Porous non-woven film

Abstract

This porous non-woven film (1) comprises polymeric fibers and includes a first material and a second material, the first material having a melting temperature higher than that of the second material. The porous non-woven film (1) is such that: - a mean thickness of the porous non-woven film is between 60 µm and 250 µm, preferably between 80 µm and 200 µm, - a density of the porous non-woven film, defined as the ratio of the mass per unit area of the porous non-woven film to the mean thickness of the porous non-woven film, is between 300 kg / m3 and 500 kg / m3, and - the relative standard deviation (RSD) from the mean thickness of the porous non-woven film is less than or equal to 10%.

Description

[0001] POROUS NON-WOVEN FILM

[0002] FIELD OF THE INVENTION

[0003] The present invention relates to a porous non-woven film comprising polymeric fibers. The invention also relates to an active article, such as an active packet or an active capsule, intended for the regulation of an atmosphere in a container or a medical device containing sensitive or odorous products, the active article having an envelope comprising a porous non-woven film and an active material arranged in the inner volume of the envelope. Examples of sensitive or odorous products include, e.g., diagnostic, pharmaceutical, nutraceutical, herbal or food products. The active material may be selected, e.g., in the group of humidity absorbers, oxygen scavengers, odor absorbers, absorbers of volatile olfactory organic compounds, humidity emitters and / or emitters of volatile olfactory organic compounds. The invention also relates to a sterile packaging, in particular for a medical device, comprising a porous non-woven film, and to a method for manufacturing a porous non-woven film.

[0004] BACKGROUND OF THE INVENTION

[0005] Containers for moisture and / or oxygen sensitive products such as, for example, diagnostic test strips or pharmaceutical tablets, typically include a chamber for housing the sensitive products and an active article dropped in the chamber to regulate the atmosphere around the sensitive products. In particular, the active article may be an active packet or an active capsule, e.g. filled with desiccant or oxygen scavenger. To allow absorption of moisture, oxygen or other volatiles and thus extend the shelf life of sensitive products, or to allow desorption of materials, the envelope of an active article is usually porous or permeable to moisture, volatiles, odorants and the like. Varied materials are used to provide the combination of mechanical strength and porosity or permeability that is required for the envelopes of active articles. Non-woven materials sold by DUPONT under the trademark TYVEK, which are spun-bonded non-woven fabrics comprising polyethylene fibers, are especially popular. By way of example, in order to form an active packet, a web of non-woven material is provided to a filling machine, which sequentially conforms the web of non-woven material to a desired shape and seals facing edges of the non-woven material together, so as to obtain an open envelope. Then, a quantity of an active material, e.g. a quantity of desiccant or oxygen scavenger, is inserted into the open envelope, and the envelope is sealed to close the active packet. The process is repeated until the length of non-woven material is exhausted, or until the desired number of active packets has been formed. In practice, two forms of non-woven materials are commonly used to form active packets, i.e. , adhesive coated non-woven materials and raw form (or uncoated) non-woven materials. An adhesive coated non-woven material is generally conformed into the packet shape and welded to itself by heat and pressure applied to seal areas, while an uncoated non-woven materials may be sealed with application of additional energy, e.g., by ultrasonic welding or impulse welding.

[0006] Non-woven materials may also be used to form at least part of an envelope of active articles other than active packets, such as active capsules, active canisters, active stoppers, etc., also filled with an active material such as, e.g., desiccant or oxygen scavenger. Here again, the non-woven material is selected to provide the required combination of mechanical strength and porosity or permeability, while allowing sealing to itself or another part of the envelope of the active article. Yet another application of non-woven materials is to form a sealable lidding film for sterile packaging, e.g. for medical devices such as inhalers, syringes, surgical instruments, etc. The medical device is commonly received in a plastic receptacle, which is closed by the lidding film made of a selected non-woven material having the double advantage of allowing the sterilization of the packaging once closed, by the passage of a sterilizing gas through the porous non-woven material, while being impermeable to bacteria.

[0007] In all of the above applications, a non-woven material is also commonly provided with a visual marking, usually printed on the web of non-woven material before its use to form an envelope for an active article or a lidding film for sterile packaging. Such marking is intended to enable the identification of the active article or the sterile packaging. In the case of active articles dropped in the same container as sensitive consumable products, the marking is also intended to avoid any confusion between the active articles and the sensitive consumable products. The marking may be an ink-printed marking, comprising a non-toxic or inert ink delivered by a printing device. As a variant, the marking may be obtained by any other marking technology known in the art, such as, e.g., laser marking.

[0008] A difficulty encountered on manufacturing lines for active articles or sterile packaging is the conveying of the web of non-woven material in such a way as to avoid variations in the tension of the web, which may cause defects in the conformation of active articles or the positioning of the lidding film, and may have a negative impact on the tightness of the seals. Welding irregularities due to non- homogeneous properties of the web of non-woven material may cause risks of leaks of active material for active articles, or risks of contamination for sterile packaging. Another difficulty, in the case of ink-printed marking of the non-woven material, is that the ink used for the marking may be degraded by the welding equipment and may separate from the web of non-woven material. This may result in the formation of ink flakes, causing problems of accumulation on the jaws of the sealing equipment, as well as possible contamination of sensitive products or sterile packaging. In addition, ink abrasion due to friction on conveyors or other equipment for distributing active articles or sterile packaging also produces a risk of contamination and increases the frequency of cleaning of manufacturing lines.

[0009] It is these drawbacks that the invention is intended more particularly to remedy by proposing a porous non-woven film, especially for the formation of active articles, such as active packets or active capsules, or the formation of lidding films for sterile packaging, whose properties ensure reliable conveying of the porous non-woven film on manufacturing lines, thus limiting variations in the tension of the film and guaranteeing high quality seals, while also avoiding risks of contamination, both on manufacturing lines and in containers containing sensitive products. DISCLOSURE OF THE INVENTION

[0010] For this purpose, a subject of the invention is a porous non-woven film comprising polymeric fibers, said porous non-woven film including a first material and a second material, the first material having a melting temperature higher than that of the second material, wherein:

[0011] - a mean thickness of the porous non-woven film is between 60 pm and 250 pm, preferably between 80 pm and 200 pm,

[0012] - a density of the porous non-woven film, defined as the ratio of the mass per unit area of the porous non-woven film to the mean thickness of the porous non-woven film, is between 300 kg / m3and 500 kg / m3, and

[0013] - the relative standard deviation (RSD) from the mean thickness of the porous non-woven film is less than or equal to 10%.

[0014] In the context of the invention, the thickness of the porous non-woven film is measured according to standard test method ISO 534:2011 , it being understood that, in the case of a sample of porous non-woven film having a surface area of less than 200 mm2, the thickness measurement is performed on the available surface area of the sample. In addition, in the context of the invention, the mass per unit area of the porous non-woven film is measured according to standard test method ASTM D3776 - Option A.

