System useful as a sterilization wrap

Abstract

To provide a sterilization wrap and a system for manufacturing and utilizing the sterilization wrap.SOLUTION: A system useful as a sterilization wrap for sterilizing an article is provided. The system comprises an outer layer comprising a thermoplastic material and an inner layer comprising a wet laid nonwoven material comprising 100% cellulosic fibers based on the dry weight of the fibers of the inner layer. The inner layer is absorbent and moisture vapor permeable and is placed in contact with the articles to be sterilized.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present disclosure relates to sterilization wraps and systems / methods for manufacturing and utilizing sterilization wraps, and more particularly to sterilization wraps having an outer layer comprising a thermoplastic material and an inner layer comprising a wet-laid nonwoven material, the outer layer being secured and bonded to the inner layer by at least a first weld area. [Background technology]

[0002] Generally, several sterilization wraps and the like are known, for example, as described in U.S. Patent Application Publication Nos. 2012 / 0227362 and 2018 / 0281344, the entire contents of each of which are incorporated herein by reference. Summary of the Invention [Problem to be solved by the invention]

[0003] There is interest in improved sterilization wraps and related methods of manufacture and use. [Means for solving the problem]

[0004] These and other inefficiencies and opportunities for improvement are addressed and / or overcome by the sterilization wraps, assemblies and methods of the present disclosure.

[0005] BRIEF SUMMARY OF THE DISCLOSURE The present disclosure provides advantageous sterilization wraps and systems / methods for making and utilizing sterilization wraps.

[0006] More particularly, the present disclosure provides an advantageous sterilization wrap having an outer layer comprising a thermoplastic material and an inner layer comprising a wet-laid nonwoven material, the outer layer being secured and joined to the inner layer by at least a first weld area.

[0007] These and other features are illustrated by the figures and detailed description that follow.

[0008] Any combination or permutation of the embodiments is contemplated. Additional advantageous features, functions, and applications of the disclosed sterilization wraps, assemblies, and methods of the present disclosure will become apparent from the following description, particularly when read in conjunction with the accompanying drawings. All references cited in this disclosure are incorporated herein by reference in their entirety.

[0009] BRIEF DESCRIPTION OF THE DRAWINGS The following figures are exemplary embodiments in which like elements are numbered the same:

[0010] Features and aspects of the embodiments are described below with reference to the accompanying drawings, in which elements are not necessarily drawn to scale.

[0011] Exemplary embodiments of the present disclosure are further described with reference to the accompanying drawings. It should be noted that the various features, steps, and feature / step combinations described below and illustrated in the figures can be arranged and organized differently to result in embodiments that still fall within the scope of the present disclosure. Reference is made to the accompanying drawings to assist those skilled in the art in making and using the disclosed sterilization wraps, assemblies, and methods. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a side perspective view of an exemplary sterilization wrap prior to welding in accordance with the present disclosure. [Figure 2] FIG. 2 is a side perspective view of an exemplary sterilization wrap after welding in accordance with the present disclosure. [Figure 3] FIG. 3 is a side cross-sectional view of the sterilization wrap of FIG. [Figure 4] FIG. 4 is a graph demonstrating that an exemplary inner layer comprising a wet-laid nonwoven material according to the present disclosure can dry faster than a layer comprising a spunbond-meltblown-spunbond (SMS) material. DETAILED DESCRIPTION OF THE INVENTION

[0013] The exemplary embodiments disclosed herein are illustrative of the presently disclosed advantageous sterilization wrap and system and methods / techniques. However, it should be understood that the disclosed embodiments are merely exemplary of the present disclosure, which may be embodied in various forms. Accordingly, the details disclosed herein with reference to exemplary sterilization wraps and associated processes / techniques for assembly and use should not be construed as limiting, but merely as a basis for teaching those skilled in the art how to make and use the presently disclosed advantageous sterilization wrap and / or alternative sterilization wraps.

[0014] Disclosed herein are advantageous sterilization wraps and related methods of their manufacture and use.

[0015] The present disclosure provides improved sterilization wraps and improved systems / methods for utilizing and manufacturing sterilization wraps.

[0016] More particularly, the present disclosure provides an advantageous sterilization wrap having an outer layer comprising a thermoplastic material and an inner layer comprising a wet-laid nonwoven material, the outer layer being secured and joined to the inner layer by at least a first weld area.

[0017] In conventional practice, some common materials used in sterilization wraps are (i) spunbond-meltblown-spunbond (SMS) materials, (ii) hydrophobic wet-laid nonwoven materials, and (iii) crepe paper. All three technologies may have inherent advantages / disadvantages in the sterilization process. Traditional nonwovens / papers used in sterilization wrap applications must be inherently water-repellent to meet the barrier standards necessary for proper sterilization and maintaining sterility over time. Water repellency can be achieved primarily through fiber type (e.g., polypropylene) or chemical treatment (e.g., fluorocarbon).

[0018] Sterilization wrap generally has two main product types based on the packaging method: sequential packaging and simultaneous packaging. The majority of the market uses simultaneous packaging. While the market desires simultaneous packaging, simultaneous packaging is generally limited to certain conventional SMS-type wraps due to the limitations of ultrasonic bonding of certain conventional wet-laid and crepe materials.

[0019] Generally, conventional sterilization wrap is a square or rectangular sheet of nonwoven / paper used to encase one or a collection of medical devices to be sterilized according to standard medical practice. Medical device sterilization standards typically require the use of two wraps to meet the sterilization efficacy and barrier protection required for both initial sterilization and maintenance of sterility over time.

[0020] Sterilization wrap can generally be separated into two product offerings based on how the medical device is wrapped in the required two sheets (sequential wrapping and co-wrapping).

[0021] Sequential packaging can be defined as two single sheets of nonwoven / paper that are individually wrapped around the medical device. The device is contained in one wrap, then repeated again with the second sheet. Generally, all three traditional material types of sterilization wrap ((i) (SMS) material, (ii) hydrophobic wet-laid nonwoven material, and (iii) creped paper) can be used in sequential packaging, and can be combined so that the two wraps used in the sterilization system are the same material or two different materials (e.g., wet-laid inner + SMS outer; creped inner + wet-laid outer; SMS inner + creped outer; etc.).

[0022] Co-packaging can be defined as two nonwoven sheets ultrasonically bonded along two edges for convenient wrapping of one or a collection of medical devices to be sterilized according to standard medical practice. The ultrasonically bonded sheets allow the medical devices to be packaged in a single packaging process, as opposed to the two steps of sequential packaging. This can reduce time and error in the sterilization process and can be considered more efficient.

