 mm. It is particularly advantageous to spray, for example by spraying (nebulization) and/or atomizing (atomization), so that at least 95% of the sprayed droplets have a diameter of 1 to 10 μm, preferably 2 to 3 μm. In fact, the use of very small diameter droplets not only advantageously limits the phenomenon of coalescence of these droplets onto the surface of the glass wall 2 and the runoff effect that may result therefrom, but also promotes contact of said droplets with glass walls 2 of complex geometry. To optimize the liquid ejection step, in addition and/or alternatively, a carrier gas, preferably an inert gas (Ar, N) may be passed₂Etc.) to eject the droplets. Of course, the liquid flow rate of the carrier gas (and therefore the number and volume of the ejected droplets) and/or the pressure are advantageously adjusted, according to the surface area of the glass wall 2 of the container 1 to be treated, so as to limit the risk of coalescence of the droplets onto the surface of the glass wall 2.

Advantageously, the liquid ejected during the ejection step of the method according to the invention is transparent and still more advantageously a colourless liquid. According to one variant, the liquid is a liquid in which the solid residual compounds are easily dispersed so as to be in suspension. According to a further advantageous variant, the liquid is a solvent for the solid residual compound, i.e. a liquid in which the solid residual compound is liable to be at least partially dissolved. In practice, the implementation of a solvent proves to be beneficial for obtaining a second particularly uniform coating, whether said coating is wet, i.e. formed by residual compounds dissolved in the solvent droplets, or conversely dry, i.e. formed by a single residual compound which is redeposited on the surface of the glass wall 2 after drying/evaporation of the solvent. Moreover, the use of a solvent may advantageously help to obtain a second coating that is significantly more transparent than the first coating.

Preferably, the solvent (or the liquid, in which case the liquid is not a solvent) is water, more preferably ultrapure water. It is also advantageously avoided to use liquids (solvents or not) that are liable to contaminate the container 1 and/or require restricted implementation and recovery devices, in particular for hygienic or environmental reasons. Therefore, in case the residual compound comprises sodium sulfate, ultrapure water will be more preferred than glycerol or dilute sulfuric acid, also referred to as solvent for sodium sulfate. The method according to the invention is therefore particularly simple, inexpensive and safe to implement.

Preferably, said spraying step is carried out on said container 1, the latter being at a temperature of between 0 and 100 ℃, and preferably at ambient temperature. The liquid is advantageously sprayed onto the surface of the glass wall 2 at ambient temperature, or possibly at a higher temperature (for example 70 ℃). If the temperature increase does tend to promote the dissolution or suspension of the residual compounds in the sprayed liquid droplets, an excessive temperature difference between the glass wall 2 and the sprayed liquid will be avoided, in order to limit in particular the risk of rapid coalescence of the droplets onto the surface of said wall 2. Furthermore, the implementation of too high a temperature may lead to too rapid evaporation of the liquid, insufficient dissolution or suspension of the residual compounds, detrimental to the good operation of the process according to the invention, i.e. its optimal operation.

Advantageously, said spraying step is carried out simultaneously on the surfaces of said inner face 4 and outer face 5 of said glass wall 2 of the container 1. In fact, although it is preferably intended to treat the surface of the inner face 4 of the glass wall 2 of the container 1 (internal treatment), said surface treatment step may or may not automatically affect the surface of the outer face 5 of said wall 2. Therefore, the first coating layer may also be formed at the surface of the outer face 5. In particular, in the above preferred case, the surface treatment step is a step of dealkalizing the glass in the vicinity of the surface of the inner face 4 of the glass wall 2 of the container 1, in which the reactive substance can escape from the housing chamber 3 of the container 1 and react with the glass in the vicinity of the surface of the outer face 5 of the glass wall 2. In this case, the simultaneous ejection of the droplets onto the surfaces of said inner face 4 and outer face 5 thus advantageously allows to modify simultaneously one or several characteristics of the residual compound on the surfaces of these faces, so as to form on each of these surfaces a more uniform and/or transparent coating comprising said residual compound.

