Sterilization wrap and method of manufacture and use

Abstract

Disclosed herein is an advantageous sterilization wrap, as well as related methods of its manufacture and use. More specifically, 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. The present disclosure also provides a method for manufacturing a sterilization wrap, the method 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.

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 in their entirety. Summary of the Invention [Problem to be solved by the invention]

[0003] There is interest in improved sterilization wraps and associated 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 specifically, 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 in 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. To assist those skilled in the art in making and using the disclosed sterilization wraps, assemblies, and methods, reference is made to the accompanying drawings. [Brief description 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. [Diagram 2] FIG. 2 is a side perspective view of an exemplary sterilization wrap after welding in accordance with the present disclosure. [Diagram 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 including a wet laid nonwoven material according to the present disclosure can dry faster than a layer including a spunbond-meltblown-spunbond (SMS) material. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

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

[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 specifically, 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. Conventional nonwovens / papers used in sterilization wrap applications may be inherently water repellent to meet the barrier standards required for proper sterilization and maintaining sterility over time. Water repellency can be achieved primarily by fiber type (e.g., polypropylene) or chemical treatment (e.g., fluorocarbons).

[0018] Generally, sterilization wrap has two main product types, sequentially wrapped and simultaneously wrapped, based on the wrapping method. The majority of the market uses simultaneously wrapped. Thus, although the market desires simultaneously wrapped, simultaneously wrapped may generally be limited to certain conventional SMS type wraps due to the limitations of ultrasonic bonding of certain conventional wet laid and crepe materials.

[0019] Generally, a 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 as well as maintaining sterility over time.

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

[0021] Sequential packaging can be defined as two single sheets of nonwoven / paper to be wrapped individually around the medical device. The device is contained in one wrap and then repeated again with the second sheet. In general, all three traditional material types of sterilization wraps ((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 sonically bonded sheets allow the medical devices to be packaged in a one-step packaging process versus the two steps of sequential packaging. This can reduce time and errors in the sterilization process and can be considered more efficient.

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

[0024] Due to the convenience of co-packaging and the efficiencies typically associated with its use, the overwhelming majority of sterilization wraps sold today are co-wraps. For example, currently over 90% of the U.S. market is sold as co-wraps, which generally consist 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. Typically, it is important that all moisture exits the wrapped environment, and thus 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 sterile packaged and droplets of water are found (referred to as a wet pack), the medical device is generally considered to be 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 wraps are typically hydrophobic / water repellent, one or more separate absorbent tray liner layers are often utilized in combination with sterilization wraps to help improve vapor moisture dissipation on the outside of the wrapped system. These tray liners are typically absorbent nonwoven fabrics or papers placed at the bottom of the tray or directly underneath the tray. The tray liner can efficiently dissipate moisture to draw vapor away from the medical device and facilitate removal from the inside 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 transmission properties, as well as improved and / or superior evaporative drying rates, over hydrophilically treated polypropylene SMS materials. Absorbent treatments on polypropylene fibers improve wicking, but polypropylene is naturally hydrophobic and adsorbent 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). Its capacity and absorbency is superior compared to hydrophilically treated SMS materials. Moisture dissipation through the exemplary wet-laid layer is better (see FIG. 4, discussed further below). The absorbent and adsorbent properties of the exemplary absorbent wet laid 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) 43 gsm polypropylene based SMS (antistatic treated and inherently hydrophobic commercial grade); (2) 70 gsm polypropylene based SMS (antistatic treated and inherently hydrophobic commercial grade); (3) 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 each 7.1in 2 A 100°C water-laid sample was applied to the wet-laid sample. The sample was then dried at 100°C. The water loss rate was measured at different time intervals. The data obtained shows 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 due to the much higher water removal capacity in the cellulose because the addition of surfactant aids in wicking of moisture (capillary action) and because the cellulose allows for absorption (absorption into the fibers). The SMS with its polypropylene fibers only provides 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 mentioned above, co-wrapping systems are the preferred type of sterilization wrap by customers. It is noted that products for co-wrapping may require sonic bonding between inner / outer layers (e.g., along two edges of the sheets). In general, sonic bonding is not a typical issue between typical SMS / SMS configurations, but adequate sonic bonding is typically less feasible for combining traditional SMS / wet-laid sheets. The present disclosure advantageously provides a wet-laid layer with enhanced ultrasonic bonding capabilities to provide an ultrasonically bonded two-sheet thermoplastic (e.g., SMS) / wet-laid sterilization wrap more easily for use in co-wrapping (e.g., to use 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) layers can advantageously achieve at least the following: (1) improved commercial robustness and viability of ultrasonically bonded co-wrap systems including 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 times - also reducing the need for wet pack generation and resterilization; (4) maintenance of required strength and barrier property requirements.

