A package comprising a sealing contact area with a nonwoven having an adhesive surface with an embossed impression pattern

Abstract

The present application relates to a package comprising a sealed contact area with a nonwoven having an adhesive surface with an embossed imprint pattern. The invention relates to a package for providing a closed interior environment capable of being sterilized, and a breathable fibrous nonwoven sheet structure useful in such a construction, wherein the nonwoven sheet structure has: at least one surface having a pre-sealed, embossed imprint pattern; and a particle barrier transmission of less than 10%, a Gurley Porosity of 40 seconds or less, and a moisture vapor transmission rate of 3500 g / m 2 per day or greater.

Description

[0001] This application is a divisional application of an invention patent application, the parent application of which was filed on September 13, 2017, with application number 201780063000.8 (PCT / US2017 / 051323) and titled "Packaging including a sealing contact area with a nonwoven fabric having an adhesive surface with an embossed pattern". Background Technology

[0002] Technical Field. This invention relates to improved packaging materials for providing a closed internal environment capable of sterilization, and breathable fiber nonwoven sheet structures suitable for use therein.

[0003] Related technical description. US Patent No. 6,034,008 of Lim et al. discloses sheet materials suitable for use in filtration and aseptic packaging, which have at least equivalent strength, weight and shielding properties to those of TYVEK® spunbond olefin nonwoven sheet materials that have been conventionally used in such applications, and also have significantly improved air and liquid permeability.

[0004] Specifically, Lim et al. disclosed “hard structure” products with full-surface bonding that have the feel of glossy paper (typically used in a variety of applications, including aseptic packaging); and “soft structure” products with point bonding and softening for apparel applications that have a more fabric-like feel.

[0005] As disclosed by Lim et al., it is believed that the bonding of the entire surface of "rigid structure" spun sheets causes shrinkage of the high surface area plexifilamentary fibers, which in turn leads to the opening of pores between the fibers. Therefore, "rigid structure" sheets typically exhibit higher wet vapor permeability and higher hydrostatic head values ​​compared to "soft structure" sheets. This greater permeability has been found to have significant practical applications in aseptic packaging materials, where increased permeability allows the material to function more effectively.

[0006] Nonwoven sheets are useful in sterilizable packaging because they allow manufacturers to first package the items and then sterilize them using gases such as steam, ethylene oxide, or combinations thereof. The sterilizing gases can penetrate the nonwoven sheet to sterilize the sealed interior of the packaging. Suitable nonwoven sheets also provide a barrier against contaminants, preventing contamination of the sterilized packaged items before opening.

[0007] It is not uncommon for sterilized packaging to be opened in a sterilized environment, and a desirable feature of nonwoven sheets is that they can be peeled off from the packaging without excessively tearing the surface of the nonwoven sheet when removed. Some argue that surface cracking (fiber tearing) of the nonwoven sheet during peeling could contaminate the sterilized environment in which the opened packaging is located.

[0008] Since most sterilized packaging materials are used in health-related environments (such as operating rooms), any improvements that help prevent or reduce any potential contamination are desirable. In packaging, any improvements, particularly in the peelability of nonwoven fabrics, are highly desirable. Summary of the Invention

[0009] This invention relates to a package for providing a closed internal environment capable of sterilization, the package comprising a breathable fiber nonwoven sheet structure, a polymer bonding layer, and a package substrate; the nonwoven sheet structure having a first surface and a second surface; the closed internal environment being formed by sealing the contact area between the first surface of the nonwoven sheet structure and the package structure, the sealed contact area being formed by the polymer bonding layer; wherein the first surface of the nonwoven sheet structure is pre-adheded with an embossed pattern at least within the sealed contact area.

[0010] The present invention also relates to a nonwoven sheet structure suitable for use in aseptic packaging, the sheet structure being breathable and having a first surface and a second surface; the first surface being bonded with an embossed pattern, and the second surface being printable; the sheet structure having a particle barrier penetration rate of less than 10%, a Gurley Hill porosity of 40 seconds or less, and a density of 3500 g / m³. 2 / day or greater wet vapor transport rate. Attached Figure Description

[0011] Figure 1 and Figure 2 These are illustrations of some embossed patterns.

[0012] Figure 3 and Figure 4 These are illustrations of some packaging bases, showing the sealing area.

[0013] Figure 5 This is a diagram showing the locations of four samples used to determine the seal strength of packaging. Detailed Implementation

[0014] This invention relates to a packaging material for providing a closed internal environment capable of sterilization, and a breathable nonwoven sheet structure useful in such a structure, wherein the nonwoven sheet structure has at least one surface pre-bonded with an embossed pattern and has a particle shielding penetration rate of less than 10%, a Glysh porosity of 40 seconds or less, and a density of 3500 g / m². 2 / day or greater wet vapor transport rate.

[0015] Surprisingly, nonwoven sheet structures with embossed adhesive surfaces have been found to be suitable for use in sealed packaging with an internal environment capable of sterilization. Surprisingly, (1) the embossed nonwoven surface provides a good seal for the packaging structure, and (2) the resulting packaging exhibits excellent peel performance (when the packaging is opened), in many cases better than sheets bonded with smooth surfaces.