[0023] Due to the fact that co-wrapping typically requires two packaging sheets to be sonically welded, the market primarily utilizes SMS materials, as polypropylene is highly compatible with ultrasonic bonding. Some alternative conventional materials (crepe and wet-laid) may have poor compatibility. Crepe paper is primarily cellulosic and generally has very poor ultrasonic bonding properties. Traditional wet-laid nonwovens, sometimes used in sterilization wrap today, can have moderate ultrasonic bonding capabilities due to their synthetic fiber and binder composition.

[0024] Due to the convenience of co-wrapping and the efficiencies generally associated with its use, the overwhelming majority of sterilization wrap sold today is co-wrap. For example, currently over 90% of the U.S. market is sold as co-wrap, which generally consists primarily of SMS nonwoven products.

[0025] Steam sterilization, one of the most common sterilization methods used in the medical industry, requires moisture to penetrate the sterilization wrap, sterilize the medical device within the wrapped container, and then completely exit the wrapped container. It is typically important that all moisture exit the wrapped environment; therefore, most sterilization standards require a minimum drying time (e.g., 20–30 minutes) to ensure that substantially all moisture is removed. If a medical device is not sterilely packaged and moisture droplets are found (referred to as a wet pack), the medical device is generally considered non-sterile and the sterilization process must be repeated. The presence of wet packs is an expensive and time-consuming problem in the medical industry due to the need for resterilization.

[0026] In general, because conventional layers of wrap are typically hydrophobic / water-repellent, one or more separate absorbent tray liner layers are often utilized in conjunction with sterilization wrap to help improve vapor / moisture dissipation on the exterior of the wrapped system. These tray liners are typically absorbent nonwoven fabrics or paper placed at or directly beneath the tray. Tray liners can efficiently dissipate moisture, drawing vapor away from the medical device and facilitating its removal from the interior of the wrapped container. Tray liners are often an extra step in the process, and therefore, users may accidentally forget to include them in the packaging process, increasing the likelihood of wet packs and resterilization, adding cost and time.

[0027] The present disclosure advantageously provides a two-sheet wrap system in which an absorbent wet-laid nonwoven serves as the inner layer and an antistatic or untreated layer comprising a thermoplastic material (e.g., SMS) serves as the outer layer. In certain embodiments, the cellulosic structure of the wet-laid material provides improved and / or superior moisture absorption and moisture vapor transmission properties, as well as improved and / or superior evaporative drying rates, compared to hydrophilically treated polypropylene SMS materials. While absorbent treatments on polypropylene fibers improve wicking, polypropylene is inherently hydrophobic and absorbent, but not absorbent, and therefore its performance may be limited. Cellulosic fibers can provide excellent wicking performance and can be absorbent (water is absorbed into the cellulosic structure, not just the surface). Compared to hydrophilically treated SMS materials, their capacity and absorbency are superior. Moisture dissipation through the exemplary wet-laid layer is better (see Figure 4, discussed further below). The absorbent and adsorbent properties of the exemplary absorbent wetlaid layer make it superior to absorbent treated SMS, and its water absorption capabilities can allow for the elimination of tray liners in the sterilization process.

[0028] In Figure 4, the graph demonstrates that an exemplary wet-laid layer according to the present disclosure can dry faster than an SMS layer. The three samples used are: (1) a 43 gsm polypropylene-based SMS (a commercially available grade with antistatic treatment and inherently hydrophobic); (2) a 70 gsm polypropylene-based SMS (a commercially available grade with antistatic treatment and inherently hydrophobic); and (3) a 51 gsm exemplary wet-laid without water repellent treatment (no wax or fluorocarbon treatment) with additional Aerosol OT (A-OT) for water absorption.

[0029] Add 0.5g of water to 7.1in of each ingredient. 2 The samples were then dried at 100°C. The water loss rate was measured at different time intervals. The resulting data indicates that the exemplary wet-laid has a faster evaporation rate compared to the SMS sample, and therefore dries at a faster rate. Without wishing to be bound by theory, it is noted that the exemplary wet-laid dries faster because the addition of surfactants aids in moisture wicking (capillary action) and because the cellulose allows for absorption (absorption into the fibers), resulting in a much higher moisture removal capacity in the cellulose. The SMS with its polypropylene fibers provides only surface wet adsorption.

[0030] Some current conventional sterilization wrap materials have some level of water repellency for good barrier performance and sterility. However, this water repellency can reduce the efficiency of moisture dissipation from the packaged device (during / after sterilization), which can lead to wet packs. Previously, absorbent tray liners could be added as an additional (separate) layer or layers, which the customer wraps during end-use, but this can cause inefficiencies and / or risk of error. Alternatively, the normally repellent SMS layer can be treated to become more absorbent, but SMS generally cannot replicate the absorbent properties of cellulosic nonwovens (due to the inherent hydrophobicity of polypropylene fibers).

[0031] The present disclosure advantageously provides a sterilization wrap in which the inner layer provides hygroscopic properties in addition to sterile barrier properties. In certain embodiments, the sterilization wrap of the present disclosure uses a wet-laid material as the inner layer of the wrap to provide the necessary absorbency for the wrap.

[0032] As noted above, co-wrapping systems are a preferred type of sterilization wrap by customers. It should be noted that products for co-wrapping may require sonic bonding between the inner and outer layers (e.g., along two edges of the sheets). While sonic bonding is generally not a typical issue between typical SMS / SMS configurations, adequate sonic bonding is typically less feasible for combining conventional SMS / wet-laid sheets. The present disclosure advantageously provides a wet-laid layer with enhanced ultrasonic bonding capabilities to more easily provide an ultrasonically bonded two-sheet thermoplastic (e.g., SMS) / wet-laid sterilization wrap for use in co-wrapping (e.g., for using a wet-laid inner layer with a specific synthetic binder and fiber content, as discussed further below).

[0033] This advantageous hybrid two-sheet packaging system of absorbent wet-laid nonwoven material + thermoplastic material (SMS) layer can advantageously achieve at least the following: (1) improved commercial robustness and viability of ultrasonically bonded simultaneous wrap systems that include wet-laid as at least one layer; (2) allowing users to eliminate tray liners in the sterilization process, increasing the convenience and efficiency of the overall sterilization system; (3) faster dry times in steam sterilization cycles, reducing sterilization process costs and turnaround time - also reducing the need for wet pack generation and resterilization; (4) maintaining necessary strength and barrier property requirements.