[0034] Referring now to the drawings, wherein like parts are designated with the same 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, comprising 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 bond regions 16A, 16B through the outer layer 12 and the inner layer 14), although the 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 non-continuous weld line and / or weld spot, hi some embodiments, each welded region 16A, 16B includes a plurality of continuous and / or non-continuous weld lines and / or weld spots.

[0041] It should be noted that various weld lines and / or weld spots may be utilized along various locations and / or positions of 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, non-binder / dispersion type materials which can take the form of glues, tapes, webs, sprays, foams utilizing hot melt adhesives, pressure sensitive adhesives, curable adhesives (e.g., polyurethanes, etc.), and without 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 may 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 is 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 is noted that various weld lines and / or weld spots may be utilized along various locations and / or 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 an exemplary embodiment, the outer layer 12 is secured and directly bonded to the inner layer 12 by at least the first weld area 16 A. In some embodiments, the outer layer 12 is secured and bonded only to the inner layer 14 by at least the 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 joined 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, the outer layer 12 comprises a nonwoven meltblown material, preferably, the outer layer 12 comprises meltblown synthetic fibers, more preferably, the outer layer 12 comprises spunbond-meltblown-spunbond (SMS) synthetic fibers, and even more preferably, the 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] The exemplary inner layer 14 is absorbent and breathable. In certain embodiments, the wet laid nonwoven material of the inner layer 14 includes cellulosic fibers, synthetic fibers, a binder, and optionally a surfactant.

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

[0053] The cellulose fibers of the inner layer may include at least one of hardwood pulp fibers, softwood pulp fibers, annual plant fibers, or cotton fibers. The inner layer 14 may include at least one of mercerized or non-mercerized cellulose fibers, or a combination thereof. The fibers may 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 Micrexed or microcreped (e.g., Micrex or microcreping the wet laid nonwoven material of the inner layer 14). The wet laid is optionally, and 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, and 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 can include synthetic fibers in an amount of 5% to 60% by weight, preferably 15% to 30%, based on the dry weight of the fibers in inner layer 14, with any synthetic binder fibers, if present, included in this percentage.

[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 can include a binder in an amount 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, based on the total dry weight of the inner layer 14.

[0059] In some embodiments, the 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, the inner layer 14 may include a surfactant in an amount of 0.5-5%, preferably 1-3%, and more preferably 1-2% 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 a simultaneous wrapping technique during a sterilization process. The exemplary sterilization wrap 10 is suitable for use to sterilize medical devices without utilizing an additional tray liner during a sterilization process.

[0064] Generally, the sterilization wrap 10 is permeable to a sterilant, such as steam. The exemplary sterilization wrap 10 exhibits microbial barrier properties and / or is 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 discussed above, the present disclosure advantageously provides a two-sheet wrap 10 or wrap system 10 in which an absorbent wet-laid nonwoven layer 14 acts as the inner layer 14 and an antistatic or untreated layer 12 comprising a thermoplastic material (e.g., SMS) acts as the outer layer 12. The cellulosic structure of the wet-laid material 14 provides improved and / or superior moisture absorption and moisture transmission properties, and improved and / or superior evaporative drying rates, over hydrophilically treated polypropylene SMS materials. The 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 water absorption capabilities can allow for the elimination of tray liners in 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 to the wrap 10.

