USE OF A COMPOSITE MATERIAL AS A PACKAGING MATERIAL, ESPECIALLY FOR STERILE PACKAGING APPLICATIONS

Description

[0001] The invention relates to the use of a composite material as a packaging material, particularly for sterile packaging applications. The invention further relates to a package comprising a composite material as described herein and to a method for providing a packaged article.

[0002] In industrial packaging applications, particularly in the technical field of medicine, there is a high demand for sterile packaging materials. Such sterile packaging materials are required for the standard packaging of various compositions and active ingredients, such as pharmaceuticals and medical fluids, or devices such as syringes or wound dressings. Sterile packaging materials must exhibit a specific combination of advantageous properties. Most importantly, they must have a relatively high level of stability. This is necessary because standard sterilization processes are carried out under harsh conditions, e.g., with γ-radiation, under heat or pressure, and / or in the presence of aggressive chemicals such as ethylene oxide. If a packaging material is not sufficiently stable, it will be damaged during the sterilization process, and the packaged item may become contaminated.Furthermore, a sterile packaging material should be mechanically stable to avoid damage and subsequent contamination during production, storage, transport, and the like. A stable packaging material should also have high air permeability as a prerequisite for sterilization with chemicals. Nevertheless, a sterile packaging material must provide a strong barrier function against germs such as bacteria or viruses. For standard applications, sterile packaging materials should also be relatively lightweight and cost-effective.

[0003] Common packaging materials, such as paper or plastic film, are not suitable for sterile goods packaging because they lack sufficient mechanical stability for the sterilization process, but also air permeability and / or barrier function.

[0004] Conventional nonwovens are also unsuitable for sterile packaging applications. Conventional spunbonded or staple fiber nonwovens have relatively large fiber diameters, ranging from approximately 10 µm to 100 µm. The relatively thick fibers give the nonwovens high mechanical strength. However, the barrier function of the nonwovens against bacteria and viruses is inadequate because the pore sizes, typically larger than 15 µm, are too large.

[0005] Fine fibers with diameters ranging from approximately 0.3 µm to 5 µm are available using a conventional meltblowing process. The pore sizes of meltblown nonwovens are small and can provide an effective barrier against bacteria or viruses. However, the very fine fibers impart only low mechanical strength to the nonwovens. Therefore, meltblown nonwovens are generally damaged by standard sterilization methods, e.g., using γ-radiation. Furthermore, the low mechanical strength increases the overall risk of damage during production and handling, as well as during subsequent decontamination. Therefore, standard meltblown nonwovens are generally unsuitable and not used for sterile packaging applications.

[0006] To overcome such well-known problems of spunbond or meltblown nonwovens, various nonwovens are laminated for use as sterile packaging. Typical materials are three- or four-layer laminates, known as SMS (spunbond-meltblown-spunbond) or SMMS materials. Different nonwoven layers can be combined and bonded together, typically by thermal bonding with thermoplastic components. This creates sandwich-like structures that offer a barrier function through the meltblown layers and mechanical strength through the spunbond layers.

[0007] A reference product for sterile medical packaging, as well as for various other applications, is commercially available under the Tyvek brand from DuPont, USA. The porous sheet material is produced from high-density polyethylene using a so-called "flash-spinning" process.

[0008] In the flash spinning process, a polymer is first dissolved in a preferably low-boiling solvent under high pressure and comparatively high temperature. At temperatures below its boiling point, the solvent is unable to dissolve the polymer. Under comparatively high pressure and temperature, the polymer solution is then sprayed through a nozzle into a lower-pressure environment and passed through a high-velocity gas stream. The solvent evaporates very quickly, and the resulting polymer threads are stretched. When the polymer threads are deposited, the porous sheet is ultimately formed. This sheet consists of a three-dimensional network of ultrafine filaments and fiber-like regions connected by nodes. The material is then consolidated by calendering with smooth or engraved rollers.The porous sheet produced by the flash spinning process differs structurally from conventional nonwovens and is described, for example, in US 2010 / 0263108 A1, US 2008 / 0220681 A1, or US 6,034,008. As a solvent-based process, the production of porous sheet materials by flash spinning is highly resource- and energy-intensive. Due to the handling of flammable, explosive, and environmentally hazardous solvents at high temperatures and pressures, it requires a high level of safety precautions to prevent the unwanted and / or spontaneous release of solvents, mixtures, or gases. Furthermore, the porous sheet materials produced by the flash spinning process are not very homogeneous. Since they are not formed from normal fibers like conventional nonwovens, the structural irregularity is relatively high.

[0009] With regard to sterile packaging applications, the use of the high-density polyethylene described above proves disadvantageous due to its melting point between 115°C and 145°C. Such a low melting point is problematic if the material is to be sterilized at elevated temperatures. Furthermore, the ability to print such materials with labels or the like, as well as their weldability, is limited.

[0010] DE60019928T2 discloses a method and use of nonwovens.

[0011] Overall, there is a continuing high demand for improved materials for sterile packaging, especially for medical applications, that overcome the above-mentioned disadvantages.

[0012] The problem underlying the invention is to provide packaging materials that at least partially overcome the above-mentioned disadvantages.