[0034] Referring now to the drawings, wherein like parts are designated with the same respective reference numerals throughout the specification and drawings, the drawings are not necessarily to scale and in certain figures parts may be exaggerated for clarity.

[0035] As shown in Figure 1, a side perspective view of an exemplary sterilization wrap 10 is shown prior to welding. Generally, as discussed further below, the exemplary sterilization wrap 10 comprises an outer layer 12 comprising a thermoplastic material and an inner layer 14 comprising a wet-laid nonwoven material, with the outer layer 12 secured and joined to the inner layer 14 by at least a first weld area 16A (Figures 2 and 3).

[0036] Figure 2 shows a side perspective view of an exemplary sterilization wrap 10 after welding. Figure 3 shows a side cross-sectional view of an exemplary sterilization wrap 10 after welding.

[0037] The present invention further provides a method for manufacturing a sterilization wrap 10, the method including providing an outer layer 12 comprising a thermoplastic material, providing an inner layer 14 comprising a wet-laid nonwoven material, and securing and joining the outer layer 12 to the inner layer 14 by at least a first weld area 16A.

[0038] In the exemplary embodiment, the outer layer 12 is secured and joined to the inner layer 14 by at least a first weld area 16A and at least a second weld area 16B. Generally, the weld areas 16A, 16B provide a weld or bond area 16A, 16B through the outer layer 12 and the inner layer 14.

[0039] In some embodiments, the welded regions 16A, 16B are ultrasonically welded regions (e.g., ultrasonic welds or bonded regions 16A, 16B through the outer layer 12 and the inner layer 14), although the present disclosure is not limited thereto. It should be noted that other welding techniques and methods can be utilized to securely bond the outer layer 12 to the inner layer 14.

[0040] Each welded region 16A, 16B can include at least one continuous and / or discontinuous weld line and / or weld spot, hi some embodiments, each welded region 16A, 16B includes multiple continuous and / or discontinuous weld lines and / or weld spots.

[0041] It should be noted that various weld lines and / or weld spots may be utilized at various locations and / or along the outer layer 12 and the inner layer 14 to secure and bond the outer layer 12 to the inner layer 14 by at least one weld region 16A (and / or 16B). It should be noted that, generally, the outer layer 12 and the inner layer 14 each do not include added adhesive material after being secured and bonded to one another. Stated differently, the outer layer 12 and the inner layer 14 may be assembled (secured and bonded to one another) without the use of additional adhesive material (but with a binder present in the inner layer 14). For example, layers 12, 14 can be assembled / secured together (with a binder present in inner layer 14) without the use of additional adhesive materials, such as, for example, glues, tapes, webs, sprays, foams utilizing hot melt adhesives, pressure sensitive adhesives, curable adhesives (e.g., polyurethanes, etc.), non-binder / dispersion type materials, etc., which can take the form of thermoplastic adhesives (e.g., ethyl vinyl acetate, ethylene-vinyl alcohol copolymers, and ionomers), or other conventional industrial adhesive chemistries.

[0042] For example, the outer layer 12 may be secured and joined to the inner layer 14 by at least a first weld area 16A along a first edge 18 of the outer layer 12 and the inner layer 14 .

[0043] As shown in FIG. 2, the outer layer 12 can be secured and joined to the inner layer 14 by at least a second weld area 16B along a second edge 20 of the outer layer 12 and the inner layer 14.

[0044] It should be noted that weld regions 16A and / or 16B (or additional weld regions 16) may be located along edges 22 and / or 24 of outer layer 12 and inner layer 14. Again, it should be noted that various weld lines and / or weld spots may be utilized at various locations and / or along positions of outer layer 12 and inner layer 14 to secure and join outer layer 12 to inner layer 14 by at least one weld region 16A (and / or 16B).

[0045] In exemplary embodiments, outer layer 12 is secured and directly bonded to inner layer 12 by at least first weld area 16 A. In some embodiments, outer layer 12 is secured and bonded only to inner layer 14 by at least first weld area 16 A.

[0046] In some embodiments, the outer layer 12 defines a thickness of thermoplastic material and the inner layer 14 defines a thickness of wet-laid nonwoven material, and the outer layer 12 is not secured or joined to another layer or thickness of material after the outer layer 12 is secured and joined to the inner layer 14 by at least the first weld region 16A.

[0047] In certain embodiments, the outer layer 12, secured and bonded to the inner layer 14 by at least the first weld area 16A, has a bond strength of 80 cN / 15 mm or greater, preferably 100 cN / 15 mm or greater, according to standard method ASTM F88.

[0048] In an exemplary embodiment, outer layer 12 comprises a nonwoven meltblown material, preferably outer layer 12 comprises meltblown synthetic fibers, more preferably outer layer 12 comprises spunbond-meltblown-spunbond (SMS) synthetic fibers, and even more preferably outer layer 12 comprises SMS polyolefin fibers, such as SMS polypropylene fibers.

[0049] Generally, exemplary outer layer 12 has a basis weight of about 35 grams per square meter (gsm) to about 85 gsm and is optionally treated with an antistatic composition. Outer layer 14 can contribute to the bacterial barrier properties of wrap 10.

[0050] In an exemplary embodiment, the inner layer 14 has a basis weight of from about 35 grams per square meter (gsm) to about 85 gsm.

[0051] An exemplary inner layer 14 is absorbent and breathable. In certain embodiments, the wet-laid nonwoven material of the inner layer 14 comprises cellulosic fibers, synthetic fibers, a binder, and optionally a surfactant.

[0052] Generally, inner layer 14 comprises cellulose fibers in an amount of 40% to 100% by weight based on the dry weight of the fibers in inner layer 14, and preferably 60% to 85% by weight based on the dry weight of the fibers in inner layer 14.

[0053] The cellulose fibers of the inner layer can include at least one of hardwood pulp fibers, softwood pulp fibers, annual plant fibers, or cotton fibers. The inner layer 14 can include at least one of mercerized and non-mercerized cellulose fibers, or a combination thereof. The fibers can be mercerized and / or non-mercerized cellulose fibers. Mercerization adds extra bulk to the fibers to increase absorption.