[0016] Ideally, any package that can be used and opened in a sterile environment should have "clean peel" or provide "sterile peel / introduction"—a medical industry term referring to the requirement that the package can be opened and its contents introduced into a sterile environment without the risk of contamination. As used herein, this superior opening performance is determined using a "fiber tear" criterion. Surprisingly, nonwoven sheet structures using at least one pre-bonded surface with an embossed pattern (in contact with the polymer bonding layer) can provide packages with clean peel and very low or virtually no fiber tearing.

[0017] Even more noteworthy is that this level of excellent peel performance was achieved without any additional coating on the fiber nonwoven sheet structure. The use of nonwoven coatings can provide improved peel performance, but the simple application of such coatings can introduce other loose particles that pose a risk to aseptic introduction.

[0018] Packaging materials used to provide a closed internal environment capable of sterilization include breathable fiber nonwoven sheet structures, polymer bonding layers, and packaging bases.

[0019] The packaging substrate can be any material that forms flexible or semi-rigid packaging, such as in the form of sachet, bag, sleeve, or blister pack. Packaging including a packaging substrate is typically used to protect packaged articles and, in the case of aseptic packaging, helps to keep the packaged articles uncontaminated until ready for use. In one practical application, the articles to be packaged are placed in the packaging substrate and then sealed using a polymer bonding layer and a breathable fiber nonwoven sheet structure to create a closed environment. The package containing the sealed articles can then be sterilized (if desired) using a suitable sterilizing gas. In some embodiments, the packaging substrate comprises polyamide (especially nylon), polypropylene, polyester (especially polyethylene terephthalate), and any combination thereof.

[0020] The packaging includes a polymer bonding layer for sealing the contact area between the nonwoven sheet structure and the packaging structure. This polymer bonding layer is preferably any flexible or semi-rigid film that is compatible with both the packaging substrate and the nonwoven sheet structure, and suitably seals the nonwoven sheet structure to the packaging substrate. Compatibility means that the polymer bonding layer does not adversely react with the nonwoven sheet or the packaging substrate and has a suitable shelf life to maintain the packaging seal until its intended use. In some preferred embodiments, the polymer bonding layer and the packaging substrate are integral. Figure 3 and Figure 4 The sealing regions 15 and 17 shown illustrate one embodiment in which the polymer bonding layer forms a sealed contact area (where the packaging substrate and the fibrous nonwoven sheet structure will come into contact).

[0021] The polymeric linker layer is preferably in the form of a film. The composition of the polymeric linker layer may include, for example, polyethylene (including low-density polyethylene), ethylene-vinyl acetate, and any combination thereof.

[0022] In some preferred embodiments, the polymer binder and the packaging substrate are integral. In some embodiments, they are combined in the same film. In this case, as used herein, the packaging substrate is defined as a “structural material,” and this structural material is integrally combined with the polymer used as the polymer binder in the film. For example, some useful structural materials include polyamides (especially nylon), polypropylene, polyesters (especially polyethylene terephthalate), and any combination thereof. Particularly desirable structural material / polymer binder combinations that can be used when the packaging substrate and the polymer binder are integral include polyamide / polyethylene, polyester / polyethylene, polypropylene / polyethylene, polypropylene / ethylene-vinyl acetate, polyamide-polypropylene / polyethylene, etc.

[0023] The fiber nonwoven sheet structure is breathable, meaning that sterilizing gases such as ethylene oxide and / or vapor can pass through the sheet without requiring excessive pressure. Specifically, the fiber nonwoven sheet structure has a Gurley porosity of 40 seconds or less (also known as Gurley porosity). This characteristic is a measure of the time it takes for a given volume of gas to pass through a region of material in which a pressure gradient exists; therefore, a lower number indicates that the material is more breathable, and a higher number indicates that the material is less permeable. In some embodiments, the fiber nonwoven sheet structure has a Gurley porosity of 10 seconds or less. In some embodiments, the fiber nonwoven sheet structure has a Gurley porosity of 5 seconds or less, and in some of the most preferred embodiments, the fiber nonwoven sheet structure has a Gurley porosity of 3 seconds or less.

[0024] Another indicator of permeability is the measurement of wet vapor transmission, with higher values ​​indicating greater permeability. This is particularly important when steam is used as part of the sterilization process. Fiber nonwoven sheet structures have a permeability of at least 3500 g / m². 2 / day or greater wet vapor transport rate. In some preferred embodiments, the fiber nonwoven sheet structure has a wet vapor transport rate of at least 7500 g / m². 2 / day or greater wet vapor transport rate. In some other embodiments, the fiber nonwoven sheet structure has a wet vapor transport rate of at least 9000 g / m². 2 / day or greater wet vapor transport rate. Preferably, the fiber nonwoven sheet structure is uncoated, giving it a more permeable sheet structure. Using a coating to improve adhesion tends to seal the surface of the nonwoven sheet structure, reducing the rate at which sterilizing gases can pass through the structure beneath it.

[0025] The fiber nonwoven sheet structure has a first surface and a second surface, wherein the first surface is bonded with an embossed pattern. As used herein, the phrase "bonded with an embossed pattern" means that the surface has at least two characteristics: first, the fiber material on the surface has been "bonded," meaning that the fiber material has been substantially solidified and stabilized by heat and pressure supplied to the sheet from a heating source (such as a roller); second, the surface has an embossed pattern that gives the surface its visual texture. As used herein, the term "pre-bonded" means embossing the fiber nonwoven sheet structure before it is incorporated into any packaging.