[0067] The present disclosure also advantageously provides a wetlaid layer 14 with enhanced ultrasonic bonding capabilities to render the ultrasonically bonded two-sheet thermoplastic material 12 (e.g., SMS) / wetlaid sterilization wrap 10 more readily available for use in co-packaging (e.g., to use a wetlaid 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 times - also reducing the need for wet pack generation and resterilization; (4) maintaining the required 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 a simultaneous wrapping technique. The exemplary inner layer 14 of the wrap / system 10 exhibits hygroscopic properties to improve the rate of moisture loss (drying rate) during a steam sterilization cycle, 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 properties 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 sonic bonding, or the like, which is made possible by the use of the improved wet laid nonwoven material of the inner layer 14.

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

[0071] Different binder polymers were tested.

[0072] To improve moisture absorption / permeability, 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 with each other in many ways.

[0075] The samples had the following base web formulation: 75% by weight of total fiber 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 various amounts of binder Acronal S728, marketed by BASF, and surfactant Aerosol OT-75, marketed by Solvay.

[0077] Samples 2, 2.1, 2.2, 2.3 and 2.4 contained the web formulation described above and contained various amounts of binder Acronal S504 and surfactant Aerosol OT-75, both 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 2 The conventional 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 improves the absorption properties significantly. In the negative case, the aggressive nature of the anionic surfactants tends to penetrate deeply into the fibers (especially cellulosic) affecting the fiber integrity. It can reduce the wet tensile strength / durability of the nonwoven. As shown in Table 2 below, adding A-OT resulted in a decrease in strength.

[0083] Also, the glass transition temperature (Tg) of the binder can be important to impart flexibility for a more efficient / productive packaging process of the 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 can make the binder more heat treatable, improving 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 the 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 the A-OT in the formulation, allowing the nonwoven to maintain adequate strength properties, both in terms of dry strength and wet strength.

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

[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 wraps, wax and fluorocarbon treatments were removed, resulting in improved water absorbency.

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

[0096] The wetlaid properties used to evaluate the performance of binders in cellulosic wetlaids 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, especially the wet tensile strength. Different mechanical properties were measured, as shown in Table 2, according to the test methods described in Test Methods below. The addition of surfactants reduced the wet tensile strength of all samples. However, the effect was rather 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 gives it a degree of chemical resistance that offsets the aggressive nature of the surfactants added to the binder.

[0099] In the case of 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 drop value were measured (test method is described below). The improvement in absorption rate was derived from the water drop measurement based on sample 4.

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

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

[0103] Comments on Table 4: To evaluate the bonding performance of the samples, each sample was individually heat sealed and subjected to bond strength testing according to the test protocol set forth in ASTM F88.

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

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

[0106] Base material: 75% by weight of NBSK pulp, 25% by weight of Teijin PET stabilized fiber (1.7detx, 15mm) (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 pH adjusted to 8 using ammonia. 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 on the Aurizon instrument were 4.5 mm width, 0.015 in. x 0.015 in. depth, and 100% amplitude, and operating speeds of 100-350 fpm, with knurled pattern anvils, using settings 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 => outer 43gsm SMS blue / inner 37gsm wet laid green; (2) Sample X1.2 => outer 43gsm SMS blue / inner 46gsm wet laid green; (3) Sample X1.3 => outer 70gsm SMS blue / inner 63gsm wet laid green.

[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 that it is possible to adhere a wet laid layer to an SMS layer with a bond strength of 100 CN / 15mm 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 the 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 with the following sterilization wrap design conditions: (1) Sample X1.4 => outer 43gsm SMS blue / inner 40gsm wet laid green; (2) Sample X1.5 => outer 70gsm SMS blue / inner 62gsm wet laid green.