[0013] Furthermore, packaging materials should be provided that are suitable for sterile packaging applications, particularly in the medical field. The packaging material should have a high barrier function against germs such as bacteria or viruses. Furthermore, it should be stable during standard sterilization processes, such as sterilization by high-energy radiation, in particular γ-radiation, under high temperature or pressure, and / or by treatment with reactive chemicals such as ethylene oxide. It should also have high mechanical strength so that it is not prone to damage such as breakage, cracking or delamination during the production process or handling. In addition, the packaging material should be relatively uniform and, in particular, have a narrow pore size distribution.

[0014] Furthermore, the packaging material should have a high degree of plastic deformability so that it can be conveniently used in standard packaging methods and applications.

[0015] Furthermore, the material should be readily available through a standard production process. Finally, it should be lightweight, particularly for cost and environmental reasons, and available through a simple, energy- and resource-efficient process.

[0016] This task is solved by using a composite material comprising a) a barrier layer, b) a carrier layer comprising a spunbonded nonwoven fabric arranged on at least one side of the barrier layer and bonded to the barrier layer by heat and pressure, wherein the barrier layer comprises a nonwoven fabric containing 1 to 70 wt.% meltblown fibers and 30 to 99 wt.% staple fibers, each based on the total weight of the nonwoven fabric, as packaging material, in particular for sterile packaging applications, characterized in that the barrier layer is produced by jointly depositing the staple fibers with the meltblown fibers.

[0017] Surprisingly, it was found according to the invention that the composite material can overcome the aforementioned disadvantages in the prior art.

[0018] The composite material is characterized by high mechanical strength and homogeneity. This prevents damage such as breakage, tearing, or delamination during production or handling when used as packaging. Furthermore, it exhibits a strong barrier function against germs such as bacteria or viruses. Furthermore, the composite material is stable during commonly used sterilization processes, such as sterilization by high-energy radiation, particularly γ-radiation, by heating and / or pressure, and by treatment with reactive chemicals such as ethylene oxide.

[0019] In addition to the composite's high stability, it also exhibits high plastic formability, making it easily suitable for standard packaging methods and applications. The composite also exhibits excellent weldability.

[0020] Furthermore, the composite material is relatively easily available in an energy- and resource-saving standard production process based on the processing of the fiber polymers from the melt.

[0021] Moreover, the composite material already has the stability and barrier properties required for use as a sterile packaging even at low areal weights, which causes comparatively low costs, for example, during its transport and has a low ecological footprint.

[0022] Due to the aforementioned advantageous properties, the composite material is excellently suitable as a packaging material, in particular for sterile packaging applications, preferably in the medical field.

[0023] As used herein, the term "use of the composite material as a packaging material" refers to the use of the composite material to at least partially enclose an object. When used for "sterile packaging applications," the composite material is used to sterilely separate it from the environment.

[0024] Preferably, the packaging material is used to completely enclose the item to be packaged. Preferably, the item is sealed into the composite material. Then, there are no holes or other openings in the packaging through which the item would still be in direct contact with the environment.

[0025] The composite material can be specifically configured for packaging purposes. For example, it can be finished using a variety of molding processes or combined with functional elements for a packaging application, such as a label. This creates a package.

[0026] As used herein, the term "packaging" refers to a material configured to package an article. The packaging may or may not already contain the article to be packaged. The packaging may be adapted to the shape of the article to be packaged. It includes the composite material and may include other functional means for a packaging application, such as labels or means for locking or closing. The article packaged in the packaging is referred to as the packaged article.

[0027] One embodiment of the invention is therefore directed to a package, in particular a sterile package, comprising a composite material as described herein.

[0028] According to the invention, the composite material is particularly suitable for the production of sterile packaging. "Sterile" means that the composite material and / or the packaging, with or without the item to be packaged, has been sterilized using a standard sterilization method. Typically, the item is packaged in the packaging before the packaged article is sterilized. The packaged article is preferably sealed in such a way that the article cannot be contaminated after sterilization without damaging the packaging.

[0029] According to the invention, the composite material comprises a barrier layer comprising a nonwoven fabric containing 1 to 70 wt.% meltblown fibers and 30 to 99 wt.% staple fibers.

[0030] The nonwoven fabric can be produced by meltblowing. In the field of nonwovens, the term "meltblowing" essentially refers to a spinning process in which thermoplastic fiber-forming polymers are melted in an extruder, pumped through die holes, and enter high-velocity air streams upon exiting the spinnerets. The hot air streams typically exit the sides of the nozzles, guiding the extruded polymer streams and resulting in the formation of very fine filaments. The filaments are deposited on a collector screen, creating a relatively fine, typically self-adhesive nonwoven web.The meltblowing process differs from conventional spunbond technology, in which the resulting polymer fibers are not guided by hot air streams from nozzles in the spinneret and thereby stretched, but the filaments are usually first cooled by cold air before the fibers are drawn onto a conveyor belt by suction.