[0015] Thanks to its specific properties in terms of thickness and density, a porous nonwoven film as disclosed above has a combination of mechanical strength and porosity or permeability, making it particularly well suited for the formation of active articles, such active packets or active capsules, or the formation of lidding films for sterile packaging. In particular, the thickness homogeneity of the porous non-woven film makes it possible to limit variations in the tension of the film, thus allowing reliable conveying and ensuring optimal welding on manufacturing lines. Thanks to the homogeneous thickness of the porous non-woven film, the welding adjustment can be made once and for all and does not need to be constantly adjusted during the manufacture of a batch. The welding can be obtained without the presence of any additional coating, thanks to the selection of the first and second materials with two different melting temperatures, e.g. with a difference of the order of 40°C between the two melting temperatures. The second material having a relatively lower melting temperature allows the welding of the porous non-woven film using conventional welding techniques, whereas the first material having a relatively higher melting temperature ensures good mechanical resistance of the porous nonwoven film.

[0016] According to one embodiment, the porous non-woven film has polymeric fibers comprising the first material and the second material on all of its main surfaces. Within the meaning of the invention, a main surface of a film is a surface transverse to the thickness direction of the film. In other words, polymeric fibers comprising the first material and the second material are present on all of the main surfaces of the porous non-woven film, preferably over its entire volume. Since both the first material and the second material, having two different melting temperatures as explained above, are present on each main surface of the porous non-woven film, preferably over its entire volume, the porous non-woven film can be welded (or sealed) to itself or to another element in any configuration, i.e. on any of its surfaces, while maintaining good mechanical strength. In one variant, the polymeric fibers that are present on all of the main surfaces of the porous non-woven film may comprise a mixture of fibers including the first material, on the one hand, and of fibers including the second material, on the other hand. In another variant, the polymeric fibers that are present on all of the main surfaces of the porous non-woven film may comprise bicomponent fibers including both the first material and the second material.

[0017] According to one embodiment, the porous non-woven film is obtained by lamination of at least two superimposed layers of porous non-woven sheet and the polymeric fibers in each layer of porous non-woven sheet comprise the first material and the second material. Due to the presence, in each layer used to form the film, of polymeric fibers comprising the first material and the second material, the adhesion between the at least two superimposed layers resulting from the lamination is optimal, since the at least two superimposed layers each have polymeric fibers having the same chemical composition. In addition, since both the first material and the second material, with adjusted melting temperatures, are present in each layer of the porous non-woven film, and thus throughout the film, the porous non-woven film can be welded (or sealed) to itself or to another element in any configuration, i.e. on any of its surfaces, while maintaining good mechanical strength and without requiring an additional sealing layer. In one variant, the polymeric fibers in each layer of porous non-woven sheet comprise a mixture of fibers including the first material, on the one hand, and of fibers including the second material, on the other hand. In another variant, the polymeric fibers in each layer of porous non-woven sheet comprise bicomponent fibers including both the first material and the second material.

[0018] In the above embodiments, the porous non-woven film can advantageously be folded back on itself in any direction, for example to form at least part of the envelope of an active packet or an active capsule, and be sealed to itself or to another element on any of its surfaces. This avoids having to position a specific surface of the porous non-woven film towards a sealing surface, which may be a sealing surface of the film itself or of another element, as is the case with asymmetric films which have a sealing layer on one surface only. In the case of bicomponent fibers, the fibers may have a sheath-core structure comprising a core based on the first material having a relatively higher melting temperature and a sheath based on the second material having a relatively lower melting temperature. In this way, the porous non-woven film can be heated so that the sheaths of the fibers are melted to provide links between adjacent fibers within the porous non-woven film, while the cores of the fibers retain their fibrous structure. The sheath-core structure of the fibers may be, e.g., a concentric sheath-core structure; an eccentric sheath-core structure in which the core is shifted off-center; a side-by-side sheath-core structure in which each of the first and second materials occupies a part of the fiber surface. In any case, whether separate fibers comprise the first material and the second material or whether they are bicomponent fibers, the second material having a relatively lower melting temperature allows the welding of the porous non-woven film using conventional welding techniques, whereas the first material having a relatively higher melting temperature ensures good mechanical resistance of the porous nonwoven film. According to one embodiment, the porous non-woven film has an opacity of between 15% and 60%, preferably between 15% and 40%. In the context of the invention, the opacity is measured according to standard test method ISO 2471. Such a high transparency of the porous non-woven film makes it possible to provide the porous non-woven film with an ink-printed marking either on its surface intended to face an inside of the envelope of an active article, or even inside the structure of the porous non-woven film, while still being visible from outside the active article or the sterile packaging. In this way, any contact between the sealing or dispensing equipment and the ink is avoided during the manufacturing of the active article or the sterile packaging. The formation of ink flakes is thus prevented, which avoids having to intervene to clean the equipment and improves the productivity of the manufacturing lines. The risks of contamination of sensitive products in containers where active articles are used are also avoided.

[0019] The high transparency of the porous non-woven film of the invention is also advantageous when the film is used in combination with a color-changing active material, the color of which changes depending on a concentration of moisture, oxygen, or other volatiles to which the active material is exposed and / or which it absorbs and / or which it emits. One example of such a color-changing active material is color-changing silica gel. In one example, the silica gel particles appear orange or yellow when dry and transition to green as the silica gel becomes saturated with moisture. The high transparency of the porous non-woven film makes it an advantageous alternative to transparent perforated polymer films made of polyethylene or polypropylene, which have lower permeability than a porous nonwoven film, and it avoids having to create a window to see the color of the colorchanging active material as in the case of a film with higher opacity. According to one embodiment, the porous non-woven film is used to form an active article, such as an active packet or an active capsule, for regulating an atmosphere in a container or a medical device containing sensitive or odorous products, the active article having an envelope comprising said porous non-woven film and defining an inner volume in which a color-changing active material is arranged. According to one embodiment, a ratio of the density (as defined above, in kg / m3) of the porous non-woven film to the opacity (in %) of the porous non-woven film is higher than 7, preferably higher than 10. This ensures that the porous non-woven film has a good transparency while still having a porosity adapted to its application for the formation of active articles, such active packets or active capsules, or for the formation of lidding films for sterile packaging.

[0020] According to one embodiment, the porous non-woven film has a Water Vapor Transmission Rate (WVTR) higher than or equal to 700 g. day1. nr2, preferably higher than or equal to 1000 g. day1. nr2, at 23°C, 50%RH. In the context of the invention, the WVTR is measured according to the “Desiccant Method” of standard test method ASTM E96 (“Standard Test Methods for Water Vapor Transmission of Materials”).

[0021] According to one embodiment, a surface free energy of the porous non-woven film is higher than or equal to 30 mN / m. In the context of the invention, the surface free energy is measured according to standard test method ISO 19403, using water and ethylene glycol as testing solvents. Thanks to the selection of such a relatively high surface free energy, the surface of the porous non-woven film has hydrophilic properties which are favorable for its marking, particularly by ink marking using a water-soluble ink. According to one feature, the porous non-woven film includes an ink-printed marking comprising a water-soluble ink, preferably a food contact grade ink.

[0022] In one embodiment, the porous non-woven film includes an ink-printed marking on a first outer surface of the porous non-woven film, the ink-printed marking being visible from the side of a second outer surface of the porous non-woven film opposite from the first outer surface.