[0026] In one embodiment, the embossed pattern in the sheet is provided by calendering a nonwoven sheet in the roll gap between a heated metal roll and an elastomeric support roll, the metal roll being patterned with raised regions or bosses extending radially outward from the surface of the roll. In some preferred embodiments, the raised regions or bosses extend 0.008 to 0.020 inches (0.20 to 0.50 mm) from the surface of the remainder of the roll. In some other embodiments, the raised regions or bosses may have a width of 0.005 to 0.025 inches (0.12 to 0.64 mm). In some preferred embodiments, the width of the raised regions or bosses may be 0.005 to 0.015 inches (0.12 to 0.38 mm).

[0027] When a fiber nonwoven sheet is pressed in the gap between a heated metal roller with raised areas or bosses and an elastomer support roller, the nonwoven sheet is given an embossed pattern with a depth substantially equivalent to the size of the bosses. Figure 1 and Figure 2 Illustrations of two potentially useful and desirable embossing patterns are provided, in which Figure 1 It is called a linen pattern, and Figure 2 It is known as the dog bone pattern.

[0028] A preferred method for embossed nonwoven sheets is to thermally bond the sheet on a modified machine, similar to Janis's US 5,972,147. Figure 2 The method described herein. In the preheating section of this modified machine, each side of the nonwoven fabric being bonded is brought into contact with multiple preheating rollers. In some preferred embodiments of the embossed nonwoven sheet described herein, the Janis machine is modified such that there are four heating rollers in this section, which operate at a temperature sufficient to substantially provide adequate surface adhesion of the sheet. The temperature will depend on the melting point of the materials being bonded. After the preheating rollers, the sheet preferably passes through only one of the multiple embossing machine sections shown, so that the embossing pattern is preferably applied to only one surface of the sheet. On each embossing machine section are embossing rollers that can be pressed onto support rollers to form a roll gap. The pressure between the embossing machine and the support rollers is expressed in pounds per line inch (pli). The support rollers are typically covered with an elastomer cover and are internally cooled by recirculating cooling media. The nonwoven sheet is then transferred to multiple cooling rollers in which the temperature of the sheet material is reduced, and then wound into a roll.

[0029] Using multiple preheated rollers operating at high temperatures not only helps bond the first surface of the nonwoven fabric to be embossed, but also provides an opposite second surface that is also bonded. This second surface is preferably printable. Furthermore, it is preferable that the second surface has a smooth surface without any embossing for optimal printability. Many packaging materials require very specific barcodes and other delicate and small markings, which necessitate a very uniform and flat surface without the texture provided by embossing.

[0030] Alternatively, the sheet surface can be first bonded, wound onto a roller, and then subsequently unwound and embossed on one side to provide a first surface with an embossed pattern. Other embossing methods are also possible, as long as they provide a fibrous nonwoven sheet with at least a first surface having an embossed pattern. Preferably, the method provides a second surface that is printable. Preferably, the second surface is uniform and does not have any embossed pattern.

[0031] In some embodiments, the nonwoven sheet structure provides good shielding against contaminants and has sufficient durability to withstand general handling without damaging or contaminating the contents of the packaging. Therefore, the nonwoven sheet structure with an embossed pattern preferably has a particle shielding penetration rate of less than 10%, as determined using a TSI 8130 instrument. This particle shielding test is believed to be useful in determining the degree of shielding provided by the sheet against contaminants, which may include those that are potentially bacterial. Furthermore, the nonwoven sheet structure with an embossed pattern preferably has a Mullen burst strength greater than 500 kPa and a measured Elmendorf tear strength greater than 2 N / m.

[0032] Fiber nonwoven sheet structures include nonwoven fabrics that can provide a stable surface with embossed patterns for contact with polymer bonding layers on packaging. Such nonwoven sheet structures can include flash-spun nonwoven sheet structures, spunbond... Nonwoven fabrics, meltblown sheets, blown sheets, and any combination thereof. The term "fiber" refers to the material in a nonwoven sheet possessing some fibrous properties. These fibrous properties can be provided by things such as short fibers, continuous or semi-continuous fibers, and / or tufted fiber structures. The fibrous material can comprise a single material or multiple materials, as a combination of different fibers or as a combination of similar fibers each comprising different materials. The term "nonwoven" refers to a planar sheet structure comprising at least one randomly distributed web of fibrous material, as opposed to a woven or knitted fabric made of interlaced yarns or interlocking loops. In some preferred embodiments, the fibrous material in the nonwoven sheet is a synthetic polymer; in some embodiments, the synthetic polymer is a thermoplastic polymer. In some preferred embodiments, the fibrous material in the nonwoven sheet structure does not contain added adhesives; that is, the fibrous material is bonded to the sheet by melting the fiber intersections in the sheet structure without adding additional adhesive compounds to the sheet.

[0033] In some embodiments, the fiber nonwoven sheet structure has a basis weight of less than 55 g / m². In some more preferred embodiments, the fiber nonwoven sheet structure has a basis weight of less than 50 g / m²; and in some most preferred embodiments, the fiber nonwoven sheet structure has a basis weight of less than 45 g / m².