[0031] Any synthetic polymers suitable for the meltblowing processes known in the art can be used for the meltblown fibers. Typically, the polymers are thermoplastic polymers that can be extruded. The meltblown fibers preferably comprise polymers selected from polyolefins such as polyethylene or polypropylene; aliphatic polyesters and aromatic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, or polylactate; aliphatic polyamides and aromatic polyamides such as polyamide 6 or polyamide 6,6; halogenated polymers such as polyvinylidene chloride or polyvinylidene fluoride; or (meth)acrylates such as polymethyl methacrylate; mixtures or copolymers thereof. Possible copolymers include, for example, copolyesters, copolyamides, polyesterpolyamides, and polyolefin copolymers.

[0032] As used herein, the term "staple fibers" refers to discontinuous fibers with lengths of 0.5 mm to 100 mm and thus includes short fibers in the length range of 0.5 to 20 mm. In a preferred embodiment, the composite material comprises staple fibers with diameters of 5 to 30 µm, more preferably 10 to 20 µm. In a preferred embodiment, the composite material comprises staple fibers with fiber lengths of 1 to 60 mm, more preferably 5 to 40 mm.

[0033] Any synthetic polymers suitable for the production processes for staple fibers known in the art can be used for the staple fibers. Typically, the polymers are thermoplastic polymers that can be extruded. Preferably, the staple fibers comprise polymers selected from polyolefins such as polyethylene or polypropylene, aliphatic polyesters and aromatic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, or polylactate, aliphatic polyamides and aromatic polyamides such as polyamide 6 or polyamide 6,6, halogenated polymers such as polyvinylidene chloride or polyvinylidene fluoride, or (meth)acrylates such as polymethyl methacrylate, mixtures, or copolymers thereof. Possible copolymers include, for example, copolyesters, copolyamides, polyesterpolyamides, and polyolefin copolymers.The use of non-thermoplastic polymer fibers, such as viscose, polyacrylonitrile or natural fibers, such as cotton or cellulose fibers, is also conceivable.

[0034] All synthetic polymers suitable for the manufacturing processes for spunbonded fabrics known in the art can be used to produce the spunbonded fabric. Typically, the polymers are thermoplastic polymers that can be extruded. According to the invention, the spunbonded fabric comprises spunbond fibers, which are also referred to herein as spunbond fibers. The spunbond fibers preferably comprise polymers selected from polyolefins such as polyethylene or polypropylene, aliphatic polyesters and aromatic polyesters such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polycarbonate, or polylactate, aliphatic polyamides and aromatic polyamides such as polyamide 6 or polyamide 6,6, halogenated polymers such as polyvinylidene chloride or polyvinylidene fluoride, or (meth)acrylates such as polymethyl methacrylate, mixtures, or copolymers thereof.Possible copolymers include copolyesters, copolyamides, polyesterpolyamides and polyolefin copolymers.

[0035] In a preferred embodiment, the fibers, i.e. the meltblown fibers, staple fibers and / or the fibers of the spunbonded nonwoven fabric, comprise at least one polymer selected from polyesters. These materials are particularly suitable for sterile packaging applications because they are sufficiently stable for sterilization with γ-radiation and / or at relatively high temperatures. Among the polyesters, polybutylene terephthalate and / or polyethylene terephthalate are particularly preferred. Likewise preferably, the fibers, i.e. the meltblown fibers, staple fibers and / or the fibers of the spunbonded nonwoven fabric, comprise at least one polymer selected from polyolefins, in particular polypropylene. These materials are particularly suitable because they are also relatively temperature-resistant.

[0036] Both the staple fibers and the spunbond fibers can be at least partially binding fibers. The term binding fibers is understood to mean that the fibers enable adhesive fiber bonds due to their thermoplastic behavior in the composite material. Typically, the binding fibers in the composite material are fused to themselves and / or other fibers. The staple fibers preferably comprise at least 90% by weight, preferably from 95% by weight to 100% by weight, of the total staple fiber content of staple fibers. Likewise preferably, the spunbond fibers comprise at least 90% by weight, preferably from 95% by weight to 100% by weight, of spunbond binding fibers, based on the total spunbond fiber content of spunbond fibers.

[0037] In a particularly preferred embodiment of the invention, the composite material comprises both spunbonded binder fibers and staple binder fibers. This allows for particularly good adhesion of the fibers or layers in the composite material.

[0038] The staple binding fibers and / or the spunbond binding fibers can be uniform fibers or multicomponent fibers. According to the invention, the staple binding fibers and / or the spunbond binding fibers, independently of one another, are particularly preferably binding fibers with a melting point of at least one component that is below 300°C and in particular from 70 to 230°C, particularly preferably from 125 to 200°C. Preferably, the staple binding fibers and / or the spunbond binding fibers, independently of one another, comprise thermoplastic polyesters and / or copolyesters, in particular polybutylene terephthalate, polyolefins, in particular polypropylene, polyamides, polyvinyl alcohol, or also copolymers, as well as copolymers and mixtures thereof.