[0023] In another embodiment, the porous non-woven film includes an ink-printed marking inside the porous non-woven film, the ink-printed marking being visible from the exterior of the porous non-woven film. According to one embodiment, the porous non-woven film is obtained by lamination of at least two superimposed layers of porous non-woven sheet, the porous nonwoven film including an ink-printed marking, originally formed on a surface of at least one of the superimposed layers and arranged inside the porous non-woven film, the ink-printed marking being visible from the exterior of the porous non-woven film.

[0024] According to one embodiment, the porous non-woven film is obtained by lamination of at least three superimposed layers of porous non-woven sheet, the porous nonwoven film including an ink-printed marking, originally formed on a surface of a central layer among the three superimposed layers and arranged inside the porous non-woven film, the ink-printed marking being visible from the exterior of the porous non-woven film.

[0025] According to one embodiment, the polymeric fibers of the porous non-woven film comprise monocomponent fibers comprising a first type of monocomponent fibers including a first material and a second type of monocomponent fibers including a second material, the first material having a melting temperature higher than that of the second material. According to one embodiment, the polymeric fibers of the porous non-woven film comprise bicomponent fibers including a first material and a second material, the first material having a melting temperature higher than that of the second material. In all cases, the second material having a relatively lower melting temperature allows the welding of the porous non-woven film using conventional welding techniques, whereas the first material having a relatively higher melting temperature ensures good mechanical resistance of the porous nonwoven film.

[0026] According to one embodiment, the polymeric fibers of the porous non-woven film comprise sheath-core fibers comprising a core based on the first material having a relatively higher melting temperature and a sheath based on the second material having a relatively lower melting temperature. In this way, the porous non-woven film can be heated so that the sheaths of the fibers are melted to provide links between adjacent fibers within the porous non-woven film, while the cores of the fibers retain their fibrous structure. The sheath-core structure of the fibers may be, e.g., a concentric sheath-core structure; an eccentric sheath-core structure in which the core is shifted off-center; a side-by-side sheath-core structure in which each of the first and second materials occupies a part of the fiber surface.

[0027] According to one embodiment, the polymeric fibers of the porous non-woven film comprise polyethylene (PE) and polypropylene (PP). In one embodiment, the polymeric fibers of the porous non-woven film include PE monocomponent fibers, on the one hand, and PP monocomponent fibers, on the other hand. In one embodiment, the polymeric fibers of the porous non-woven film include sheath-core bicomponent fibers having a PE sheath and a PP core. In this way, the PE having a relatively lower melting temperature allows the welding of the porous non-woven film using conventional welding techniques, whereas the PP having a relatively higher melting temperature ensures good mechanical resistance of the porous nonwoven film.

[0028] According to one embodiment, the polymeric fibers of the porous non-woven film comprise a first poly( lactic acid) (PLA-1 ) and a second poly(lactic acid) (PLA-2), the first poly(lactic acid) (PLA-1 ) having a melting temperature higher than that of the second poly(lactic acid) (PLA-2). In one embodiment, the polymeric fibers of the porous non-woven film include PLA-1 monocomponent fibers, on the one hand, and PLA-2 monocomponent fibers, on the other hand. In one embodiment, the polymeric fibers of the porous non-woven film include sheath-core bicomponent fibers having a low melt PLA-2 sheath and a high melt PLA-1 core. In this way, low melt PLA-2 allows the welding of the porous non-woven film using conventional welding techniques, whereas the high melt PLA-1 ensures good mechanical resistance of the porous non-woven film.

[0029] According to one feature, a mean diameter of the polymeric fibers of the porous nonwoven film is between 10 pm and 35 pm. Advantageously, the distribution of the mean diameter of the polymeric fibers of the porous non-woven film is narrow so as to ensure good thickness homogeneity of the film.

[0030] According to one feature, a mean length of the polymeric fibers of the porous nonwoven film is between 25 mm and 50 mm. Advantageously, the length of the polymeric fibers of the porous non-woven film is sufficiently high to allow entanglement in the structure of the non-woven, while avoiding the risk of fibers leaking out of the film likely to generate pollution.

[0031] Another subject of the invention is an active article, such as an active packet or an active capsule, for regulating an atmosphere in a container or a medical device containing sensitive or odorous products, the active article comprising an envelope defining an inner volume and an active material arranged in the inner volume of the envelope, the envelope comprising a porous non-woven film as described above. In one embodiment, the active material arranged in the inner volume of the envelope is a color-changing active material, i.e., an active material whose color changes depending on a concentration of moisture, oxygen, or other volatiles to which the active material is exposed and / or which it absorbs and / or which it emits.

[0032] The active material capable of regulating the atmosphere in a container or a medical device may be any type of active material. In particular, the active material may belong to a group of: humidity absorbers (or desiccants); oxygen absorbers (or oxygen scavengers); odor absorbers; absorbers of volatile olfactory organic compounds; emitters of humidity; emitters of volatile organic compounds such as a fragrance, an aroma, a nutrient; and mixtures thereof. It is understood that, within the meaning of the present disclosure, the term "absorb", when referring to a given active material, is used to encompass all chemical and physical phenomena by which a gas may be retained by said active material. In particular, this includes bulk phenomena, generally referred to as “absorption”, where gas molecules enter the active material; or surface phenomena, generally referred to as “adsorption”, where gas molecules attach to the surface of the active material. Optionally, the active material may comprise or consist of an inorganic desiccant material, optionally selected from the group comprising molecular sieves, zeolites, silica gel, clay, hydrate salts, metal oxides, and mixtures thereof.

[0033] According to one embodiment, the porous non-woven film of the envelope includes an ink-printed marking arranged either inside the porous non-woven film or on an outer surface of the porous non-woven film turned toward the inner volume of the envelope, the ink-printed marking being visible from the exterior of the active article. According to one embodiment, the envelope of the active article comprises at least one seal obtained by welding a web of the porous non-woven film, in particular by heat-sealing, ultrasonic welding, impulse welding.

[0034] Another subject of the invention is a sterile packaging, in particular for a medical device such as an inhaler, a syringe, a surgical instrument, etc., comprising a porous non-woven film as described above. The porous non-woven film may form a sealable lidding film for closing a plastic receptacle in which the medical device is received. Advantageously, the properties of the porous non-woven film, in particular in terms of porosity and permeability, are selected so as to allow the sterilization of the packaging once closed, by the passage of a sterilizing gas through the porous non-woven material, while being impermeable to bacteria. The sealing properties of the porous non-woven film are also adapted to ensure both durable seals, that resist transportation, shipping and storage, and peelability of the film so as to deliver the medical device effectively. In this respect, the high thickness homogeneity of the film is key to control the sealing process and ensure quality and uniformity of the seal of the porous non-woven film to the plastic receptacle.

[0035] Another subject of the invention is a method for manufacturing a porous non-woven film as described above, comprising steps of: providing at least two layers of porous non-woven sheet; laminating the at least two layers of porous sheet, in particular by heat calendering, to obtain a porous non-woven film.

[0036] According to one embodiment, after the lamination step, an outer surface of the porous non-woven film is marked by ink printing.