[0034] Preferred fiber materials for nonwoven sheet structures are tufted fibers. As used herein, tufted fibers refer to a large number of thin, ribbon-like membrane-fiber networks of arbitrary length and having an average fibril thickness of less than about 4 micrometers and a median width of less than about 25 micrometers. In a tufted fiber structure, the membrane-fibers are generally aligned coaxially with the longitudinal axis of the structure and are intermittently combined and separated at irregular intervals at different locations throughout the length, width, and thickness of the structure to form a continuous three-dimensional network. Such structures are described in further detail in U.S. Patent Nos. 3,081,519 and 3,227,794.

[0035] A preferred method for manufacturing fibrous nonwoven sheet structures with tufted fiber materials is by flash spinning. The resulting fibrous nonwoven sheet structure containing tufted membrane-fiber elements is also known as a flash-spun tufted sheet.

[0036] Thus, preferred fiber nonwoven sheets suitable for further bonding and embossing can be manufactured using general flash spinning techniques as described in U.S. Patent No. 3,227,794 to Anderson and U.S. Patent No. 3,860,369 to Brethauer et al. Particularly preferred fiber nonwoven sheets suitable for further bonding and embossing can be manufactured using spinning solutions comprising high-density polyethylene and hydrocarbon spinning agents, as described, for example, in U.S. Patent Nos. 6,010,970; 7,338,916; 8,048,513; and 6,034,008. Preferably, the fiber nonwoven sheets suitable for further bonding have improved permeability and shielding strength properties by flash spinning the sheet from a hydrocarbon spinning solution containing between 12% and 20% polyethylene by weight and maintained at a temperature above 180ºC prior to flash evaporation; in some embodiments, this temperature is between 185ºC and 195ºC prior to flash evaporation.

[0037] The fiber material in the nonwoven sheet is preferably a polyolefin. Polyolefins may include polyethylene, polypropylene, polymethylpentene, polybutene, and combinations thereof. Preferably, the polyolefin is polyethylene.

[0038] Polyethylene includes not only homopolymers of ethylene, but also copolymers in which at least 85% of the repeating units are derived from ethylene. Preferred polyethylene is linear high-density polyethylene having an upper limit of its melt range of about 130.0ºC to 137.0ºC and a density of 0.94 to 0.98 g / cm³. 3 The density is within the range of 0.1 to 100 (preferably between 0.1 and 4) and the melt flow index is as defined by ASTM D-1238-57T, Condition E. Polypropylene includes not only homopolymers of propylene but also copolymers in which at least 85% of the repeating units are derived from propylene units.

[0039] The packaging, comprising a breathable nonwoven sheet structure, a polymer bonding layer, and a packaging base, provides a closed internal environment capable of sterilization. This closed environment is created by sealing the contact area between the pre-bonded, embossed first surface of the nonwoven fabric and the packaging structure using the polymer bonding layer.

[0040] In some embodiments, the packaging may be a type of pouch made of a membrane having a cavity for the material to be packaged, wherein a fibrous nonwoven sheet seals the packaging. In this embodiment, preferably, a polymer bonding layer is integral with the membrane of the pouch, and this bonding layer is essentially a membrane exposed on the inside of the pouch that allows it to contact the fibrous nonwoven sheet.

[0041] Alternatively, in some embodiments, the packaging may be a type of blister packaging, wherein the packaging substrate has a thermoformed blister cavity for the material to be packaged and a fiber nonwoven sheet structure provides a cap for the packaging. Again, in a preferred embodiment, the polymer bonding layer is integral, forming the inner surface of the thermoformed cavity, and contacts the fiber nonwoven sheet sealing the cavity together with the cap of the packaging.

[0042] Plan views of the two types of packaging bases with cavities 16 and 18 are respectively in Figure 3 and Figure 4 As shown, the packaging substrate has sealing regions 15 and 17 surrounding the cavity. When the cavity is sealed, a fiber nonwoven sheet structure covers both the sealing regions and the cavity. A polymer bonding layer is arranged in the sealing regions, between the packaging substrate including the cavity and the fiber nonwoven sheet material. It is preferred that the polymer bonding layer be integral with the packaging substrate.

[0043] In some embodiments, packaging is manufactured by forming a desired packaging substrate with a polymer bonding layer, filling the cavity with the material to be packaged, applying a pre-bonded nonwoven sheet structure with an embossed pattern (the embossed pattern is in contact with the polymer bonding layer), and then sealing. In some embodiments, the nonwoven sheet structure may be a blister pack cap. The packaging is then sealed by heat, pressure, or a combination of both.

[0044] In some embodiments, a heated platen heat-sealing component is typically used. While the cavity containing the article to be packaged is completely sealed, some other areas on the package may not need to be completely sealed if desired, to provide a starting point for peeling off the nonwoven sheet structure before removing the product. If the nonwoven sheet structure is not pre-printed before sealing, it can be printed either before or after heat sealing.

[0045] While preferred packaging embodiments are pouches or blister packs, it should be understood that any flexible or semi-rigid packaging, including pouches, bags, or sleeves, may use a pre-bonded, embossed fiber nonwoven sheet structure as a breathable feature.