Moreover, such simultaneous ejection of droplets at the surface of the inner face 4 and outer face 5 advantageously allows to simplify the ejection step. The spraying step can then in fact be easily achieved by means of fixed spraying devices (for example of the nozzle type) and is positioned outside said container 1, preferably above and opposite to the ring 9 and the opening 10 of the container 1, as schematically illustrated in figure 3. Therefore, it is not necessary to use a complicated mobile injection device (e.g. pipette or tube type) to be introduced into the accommodation chamber 3 of the container 1 to be treated through the opening 10 of the container to be treated in order to eject a liquid droplet, which may further require at least temporary fixation of the container 1.

Advantageously, as shown in fig. 3, during said spraying step, said droplets are preferably sprayed substantially according to a spray cone, advantageously solid, and having an angle θ preferably comprised between 20 ° and 100 °, according to the geometry and dimensions of the container to be treated and to the distance separating the spraying means from the ring 9 and the opening 10 of the container 1.

Preferably, the method according to the invention comprises, after said spraying step, a step of forced drying of said glass wall 2, i.e. a step of accelerated and controlled drying of said glass wall 2. The drying step may advantageously be carried out by spraying a drying gas (air or inert gas) onto the surface of the glass wall 2E.g. Ar, N₂Etc.) to dry the glass wall 2 by controlled evaporation of the droplets. As an alternative, it is possible to envisage the container 1 being placed vertically, with the ring 9 directed towards the top, in an upward forced flow of drying gas. Advantageously, the forced drying step is carried out after a contact time of the order of seconds between the droplets and the first coating layer (typically between 1 and 5s, in particular according to the geometry and dimensions of the container to be treated, or also according to the nature of the residual compounds and/or of the sprayed liquid). At the end of this drying step, the second coating is thus obtained by redepositing the residual compounds on the surface of the glass wall 2, said second coating being more uniform and/or transparent than the first initial coating.

Advantageously, the method according to the invention comprises, after said spraying step, a step of optical inspection (preferably visual inspection) of said glass wall 2, the purpose of which is in particular to search for the potential presence of glass defects. Advantageously, said optical inspection step can be carried out by any known means and according to any known visual inspection method. Preferably, said optical inspection step can be carried out by means of known manual visual inspection devices, advantageously automatic, designed to detect and identify contrast defects, for example. Of course, the optical inspection step may instead be performed manually by an operator, for example, visually.

Preferably, the optical inspection step is performed after the forced drying step. In this way, any visual disturbances, any undesired optical effects that could potentially be generated by the presence of the droplets at the surface of the glass wall 2 of the container 1 under inspection, as well as the potential coalescence and runoff of the droplets during inspection, are limited as much as possible.

The applicant has carried out studies by Scanning Electron Microscopy (SEM) in order to observe on a microscopic scale the effect of the method according to the invention on the surface of the glass wall 2. During the study, wall fragments of the first and second type II glass vials, both obtained from conventional soda-lime-silica (type III) glass vials subjected to ammonium sulfate surface dealkalization treatment, were compared. Unlike the first vial (control vial), the second vial has been subjected to the method according to the invention, the liquid ejected as droplets being ultrapure water.

An SEM photograph of the surface portion of the glass wall chip of the first vial is shown in figure 4. In fig. 5, by way of comparison, an SEM photograph of a surface portion of a glass wall chip of a second vial treated according to the invention is shown.

As shown in fig. 5, the presence of a coating comprising residual compounds (here sodium sulphate particles) at the surface of the glass wall of the second vial treated according to the invention was effectively confirmed by observation with a scanning electron microscope. The spraying step of the method according to the invention is therefore substantially different from the step of cleaning the glass wall. It was also observed that, in the absence of treatment (fig. 4), the particles G of residual compound present at the wall surface of the first vial corresponded to agglomerates of smaller particles. Their morphology appears to be substantially faceted, their shape being relatively complex, as shown schematically in figure 6 (a). Even a certain porosity of these particles G can be observed. On the other hand, after treatment according to the method of the invention (fig. 5), the density of the particles at the surface (number of particles per surface unit) is slightly reduced, the shape of the particles G 'is softer, the particles G' appear completely round or also rounded (as schematically shown in fig. 6 (b)). The small particles contributing to the opacity of the first coating are attenuated or even disappear. The largest particles are themselves polished by the ejected droplets.