[0039] According to the invention, the staple binding fibers and / or the spunbond binding fibers are particularly preferably, independently of one another, multicomponent fibers, preferably bicomponent fibers, in particular core / sheath fibers. Core / sheath fibers contain at least two fiber polymers with different softening and / or melting temperatures. The core / sheath fibers preferably consist of these two fiber polymers. The component with the lower softening and / or melting temperature is found on the fiber surface (sheath), and the component with the higher softening and / or melting temperature is found in the core. In a particularly preferred embodiment, both the staple binding fibers and the spunbond binding fibers are bicomponent fibers.More preferably, the staple binding fibers and / or the spunbond binding fibers independently of one another have a sheath with a melting point which is below 300°C and in particular from 70 to 230°C, particularly preferably from 125 to 200°C.

[0040] In core / sheath fibers, the binding function can be performed by the polymers arranged on the surface of the fibers. A wide variety of polymers can be used for the sheath. According to the invention, preferred polymers for the sheath are polybutylene terephthalate (PBT), polyamide (PA), polyethylene (PE), copolyamides, and / or copolyesters. A wide variety of polymers can also be used for the core. According to the invention, preferred materials for the core are polyesters (PES), in particular polyethylene terephthalate (PET) and / or polyethylene naphthalate (PEN) and / or polyolefins (PO).

[0041] The use of core-sheath binder fibers is preferred according to the invention, since this allows a particularly homogeneous distribution of the binder component in the nonwoven fabric as well as in the composite material.

[0042] Other preferred bicomponent fibers are so-called "side-by-side" fibers. These "side-by-side" fibers contain two segments extending in the fiber direction, each of which has fiber polymers with different softening and / or melting temperatures. The segments can be arranged evenly or irregularly, for example, eccentrically. "Island-in-the-sea" fibers are also conceivable.

[0043] Preferably, the core / sheath and / or side-by-side fibers comprise fiber polymers that differ in their softening and / or melting temperature by at least 5°C, more preferably 10°C, and especially by more than 20°C.

[0044] The use of monocomponent binding fibers is also conceivable, provided they can be at least partially thermally fused. The choice of monocomponent binding fibers depends on the matrix fiber used. For example, polyamide 6 binding fibers are suitable for binding polyamide 6.6 matrix fibers, and copolyesters are suitable for binding polyethylene terephthalate.

[0045] In a further preferred embodiment of the invention, the melting and / or decomposition temperature of the fiber polymers of at least one fiber type, i.e. the meltblown, staple and / or spunbond fibers, is relatively high.

[0046] Preferably, the melting and / or decomposition temperature of the fiber polymers of the meltblown fibers is above 140°C, for example, 160 to 400°C, preferably above 180°C, for example, 180 to 400°C, or above 200°C, for example, 200 to 400°C. Such a melting temperature is also advantageous for sealing the packaging, as it ensures stability of the base material, for example, during thermal sealing with another material.

[0047] Likewise preferably, the melting and / or decomposition temperature of the fiber polymers of at least one fiber component of the staple and / or spunbonded binding fibers, in particular of the core of the staple and / or spunbonded binding fibers when they are formed as core / sheath fibers, is above 140°C, for example 160 to 400°C, preferably above 180°C, for example 180 to 400°C, or above 200°C, for example 200 to 400°C. Such a melting temperature is also advantageous for closing the packaging, since it ensures stability of the base material, for example during thermal sealing with another material.

[0048] In one embodiment of the invention, the meltblown fibers and the staple fibers of the barrier layer are evenly distributed in the nonwoven fabric.

[0049] The meltblown fibers in the composite material according to the invention have, in each case based on the total weight of the meltblown fibers, preferably at least 60 wt.%, for example 60 to 100 wt.%, more preferably at least 70 wt.%, for example 70 to 100 wt.%, a fiber diameter of 0.1 to 50 µm, more preferably 0.3 to 30 µm and in particular 0.5 to 10 µm.

[0050] The staple fibers in the composite material according to the invention preferably have average fiber diameters of 5 to 50 µm, more preferably 7 to 20 µm.

[0051] However, fibers with smaller fiber diameters may also be included, e.g., nanocellulose with fiber diameters of less than 100 nm. Staple fibers with fiber diameters of more than 50 µm are also possible. The spunbonded fibers in the composite material according to the invention preferably have average fiber diameters of 5 to 100 µm, particularly preferably 10 to 50 µm.

[0052] According to the invention, the barrier layer is produced by jointly depositing the staple fibers with the meltblown fibers.

[0053] This is advantageous because it gives the barrier layer a particularly high degree of homogeneity. The staple fibers and the meltblown fibers are preferably deposited on the carrier layer. This is advantageous because it enables particularly close contact and thus a particularly good bond between the layers. The barrier layer is particularly preferably produced by blowing the staple fibers into the meltblown stream that is deposited on the carrier layer.

[0054] According to the invention, the barrier layer and carrier layer are preferably bonded together by heat and pressure. As is known in the art, such thermal bonding can be carried out in such a way that the basic fiber structure of the two layers is at least partially retained. Only enough thermal energy is introduced to ensure that the fibers are not completely melted, but only softened, creating bonding sites throughout the composite material.