[0046] The resulting packaging has a closed internal environment for the articles to be packaged, which is formed by sealing a contact area between a first surface of a nonwoven sheet structure and a packaging substrate, wherein the sealed contact area is a polymer bonding layer, and the first surface of the nonwoven sheet structure is pre-adheded with an embossed pattern at least within the sealed contact area. In some embodiments, the resulting packaging has a closed internal environment comprising articles packaged in a closed environment, which is formed by sealing a contact area between a first surface of a nonwoven sheet structure and a packaging substrate, wherein the sealed contact area is a polymer bonding layer, and the first surface of the nonwoven sheet structure is pre-adheded with an embossed pattern at least within the sealed contact area.

[0047] In some embodiments, the formed package is a heat-sealed peelable package. As defined herein, the phrase "peelable package" means sealing a sheet structure to a package having a "peelable seal." As defined herein, the phrase "peelable seal" means that the sheet structure sealed to the package has an average peak load seal strength of at least 0.5 psi up to 4 psi or less. This means that the sheet structure can be manually removed from the sealed package by applying a seal of at least 0.5 psi and at most 4 psi. In some preferred embodiments, the maximum average peak load seal strength is 3 psi or less. Furthermore, because the fiber nonwoven sheet structure has at least one surface with an embossed pattern bonded to it, it allows the surface with the embossed pattern bonded to form a "peelable seal" with the package.

[0048] One measure of seal integrity is characterized by a dye penetration test as described in ASTM F1929-12. Surprisingly, it was found that packaging made of nonwoven sheet structures pre-bonded with embossed patterns and attached to the polymer bonding layer in the sealed area via the embossed surface had no negative impact on the dye penetration test.

[0049] The resulting packaging exhibits excellent sealing and peel properties. Surprisingly, the use of fiber-reinforced nonwoven sheet structures with at least one pre-bonded, embossed surface (in contact with the polymer bonding layer) can provide packaging with clean peel and very low or virtually no fiber tearing. Surprisingly, peel characteristics are further improved when the surface of the embossed nonwoven sheet is sealed to a film.

[0050] Improved peel characteristics are demonstrated by showing both a reduction in the percentage of packaged material with fiber tears and / or a decrease in the severity of fiber tears. Specifically, it has been found that nonwoven sheet structures with at least one surface having an embossed pattern have a significant reduction in packaged material that does not provide clean peel when compared to non-embossed materials. In particular, it has been found that using embossed sheet structures can provide at least a 25% reduction in packaged material with visible fiber tears, preferably at least a 30% reduction, or even higher, compared to non-embossed structures.

[0051] Furthermore, it has been found that the sealing strength, as measured by both average load and average peak load, is improved compared to structures using non-embossed fiber nonwoven sheets. In other words, both sealing strength and peel quality are improved by using an embossed surface on the surface of the fiber nonwoven sheet structure in contact with the polymer bonding layer.

[0052] Test methods Basis weight. Measure the basis weight according to ASTM D3776 (2009).

[0053] Gurley porosity (or simply "Gurley porosity"; the phrase is used interchangeably throughout this text) is a measure of the permeability of a sheet material to gaseous matter. Specifically, it is a measure of the time it takes for a given volume of gas to pass through a region of material in which a pressure gradient exists. Gurley porosity was measured according to TAPPI T-460 OM-88 using a Lorentzen & Wettre SE 166 or 516 from the Swedish company, HISTA. This test measured the time required to push 100 cubic centimeters of air through a 28.7 mm diameter sample (with an area of ​​1 square inch) at a water pressure of approximately 1.21 kPa (4.9 inches). The results are expressed in seconds, commonly referred to as the Gurley second. The reported values ​​represent the average of at least 12 individual measurements.

[0054] Moist vapor transmission rate. Moist vapor transmission rate (MVTR) was measured according to EN ISO 12572, Humid and thermal properties of building materials and products, Climate C, 2001. Measurements were performed using a multi-stage method, with a relative humidity of 100% in the cup, an airflow of 2.5 m / s above the sample, and measurement intervals of 30 minutes. The resulting MVTR was determined based on the weight loss of water in the sample. The reported value represents the average of at least one measurement. Measurements were performed on a Gintronic Gravitest 6400 balance from MRSSeitter GmbH, Lenning-Brück, Germany, equipped with an ES 420A balance.

[0055] Particle transmittance. Particle transmittance was measured on a TSI 8130 instrument from TSI Corporation, Ramsey County, Minnesota, USA. The TSI 8310 is an instrument used for measurements according to NIOSH procedure numbers RCT-APR-STP-57,58,59. For analysis, the TSI 8130 instrument was used, with a flow rate of 2.3 L / min for sodium chloride particles. To achieve the 2.3 L / min flow rate, the control valve was closed, and the air flow was generated solely by air passing through the downstream photometer. The sodium chloride particle distribution had a median diameter of 0.075 µm, a mass-mean diameter of 0.3 µm, and a geometric standard deviation of 1.8. Measurements were taken with a rise time of 25 seconds and a measurement time of 4 seconds. Transmittance was measured based on the difference in light intensity between the upstream and downstream photometers. The reported transmittance is the average of at least 6 measurements. Alternatively, particle transmittance can be expressed as a logarithmic decrease based on the following formula: LRV-TSI 8130 = -log10 (penetration rate [%] / 100) Elmendorf tear. Elmendorf tear is measured according to ISO 1974:1990; Paper – Determination of tearing resistance (Elmendorf method). The Elmendorf tear is measured on a 09 ED tear tester from Lorentzen & Wettre GmbH, Schistos, Sweden. Elmendorf tear is measured in both the machine direction (MD) and the transverse direction (XD).