[0037] According to another embodiment, before the lamination step, the surface of at least one of the layers of porous non-woven sheet is marked by ink printing, then the layers of porous non-woven sheet are laminated, in particular by heat calendering, so that each ink-printed surface is covered by at least one other layer of porous nonwoven sheet. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Features and advantages of the invention will become apparent from the following description of several embodiments of a porous non-woven film according to the invention, this description being given merely by way of example and with reference to the appended drawings in which:

[0039] Figure 1 is a perspective front view of a humidity control packet having an envelope comprising a porous non-woven film according to a first embodiment of the invention;

[0040] Figure 2 is a perspective rear view of the humidity control packet of Figure 1 ;

[0041] Figure 3 is a cross section of a closable bottle containing a plurality of pharmaceutical tablets and the humidity control packet of Figure 1 for regulating the relative humidity in the bottle;

[0042] Figure 4 is a cross section according to plane IV of Figure 2;

[0043] Figure 4A is a scanning electron microscope (SEM) view of the detail A of Figure 4 with a magnification factor of 590;

[0044] Figure 4B is a scanning electron microscope (SEM) view in the direction of the arrow B of Figure 4 with a magnification factor of 340;

[0045] Figure 5 is a schematic view of a manufacturing line for manufacturing the porous non-woven film forming the envelope of the humidity control packet of Figures 1 to 4, by lamination of several layers, the porous non-woven film being represented schematically in this figure as a multilayer to aid understanding of its manufacturing process, however it is understood that, in practice, the different layers used to form the porous non-woven film are fused in the resulting porous non-woven film and the thickness of the resulting porous non-woven film is generally less than the sum of the thicknesses of the different layers used to form it; Figure 6 is a schematic view of a manufacturing line for producing humidity control packets as shown in Figures 1 to 4, using the porous non-woven film manufactured in Figure 5 to form the envelopes of the humidity control packets;

[0046] Figure 7 is a cross section similar to Figure 4 for a humidity control packet having an envelope comprising a porous non-woven film according to a second embodiment of the invention;

[0047] Figure 8 is a schematic view of a manufacturing line for manufacturing the porous non-woven film forming the envelope of the humidity control packet of Figure 7, by lamination of several layers, the porous non-woven film being represented schematically in this figure as a multilayer to aid understanding of its manufacturing process, however it is understood that, in practice, the different layers used to form the porous non-woven film are fused in the resulting porous non-woven film and the thickness of the resulting porous non-woven film is generally less than the sum of the thicknesses of the different layers used to form it;

[0048] Figure 9 is a cross section similar to Figure 4 for a humidity control packet having an envelope comprising a porous non-woven film according to a third embodiment of the invention;

[0049] Figure 10 is a schematic view of a manufacturing line for manufacturing the porous non-woven film forming the envelope of the humidity control packet of Figure 9, by lamination of several layers, the porous non-woven film being represented schematically in this figure as a multilayer to aid understanding of its manufacturing process, however it is understood that, in practice, the different layers used to form the porous non-woven film are fused in the resulting porous non-woven film and the thickness of the resulting porous non-woven film is generally less than the sum of the thicknesses of the different layers used to form it;

[0050] Figure 11 is a comparative graph of the thickness homogeneity for four porous nonwoven films, including two porous non-woven films according to the invention and two porous non-woven films of the prior art; Figure 12 is a comparative graph of the opacity for the same four porous non-woven films as in Figure 11 , including two porous non-woven films according to the invention and two porous non-woven films of the prior art;

[0051] Figure 13 is a perspective front view similar to Figure 1 for a humidity control packet having an envelope comprising a porous non-woven film according to the first embodiment of the invention, which differs from the packet of Figure 1 in that it has three side seals instead of a longitudinal seal and two side seals;

[0052] Figure 14 is a perspective front view similar to Figure 1 for a humidity control packet having an envelope comprising a porous non-woven film according to the first embodiment of the invention, which differs from the packet of Figure 1 in that it has four side seals instead of a longitudinal seal and two side seals;

[0053] Figure 15 is a perspective view of a humidity control capsule having an envelope comprising a porous non-woven film according to the first embodiment of the invention;

[0054] Figure 16 is a schematic view of a device for thermoforming a disc of a porous nonwoven film according to the first embodiment of the invention, to form the body portion of the capsule of Figure 15; and

[0055] Figure 17 is a perspective view of a sterile packaging for a medical device, e.g., a syringe, the lidding film of which comprises a porous non-woven film according to the first embodiment of the invention.

[0056] ILLUSTRATIVE EMBODIMENTS OF THE INVENTION

[0057] In the first embodiment shown in Figures 1 to 6, the porous non-woven film 1 is used to form a humidity control packet 6 for regulating an atmosphere in a container or a medical device containing moisture-sensitive products. By way of example, as illustrated in Figure 3, the packet 6 may control humidity inside a bottle 7 containing pharmaceutical tablets 8 that are sensitive to moisture. The humidity control packet 6 comprises an envelope 60 made of the porous non-woven film 1 . The porous nonwoven film 1 is shaped and welded to itself so as to define an inner volume in which a desiccant material 4 is received. By way of example, the desiccant material 4 may comprise particles of an inorganic desiccant material such as silica gel, molecular sieve and / or activated clay. As shown in Figures 1 and 2, the humidity control packet 6 comprises a longitudinal seal 63 and two side seals 67 and 68. The humidity control packet 6 also comprises two ink-printed markings 17, respectively a logo and product name on its front side and ‘DO NOT EAT’ on its rear side. In particular, each ink-printed marking 17 may comprise a water-soluble ink, preferably a food contact grade ink.

[0058] In the first embodiment, each ink-printed marking 17 is present on an outer surface 14 of the porous non-woven film, and is visible from the side of the other outer surface 16 of the porous non-woven film opposite from the outer surface 14. Advantageously, the outer surface 14 of the porous non-woven film 1 is turned toward the inner volume of the envelope 60 of the humidity control packet 6. In this way, each ink-printed marking 17 is not accessible from the exterior of the packet 6, thus limiting the risks of ink contamination on manufacturing lines and also in the bottle 7, where the ink cannot migrate to the pharmaceutical tablets 8. Still, each ink-printed marking 17 is visible from the exterior of the packet 6, thus efficiently providing information to a user.

[0059] As shown schematically in Figure 5, the porous non-woven film 1 of the first embodiment is obtained by lamination of three superimposed individual layers 11 , 12, 13 of porous non-woven sheet. The sheet of each of the three layers 11 , 12, 13 is a non-woven comprising polymeric fibers 10 having a sheath-core structure. By way of example, the fibers 10 comprise a polyethylene (PE) sheath 102 and a polypropylene (PP) core 101 , with a concentric sheath-core structure as shown schematically in Figure 4A. The PE sheath 102 of the fibers having a relatively lower melting temperature allows the welding of the porous non-woven film 1 using conventional welding techniques, whereas the PP core 101 having a relatively higher melting temperature ensures good mechanical resistance of the porous nonwoven film 1 . The morphology of the fibers 10 can be seen in the SEM view of Figure 4B. In the example shown, a mean diameter of the fibers 10 is 15 pm and a mean length of the fibers 10 is 38 mm. The individual layers 11 , 12, 13 each have a mean thickness of the order of 120 m and a mass per unit area of the order of 20 g / m2. The three layers 11 , 12, 13 are assembled by heat calendering, by application of a combination of heat and pressure as the layers pass through heated calender rolls, thus intimately welding the three layers 11 , 12, 13 together. It can be seen in the cross section of Figure 4A that, in the resulting porous non-woven film 1 , the individual layers 11 , 12, 13 are completely intertwined with one another so that they cannot be distinguished anymore and cannot be delaminated. In addition, as visible in the SEM view of Figure 4B, heat calendering produces an entanglement of the fibers 10 with welding points (or melting points) distributed throughout the volume of the porous non-woven film 1. At these welding points, the PE sheaths 102 of the fibers 10 are melted to provide links between adjacent fibers within the porous non-woven film 1 , while the PP cores 101 of the fibers 10 retain their fibrous structure. It can be observed that the welding points, i.e. the areas within the porous non-woven film where the fibers 10 are fused together, are distributed in a pattern, which can be considered as a bonding pattern. Such a bonding pattern is generally not present in porous nonwoven materials used in the prior art for the same applications, such as non-woven materials sold by DUPONT under the trademark TYVEK.