[0055] According to the invention, the composite material is preferably produced by a process comprising the following process steps a) producing a barrier layer comprising a nonwoven fabric containing 1 to 70% by weight of meltblown fibers and 30 to 99% by weight of staple fibers, b) arranging at least one carrier layer comprising a spunbonded nonwoven fabric on at least one side of the barrier layer c) bonding the barrier layer and the carrier layer by means of heat and pressure.

[0056] In a preferred embodiment, thermal bonding is achieved by calendering. In this standard process, a nonwoven fabric is passed through a pair of calender rolls, which are typically heated. The conditions of the calendering step are preferably adjusted so that only partial melting of the fibers occurs, so that the nonwoven fabric is thermally bonded to a desired extent. The amount of adhesion and bond strength can be adjusted, for example, by changing the speed of the calender rolls, the pressure, the distance between the nips, and the temperature. This makes it possible to achieve a degree of thermal bonding such that a desired mechanical strength is achieved, whereby the basic fiber structure, particularly in the core of the nonwoven fabric, can be substantially retained or at least maintained to a desired degree.For example, the composite of barrier layer and carrier layer can be calendered with a pair of calender rolls with one or more of the following settings: . a speed of the rollers between 1 and 200 m / min, preferably between 50 and 180 m / min, a line pressure on the rollers between 1 and 1000 N / mm bar, preferably between 50 and 500 N / mm bar, a distance between the roller gaps between 0.01 mm and 5 mm, preferably between 0.001 mm and 3 mm, a temperature of the rollers between 10°C and 400°C, preferably between 150°C and 280°C.

[0057] Calendering can be performed over the entire surface of the barrier layer and / or carrier layer, or parts thereof, if the roll surface is patterned. According to the invention, calendering is preferred for thermal bonding because the mechanical strength of the nonwoven fabric and the entire composite material can be increased while the fiber structure of the nonwoven fabric is essentially maintained.

[0058] In a preferred embodiment, the basis weight of the composite material is between 10 g / m 2 and 200 g / m 2 . Preferably, the basis weight is between 20 and 140 g / m 2 , more preferably between 50 g / m 2 and 120 g / m 2 . Preferably, the basis weight is not higher than 200 g / m 2 , preferably not higher than 140 g / m 2 and in particular not higher than 120 g / m 2 or even 100 g / m 2 . Preferably, the basis weight is at least 10 g / m 2 or at least 20 g / m 2 or, in a specific embodiment, at least 50 g / m 2 . According to the invention, the basis weight is measured in accordance with DIN ISO 9073-1 (1989). The basis weight is preferably adjusted so that the packaging has the respectively required mechanical strength and barrier function.

[0059] In a preferred embodiment, the tensile strength of the composite material in the machine and transverse directions is at least 100 N / 5 cm. The tensile strength is preferably at least 125 N / 5 cm, more preferably at least 150 N / 5 cm. The tensile strength is preferably in the range of 100 N / 5 cm to 600 N / 5 cm and especially in the range of 150 N / 5 cm to 500 N / 5 cm. The tensile strength is determined according to ISO 1924-2 (2009). The tensile strength is also an indicator of suitability as packaging, in particular for sterile medical packaging. The high tensile strength shows that the material is suitable for sterilization and typical packaging applications.

[0060] In a preferred embodiment, the elongation of the composite material in the machine and transverse directions is at least 5%. Preferably, the elongation is at least 10%, even more preferably at least 20%. Preferably, the elongation is in the range of 5% to 50%, more preferably between 10% and 40%, and most preferably between 20% and 30%. The elongation is determined according to ISO 1924-2 (2009). Such a high elongation is advantageous because the nonwoven has sufficient flexibility and elastic and plastic deformability, which is required for standard packaging applications. The flexibility gives the packaging material additional stability and reduces the risk of damage, for example, through puncture. According to the invention, it is particularly advantageous that the high flexibility can be achieved despite the high mechanical strength and high air permeability. According to the prior art, e.g.In flash-spun porous sheets for medical applications, it is difficult to combine high air permeability with high mechanical strength and flexibility. Typically, porous sheets used in the prior art exhibit relatively low flexibility, as indicated by elongation.

[0061] In a preferred embodiment, the tear strength of the composite material in the machine and transverse directions is at least 1 N. The tear strength is preferably at least 1.5 N, preferably at least 2 N. The tear strength is preferably in the range of 1 N cm to 5 N and especially in the range of 2 N to 4 N. The tear strength is determined according to EN21974 (1994).

[0062] In a preferred embodiment, the thickness of the composite material in the machine and transverse directions is at least 50 µm. The thickness is preferably at least 100 µm, preferably at least 150 µm. The thickness is preferably in the range of 100 µm to 500 µm, and especially in the range of 150 µm to 300 µm. The thickness is determined according to EN ISO 534 (2012).