[0054] In some embodiments, the wet-laid nonwoven material of the inner layer 14 is Micrex or microcreped (e.g., Micrex or microcreping the wet-laid nonwoven material of the inner layer 14). The wet-laid is optionally, but preferably, Micrexed, which aids in drapeability, softness, barrier properties, and absorbent capacity.

[0055] In some embodiments, the inner layer 14 comprises synthetic fibers, preferably polyester staple fibers, more preferably polyethylene terephthalate (PET) fibers. In certain embodiments, the inner layer 14 comprises man-made cellulosic fibers (e.g., lyocell or rayon).

[0056] For example, inner layer 14 may contain 5% to 60% synthetic fibers by weight, preferably 15% to 30%, based on the dry weight of the fibers in inner layer 14, including any synthetic binder fibers, if present.

[0057] In an exemplary embodiment, inner layer 14 includes a binder, which includes an acrylic dispersion with acrylonitrile, preferably at least one of anionic acrylate-styrene and / or anionic acrylate-styrene-acrylonitrile.

[0058] For example, the inner layer 14 may include the binder in an amount of 15 to 40 weight percent, preferably 15 to 30 weight percent, more preferably 18 to 28 weight percent, and even more preferably 20 to 25 weight percent, based on the total dry weight of the inner layer 14.

[0059] In some embodiments, inner layer 14 comprises a surfactant, preferably an anionic surfactant, such as ammonium lauryl sulfate, sodium laureth sulfate, sodium lauryl sarcosinate, sodium myreth sulfate, sodium pareth sulfate, sodium stearate, sodium lauryl sulfate, alpha olefin sulfonate, and ammonium laureth sulfate, more preferably sodium bis(2-ethyl-1-hexyl) sulfosuccinate.

[0060] For example, inner layer 14 may include surfactant in an amount of 0.5 to 5%, preferably 1 to 3%, and more preferably 1 to 2% of the binder mixture.

[0061] Table 1 below provides a summary of exemplary components / ingredients and exemplary amounts of the components / ingredients of the wet-laid nonwoven material of the inner layer 14.

[0062] Generally, the total basis weight of the sterilization wrap 10 can be from about 70 grams per square meter (gsm) to about 170 gsm.

[0063] The exemplary sterilization wrap 10 is suitable for use to sterilize medical devices utilizing simultaneous wrapping techniques during the sterilization process. The exemplary sterilization wrap 10 is suitable for use to sterilize medical devices without utilizing an additional tray liner during the sterilization process.

[0064] Generally, the sterilization wrap 10 is permeable to a sterilizing agent, such as steam. Exemplary sterilization wraps 10 exhibit microbial barrier properties and / or are impermeable to bacteria. In certain embodiments, the sterilization wrap 10 meets the requirements of European Standard EN 868 Part 2 as a sterile barrier system. In some embodiments, the sterilization wrap 10 meets the requirements of International Standard ISO 11607 Part 1 as a sterile barrier system.

[0065] Thus, as described above, the present disclosure advantageously provides a two-ply sheet wrap 10 or wrap system 10 in which an absorbent wet-laid nonwoven layer 14 serves as the inner layer 14 and an antistatic or untreated layer 12 comprising a thermoplastic material (e.g., SMS) serves as the outer layer 12. The cellulosic structure of the wet-laid material 14 provides improved and / or superior moisture absorption and vapor transmission properties, as well as improved and / or superior evaporative drying rates, over hydrophilically treated polypropylene SMS materials. Cellulosic fibers can provide superior wicking performance and can be absorbent. The absorbent and adsorbent properties of the exemplary absorbent wet-laid layer 14 make it superior to absorbent-treated SMS, and its moisture absorption capabilities can enable the elimination of tray liners during the sterilization process.

[0066] The present disclosure also advantageously provides a sterilization wrap 10 in which the inner layer 14 provides hygroscopic properties in addition to sterile barrier properties. The sterilization wrap 10 of the present disclosure uses a wet-laid material 14 as the inner layer 14 of the wrap 10 to provide the necessary absorbency for the wrap 10.

[0067] The present disclosure also advantageously provides a wet-laid layer 14 with enhanced ultrasonic bonding capabilities to render the ultrasonically bonded two-sheet thermoplastic material 12 (e.g., SMS) / wet-laid sterilization wrap 10 more readily suitable for use in co-packaging (e.g., for use with a wet-laid inner layer 14 having a particular synthetic binder and fiber content, as described above).

[0068] This advantageous hybrid two-sheet wrap 10 and packaging system of absorbent wet-laid nonwoven material 14 + thermoplastic material (e.g., SMS) layer 12 can advantageously achieve at least the following: (1) improved commercial robustness and viability of ultrasonically bonded simultaneous wraps 10 and wrap systems including wet-laid as at least one layer 14; (2) allowing users to eliminate tray liners in the sterilization process, increasing the convenience and efficiency of the overall sterilization system; (3) faster dry times in steam sterilization cycles, reducing sterilization process costs and turnaround time - also reducing the need for wet pack generation and resterilization; and (4) maintaining the necessary strength and barrier property requirements of the wrap 10.

[0069] The present disclosure advantageously provides a sterilization wrap 10 including two layers 12, 14 that can be joined along two edges 18, 20 to provide a wrap 10 or wrap system 10 suitable for use in simultaneous wrapping techniques. The exemplary inner layer 14 of the wrap / system 10 exhibits hygroscopic properties, improving the rate of moisture loss (drying rate) during a steam sterilization cycle and thereby reducing the prevalence of wet pack formation. The inner layer 14 that provides this absorbency can include a wet-laid nonwoven material. The outer layer 12 of the wrap / system 10 provides the necessary strength characteristics for the wrap 10 and can include a polyolefin SMS nonwoven, or the like. The layers 12, 14 can be joined together along one or more edges 18, 20 of the wrap / system 10 by ultrasonic bonding, or the like, which is made possible by the use of an improved wet-laid nonwoven material for the inner layer 14.

[0070] The present disclosure is further illustrated by the following non-limiting examples. [Example]

[0071] Different binder polymers were tested.

[0072] To improve moisture absorption / breathability, the samples were not treated with water repellent treatments such as wax and fluorocarbon treatments. Sample 4, a cellulose wetlaid containing only Hycar 26430x6 binder, served as a reference.

[0073] Samples according to the present disclosure were optimized for a combination of strength, softness / flexibility, and absorbency properties.

[0074] Desirably, a cellulose wetlaid has suitable mechanical properties, is as soft as possible, and is also highly absorbent, however these properties can interact in many ways.