[0056] Mullen burst strength. The Mullen burst strength was measured according to ISO 2758:2001, Paper – Determination of bursting strength. The Mullen burst strength was measured using a Lorenzen & Wettre model 519L from Lorenzen & Wettre, Sweden, integrated into the Autoline 400 system.

[0057] Sealing strength. Sealing strength is measured using the "free tail" method according to Appendix C of ASTM F88 / F88M. For example... Figure 5 As shown, four strips of each test package 25 are cut at defined locations with a width of 1 inch to test seal 20. The strip edges are well-defined and perpendicular to the direction of the seal. The most rigid part of the seal is placed on the upper clamp. The produced nonwoven sheet is the most rigid part of the seal and is therefore placed on the upper clamp. The seal is tested at a gripping-separation rate of 300 mm / min. The number of measurements for each test item is at least equal to 24. The seal strength is reported as both the average of the seal strength under average load and the average of the seal strength under peak load, in pounds per inch (lbf / in).

[0058] Dye Penetration. Dye penetration is performed according to ASTM F1929-12, "Standard Test method for Detecting Seal Leaks in Porous Medical Packaging by Dye Penetration." ASTM F1929-12 defines a procedure to detect and locate leaks in the edge seal of a package formed between a transparent material and a porous sheet material that are equal to or larger than a channel formed by a 50 µm (0.002 inch) line. A dye penetrating agent solution is locally applied to the seal edge to test for leaks. After a specified time of 5 seconds of contact with the dye penetrating agent, the dye penetration of the package is visually inspected. If no channel is visually observed, the package "passes" the dye penetration test.

[0059] Printing. Linear barcodes or 2D data matrices are printed onto the nonwoven sheet. The linear barcodes are tested according to ISO 15416, and the 2D data matrices are tested as described in ISO 15415.

[0060] Fiber tearing. Fiber tearing is determined by visual inspection of opened packages. Packages are opened manually as follows: Hold the nonwoven sheet with one hand and the film with the other. Each package is opened in approximately one second. The package is not opened until the lower edge seal is reached. In other words, the package is not fully opened, but only at the top and side seals. After opening each package, the surface of the nonwoven sheet sealed to the film is inspected. This surface should be uniform and continuous, without any peeling or tearing of the nonwoven sheet. If peeling or tearing of the nonwoven sheet is present, the package has fiber tearing. The above procedure is performed on at least 50 packages. The percentage of packages showing fiber tearing is determined by dividing the number of packages showing fiber tearing by the total number of opened packages. Alternatively, fiber tearing can be determined according to EN 868-5 (2009), Annex E. However, this standard does not account for some smaller visually perceptible fiber lengths. As illustrated in the examples and as defined herein, “package showing fiber tears” is a package with any length of fibers (visible to the naked eye) attached after opening.

[0061] Examples 1 and 2 Using a generic flash spinning method as described in Examples 9-15 of U.S. Patent No. 6,034,008, such as that of Lim et al. (except that the polymer concentration in the spinning solution is 17% by weight and the spinning temperature is 195ºC), unfinished fiber nonwoven sheets for further bonding and embossing are produced from a spinning solution containing high-density polyethylene and a n-pentane spinning agent. The polyethylene has a melt flow index of approximately 0.75 g / 10 min at 2.16 kg / 190ºC (as measured by ASTM D1238-13). Two nonwoven sheets with different basis weights are produced.

[0062] Then, by means of the method described in Janis's U.S. Patent No. 5,972,147, particularly that patent... Figure 2 The improved apparatus shown in the figure bonds an unfinished nonwoven fiber sheet with an embossed pattern. In the method shown in the figure, the sheet is alternately wrapped and preheated by a single set of two preheating rollers, then bonded in the gap between two sets of two calendering rollers, wherein the first set of rollers bonds one side of the sheet and the second set of rollers bonds the other side of the sheet; the sheet is then cooled by a single set of two cooling rollers.

[0063] Specifically, Janis's method was modified to use a separate set of preheating rolls, so that the sheet alternately wraps around four (as opposed to two) preheating rolls with no gap between them. Furthermore, only the second set of calendering rolls clamps the sheet, operating at a gap pressure of approximately 200 psi. The first set of calendering rolls is left open and not clamping the sheet. The sheet is then cooled using two cooling rolls from both sets (as opposed to two from a single set).

[0064] The specific equipment arrangement includes wrapping the bottom of the sheet around a first preheating roller (PH1), wrapping the top of the sheet around a second preheating roller (PH2), then wrapping the bottom of the sheet around a third preheating roller (PH3), and finally wrapping the top of the sheet around a second preheating roller (PH4). Because the first set of calendering rollers does not clamp the sheet, the top surface of the sheet is not embossed. The second set of calendering rollers bonds the bottom surface of the sheet and embosses a flax-like pattern (such as...) on the surface of the sheet. Figure 1 (As shown).

[0065] The sheet is then transferred to a cooling section and then wound into a roll. The temperatures of the preheating rollers and the embossing machine are shown in Table 1, and the properties of the resulting sheet are summarized in Table 2.

[0066] Table 1 .

[0067] Table 2 .