[0063] In a preferred embodiment, the puncture resistance of the composite material in the machine and transverse directions is at least 5000 J / m 2< . The puncture resistance is preferably at least 6000 J / m 2< , more preferably at least 7000 J / m 2< . The puncture resistance is preferably in the range of 2000 J / m 2< to 10000 J / m 2< and especially in the range of 6000 J / m 2< to 9000 J / m 2< . The puncture resistance is determined according to ASTM D3420 (1994). In a preferred embodiment, the average pore size of the composite material measured according to DIN ASTM E1294 (1999) is at least 0.5 µm, preferably at least 1 µm. The average pore size is preferably in the range of 1 µm to 15 µm, and especially in the range of 2 µm to 10 µm. If the average pore size is below 0.5 µm, the sterilization efficiency is generally lower, and if the average pore size is greater than 20 µm, the probability of bacteria / viruses passing through is too high.

[0064] Preferably, the burst strength of the composite material, measured according to ISO 2758 (2014), is at least 200 kPa, preferably at least 500 kPa, more preferably at least 700 kPa. The burst strength of the composite material may be below 2000 kPa or below 1500 kPa. Preferably, the burst strength is in the range of 200 kPa to 2000 kPa, preferably 300 kPa to 1500 kPa or 500 kPa to 1500 kPa. The inventive packages have been found to have a high burst strength. Burst strength is an indicator of the mechanical stability of a material suitable for packaging applications under pressure. For sterilization applications under vacuum, a high burst strength is required. In sterilization applications, a package may be subjected to pressure during the injection of sterilization gases, followed by the removal of the gases.The high burst strength of the inventive composite material indicates that it is suitable for such standard sterilization procedures.

[0065] In a preferred embodiment, the air permeability of the composite material is at least 200 mL / min. Preferably, the air permeability is at least 300 ml / min, most preferably at least 400 ml / min. In particular, the air permeability is in the range from 200 ml / min to 1,000 ml / min, or specifically in the range from 300 ml / min to 800 ml / min. The air permeability is preferably determined according to ISO 5636-3 (2013; Bendtsen test). High air permeability is particularly required for standard sterilization processes in which a package is sterilized with gaseous chemicals or steam. In such a process, for example with ethylene oxide, the package is sealed and the packaged article is subjected to a sterilization treatment in which the sterilizing agent penetrates the package.It has been found that the composite material used according to the invention has sufficient permeability for such sterilization processes.

[0066] In a preferred embodiment, the composite material is printable. Therefore, it can be marked with labels, tags, or the like using a simple printing process.

[0067] In a preferred embodiment, the composite material is stable at relatively high temperatures. Preferably, the package is stable at temperatures up to 140°C, preferably up to 200°C, or even up to 220°C. This means that the structure is not significantly disrupted and the polymers are not melted at such temperatures. Such thermostable composite materials can be sterilized at high temperatures, which is a great advantage for various sterilization applications.

[0068] The invention also relates to a package, in particular a sterile package, comprising a composite material as described herein. The preferred embodiments described with reference to the inventive use are also preferred embodiments for the inventive package.

[0069] In a preferred embodiment, a package obtained from the composite material is and / or will be sterilized by γ-radiation (gamma radiation). This process is also referred to as γ-X-ray sterilization. Gamma rays are high-energy and are known to chemically modify or destroy substrates with low mechanical strength. However, the package can be provided with high mechanical strength so that it can be subjected to efficient sterilization by γ-radiation.

[0070] In a preferred embodiment, the package is a medical package. The term "medical package" refers to all sterile packages that are specifically required in the technical fields of pharmacy and healthcare. For example, a medical package can include a packaged item that is a pharmaceutical composition, such as a drug or a liquid, or a medical device, such as a catheter, a syringe, a wound dressing, or the like. In the medical package, there is a high need for safe and cost-effective sterile packaging material, since basically all relevant devices and pharmaceutical compositions must be provided and maintained in sterile form. In addition, there is a high need for lightweight, simple packages in the medical field.The packaging according to the invention is ideally suited to such requirements because it combines various advantageous properties, such as high mechanical strength, high barrier function due to low porosity, good air permeability, low weight, and relatively simple production. In particular, the material is strong enough for standard sterilization by γ-radiation, steam, or chemicals.

[0071] Also described is a packaged article packaged with a composite material as described herein. The invention also relates to the use of the composite material for packaging an article as described herein. Preferably, the article is a medical article, and the composite material is configured as medical packaging. In another embodiment, the article is a cosmetic article, and the packaging is cosmetic packaging. Preferably, the article is a sterile article, and the packaging is sterile packaging.

[0072] In principle, the inventive use applies to the packaging of all objects, in particular a medical object, which is packaged with the composite material and subsequently sterilized. The packaged medical object can be a composition or a device. For example, the composition could be a pharmaceutical composition, such as a medicament, or another solid or liquid agent or composition used in the medical field. The device can be a disposable article, such as a syringe or a wound dressing. Preferably, the medical object is used in a medical treatment, such as therapy, diagnosis, or surgery.

[0073] The invention also relates to a method for providing a packaged article, comprising (a) providing the article and a composite material comprising a barrier layer, a carrier layer comprising a spunbonded nonwoven fabric arranged on at least one side of the barrier layer and bonded to the barrier layer by heat and pressure, wherein the barrier layer comprises a nonwoven fabric containing 1 to 70 wt.% meltblown fibers and 30 to 99 wt.% staple fibers, each based on the total weight of the nonwoven fabric, wherein the barrier layer is produced by co-depositing the staple fibers with the meltblown fibers. b) packaging the article in the composite material; and (c) optionally sterilizing the packaged article.