[0116] In pre-vacuum steam sterilization, the medical instrument trays and all accessories must 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 a wrapped medical instrument tray 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 in a wrapped instrument tray that voids the sterility of the items found within the tray.

[0117] Samples X1.4 and X1.5 were tested by standard drying time tests commonly available at commercial sterilization validation laboratories such as Highpower Laboratories or Nelson Laboratories. This study determines the appropriate drying time of sterilization wraps when processed in a steam pre-vacuum sterilization cycle. Instrument trays are loaded with simulated medical devices to a pre-determined weight, processed in a steam pre-vacuum cycle at 132°C for 4 minutes exposure, and allowed to dry for a pre-determined period. After the cycle is complete, the instrument trays are re-weighed and evaluated by comparing pre- and post-sterilization weights. Additionally, the instrument trays, contents, and sterilization wraps are evaluated for visual moisture retention. A common component found on the inside of a wrapped system is the inclusion of a tray liner, i.e., an absorbent sheet that is placed at or directly under the bottom of the instrument tray. The tray liner acts as an absorbent extension of the entire system, increasing the moisture permeability properties of the system and improving drying performance (and reducing instances of wet pack). 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 equipment with no tray liner. For comparison, a commercial simultaneous wrap (2 polypropylene based SMS, 50 gsm each) had a verified dry time of 20 minutes on a similar 9 lb tray equipment with tray liner. With the same equipment weight, the dry time was reduced by 40% without the tray liner.

[0120] Sample X1.5 was tested over a 20 minute dry time with a 25 lb tray equipment and no tray liner. For comparison, a commercial simultaneous wrap (2 polypropylene based SMS, each 85 gsm) had a verified dry time of 30 minutes on a similar 24 lb tray equipment with tray liner. With the same equipment weight, drying time was reduced by 33% without the 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 by a half-cycle sterilization validation test utilizing the newly verified drying times described above. Half-cycle sterilization validation is a study commonly available at commercial 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 make it difficult to sterilize the location of the medical device and treated with a pre-vacuum sterilization cycle for half the intended exposure time. The test assumes a worst-case sterilization environment that provides 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 minute exposure time) 50% shorter exposure time Drying time (12 minutes) Equipment Tray Weight: 9lb 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 minute exposure time) 50% shorter exposure time Drying time (20 minutes) Equipment Tray Weight: 25lb 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 number 2: Microbial aerosol challenge test: Samples X1.4 and X1.5 were also tested for additional barrier property performance by microbial aerosol challenge testing. The microbial aerosol challenge testing is an industry-recognized test at a commercial sterilization validation laboratory such as Highpower Laboratories or Nelson Laboratories. The intent of the test is to determine the ability of the sterilization wrap to maintain the integrity of the sterile packaging after an aerosol challenge of biological spores. Wrapped medical device trays were prepared with samples X1.4 and X1.5, each at the desired device tray weight. The wrapped trays were then processed through a standard steam pre-vacuum cycle at 132°C with 4 minutes exposure and drying times specific to the sample. After completion of the pre-vac sterilization process, 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 packages were aseptically opened and the contents were tested for biological presence. 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: 9lb Test result: Pass Sample X1.5 Pre-Vac steam conditions (132°C, 2 minute exposure time) 50% shorter exposure time Drying time (20 minutes) Equipment Tray Weight: 25lb Test result: Pass

[0124] [Table 6]

[0125] The present disclosure further includes 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 contain 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 wherein the outer layer comprises meltblown synthetic fibers, more preferably wherein the outer layer comprises spunbond-meltblown-spunbond (SMS) synthetic fibers, and even more preferably wherein 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 a medical device without utilizing an additional tray liner during the sterilization process.

[0136] Example 11. The sterilization wrap of any one of the preceding examples, 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] Aspect 13. The sterilization wrap of any one of the preceding aspects, 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 of any one of the preceding aspects, wherein the sterilization wrap meets the requirements of international standard ISO 11607 Part 1 as a sterile barrier system.