[0068] Comparison Example A Using a generic flash spinning method as described in Examples 9-15 of U.S. Patent No. 6,034,008, such as that of Lim et al. (except that the polymer concentration in the spinning solution is 17% by weight and the spinning temperature is 185ºC), unfinished fibrous nonwoven sheets for further bonding and embossing are produced from a spinning solution containing high-density polyethylene and a n-pentane spinning agent. The polyethylene has a melt flow index of approximately 0.7 g / 10 min at 2.16 kg / 190ºC (as measured by ASTM D1238-13).

[0069] The unfinished fiber nonwoven sheet is then bonded generally using a steam pressure of 66.7 psia, as described in David's U.S. Patent No. 3,532,589. This is a method for producing "hard-structure" nonwoven sheets described in Lim et al.'s U.S. Patent No. 6,034,008. In this method, the nonwoven sheet is then passed over a heated drum, followed by a cooled drum, and then another heated and cooled drum to thermally bond the two sides of the material. The heated drum is held at a temperature that causes partial melting of the nonwoven material to induce bonding of the sheet. The properties of the resulting sheet are summarized in Table 3.

[0070] Table 3 .

[0071] Example 3 Then, using a Multivac R535 device, the resulting nonwoven sheets from Example 1 and Comparative Example A (each having 44 g / m) were processed. 2 The basis weight is used to produce medical packaging. The Multivac R535 device manufactures four packages on a single substrate, each package having a machine direction length of 200 mm, a lateral length of approximately 95 mm, and a seal width of approximately 7.5 mm. Figure 3 As shown in size 5, a nonwoven sheet is attached to the packaging substrate in the sealed contact area using two different bonding film materials. Film 1 is Multifol GA Tyvek®, a 100 µm polyamide / polyethylene peelable film from SüdpackVerpackungen GmbH & Co. KG in Oxenhausen, Germany. Film 2 is Wipak® MLE 135 TF PEEL, a polyethylene / polyamide / polyethylene film from Wipak in Nastola, Finland.

[0072] In all cases, the nonwoven sheet of Example 1 was bonded and the nonwoven surface, embossed with a linen-like pattern, was sealed to the film. All packages were manufactured with a sealing pressure of 6.5 bar and a residence time of 1.2 seconds. The sealing temperature of each film was set at at least two levels – resulting in different seal strengths. The packages were then opened by peeling the nonwoven fabric from the bonding film.

[0073] The sealing temperature and the resulting sealing strength values ​​are given in Table 4. As the sealing temperature increases, the average peak sealing strength and average sealing strength of the individual films increase. Furthermore, at higher sealing strengths, the percentage of fiber tearing in the packaging increases. However, in each case, nonwoven sheets with embossed patterns exhibit improved fiber tearing (peeling) and sealing performance, with the percentage of fiber tearing decreasing from 32% to 73%.

[0074] Table 4 .

[0075] Example 4 and Comparative Example B Using 47 g / m 2 The nonwoven sheet of basis weight was repeated in Example 2 with the same embossed flax-like pattern; however, the unfinished sheet was bonded using the embossing conditions shown in Table 5. The resulting bonded nonwoven sheet had a Glyph porosity of 3.6 seconds.

[0076] For Comparative Example B, the process was repeated using the same basis weight sheet and the temperature conditions shown in Table 5, but without embossing the bottom of the sheet. (The sheet was not clamped in the calendering rolls.) The resulting nonwoven sheet was bonded without any embossing and had a Glyph porosity of 2 seconds.

[0077] Table 5 .

[0078] Then, using an Autovak M320 machine (Hong Kong, China), the resulting nonwoven sheet with an adhesive and embossed linen-patterned surface, and an unembossed adhesive nonwoven sheet, are used to produce medical packaging. This Autovak machine simultaneously produces packaging with a machine-direction length of approximately 190 mm and a transverse length of 127 mm, and a sealing width of 10 mm (e.g., ...). Figure 4Two types of packaging (shown in size 10) were used. A nonwoven sheet was attached to the packaging substrate in the sealing contact area using a 135 µm thick polyamide / polyethylene peelable bonding film (code UGBLGV340C, from Xiangfu (Zhongshan) Film Packaging Co., LTD, 180, Zhongshan 5th Rd, Guangdong, China). The film was preheated in the forming zone. The temperature in the forming zone was 105ºC, and the dwell time was set to 1.0 second. The sealing temperature of all packaging was set to 120ºC. The dwell time was adjusted to vary the resulting packaging seal strength. Sealing time and seal strength are shown in Table 6. The packaging was then opened by peeling the nonwoven sheet from the bonding film. As shown in Table 6, packaging using only bonded but unembossed nonwoven sheets has higher sealing strength characteristics, but exhibits completely unacceptable fiber tearing properties, while packaging using embossed nonwovens has acceptable sealing strength characteristics and excellent fiber tearing (peeling) properties.

[0079] Table 6 .

[0080] Examples 5, 6, and 7 These examples demonstrate that embossing can be applied to the nonwoven sheet as a separate step after bonding. Comparative Example B is repeated using two different nonwoven sheet basis weights, where the nonwoven sheet is bonded but not embossed. The bonded sheet is wound onto a roller. The bonded nonwoven sheet roll is then unwound and embossed on one surface by clamping the sheet with a set of heated calendering rollers, this time providing one surface of the sheet with a embossed pattern. Figure 2 The embossed pattern shown is a dog-bone pattern instead of a linen pattern. The bonding and subsequent embossing conditions are shown in Table 7. The packaging was manufactured using the same bonding film as in Example 4, with the embossed surface in contact with the bonding film. The results are shown in Table 8.