[0075] The samples had the following base web formulation: 75% by weight of total fibers Northern Bleached Softwood Kraft (NBSK) pulp; 25% by weight of total fiber: Teijin PET stabilized fiber (1.7 dtex and 15 mm).

[0076] Samples 1, 1.1, 1.2, 1.3 and 1.4 contained the base web formulation described above and contained varying amounts of the binder Acronal S728, commercially available from BASF, and the surfactant Aerosol OT-75, commercially available from Solvay.

[0077] Samples 2, 2.1, 2.2, 2.3 and 2.4 contained the above web formulation and contained various amounts of binder Acronal S504 and surfactant Aerosol OT-75, commercially available from BASF.

[0078] Sample 3 contained the above web formulation and a mixture of equal amounts of Acronal S728 and S504 and Aerosol OT-75.

[0079] Sample 4 contained the base web formulation described above and contained Hycar 26430x6 binder, and Sample 4.1 contained the base web formulation described above and surfactant Aerosol OT-75.

[0080] Comparative Examples 2.1 and 2.2 are 70 and 43 g / m, respectively. 2 The prior art polypropylene-based SMS was

[0081] [Table 1]

[0082] The addition of A-OT can be a great help in some ways, but a pain in others. In the positive case, it significantly improves absorption properties. In the negative case, the aggressive nature of anionic surfactants tends to penetrate deeply into fibers (especially cellulosic) affecting fiber integrity. It can reduce the wet tensile strength / durability of nonwovens. As shown in Table 2 below, adding A-OT resulted in a decrease in strength.

[0083] The glass transition temperature (Tg) of the binder can also be important for imparting flexibility for a more efficient / productive packaging process for equipment trays. It can also affect ultrasonic bonding performance. Acronal S 504 has a Tg of 4°C, and Acronal S 728 has a Tg of 23°C.

[0084] The lower the Tg of the binder, the softer the nonwoven fabric tends to be.

[0085] Also, a lower Tg makes the binder more heat treatable, which can improve welding performance, especially ultrasonic bonding properties.

[0086] However, polymers with low Tg often have poor strength properties, especially dry strength.

[0087] Note that acrylonitrile is often added to the polymer backbone to impart toughness, which is important considering these binder systems are not self-crosslinking, so moisture / chemical resistance must come from the polymer backbone.

[0088] Acrylonitrile-based copolymers are known to be more robust, especially in terms of chemical resistance. They can be useful in applications where solvent resistance is required.

[0089] The inventors have realized that the use of a binder containing acrylonitrile can offset the aggressive nature of A-OT in the formulation, allowing the nonwoven to maintain adequate strength properties in terms of both dry strength and wet strength.

[0090] Also, the acrylonitrile is not such a large component of the polymer backbone that it adversely affects the acoustic bonding, and the benefits of the very soft thermoplastic butyl acrylate backbone are still obtained.

[0091] [Table 2]

[0092] [Table 3]

[0093] [Table 4]

[0094] Comments on Tables 2 and 3: To minimize wet pack formation and improve drying time of the sterilization wrap, wax and fluorocarbon treatments were removed, resulting in improved water absorption.

[0095] The water absorption achieved with Hycar 26430x6 was not entirely satisfactory, so different binder compositions were tested to further improve the water absorption.

[0096] The wetlaid properties used to evaluate the performance of binders in cellulosic wetlaid were: strength / durability; softness / flexibility; absorbency / breathability.

[0097] To further improve the water absorption of the wet-laid media, additional surfactants were added. However, the addition of surfactants had a detrimental effect on certain mechanical properties of the wet-laid media, particularly wet tensile strength. The different mechanical properties shown in Table 2 were measured according to the test methods described in the "Test Methods" section below. The addition of surfactants reduced the wet tensile strength of all samples. However, the effect was somewhat more moderate for samples containing Acronal S 504 binder.

[0098] This binder is believed to be less susceptible because Acronal S 504 has acrylonitrile added to the polymer backbone, which confers a degree of chemical resistance that offsets the aggressive nature of the surfactants added to the binder.

[0099] For sterilization wraps, among the different mechanical properties measured, wet tensile strength may be important since the preferred sterilization method is steam sterilization. The other mechanical properties are less affected by the addition of surfactants and show some variation, but remain at an acceptable level.

[0100] Comments on Table 3: As mentioned above, one of the important properties for selecting a binder was water absorption and moisture permeability. To evaluate these properties, water absorption capacity and water droplet values ​​were measured (test method described below). The improvement in absorption rate was derived from the water droplet measurement using Sample 4 as a reference.

[0101] This data indicates that Acronal S 504 does not actually improve absorption properties when used alone. However, Acronal S 728 appears to have inherent water absorption properties. Introducing surfactants into the binders of samples containing Acronal S 504 and Acronal S 728 substantially improved absorption properties. The surfactants had very limited effect on Sample 4.1, which contained Hycar 26430x6.

[0102] As mentioned above, Acronal S 728 appears to have better water absorption, but surfactants appear to affect the wet strength properties of wet-laid media containing Acronal S 728 binder more than wet-laid media containing Acronal S 504 binder.

[0103] Comments on Table 4: To evaluate the bonding performance of the samples, each sample was heat sealed independently and measured to ASTM Bond strength tests were performed according to the test protocol described in F88.

[0104] All samples tested demonstrated relatively good bond strength performance. This data indicates that for wet-laid media, the optimum binder content may be 15-30% by weight, preferably 18-28% by weight. If the binder amount is too low, there is not enough material to achieve an acceptable level of bonding. If the binder amount is too high, the fiber contribution to bonding tends to decrease, thus reducing the overall bond strength of the wet-laid media.

[0105] Ultrasonic welding by SMS Based on these initial findings, exemplary recipes were further tested for ultrasonic bonding performance, including the following recipes:

[0106] Main ingredient: NBSK pulp 75% by weight, Teijin PET stabilized fiber (1.7detx, 15mm) 25% by weight (% by weight of total fiber).

[0107] Binder mixture: 97% Acronal S 504, 2% by weight Aerosol OT, 1% by weight green pigment (for optional coloring) and ammonia used to adjust the pH to 8. The binder mixture accounted for 22% by weight of the total dry weight of the wet laid.

[0108] Different samples with different basis weights were prepared and assembled into polypropylene-based SMS layers using ultrasonic bonding. The ultrasonic bonding parameters for the Aurizon instrument were 4.5 mm width, 0.015 in x 0.015 in depth, and 100% amplitude, with operating speeds of 100-350 fpm, using a knurled pattern anvil with a pressure setting of 55 psi for the double pattern anvil and 35 psi for the single anvil.