This microscopic observation of the change in the conformation and morphology of the particles at the surface of the glass wall of the container treated according to the method of the invention allows to explain the more homogeneous nature of the secondary coating formed and advantageously also the more transparent nature of the secondary coating.

Furthermore, in order to characterize more specifically the improvement in transparency of the glass wall 2 of the container 1 which can advantageously be provided by the processing method according to the invention, as described below, additional transparency comparison measurements have been carried out on glass containers of type II which have not been subjected to the method according to the invention and on glass containers of type II which have been subjected to said method.

Thus, three different glass-walled containers were analyzed and compared, namely:

-a container R₁: a50 ml type III molded vial (90% capacity: 54ml) made of white soda-lime-silica glass;

-a container R₂: 50ml type II vials (90% capacity: 54ml), type III molded vials made of white soda-lime-silica glass (and R₁Same) is subjected to an ammonium sulphate dealkalization treatment, not obtained according to the process of the invention;

-a container R₃: 50ml type II vials (90% capacity: 54ml) from which type III molded vials made of white soda-lime-silica glass were subjected to ammonium sulfate dealkalization (with R)₂Same), and successively carrying out the spraying step (inner and outer) and the forced drying step of the method according to the invention;

FIG. 7 schematically shows a method for measuring these containers R₁、R₂And R₃The respective transparency was maintained. Container R₁、R₂And R₃Each of which is located on a horizontal support 11 in front of a black background 12 provided with horizontal white stripes (test pattern). These white stripes are formed by grooves 13 cut into a black background behind which a white light source is located (not shown). By means of a digital reflex camera, a container R is photographed in complete darkness in front of a black background 12₁、R₂And R₃A photograph of each of the above. Then, the photographed pictures are converted into 8-bit gray-scale digital images, respectively, by image processing software (e.g., the above-mentioned "ImageJ" software). Then, based on the image thus obtained, the transparent container R is drawn along a vertical line corresponding to the height of the container along its rotation axis₁、R₂And R₃A grey scale map corresponding to the light intensity of the glass wall.

The resulting graph is shown in fig. 8. The transmitted light intensity is indicated on the ordinate axis (in grey levels) and is shown along the container R on the abscissa axis (in pixels)₁、R₂And R₃The distance between the ring of rotation axes of the containers and the bottom of the containers. In Table 1 below, by considering only the stripesThe light intensities associated with the two central horizontal lines of (A) are compared for the container R₁、R₂And R₃Is an average of the intensities of the transmitted light collected from each of the sensors.

TABLE 1

It was thus observed that the containers R obtained according to the process of the invention₃Than a vessel R not subjected to the process according to the invention₂Appears much more transparent. However, since in the container R₃In the vessel R, there is a residual compound (here sodium sulphate) on the surface of the glass wall₃Seems to be better than the vessel R which is not subjected to dealkalization treatment₁And is slightly opaque. Advantageously, considering a type III container R₁Having a transparency of 100%, container R₃(in the container R₁After the dealkalization treatment has been carried out, but not after subjecting it to the treatment process according to the invention) advantageously has a relative transparency of from 80 to 100%, in particular whether the optional forced drying step of the treatment process according to the invention has been carried out or not.

Furthermore, the applicant has carried out a complementary analysis to investigate the persistence of the transparency improvement provided by the method according to the invention. These analyses show that the level of transparency of the glass wall of the container obtained at the end of the treatment process according to the invention does not decrease significantly after oven ageing at 60 ℃ for 8 hours.

Tests were also carried out in order to investigate the effect of the method according to the invention on the hydrolysis resistance HR of the glass-walled container surface at the end of the method. In particular, as described below, comparative measurements were made between a type III glass container not subjected to the method of the present invention and a type II glass container subjected to the method.