[0060] Figure 5 illustrates schematically an example of a manufacturing line for manufacturing the porous non-woven film 1 by heat calendering. A sheet of each individual layer 11 , 12, 13 is supplied from a respective reel 21 , 22, 23. The three individual layers 11 , 12, 13 are then assembled by heat calendering, by passing through heated and pressurized calender rolls 24, 24’, so that a combination of heat and pressure is applied to the three individual layers. By way of example, in the case of PE / PP sheath-core fibers as described above, the calendering temperature can be comprised between 140°C and 180°C, while the calendering pressure can be comprised between 0.08 MPa and 0.2 MPa. In Figure 5, only one pair of calender rolls 24, 24’ is shown, however it is understood that a manufacturing line for manufacturing a porous non-woven film according to the invention may comprise several pairs of calender rolls and as many steps of heat calendering as required to obtain a homogeneous porous non-woven film. The calender rolls, in particular the upper calender rolls, may advantageously be provided with a template or a pattern for forming welding points by locally melting the PE sheaths 102 of the fibers 10 to provide links between adjacent fibers, thus resulting in a bonding pattern as mentioned above. The assembled three-layer porous non-woven is then conveyed by guiding rollers 25 to a flexographic printing device 26, configured to mark the outer surface 14 of the three-layer porous non-woven with each ink-printed marking 17, thus resulting in the porous non-woven film 1.

[0061] In the example illustrated in Figure 5, the printing device 26 is in line with the calendering device. However, in a variant, the printing can take place offline, independently of the lamination process. In addition, flexographic printing is only one example of a possible marking technology for marking the porous non-woven film. As a variant, the marking may be obtained by any other marking techniques known in the art, in particular other ink marking techniques than flexographic printing, or laser marking.

[0062] In the non-limiting example shown in the figures:

[0063] - a mean thickness of the porous non-woven film 1 is 147 pm, measured according to standard test method ISO 534:2011 , with a relative standard deviation (RSD) from the mean thickness of 8%;

[0064] - a density of the porous non-woven film 1 , defined as the ratio of the mass per unit area of the porous non-woven film 1 to the mean thickness of the porous non-woven film 1 , is 409 kg / m3, the mass per unit area of the porous non-woven film 1 being measured according to standard test method ASTM D3776 - Option A;

[0065] - an opacity of the porous non-woven film 1 is 33.01 %, measured according to standard test method ISO 2471 ;

[0066] - a ratio of the density of the porous non-woven film 1 to the opacity of the porous non-woven film 1 is 12.4;

[0067] - a Water Vapor Transmission Rate (WVTR) of the porous non-woven film 1 is of the order of 1340 g. day1. nr2, at 23°C, 50%RH, measured according to the “Desiccant Method” of standard test method ASTM E96 (“Standard Test Methods for Water Vapor Transmission of Materials”).

[0068] Thanks to its above properties, the porous non-woven film 1 has a good transparency while still having a porosity adapted to its application for the formation of active articles, such active packets or active capsules, or lidding films for sterile packaging. The porous non-woven film 1 also has a combination of mechanical strength and permeability, making it particularly well suited for these applications. The high thickness homogeneity of the porous non-woven film ensures optimal welding on manufacturing lines, which can be obtained without the presence of any additional coating, thanks to the selection of the PE / PP sheath-core structure of the fibers 10 with adjusted melting temperatures.

[0069] Figure 6 illustrates schematically an example of a continuous manufacturing line 9 for manufacturing humidity control packets 6 as shown in Figures 1 and 2, using the porous non-woven film 1 described above. Successive operations are performed in the manufacturing line 9. First, the envelope 60 of the successive packets 6 is shaped, partially sealed and brought into a filling station 94 in an open configuration. For this purpose, an elongated web of porous non-woven film 1 is supplied from a reel 91 and wrapped around a mandrel 92 into a tubular shape comprising a longitudinal overlapping sealing area. The longitudinal seal 63 is then formed in the overlapping area, by welding the web of porous non-woven film 1 , e.g. by ultrasonic welding, in a longitudinal welding station 93.

[0070] Then, the tube of porous non-woven film 1 is advanced toward a transverse welding station 95, positioned downstream of the longitudinal welding station 93, in which a transverse seal is formed by welding the web of porous non-woven film 1 transversally to the longitudinal seal 63, e.g. by ultrasonic welding. The transverse seal formed in the transverse welding station 95 is designed to simultaneously form a first side seal 67 of an upstream packet 6 to be filled with desiccant 4 in the filling station 94, and a second side seal 68 of a downstream packet 6 which has already been filled with desiccant 4 in the filling station 94.

[0071] When the transverse seal has been formed in the transverse welding station 95, the desired weight desiccant 4 is inserted in the envelope 60 of the packet 6 which is received in the filling station 94. Once it has been filled with the desiccant 4, the packet 6 which is received in the filling station 94 is advanced until its downstream end reaches a cutting station 96, positioned downstream of the transverse welding station 95, and in this position its open upstream end is received in the transverse welding station 95.

[0072] Then, a new transverse seal is formed in the transverse welding station 95, thus forming a second side seal 68 of the packet 6 to close the upstream end of the packet 6. As explained previously, the transverse seal formed in the transverse welding station 95 also forms a first side seal 67 of an upstream packet 6 to be filled with desiccant 4 in the filling station 94. While the upstream end of the packet 6 is closed in the transverse welding station 95, the junction between the packet 6 and a downstream packet 6 is also cut in the cutting station 96, thus separating the first side seal 67 of the packet 6 from the second side seal 68 of the downstream packet 6.

[0073] In the next step, the second side seal 68 of the packet 6 reaches the cutting station 96, where the junction between the packet 6 and an upstream packet 6 is cut. The packet 6 filled with desiccant is thus detached from the rest of the web of porous non-woven film 1 and falls on a conveyor 97 configured to move the packets 6 to a control station 98, in which each packet 6 may be visually inspected for various quality attributes, such as the marking quality, welding quality, and more generally the presence of any visual defect.

[0074] Of course, the manufacturing line shown in Figure 6 illustrates only one example of a possible method for manufacturing humidity control packets from a porous nonwoven film according to the invention. It is understood that other manufacturing methods known in the art may be used in the context of the invention, in particular the packets 6 may not be cut after their formation, but rolled into a continuous strip on a reel or “fan-folded” in a cardboard box.