[0109] The samples were prepared as follows: (1) Sample X1.1 => 43gsm SMS blue outside / 37gsm wet-laid green inside; (2) Sample X1.2 => 43gsm SMS blue outside / 46gsm wet-laid green inside; (3) Sample X1.3 => 70gsm SMS blue outside / 63gsm wet-laid green inside.

[0110] The bond strength between the wet-laid layer and the SMS layer of Samples X1.1 and X1.3 was measured according to standard method ASTM F88. The bond strengths of Samples X1.1 and X1.3 were 232 cN / 15 mm and 237 cN / 15 mm, respectively.

[0111] Advantageously and surprisingly, it has been found possible to adhere a wet laid layer to an SMS layer with a bond strength of 100 CN / 15 mm or greater.

[0112] [Table 5]

[0113] In Table 2, the X values ​​are derived from the MD and CD measurements as follows: (1) X grab tensile = square root (MD grab tensile * CD grab tensile); (2) X wet tensile = square root (MD wet tensile * CD wet tensile); (3) X trap tear = square root (MD trap tear * CD trap tear).

[0114] In Table 3, sample 4 was used as a reference and water drop measurements were used to calculate the improvement in absorption rate.

[0115] Drying Time Validation Study: Pre-vacuum Steam: Dry time testing was completed for the following sterilization wrap design conditions: (1) Sample X1.4 => 43gsm SMS blue exterior / 40gsm wet-laid green interior; (2) Sample X1.5 => 70gsm SMS blue exterior / 62gsm wet-laid green interior.

[0116] Pre-vacuum steam sterilization requires that medical instrument trays and all accessories be completely free of moisture after sterilization. Moisture can provide a vector for microorganisms to enter a closed containment system and potentially contaminate the contents within that enclosed system. There are many variables that can cause moisture to be retained in a sterile containment system, and establishing the time required to completely dry wrapped medical instrument trays is important to minimize the risk of developing a "wet pack" after the sterilization process. A wet pack is an industry-understood term for the presence of moisture within a wrapped instrument tray, which voids the sterility of the items found within the tray.

[0117] Samples X1.4 and X1.5 were tested using a standard drying time test commonly available at commercial sterilization validation laboratories, such as Highpower Laboratories or Nelson Laboratories. This study determines the appropriate drying time for sterilization wraps when processed in a steam pre-vacuum sterilization cycle. Instrument trays are loaded with simulated medical devices to a predetermined weight, processed in a steam pre-vacuum cycle at 132°C for 4 minutes, and allowed to dry for a predetermined period. After the cycle is complete, the instrument trays are reweighed and evaluated by comparing the pre- and post-sterilization weights. Additionally, the instrument trays, contents, and sterilization wraps are visually evaluated for moisture retention. A common component found inside wrapped systems is the inclusion of a tray liner, i.e., an absorbent sheet placed at or directly beneath the instrument tray. The tray liner acts as an absorbent extension of the overall system, increasing the system's moisture vapor transmission characteristics and improving drying performance (and reducing instances of wet packs). For Samples X1.4 and X1.5, a tray liner was not included in the wrap system.

[0118] The results of the drying time study were as follows:

[0119] Sample X1.4 was tested for a 12 minute dry time using a 9 lb tray machine without a tray liner. For comparison, a commercially available simultaneous wrap (two polypropylene-based SMS, 50 gsm each) had a verified dry time of 20 minutes on a similar 9 lb tray machine with a tray liner. With the same machine weight, the dry time was reduced by 40% without a tray liner.

[0120] Sample X1.5 was tested over a 20 minute dry time using a 25 lb tray machine without a tray liner. For comparison, a commercially available simultaneous wrap (two polypropylene-based SMS, each 85 gsm) had a verified dry time of 30 minutes on a similar 24 lb tray machine with a tray liner. With the same machine weight, the dry time was reduced by 33% without a tray liner.

[0121] Barrier property test: Barrier Test No. 1: Pre-vacuum Steam Sterilization Validation by Half-Cycle Study: Samples X1.4 and X1.5 were tested for barrier property performance using a half-cycle sterilization validation test utilizing the newly validated drying time described above. Half-cycle sterilization validation is a commonly available study at commercially available sterilization validation laboratories, such as Highpower Laboratories or Nelson Laboratories. The purpose of this study was to determine the sterilization effectiveness of sterilization wraps loaded with simulated medical devices inoculated with a minimal amount of biological spores that would be difficult to sterilize in the location of the medical device and then subjected to a pre-vacuum sterilization cycle for half the intended exposure time. The test simulates a worst-case sterilization environment, providing a high probability of barrier performance if the sterilization wrap is found to eradicate the biological spores under the test conditions. In this study, the temperature remained the same (132°C), but the exposure time was reduced from 4 minutes to 2 minutes. The results of the half-cycle test were as follows: Sample X1.4 Pre-Vac steam conditions (132°C, 2 minutes exposure time) 50% shorter exposure time Drying time (12 minutes) Equipment Tray Weight: 9 lb Test Results: All biological indicator test samples were negative for growth and all inoculated biological spores were killed. Sample x1.5 Pre-Vac steam conditions (132°C, 2 minutes exposure time) 50% shorter exposure time Drying time (20 minutes) Equipment Tray Weight: 25 lb Test Results: All biological indicator test samples were negative for growth and all inoculated biological spores were killed.

[0122] This study demonstrated that both high and low basis weight versions of the exemplary wrap had effective sterilization efficacy with reduced drying times.

[0123] Barrier Test No. 2: Microbial Aerosol Provocation Test: Samples X1.4 and X1.5 were also tested for additional barrier property performance using a microbial aerosol challenge test. This is an industry-accepted test performed by commercially available sterilization validation laboratories, such as Highpower Laboratories or Nelson Laboratories. The test was designed to determine the ability of the sterilization wrap to maintain the integrity of the sterile packaging after an aerosol challenge with biological spores. Wrapped medical device trays were prepared using Samples X1.4 and X1.5 at each desired device tray weight. The wrapped trays were then subjected to a standard steam pre-vacuum cycle at 132°C with a 4-minute exposure and drying time specific to the sample. After the pre-vacuum sterilization process was completed, the wrapped device tray system was showered with an aerosol concentration of biological spores to challenge the permeability of the wrap to microorganisms. After the 30-minute aerosol challenge, the package was aseptically opened, and the contents were tested for the presence of biologicals. The results of the half-cycle test were as follows: Sample X1.4 Pre-Vac steam conditions (132°C, 4 minutes exposure time) Drying time (12 minutes) Equipment Tray Weight: 9 lb Test result: Pass Sample x1.5 Pre-Vac steam conditions (132°C, 2 minutes exposure time) 50% shorter exposure time Drying time (20 minutes) Equipment Tray Weight: 25 lb Test result: Pass

[0124] [Table 6]

[0125] The present disclosure further encompasses the following aspects.