[0074] The method is also a method for providing a packaged article. Preferably, the packaged article is a medical article as described above. The method is also a method for sterilizing a packaged article when step (c) is applied. Preferably, the packaging in step (b) is carried out such that the article is sealed, i.e., completely shielded from the environment by the packaging.

[0075] In a preferred embodiment, the method comprises, before step (a), the steps of (a1) producing the carrier layer in a spunbond process and producing the barrier layer in a meltblown process with simultaneous deposition of the staple fibers with the meltblown fibers and (a2) thermally bonding the barrier layer to the carrier layer on at least one side of the barrier layer to obtain the composite material.

[0076] Preferably, the staple fibers and the meltblown fibers are mixed together in step (a1) by blowing the staple fibers into a meltblown fiber stream.

[0077] After step (a2), the composite material can be converted into the packaging by further steps, e.g., by applying a label. In a preferred embodiment, steps (a1) to (b), and optionally with the additional step (c), are carried out sequentially in a single process. Alternatively, a composite material can be obtained after steps (a1) and (a2), while the packaging of an article is carried out separately, e.g., by a supplier of medical supplies.

[0078] The preferred embodiments described with respect to the inventive use are also preferred embodiments for the inventive method.

[0079] The inventive uses, packages, and methods solve the problem underlying the invention. The composite material is suitable for the sterile packaging of objects, such as medical articles. The composite material has high mechanical strength and a high barrier function against germs such as bacteria or viruses. The composite material has sufficient stability, making it suitable for standard sterilization processes such as γ-radiation, high-temperature treatment, or chemical sterilization. It has sufficient porosity for sterilization treatment with chemicals. Its mechanical strength and high elastic and plastic deformability are of great advantage for standard packaging processes and applications. All advantageous properties can be achieved with a product with a relatively low basis weight. Overall, the composite material is suitable for simple and efficient packaging of objects. Character description

[0080] Figure 1 shows an SEM image of the cross section of an exemplary barrier layer. Examples

[0081] The composite materials of the invention were prepared as described below. Example 1:

[0082] PET / CoPET Bico staple binding fiber: Length - 38 mm Fineness - 2.2 dTex CoPET (melting point) - 180°C Meltblown PET: Fiber diameter - 0.3 to 2 µm Spunbond binding fibers PET / CoPET: Fiber diameter - 7 to 30 µm CoPET (melting point) - 180°C

[0083] The homogeneously carded PET / CoPET bico staple fibers are continuously blown into the meltblown stream via a tertiary air duct (TAC). The fibers mix with the meltblown PET fiber stream and are deposited onto the spunbonded nonwoven fabric by suction. The resulting nonwoven fabric is then compressed by a pair of calender rolls, creating a homogeneously shaped composite material suitable for sterilization due to its high temperature stability. The use of meltblown fibers results in relatively small pore sizes in the composite material, resulting in a good barrier effect against viruses and bacteria. Nevertheless, the composite material exhibits sufficient air permeability, which is important for sterilization. Example 2:

[0084] PET / CoPET bi-staple fiber: Length - 32 mm Gauge - 1.7dTex CoPET (Melting point) - 180°C Meltblown PET: Fiber diameter - 0.3 to 3 µm Spunbond PET / CoPET: Fiber diameter - 7 to 30 µm CoPET (melting point) - 180°C

[0085] The homogeneously carded PET / CoPET bico staple fibers are continuously blown into the meltblown stream via a tertiary air duct (TAC). The fibers mix with the meltblown PET fiber stream and are deposited onto the spunbonded nonwoven fabric by suction. The resulting nonwoven fabric is then compressed by a pair of calender rolls, creating a homogeneously shaped composite material suitable for sterilization due to its high temperature stability. The use of meltblown fibers results in relatively small pore sizes, resulting in a good barrier effect against viruses and bacteria. Nevertheless, the composite material exhibits sufficient air permeability, which is important for sterilization. Measurement methods:

[0086] Basis weight is defined as the mass per unit area and is measured in grams per square meter (g / m²). The basis weight of nonwovens is measured according to ISO 9073-1 (1989).

[0087] The thickness of nonwovens is measured in µm according to EN ISO 534 (2012).

[0088] Pore ​​size measurements of nonwovens were performed using a Porous Materials Inc. (PMI) tester (Porous Materials Inc., US). The ASTM E 1294 (1989) standard for measuring the pore size of sterile packaging products was followed. The pore size measurements were based on the displacement of a low-surface-tension wetting fluid (GALDEN HT 230 brand; Solvay, IT) from a pore by a gas.

[0089] The tensile strength (breaking strength) and elongation of nonwoven fabrics were measured using a tensile testing machine according to ISO 1924-2 (2009). To measure the tensile strength and elongation of the nonwoven fabric, five strips were cut from the machine and cross directions (MD&CD) at different locations on the sample. The cut samples were clamped onto the clamps of the tensile testing machine and pulled at a constant stretching speed. The tensile strength and elongation were then recorded and averaged for each sample.