Thus, two or less glass-walled containers were analyzed and compared;

-a container R₄: 50ml type II vials (90% capacity: 54ml) obtained from type III molded vials made of white soda-lime-silica glass, which were subjected to an ammonium sulphate dealkalization treatment and which were not subjected to the process according to the invention (conventionalType II vials);

-a container R₅: 50ml type II vials (90% capacity: 54ml) from which type III molded vials made of white soda-lime-silica glass were subjected to ammonium sulfate dealkalization (with R)₁Same) and obtained by carrying out the process according to the invention (inner and outer);

these containers R were measured after 1 hour of sterilization in an autoclave with ultrapure water at 121 ℃ according to the instructions of the European pharmacopoeia 9 th edition chapter 3.2.1₄And R₅Hydrolysis resistance HR of the respective glass wall surface. For the vial type considered, the HR limit is 0.5ml HCl N/100 for 100ml autoclaved (extract water) according to the european pharmacopoeia.

The results obtained are shown in table 2 below:

	R4	R5
			superficial HR (ml HCl N/100)	0.05±0.05	0.08±0.05

TABLE 2

Thus, the measurement of the surface hydrolysis resistance HR shows that the method according to the invention advantageously has no significant effect on the level of hydrolysis resistance provided to the container by the dealkalization treatment step to which the container has previously been subjected. The HR value is advantageously kept substantially between 5% and 25% of the HR limit indicated by the european pharmacopoeia for the type of container under consideration.

Moreover, the applicant carried out these same containers R according to the following protocol₄And R₅Comparative study of the behaviour of oven ageing at 60 ℃:

-containers R according to the process of the invention₄And R₅A liquid ejection step (here ultrapure water) is performed,

baking the container for 2 to 8 hours at the temperature of minus 60 ℃,

-sterilizing the container with ultrapure water in an autoclave for 1 hour at 121 ℃, then baking the container for 2 to 8 hours at 60 ℃, then

The surface resistance to hydrolysis HR (HR value of 0.5ml HCl N/100 for 100ml autoclaved according to the European pharmacopoeia, in accordance with European pharmacopoeia, 9 th edition, chapter 3.2.1).

The results obtained are shown in table 3 below:

TABLE 3

Measurements of the resistance HR of the surface to hydrolysis after oven aging show that the method according to the invention has no significant effect on the permanence of the level of resistance to hydrolysis provided to the container by the dealkalization step to which the container has previously been subjected.

Advantageously, the process of the invention is an on-line process for industrial implementation. For this purpose, the different steps described above can advantageously be integrated directly into the industrial process for manufacturing glass-walled containers, carried out in a preferably automated manner.

The invention also relates per se to a plant 14 for treating containers 1, said containers 1 comprising a glass wall 2 defining a cavity 3 for containing a product, said glass wall 2 having an inner face 4 positioned facing said containing cavity 3 and an opposite outer face 5. The plant 14 in question is advantageously a plant which allows the implementation of the treatment method according to the invention, so that the description given above in relation to the method according to the invention remains valid and applicable to the present plant, mutatis mutandis. It is preferably an industrial installation, advantageously automated, designed to process a large number of containers substantially continuously. Preferably, the plant 14 is designed to be integrated directly in the glassware line, downstream of the forming machine of the containers 1.

A particularly preferred embodiment of the installation 14 according to the invention is shown in fig. 9. The arrows in fig. 9 indicate the preferred direction of advancement of the container 1 with respect to the different stations comprising the installation 14, as will be described in detail hereinafter. The terms "upstream" and "downstream" used hereinafter will preferably be interpreted in view of the direction of advance of the containers 1 (indicated by the arrow) within the installation 14 according to the invention.

According to the invention, the plant 14 comprises a surface treatment station 15 for surface treating the glass wall 2 for subjecting the container 1 to a surface treatment step of the glass wall 2, resulting in the formation of a first coating comprising solid residual compounds on the glass wall 2. Advantageously, said surface treatment station 15 is designed to allow the surface treatment steps described above with respect to the method according to the invention to be carried out. More precisely, the surface treatment station 15 is a station for dealkalizing glass in the vicinity of the inner face 4 of the glass wall 2. The dealkalizing station can therefore advantageously be designed to allow introduction of the sulfur-containing substance, such as in particular ammonium sulfate, into the containing chamber 3 of the container 1 through the opening 10 of the container 1.