[0126] Aspect 1. A sterilization wrap comprising an outer layer comprising a thermoplastic material and an inner layer comprising a wet-laid nonwoven material, the outer layer being secured and joined to the inner layer by at least a first weld area.

[0127] Aspect 2. The sterilization wrap of Aspect 1, wherein the outer layer is directly secured and directly joined to the inner layer by at least the first weld area.

[0128] Aspect 3. The sterilization wrap of any one of the preceding aspects, wherein the outer layer defines a thickness of thermoplastic material and the inner layer defines a thickness of wet-laid nonwoven material, and the outer layer is not secured or joined to another layer or thickness of material after the outer layer is secured and joined to the inner layer by at least the first weld area.

[0129] Aspect 4. The sterilization wrap of any one of the preceding aspects, wherein the outer layer is secured and joined to the inner layer by at least the first weld area along a first edge of the outer layer and the inner layer.

[0130] Aspect 5. The sterilization wrap of aspect 4, wherein the outer layer is secured and joined to the inner layer by at least a second weld area along a second edge of the outer layer and the inner layer.

[0131] Embodiment 6. The sterilization wrap of any one of the preceding embodiments, wherein the outer layer and the inner layer each do not include an added adhesive material.

[0132] Aspect 7. The sterilization wrap of any one of the preceding aspects, wherein the outer layer comprises a nonwoven meltblown material, preferably, the outer layer comprises meltblown synthetic fibers, more preferably, the outer layer comprises spunbond-meltblown-spunbond (SMS) synthetic fibers, and even more preferably, the outer layer comprises SMS polyolefin fibers, such as SMS polypropylene fibers.

[0133] Aspect 8. The sterilization wrap of any one of the preceding aspects, wherein at least one of the first welded area or the second welded area is an ultrasonic welded area.

[0134] Aspect 9. The sterilization wrap of any one of the preceding aspects, wherein the sterilization wrap is suitable for use to sterilize a medical device utilizing simultaneous wrapping techniques during a sterilization process.

[0135] Aspect 10. The sterilization wrap of any one of the preceding aspects, wherein the sterilization wrap is suitable for use to sterilize medical devices without utilizing an additional tray liner during the sterilization process.

[0136] Embodiment 11. The sterilization wrap of any one of the preceding embodiments, wherein the wet-laid nonwoven material comprises cellulosic fibers, synthetic fibers, a binder, and optionally a surfactant.

[0137] Aspect 12. The sterilization wrap of any one of the preceding aspects, wherein the sterilization wrap has a total basis weight of about 70 grams per square meter (gsm) to about 170 gsm.

[0138] Embodiment 13. The sterilization wrap of any one of the preceding embodiments, wherein the inner layer is absorbent and moisture-permeable.

[0139] Aspect 14. The sterilization wrap of any one of the preceding aspects, wherein the sterilization wrap is permeable to a sterilant, such as steam.

[0140] Aspect 15. The sterilization wrap of any one of the preceding aspects, wherein the sterilization wrap exhibits microbial barrier properties and is impermeable to bacteria.

[0141] Aspect 16. The sterilization wrap of any one of the preceding aspects, wherein the sterilization wrap meets the requirements of European Standard EN 868 Part 2 as a sterile barrier system.

[0142] Aspect 17. The sterilization wrap is a sterile barrier system that complies with the international standard ISO 11607 10. The sterilization wrap of any one of the preceding aspects, which meets the requirements of Part 1.

[0143] Aspect 18. The sterilization wrap of any one of the preceding aspects, wherein the outer layer has a basis weight of about 35 grams per square meter (gsm) to about 85 gsm, and / or the inner layer has a basis weight of about 35 grams per square meter (gsm) to about 85 gsm.

[0144] Aspect 19. The sterilization wrap of any one of the preceding aspects, wherein the inner layer comprises cellulose fibers in an amount of 40% to 100% by weight, based on the dry weight of the fibers in the inner layer, preferably 60% to 85% by weight, based on the dry weight of the fibers in the inner layer, and the cellulose fibers comprise at least one of hardwood fibers, softwood fibers, annual plant fibers, or cotton fibers.

[0145] Aspect 20. The sterilization wrap of any one of the preceding aspects, wherein the inner layer comprises at least one of mercerized or non-mercerized cellulose fibers, or a combination thereof.

[0146] Aspect 21. The sterilization wrap of any one of the preceding aspects, wherein the inner layer is Micrex or Microcreped.

[0147] Aspect 22. The sterilization wrap of any one of the preceding aspects, wherein the inner layer comprises synthetic fibers, preferably polyester staple fibers, more preferably polyethylene terephthalate (PET) fibers, and wherein the inner layer comprises synthetic fibers in an amount of 5% to 60% by weight, preferably 15% to 30%, based on the dry weight of the fibers in the inner layer, and wherein optional synthetic binder fibers, if present, are included in this percentage.

[0148] Aspect 23. The sterilization wrap of any one of the preceding aspects, wherein the inner layer comprises a binder, preferably at least one of anionic acrylate-styrene and / or anionic acrylate-styrene-acrylonitrile, and more preferably the binder comprises an acrylic dispersion with acrylonitrile.

[0149] Aspect 24. The sterilization wrap of any one of the preceding aspects, wherein the inner layer comprises a binder in an amount, expressed as a weight percentage based on the total dry weight of the inner layer, of 15% to 40% by weight, preferably 15 to 30% by weight, more preferably 18 to 28% by weight, and even more preferably 20 to 25% by weight.