[0075] In the second embodiment shown in Figures 7 and 8, elements that are similar to those of the first embodiment have the same references. The porous non-woven film 3 of the second embodiment differs from the first embodiment in that the ink- printed marking 39 is arranged inside the porous non-woven film 3, instead of being provided on an outer surface of the porous non-woven film. In the example shown in Figure 8, the assembly of the three individual layers 31 , 32, 33 is performed sequentially, by first assembling a first layer 31 and a second layer 32, then printing an outer surface 35 of the two-layer porous non-woven with each ink-printed marking 39, before assembling a third layer 33 with the printed two-layer porous non-woven.

[0076] More precisely, a sheet of each individual layer 31 , 32 is supplied from a respective reel 21 , 22, and the two individual layers 31 , 32 are assembled by heat calendering, by passing through a first pair of heated calender rolls 24, 24’, where a combination of heat and pressure is applied to the two individual layers. The assembled two- layer porous non-woven is then conveyed by guiding rollers 25 to a flexographic printing device 26 configured to mark each ink-printed marking 39 on an outer surface 35 of the second layer 32 which is turned away from the first layer 31 . The printed two-layer non-woven is then assembled by heat calendering with a third individual layer 33 supplied from a respective reel 23, by passing through a second pair of heated calender rolls 28, 28’, where a combination of heat and pressure is applied to the layers, thus resulting in the porous non-woven film 3.

[0077] Here again, it is understood that the number of calender rolls shown in Figure 8 is not limitative, and a manufacturing line for manufacturing a porous non-woven film according to the invention may comprise as many pairs of calender rolls as required to obtain a homogeneous porous non-woven film. The calender rolls, in particular the upper calender rolls, may advantageously be provided with a template or a pattern for forming welding points by locally melting the fibers 10 to provide links between adjacent fibers, thus resulting in a bonding pattern as mentioned above. In the resulting porous non-woven film 3 according to the second embodiment, the individual layers are completely intertwined with one another so that they cannot be distinguished anymore and cannot be delaminated, and the morphology of the fibers is similar to that shown in the SEM view of Figure 4B.

[0078] In the second embodiment, the ink of the marking 39 printed on the surface 35 of the second layer 32 may spread during assembly with the third layer 33, due to the heat and pressure applied for heat calendering. Advantageously, the initial marking printed on the surface 35 of the second layer 32 is designed to deform during calendering with the third layer 33, e.g. the initial marking may have thinner lines, so that the spreading of the ink resulting from heat calendering produces the desired visual appearance of the final marking.

[0079] In the third embodiment shown in Figures 9 and 10, elements that are similar to those of the first embodiment have the same references. The porous non-woven film 5 of the third embodiment differs from the first embodiment in that it is obtained by assembly of only two individual layers of non-woven, instead of three layers as in the first embodiment. In the third embodiment, as shown in Figure 10, a sheet of each individual layer 51 , 52 is supplied from a respective reel 21 , 22, and the two individual layers 51 , 52 are assembled by heat calendering, by passing through a pair of heated calender rolls 24, 24’, where a combination of heat and pressure is applied to the two individual layers. The assembled two-layer porous non-woven is then conveyed by guiding rollers 25 to a flexographic printing device 26 configured to mark the outer surface 54 of the three-layer porous non-woven with each ink- printed marking 57, thus resulting in the porous non-woven film 5.

[0080] Here again, it is understood that the number of calender rolls shown in Figure 10 is not limitative, and a manufacturing line for manufacturing a porous non-woven film according to the invention may comprise as many pairs of calender rolls as required to obtain a homogeneous porous non-woven film. The calender rolls, in particular the upper calender rolls, may advantageously be provided with a template or a pattern for forming welding points by locally melting the fibers 10 to provide links between adjacent fibers, thus resulting in a bonding pattern as mentioned above. In the resulting porous non-woven film 5 according to the third embodiment, the individual layers are completely intertwined with one another so that they cannot be distinguished anymore and cannot be delaminated, and the morphology of the fibers is similar to that shown in the SEM view of Figure 4B.

[0081] Figure 13 shows a variant of a humidity control packet having an envelope comprising a porous non-woven film according to the invention. In Figure 13, the humidity control packet 106 differs from the humidity control packet 6 of Figure 1 in that the film forming the envelope is folded on itself to form one side of the packet, and three side seals 161 , 167, 168 are provided instead of one longitudinal seal 63 and two side seals 67, 68 as shown in Figure 1. In Figure 13, the envelope 160 of the packet 106 comprises a porous non-woven film 1 as described above with reference to the first embodiment, it being understood that, in a variant, the envelope 160 may also comprise a porous non-woven film 3 or 5 according to the second or third embodiment, or any other porous non-woven film according to the invention.

[0082] Figure 14 shows another variant of a humidity control packet having an envelope comprising a porous non-woven film according to the invention. In Figure 14, the humidity control packet 206 differs from the humidity control packet 6 of Figure 1 in that two blanks of porous non-woven film are provided and attached to each other by a continuous peripheral seal to form the envelope of the packet. In the example shown in Figure 14, the packet 206 has a quadrilateral shape and includes four side seals 261 , 262, 267, 268. Of course, as a variant, the packet may have any other shape, with an adapted design of its peripheral seal, e.g. the packet may have a circular shape and a circular peripheral seal. In Figure 14, the envelope 260 of the packet 206 comprises a porous non-woven film 1 as described above with reference to the first embodiment, it being understood that, in a variant, the envelope 260 may also comprise a porous non-woven film 3 or 5 according to the second or third embodiment, or any other porous non-woven film according to the invention.

[0083] Figure 15 shows another possible application of a porous non-woven film according to the invention, i.e. , a humidity control capsule. The envelope 360 of the humidity control capsule 306 comprises a lid portion 361 and a cup-shaped body portion 362. In this example, the lid portion 361 and the body portion 362 are both formed from a respective blank, or disc, of porous non-woven film according to the invention. It is understood that, in a variant of a capsule of the invention, only one among the lid portion and the body portion may be formed from a porous non-woven film according to the invention, and the other portion may be formed from any material suitable for its application. In the example of Figure 15, the cup-shaped body portion 362 of the capsule 306 illustrates the ability of a porous non-woven film of the invention to be thermoformed, in particular to form a self-supporting receptacle.

[0084] In this regard, Figure 16 schematically illustrates a device for thermoforming a disc 310 of a porous non-woven film 1 according to the first embodiment, to form the body portion of the capsule 306. It is understood that, in a variant, the disc 310 may comprise a porous non-woven film 3 or 5 according to the second or third embodiment, or any other porous non-woven film according to the invention. Advantageously, a porous non-woven film according to the invention can be shaped by thermoforming at a temperature of between 80°C and 110°C.

[0085] Thermoforming may be carried out according to any techniques known in the art, particularly using a preheated form having a top platen 382 and a bottom platen 384 as shown in Figure 16. In Figure 16, a disc 310 of porous non-woven film 1 is placed between the top platen 382 and the bottom platen 384. A ring 386 is also provided to hold the disc 310 in place. Then, top platen 382 is pressed downward in the axial direction X, as shown by the arrow F, through the opening of the ring 386, so as to thermally deform the disc 310 into a cup-shape. The web of the disc 310 may be preheated to facilitate thermoforming. Advantageously, a disc 310 of porous nonwoven material film according to the invention can be thermoformed to undergo deformation to a depth in the axial direction X of between 1 cm and 5 cm without suffering mechanical failure of the porous non-woven material film.