[0090] The air permeability of nonwovens was measured according to ISO 5636-3 (2013; Bendtsen test).

[0091] The tear strength of nonwovens was determined according to the European standard EN21974 (1994).

[0092] The bursting strength of nonwovens was measured using a burst pressure gauge according to ISO 2758 (2014).

[0093] The puncture resistance of nonwovens is measured according to ASTM D3420 (1994).

[0094] The measurement results for the inventive examples 1&2 are summarized in the following table and are compared with the commercial product (Tyvek ®< ). Characteristics Unit standard Tyvek ®< Example 1 Example 2 Basis weight g / m2 EN ISO 536 (Tyvek) DIN ISO 9073-1 80 75 85 thickness µm EN ISO 534 171 162 184 polymer HDPE PET PET Thermal stability °C DIN ISO 11357-3 (2013) Up to 125°C Up to 250°C Up to 250°C Tensile strength N / 5cm ISO 1924-2 174 162 182 Stretching % 22 21 20 Pore ​​size distribution µm ASTM 2-8 1-10 1-10 E1294 Tear resistance N EN 21974 3.1 2.9 3.2 Puncture resistance J / m 2 ASTM D3420 8354 7974 8471 Burst strength kPa ISO 2758 1199 1241 1331 Air permeability mL / min ISO 5636-3 542 579 514

[0095] It is shown that the composite materials according to the invention exhibit higher thermal stability than the reference material, while maintaining comparably good mechanical properties and pore size distribution. Due to the use of PET material, the composite material according to the invention can be easily sterilized and welded. In contrast, the interlayer adhesion and printability of the reference product are poorer.

Claims

1. Use of a composite material comprising a) a barrier ply, b) a support ply which comprises a spunbonded web and which is arranged on at least one side of the barrier ply and bonded to the barrier ply by heat and pressure, the barrier ply comprising a nonwoven web which contains 1% to 70% by weight of meltblown fibres and 30% to 99% by weight of staple fibres, based in each case on the total weight of the nonwoven web, as packaging material, in particular for sterile packaging applications, characterized in that the barrier ply is produced by jointly laying down the staple fibres with the meltblown fibres.

2. Use according to Claim 1, characterized in that the meltblown fibres, the staple fibres and / or the fibres of the spunbonded web comprise at least one polymer selected from polyesters and / or polyolefins.

3. Use according to Claim 1 or 2, characterized in that at least a proportion of the staple fibres are staple binding fibres and / or at least a proportion of the fibres of the spunbonded web are spunbonded binding fibres, the composite material preferably comprising both spunbonded binding fibres and staple binding fibres.

4. Use according to Claim 3, characterized in that the staple binding fibres and / or the spunbonded binding fibres are each independently bicomponent fibres, in particular core / sheath fibres.

5. Use according to one or more of the preceding claims, characterized in that the barrier ply is produced by blowing the staple fibres into a meltblown stream which is laid down on the support ply.

6. Use according to one or more of the preceding claims, characterized in that the basis weight of the composite material is between 10 g / m2 and 200 g / m2.

7. Use according to one or more of the preceding claims, characterized in that the thickness of the composite material in the machine direction and transverse direction is at least 50 µm.

8. Use according to one or more of the preceding claims, characterized in that the average pore size of the composite material measured in accordance with DIN ASTM E1294 (1999) is in the range from 1 µm to 15 µm.

9. Use according to one or more of the preceding claims, characterized in that the air permeability of the composite material is at least 200 mL / min.

10. Use according to one or more of the preceding claims, characterized in that the barrier ply and the support ply are bonded to each other by heat and pressure.

11. Use according to one or more of the preceding claims, characterized in that the composite material is designed as medical packaging and the composite material is used for packaging a medical article.

12. Packaging, in particular sterile packaging, comprising a composite material comprising a) a barrier ply and b) a support ply which comprises a spunbonded web and which is arranged on at least one side of the barrier ply and bonded to the barrier ply by heat and pressure, the barrier ply comprising a nonwoven web which contains 1% to 70% by weight of meltblown fibres and 30% to 99% by weight of staple fibres, based in each case on the total weight of the nonwoven web, characterized in that the barrier ply is produced by jointly laying down the staple fibres with the meltblown fibres.

13. Packaging according to Claim 12, characterized in that the meltblown fibres, the staple fibres and the fibres of the spunbonded web comprise at least one polymer selected from polyesters.

14. Process for providing a packaged article, comprising (a) providing the article and a composite material comprising - a barrier ply, - a support ply which comprises a spunbonded web and which is arranged on at least one side of the barrier ply and bonded to the barrier ply by heat and pressure, the barrier ply comprising a nonwoven web which contains 1% to 70% by weight of meltblown fibres and 30% to 99% by weight of staple fibres, based in each case on the total weight of the nonwoven web, the barrier ply having been produced by jointly laying down the staple fibres with the meltblown fibres, (b) packaging the article in the composite material and (c) optionally sterilizing the packaged article.

15. Process according to Claim 14, characterized in that the meltblown fibres, the staple fibres and the fibres of the spunbonded web comprise at least one polymer selected from polyesters.