[0150] Aspect 25. The sterilization wrap of any one of the preceding aspects, wherein the inner layer comprises a surfactant, the surfactant comprising an anionic surfactant, preferably ammonium lauryl sulfate, sodium laureth sulfate, sodium lauryl sarcosinate, sodium myreth sulfate, sodium pareth sulfate, sodium stearate, sodium lauryl sulfate, alpha olefin sulfonate, and ammonium laureth sulfate, more preferably sodium bis(2-ethyl-1-hexyl) sulfosuccinate, and the inner layer comprises the surfactant in an amount of 0.5-5%, preferably 1-3%, and more preferably 1-2% of the binder mixture.

[0151] Aspect 26. The sterilization wrap of any one of the preceding aspects, wherein the outer layer secured and joined to the inner layer by at least the first weld region has a bond strength of 80 cN / 15 mm or greater, preferably 100 cN / 15 mm or greater, according to standard method ASTM F88.

[0152] Aspect 27. The sterilization wrap of any one of the preceding aspects, wherein at least one of the first welded area or the second welded area comprises a plurality of continuous and / or discontinuous weld lines and / or weld spots.

[0153] Aspect 28. The sterilization wrap of any one of the preceding aspects, wherein the outer layer is treated with an antistatic composition.

[0154] Aspect 29. A method for manufacturing a sterilization wrap, comprising: providing an outer layer comprising a thermoplastic material; providing an inner layer comprising a wet-laid nonwoven material; and securing and joining the outer layer to the inner layer by at least a first weld area.

[0155] Aspect 30. The method of aspect 29, wherein the outer layer is directly secured and directly joined to the inner layer by at least the first weld region.

[0156] Aspect 31. The method of any one of Aspects 29 or 30, wherein the outer layer defines a thickness of thermoplastic material, the inner layer defines a thickness of wet-laid nonwoven material, and the outer layer is not secured or joined to another layer or thickness of material after the outer layer is secured and joined to the inner layer by at least the first weld region.

[0157] Aspect 32. The method of any one of aspects 29 to 31, further comprising fixing and joining the outer layer to the inner layer by at least the first welding area and at least a second welding area, wherein the outer layer is fixed and joined to the inner layer by at least the first welding area along a first edge of the outer layer and the inner layer, and the outer layer is fixed and joined to the inner layer by at least the second welding area along a second edge of the outer layer and the inner layer.

[0158] Aspect 33. The method of any one of Aspects 29 to 32, wherein the outer layer and the inner layer each do not contain an added adhesive material.

[0159]

[0039] Aspect 34. The method of any one of Aspects 29-33, wherein the outer layer comprises a nonwoven meltblown material, preferably, the outer layer comprises meltblown synthetic fibers, more preferably, the outer layer comprises spunbond-meltblown-spunbond (SMS) synthetic fibers, and even more preferably, the outer layer comprises SMS polyolefin fibers, such as SMS polypropylene fibers.

[0160] Aspect 35. The method of any one of aspects 29 to 34, wherein at least one of the first welded area or the second welded area is an ultrasonic weld.

[0161] Aspect 36. The method of any one of aspects 29 to 35, further comprising utilizing the sterilization wrap to sterilize a medical device via a simultaneous wrapping technique and without utilizing an additional tray liner during the sterilization process.

[0162] Embodiment 37. The method of any one of embodiments 29-36, wherein the wet-laid nonwoven material comprises cellulose, synthetic fibers, a binder, and optionally a surfactant.

[0163] Aspect 38. The method of any one of aspects 29 to 37, wherein the outer layer, fixed and joined to the inner layer by at least the first weld region, has a bond strength of 80 cN / 15 mm or more, preferably 100 cN / 15 mm or more, according to standard method ASTM F88.

[0164] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are presently unforeseen or may be unforeseeable may occur to applicant or others skilled in the art. Accordingly, the appended claims as filed, and the appended claims as they may be amended, are intended to cover all such alternatives, modifications, improvements, and substantial equivalents.

[0165] All ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other (e.g., the range "up to 25 wt.%, or more specifically, 5 wt.% to 20 wt.%" includes the endpoints of the range "5 wt.% to 25 wt.%" and all intermediate values). A "combination" is inclusive of blends, mixtures, alloys, reaction products, and the like. Terms such as "first," "second," and the like do not denote order, quantity, or importance, but rather are used to distinguish one element from another. The terms "a," "an," and "the" do not denote limitations of quantity and should be construed to encompass both the singular and the plural unless otherwise indicated herein or clearly contradicted by context. "Or" means "and / or" unless otherwise stated. References throughout this specification to "some embodiments," "embodiments," and the like mean that a particular element described in connection with an embodiment is included in at least one embodiment described herein and may or may not be present in other embodiments. Furthermore, it is understood that the described elements can be combined in any suitable manner in the various embodiments. "Combinations thereof" is open and includes any combination that includes at least one of the recited components or properties, optionally with a similar or equivalent component or property that is not recited.

[0166] Unless otherwise defined, technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which this application belongs. All cited patents, patent applications, and other references are incorporated herein by reference in their entirety. However, if a term of this application contradicts or conflicts with a term of the incorporated reference, the term of this application shall take precedence over the conflicting term of the incorporated reference.

[0167] Unless otherwise specified herein, all test specifications are the latest specifications in effect as of the filing date of this application or, if priority is claimed, as of the filing date of the earliest priority application in which the test specifications appear.

[0168] While the presently disclosed sterilization wrap, system, and method have been described with reference to exemplary embodiments thereof, the present disclosure is not limited to such exemplary embodiments and / or implementations. Rather, the presently disclosed sterilization wrap, system, and method are suitable for numerous implementations and applications, as will be readily apparent to those skilled in the art from the disclosure herein. The present disclosure expressly encompasses such modifications, enhancements, and / or variations of the disclosed embodiments. Because numerous changes can be made to the above-described configurations and many widely different embodiments of the present disclosure can be made without departing from the scope of the present disclosure, it is intended that all matter contained in the drawings and specification be interpreted in an illustrative and not a limiting sense. Additional modifications, changes, and substitutions are contemplated in the foregoing disclosure. Accordingly, it is appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the present disclosure.

Claims

1. 1. A system useful as a sterilization wrap for sterilizing an item, comprising: an outer layer comprising a thermoplastic material; an inner layer comprising a wet-laid nonwoven material comprising 100% cellulosic fibers based on the dry weight of the fibers contained in the inner layer; The system wherein the inner layer is absorbent and breathable and is placed in contact with the article to be sterilized.

2. The system of claim 1 , wherein the inner layer is creped.

3. 3. The sterilization wrap of claim 1, wherein the system provides a drying time of 20 minutes or less.

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