Preferably, the plant 14 according to the invention comprises a station for annealing said containers 1, for example of the arched type. To simplify the design of the facility 14, the surface treatment station 15 may potentially be incorporated with (or integrated into) the annealing station. Alternatively, the surface treatment station 15 may be located upstream of the annealing station.

As schematically shown in fig. 9, the plant 14 according to the invention comprises a spraying station 16 for spraying droplets onto the surface of the glass wall 2, said spraying station 16 being located downstream of the surface treatment station 15. Advantageously, said spraying station 16 is designed to allow the spraying step described above with respect to the method according to the invention to be carried out. Advantageously, and based on the above, the spraying station 16 is designed and configured to allow the final formation of a second coating on the glass wall from the first coating, which second coating comprises the residual compounds and is more transparent and/or more homogeneous than the first coating.

Preferably, said spraying station 16 comprises at least one spraying device 17 (for example of the nozzle or sprinkler type), advantageously configured to be positioned, in operation, outside the container 1 and, more preferably, above and opposite the ring 9 and the opening 10 of the container 1, as schematically illustrated in fig. 3 and 10. Preferably, said spraying means 17 are designed to be stationary with respect to the container 3 when said spraying means 17 are operated. The spraying station 16 is therefore advantageously free of any complex mobile injection means (for example, a pipette or a tube type) which would be designed to be introduced into the housing chamber 3 of the container 1 to be treated through the opening 10 of the container 1 to be treated, in order to spray the liquid droplets. Such a configuration helps simplify the design and implementation and robustness of the facility 14 according to the present invention. Of course, however, the installation 14 according to the invention may comprise a spraying station 16 which is to be provided with such a mobile injection device.

Preferably, said spraying station 16 is designed and configured to spray said droplets in the form of a mist, i.e. in the form of very fine droplets (liquid aerosol) having an average diameter typically smaller or even much smaller than 1mm suspended in the ambient air. For example, the spraying means 17 of the spraying station 16 may comprise a nozzle provided with an outlet orifice of fixed or variable diameter from which the droplets will be sprayed in the average form of a spray cone, advantageously solid. Still more preferably, the ejection means 17 are designed to eject droplets of the liquid having an average diameter between 1 and 10 μm, preferably between 2 and 3 μm. For this purpose, the spraying means 17 preferably comprise a piezoelectric or ultrasonic atomizer or nebulizer. Other suitable injection devices are of course also conceivable.

Advantageously, the injection device 17 can be designed and configured to pass a pressurized carrier gas, preferably an inert gas (Ar, N)₂Etc.) to eject the droplets. Preferably, the ejection station 16 comprises means for adjusting the quantity and temperature of the ejected droplets and, if necessary, the pressure of the carrier gas.

Preferably, the spraying station 16 is designed and configured to spray droplets of the liquid simultaneously onto the surfaces of the inner face 4 and outer face 5 of the glass wall 2. For example, the spraying station 16 may comprise a plurality of spraying devices 17 or nozzles, at least one of which is arranged opposite the opening 10 of the container 1, the other spraying devices or nozzles being arranged opposite the outer face 5 of the glass wall 2 of the container 1, as described above. Preferably, however, the spray device 17 is configured to be positioned above and opposite the ring 9 and the opening 10 of the container 1 in operation.

Advantageously, said spraying station 16 comprises means (not shown) for adjusting the distance between said spraying means 17 and said glass wall 2, in particular for adjusting the distance between the spraying means 17 on the one hand and the opening 10 and the ring 9 of the container 1 to be treated on the other hand. The injection station 16 preferably comprises, in addition or as an alternative, means for adjusting the angle θ of the injection cone of said injection means 17 (fig. 3) so that said angle θ is preferably between 20 ° and 100 °. The spraying station 16 can therefore be adapted to different geometries and sizes of the containers to be treated. Adjusting the angle θ of the droplet ejection cone by means of the ejection means 17 advantageously further facilitates the simultaneous ejection of droplets of said liquid onto the surfaces of said inner face 4 and outer face 5 of said glass wall 2.