[0081] Table 7 (* - Not measured).

[0082] Table 8 .

[0083] The package is then opened by peeling the nonwoven fabric from the connecting film. As shown in Table 8, the package using the embossed nonwoven fabric exhibits excellent peel performance.

[0084] Example 8 The shielding and mechanical properties of the nonwoven sheet structures with embossed patterns used in Test Examples 1 through 7. All of these inventive sheet structures exhibit an Elmendorf tear strength greater than 2.0 N and a Maren burst strength greater than 500 kPa. Using a TSI 8130 apparatus operating at a flow rate of 2.3 L / min, all inventive sheet structures showed a particle shielding penetration rate of less than 10%. The unembossed side of each nonwoven structure underwent printing in the form of linear barcodes and 2D data matrices, yielding good visual results.

Claims

1. A packaging material for providing a closed internal environment capable of sterilization, the packaging material comprising a breathable fiber nonwoven sheet structure, a polymer bonding layer, and a packaging material base. The nonwoven sheet structure has a first surface and a second surface; The enclosed internal environment is created by sealing the contact area between the first surface of the nonwoven sheet structure and the packaging structure; the sealed contact area is formed by the polymer bonding layer. The first surface of the nonwoven sheet structure has an embossed pattern pre-adheded at least within the sealed contact area, and The second surface of the nonwoven sheet structure has a smooth surface without any embossing.

2. The packaging as claimed in claim 1, wherein, The polymer bonding layer is integral with the packaging substrate.

3. The packaging as claimed in claim 1, wherein, The polymer bonding layer and the packaging substrate are combined in the form of a film.

4. The packaging as described in any one of claims 1 to 3, wherein, The nonwoven sheet structure of this fiber is tufted.

5. The packaging as claimed in claim 4, wherein, The fiber nonwoven sheet structure comprises polyethylene filaments.

6. A fiber nonwoven sheet structure suitable for use in aseptic packaging, the sheet structure being breathable and having a first surface and a second surface; The first surface is bonded with an embossed pattern, and the second surface is printable; The second surface has a smooth surface without any embossing; This sheet structure has a particle shielding penetration rate of less than 10%, a Glysh porosity of 40 seconds or less, and a density of 3500 g / m³. 2 / day or greater wet vapor transport rate.

7. The fiber nonwoven sheet structure as described in claim 6, having a Glysh porosity of 10 seconds or less.

8. The fiber nonwoven sheet structure as described in claim 6 or 7, having a density of 7500 g / m². 2 / day or greater wet vapor transport rate.

9. The fiber nonwoven sheet structure as described in claim 8, having a density of 9000 g / m². 2 / day or greater wet vapor transport rate.

10. The fiber nonwoven sheet structure according to any one of claims 6 to 9, wherein, The sheet structure is filamentous.

11. The fiber nonwoven sheet structure of claim 10, comprising polyethylene filaments.

12. A breathable nonwoven sheet structure with an embossed pattern pre-bonded to the first surface is used to provide packaging with clean peel and very low or no fiber tearing. The packaging material includes the breathable fiber nonwoven sheet structure, the polymer bonding layer, and the packaging material base. The nonwoven sheet structure has a first surface and a second surface; The first surface of the nonwoven sheet structure and the packaging structure form a closed internal environment by sealing the contact area between them, and the sealed contact area is formed by the polymer bonding layer. The second surface of the nonwoven sheet structure has a smooth surface without any embossing.

13. The use as described in claim 12, wherein, The polymer bonding layer is integral with the packaging substrate.

14. The use as described in claim 12, wherein, The polymer bonding layer and the packaging substrate are combined in the form of a film.

15. The use as described in any one of claims 12 to 14, wherein, The nonwoven sheet structure of this fiber is tufted.

16. The use as described in claim 15, wherein, The fiber nonwoven sheet structure comprises polyethylene filaments.

17. A breathable fiber nonwoven sheet structure with an embossed pattern pre-bonded on the first surface is used to provide aseptic packaging with clean peel and very low or no fiber tearing. The nonwoven sheet structure has a first surface and a second surface that can be printed on, and the second surface has a smooth surface without any embossing. This sheet structure has a particle shielding penetration rate of less than 10%, a Glysh porosity of 40 seconds or less, and a density of 3500 g / m³. 2 / day or greater wet vapor transport rate.

18. The use as claimed in claim 17, wherein the fiber nonwoven sheet structure has a Glysh porosity of 10 seconds or less.

19. The use as described in claim 17 or 18, wherein the fiber nonwoven sheet structure has a density of 7500 g / m². 2 / day or greater wet vapor transport rate.

20. The use as described in claim 19, wherein the fiber nonwoven sheet structure has a density of 9000 g / m². 2 / day or greater wet vapor transport rate.

21. The use as claimed in any one of claims 17 to 20, wherein the fiber nonwoven sheet structure is tufted.

22. The use as claimed in claim 21, wherein the fiber nonwoven sheet structure comprises polyethylene filaments.

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