[0086] As visible in Figure 15, the body portion 362 obtained by thermoforming the porous non-woven film 1 includes a bottom wall 363, a cylindrical or frustoconical side wall 364, and an annular flange 365. The annular flange 365 defines an opening at the top end of the body portion 362 opposite from the bottom wall 363. The side wall 364 and the bottom wall 363 define an inner compartment 366 of the capsule 306, suitable for receiving an active material, e.g., a desiccant material 4. The lid portion 361 , configured to close the opening of the body portion 362 in such a way that the active material is retained inside the envelope 360, also comprises a disc of porous non-woven film 1 , which is attached to the flange 365 of the body portion 362 by a peripheral seal 367, e.g. obtained by heat-sealing, ultrasonic welding, impulse welding, etc.

[0087] Figure 17 shows yet another possible application of a porous non-woven film according to the invention, i.e., a sealable lidding film for a sterile packaging. In the example shown in Figure 17, the sterile packaging 407 is intended for a medical device, which is a syringe 408 in the illustrated example. The sterile packaging 407 comprises a plastic tray 472, e.g. based on polyethylene terephthalate (PET), and a lidding film 471 comprising a porous non-woven film according to the invention. The lidding film 471 is attached to a flange 475 of the plastic tray 472 by a peripheral seal 477, e.g. obtained by heat-sealing, ultrasonic welding, impulse welding, etc. In Figure 17, the lidding film 471 comprises a porous non-woven film 1 as described above with reference to the first embodiment, it being understood that, in a variant, the lidding film 471 may also comprise a porous non-woven film 3 or 5 according to the second or third embodiment, or any other porous non-woven film according to the invention.

[0088] Advantageously, the properties of the porous non-woven film 1 forming the lidding film 471 , in terms of porosity and permeability, allow the sterilization of the packaging 407 once closed, by the passage of a sterilizing gas through the porous non-woven material 1 , while being impermeable to bacteria. The sealing properties of the porous non-woven film 1 are also adapted to ensure both durable seals, that resist transportation, shipping and storage, and peelability of the film so as to deliver the medical device effectively. In this respect, the high thickness homogeneity of the porous non-woven film of the invention allows control of the sealing process and ensures quality and uniformity of the seal of the lidding film 471 to the plastic tray 472.

[0089] EXAMPLES

[0090] Two different porous non-woven films according to the invention were produced, including a two-layer film similar to that described in the third embodiment, with reference to Figures 8 and 9, and a three-layer film similar to that described in the first embodiment, with reference to Figures 1 to 4.

[0091] As comparative examples, two different porous non-woven films sold by DUPONT under the trademark TYVEK were also provided, including a coated film having the reference TYVEK 2FS and an uncoated film having the reference TYVEK 1059B.

[0092] The thickness of each porous non-woven film was measured according to standard test method ISO 534:2011 . The results are shown in Table 1 below and in the graph of Figure 11 .

[0093] Table 1

[0094] The opacity of each porous non-woven film was measured according to standard test method ISO 2471 . The results are shown in Table 2 below and in the graph of Figure 12.

[0095] Table 2 The surface free energy of each uncoated porous non-woven film was measured according to standard test method ISO 19403, using water and ethylene glycol as testing solvents. The results are shown in Table 3 below.

[0096] Table 3

[0097] As can be seen from the above results, the porous non-woven films according to the invention (2-layer and 3-layer) have a thickness homogeneity higher than that of the non-woven materials of the prior art, allowing reliable conveying and optimal welding of a porous non-woven film according to the invention on manufacturing lines. In particular, thanks to the homogeneous thickness of a porous non-woven film according to the invention, the welding adjustment is made once and for all and does not need to be constantly adjusted during the manufacture of a batch. In addition, the provision of two materials with two different melting temperatures in a porous non-woven film according to the invention, e.g. with a difference of the order of 40°C between the two melting temperatures, makes it possible to print a porous non-woven film according to the invention on any side, and also weld it on any side, which eliminates the need to select a specific side of the film on manufacturing lines.

[0098] The above results also show that the opacity of the porous non-woven films according to the invention (2-layer and 3-layer) is much lower than that of the nonwoven materials of the prior art. Thanks to its high transparency, it is possible to include a marking on a porous non-woven film according to the invention either on a side of the film facing away from a user, or inside the structure of the film as illustrated in the second embodiment described above, with in both cases associated advantages in terms of limiting the risks of contamination and reducing the need for cleaning equipment.

[0099] The surface free energy results above show that the surface of the porous nonwoven films according to the invention (2-layer and 3-layer) have hydrophilic properties, whereas the surface of the uncoated non-woven material of the prior art is hydrophobic. The hydrophilic properties are favorable for the marking of porous non-woven film according to the invention, particularly by ink marking using a water- soluble ink.

[0100] The invention is not limited to the examples described and shown.

[0101] In particular, a porous non-woven film according to the invention may be obtained by laminating any number of individual layers higher than or equal to two. Heat calendering is a particularly advantageous lamination method, however other lamination methods known in the art can also be considered in the context of the invention. Marking of a porous non-woven film of the invention can also be carried out using various technologies such as, for example, ink marking, laser marking, etc., and it can be carried out in line with lamination, or offline, independently of lamination.

[0102] As illustrated in the above examples, a marking may be provided on an outer face of a porous non-woven film of the invention or even inside the film, and this can be carried out whatever the number of layers used to produce the film. In particular, there may be a marking inside a porous non-woven film obtained by lamination of two layers, even if this has not been explicitly described above. There may also be a combination of markings on at least one outer surface of the porous non-woven film of the invention and inside the porous non-woven film.

[0103] Instead of bicomponent fibers, a porous non-woven film according to the invention may comprise a first type and a second type of monocomponent fibers, where the first type of fibers is based on a first material having a relatively higher melting temperature and the second type of fibers is based on a second material having a relatively lower melting temperature. In the case of bicomponent fibers, the fibers may also have other bicomponent compositions than a combination of polyethylene (PE) and polypropylene (PP) as described in the above examples. In particular, the PE / PP composition of the fibers may be replaced by a poly(lactic acid) composition with two melting points, thus providing biodegradability to the porous non-woven film.

[0104] Other examples of suitable bicomponent fibers include, without limitation: fibers having a high density polyethylene (HDPE) sheath and a polyethylene terephthalate (PET) core; fibers having a PET copolymer sheath and a PET core; fibers having a polycyclohexylenedimethylene terephthalate (PCT) sheath and a polypropylene (PP) core; fibers having a PCT sheath and a PET core; fibers having a polyethylene terephthalate glycol (PETG) sheath and a PET core; fibers having a HDPE sheath and a PET core; fibers having a linear low-density polyethylene (LLDPE) sheath and a PET core; fibers having a PP sheath and a PET core; fibers having a nylon 6 sheath and a nylon 66 core.