Preferably, the plant 14 comprises a forced drying station 18 for forced drying of the glass wall 2, located downstream of the spraying station 16. Advantageously, said forced drying station 18 is designed to allow the implementation of the forced drying step described above with respect to the method according to the invention. The forced drying station 18 preferably comprises means for spraying a drying gas (air or an inert gas, for example Ar, N) against the surface of the glass wall 2₂Etc.) and preferably from the outside of the vessel 3 (not shown, e.g. a nozzle or ramp type). Advantageously, said forced drying station 18 is designed and configured to spray a forced drying gas flow simultaneously against the respective surfaces of the inner face 4 and of the outer face 5 of the glass wall 2, respectively.

Advantageously, the plant 14 comprises an optical inspection station 19 for optically inspecting said glass wall 2, located downstream of said spraying station 16. Advantageously, said forced drying station 18 is designed to allow the optical inspection steps described above with respect to the method according to the invention to be carried out. The optical inspection station 19 may comprise any known means for optical inspection, in particular visual inspection, suitable for inspecting glass defects on the glass wall 2 of the container 1. Preferably, it comprises at least one manual visual inspection device, advantageously automatic, designed for example to detect and identify contrasting defects at the glass wall 2 of the container 1. Preferably, it is a device that operates in the visible region of the electromagnetic spectrum. Of course, on the contrary, the optical inspection station 19 may comprise known means for manual visual inspection of the glass wall 2. Preferably, said optical inspection station 19 is located downstream of said forced drying station 18, so that the glass wall 2 of the container 1 is advantageously substantially free of droplets when said container 1 arrives at the optical inspection station 19 from said forced drying station 18.

Preferably, the plant 10 also comprises conveying means 20, for example belt, chain or roller conveying means, to ensure that the containers 1 are conveyed upwards from the surface treatment station 15 to the spraying station 16 and, advantageously, from said spraying station 16 to the optical inspection station 19, by passing preferably through the forced drying station 18.

By now it has been disclosed that the basic idea of the invention described above, which is to obtain a second coating layer comprising residual compounds and being more transparent and/or more homogeneous than the first coating layer, from a first coating layer comprising residual compounds by ejecting droplets of a liquid, can be extended to surface treatment steps (and corresponding treatment stations) of different nature. In fact, this concept may find more general interest from the moment that we have a glass-walled container comprising solid residual compounds deposited on the glass wall and resulting from surface treatment steps to which said container has been previously subjected, and the presence of which is particularly liable to hamper the optical inspection of the container.

Therefore, the invention may be such that:

-a method for treating a container having a glass wall delimiting a cavity for containing a product, said glass wall having an inner face positioned facing said containing cavity and an opposite outer face, said glass wall being provided with a first coating comprising solid residual compounds resulting from a surface treatment step of said glass wall to which said container has been previously subjected, said method comprising a step of spraying droplets of a liquid onto the surface of said glass wall so as to form, from said first coating, a second coating on said glass wall, said second coating comprising said residual compounds and being more transparent and/or more homogeneous than said first coating.

And/or

-a plant for treating containers having a glass wall delimiting a cavity for containing a product, said glass wall having an inner face positioned facing said containing cavity and an opposite outer face, said plant comprising a station for surface treating said glass wall, for subjecting said containers to a step of surface treatment of said glass wall, resulting in the formation of a first coating comprising solid residual compounds on said glass wall, said plant comprising a station for spraying droplets of a liquid onto the surface of said glass wall, said spraying station being located downstream of said surface treatment station.

Possibility of industrial application

The invention finds its industrial application in the field of methods and installations for treating glass-walled containers, and in particular in the field of methods and apparatuses for treating pharmaceutical or diagnostic glass primary packages.