[0105] In addition, the fibers of a porous non-woven film according to the invention may have sheath-core configurations other than the concentric sheath-core structure illustrated in Figure 4A, e.g., an eccentric sheath-core structure or a side-by-side sheath-core structure.

[0106] An active article according to the invention may also be of any type, as long as it comprises an envelope at least partly formed from a porous non-woven film of the invention and an active material arranged in the inner volume of the envelope. It may be, e.g., an active packet, an active capsule, an active canister, an active stopper, etc. Depending on the nature of the active material received in its envelope, an active article according to the invention may also be configured to absorb and / or release various gases to regulate the atmosphere in a container or a medical device containing sensitive or odorous products, including, e.g., moisture, oxygen, volatile olfactory organic compounds such as fragrances, flavors, nutrients, etc.

Claims

CLAIMS1 . Porous non-woven film (1 ; 3; 5) comprising polymeric fibers (10), said porous non-woven film including a first material and a second material, the first material having a melting temperature higher than that of the second material, wherein:- a mean thickness of the porous non-woven film is between 60 pm and 250 pm, preferably between 80 pm and 200 pm,- a density of the porous non-woven film, defined as the ratio of the mass per unit area of the porous non-woven film to the mean thickness of the porous non-woven film, is between 300 kg / m3and 500 kg / m3, and- the relative standard deviation (RSD) from the mean thickness of the porous non-woven film is less than or equal to 10%.

2. Porous non-woven film according to claim 1 , wherein the porous non-woven film (3) has polymeric fibers (10) comprising the first material and the second material on all of its main surfaces.

3. Porous non-woven film according to claim 1 or claim 2, wherein the porous non-woven film (3) is obtained by lamination of at least two superimposed layers (31 , 32, 33) of porous non-woven sheet, wherein the polymeric fibers (10) in each layer (31 , 32, 33) of porous non-woven sheet comprise the first material and the second material.

4. Porous non-woven film according to any one of the preceding claims, wherein the porous non-woven film (1 ; 3; 5) has an opacity of between 15% and 60%, preferably between 15% and 40%.

5. Porous non-woven film according to any one of the preceding claims, wherein a ratio of the density of the porous non-woven film (1 ; 3; 5) to the opacity of the porous non-woven film (1 ; 3; 5) is higher than 7, preferably higher than 10.

6. Porous non-woven film according to any one of the preceding claims, wherein the porous non-woven film (1 ; 3; 5) has a Water Vapor Transmission Rate(WVTR) higher than or equal to 700 g. day-1.nr2, preferably higher than or equal to 1000 g. day1. nr2, at 23°C, 50%RH.

7. Porous non-woven film according to any one of the preceding claims, wherein a surface free energy of the porous non-woven film (1 ; 3; 5) is higher than or equal to 30 mN / m.

8. Porous non-woven film according to any one of the preceding claims, wherein the porous non-woven film (1 ; 3; 5) includes an ink-printed marking (17; 39; 57) comprising a water-soluble ink.

9. Porous non-woven film according to any one of the preceding claims, wherein the porous non-woven film (1 ; 5) includes an ink-printed marking (17; 57) on a first outer surface (14; 54) of the porous non-woven film, wherein the ink- printed marking (17; 57) is visible from the side of a second outer surface (16; 56) of the porous non-woven film opposite from the first outer surface.

10. Porous non-woven film according to any one of the preceding claims, wherein the porous non-woven film (3) includes an ink-printed marking (39) inside the porous non-woven film, wherein the ink-printed marking (39) is visible from the exterior of the porous non-woven film.11 . Porous non-woven film according to any one of the preceding claims, wherein the porous non-woven film (3) is obtained by lamination of at least two superimposed layers (31 , 32, 33) of porous non-woven sheet, the porous nonwoven film including an ink-printed marking (39), originally formed on a surface (35) of at least one of the superimposed layers and arranged inside the porous non-woven film, wherein the ink-printed marking (39) is visible from the exterior of the porous non-woven film.

12. Porous non-woven film according to any one of the preceding claims, wherein the polymeric fibers (10) of the porous non-woven film (1 ; 3; 5) comprise polyethylene (PE) and polypropylene (PP).

13. Porous non-woven film according to any one of the preceding claims, wherein the polymeric fibers (10) of the porous non-woven film (1 ; 3; 5) comprise a first poly(lactic acid) (PLA-1 ) and a second poly(lactic acid) (PLA-2), wherein the first poly(lactic acid) (PLA-1 ) has a melting temperature higher than that of the second poly(lactic acid) (PLA-2).

14. Porous non-woven film according to any one of the preceding claims, wherein the polymeric fibers (10) of the porous non-woven film (1 ; 3; 5) comprise bicomponent fibers including a first material and a second material, the first material having a melting temperature higher than that of the second material, optionally the polymeric fibers of the porous non-woven film comprise sheathcore fibers comprising a core based on the first material and a sheath based on the second material.

15. Porous non-woven film according to any one of the preceding claims, wherein a mean diameter of the polymeric fibers (10; 30; 50) of the porous non-woven film (1 ; 3; 5) is between 10 pm and 35 pm.

16. Active article, such as an active packet (6; 6’; 6”; 106; 206) or an active capsule (306), for regulating an atmosphere in a container or a medical device containing sensitive or odorous products, the active article comprising an envelope (60; 160; 260; 360) defining an inner volume and an active material (4) arranged in the inner volume of the envelope, wherein the envelope comprises a porous non-woven film (1 ; 3; 5) according to any one of claims 1 to 15.

17. Active article according to claim 16, wherein the porous non-woven film (1 ; 3; 5) of the envelope (60; 160; 260; 360) includes an ink-printed marking (17; 39; 57) arranged either inside the porous non-woven film (3) or on an outer surface (14; 54) of the porous non-woven film (1 ; 5) turned toward the inner volume of the envelope, wherein the ink-printed marking (17; 39; 57) is visible from the exterior of the active article.

18. Active article according to claim 16 or claim 17, wherein the envelope (60; 160; 260; 360) comprises at least one seal (63, 67, 68; 161 , 167, 168; 261 , 262, 267, 268; 367) obtained by welding a web of the porous non-woven film (1 ; 3; 5), in particular by heat-sealing, ultrasonic welding, impulse welding.

19. Sterile packaging, in particular for a medical device, comprising a porous nonwoven film (1 ; 3; 5) according to any one of claims 1 to 15.

20. Method for manufacturing a porous non-woven film according to any one of claims 1 to 15, comprising steps of:- providing at least two layers (11 , 12, 13; 31 , 32, 33; 51 , 52) of porous non-woven sheet;- laminating the at least two layers of porous non-woven sheet, in particular by heat calendering, to obtain a porous non-woven film (1 ; 3; 5).

21. Method according to claim 20, wherein, after the lamination step, an outer surface (14; 54) of the porous non-woven film (1 ; 3; 5) is marked by ink printing.

22. Method according to claim 20 or claim 21 , wherein, before the lamination step, the surface (35) of at least one (32) among the at least two layers (31 , 32, 33) of porous non-woven sheet is marked by ink printing, then the layers of porous non-woven sheet (31 , 32, 33) are laminated, in particular by heat calendering, so that each ink-printed surface (35) is covered by at least one other layer (33) of porous non-woven sheet.

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