[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 cellulosic fibers, or a combination thereof.

[0146] Aspect 21. The sterilization wrap of any one of the preceding aspects, wherein the inner layer is microlex 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 any 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, 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, based on a weight percentage of 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 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, 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 area has a bond strength of 80cN / 15mm or more, preferably 100cN / 15mm or more, 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 includes 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 area.

[0156] Aspect 31. The method of any one of Aspects 29 or 30, 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.

[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 welded area and at least a second welded area, wherein the outer layer is fixed and joined to the inner layer by at least the first welded 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 welded 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 added adhesive material.

[0159] Example 34. The method of any one of Examples 29 to 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] Example 37. The method of any one of Examples 29 to 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 welded region, has a bond strength of 80cN / 15mm or more, preferably 100cN / 15mm or more, according to standard method ASTM F88.

[0164] While particular embodiments have been described, alternatives, modifications, variations, improvements, and substantial equivalents that are not presently foreseen or may not be foreseen may occur to applicant or other persons skilled in the art. Accordingly, the appended claims as filed, and 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 can be combined independently of one another (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). "Combination" includes blends, mixtures, alloys, reaction products, and the like. Terms such as "first," "second," and the like do not denote any order, quantity, or importance, but are used to distinguish one element from another. The terms "a," "an," and "the" do not denote any limitation on 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 indicated. 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. It is further understood that the described elements can be combined in any suitable manner in the various embodiments. "Combinations thereof" is open and includes any combination containing at least one of the recited components or properties, optionally with similar or equivalent components or properties that are 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 conflicts or contradicts 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, the filing date of the earliest priority application in which the test specifications appear.

[0168] Although the disclosed sterilization wrap, system and method have been described with reference to exemplary embodiments thereof, the disclosure is not limited to such exemplary embodiments and / or implementations. Rather, the disclosed sterilization wrap, system and method are suitable for many implementations and applications, as will be readily apparent to those skilled in the art from the disclosure herein. The disclosure expressly encompasses such modifications, enhancements and / or variations of the disclosed embodiments. Since many changes can be made to the above 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 should be interpreted as illustrative and not in a limiting sense. Additional modifications, changes and substitutions are contemplated in the foregoing disclosure. It is therefore appropriate that the appended claims be construed broadly and in a manner consistent with the scope of the present disclosure.

Claims

1. 1. A sterilization wrap comprising: an outer layer comprising a thermoplastic material; an inner layer comprising a wet laid nonwoven material; The sterilization wrap, wherein the outer layer is secured and joined to the inner layer by at least a first weld area.

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

3. the outer layer defines a thickness of a thermoplastic material and the inner layer defines a thickness of a wet laid nonwoven material; 10. The sterilization wrap of any one of the preceding claims, wherein 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.

4. 2. The sterilization wrap of any one of the preceding claims, 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.

5. 5. The sterilization wrap of claim 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.

6. 2. The sterilization wrap of any one of the preceding claims, wherein the outer layer and the inner layer are each free of added adhesive material.

7. 10. The sterilization wrap of any one of the preceding claims, 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, even more preferably the outer layer comprises SMS polyolefin fibers such as SMS polypropylene fibers.

8. 6. The sterilization wrap of claim 5, wherein at least one of the first welded area or the second welded area is an ultrasonic welded area.

9. 2. The sterilization wrap of any one of the preceding claims, wherein the sterilization wrap is suitable for use to sterilize a medical device using a simultaneous wrapping technique during a sterilization process.

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

11. 2. The sterilization wrap of any one of the preceding claims, wherein the wet laid nonwoven material comprises cellulosic fibers, synthetic fibers, a binder, and optionally a surfactant.

12. 2. The sterilization wrap of any one of the preceding claims, wherein the sterilization wrap has a total basis weight of from about 70 grams per square meter (gsm) to about 170 gsm.

13. 2. The sterilization wrap of any one of the preceding claims, wherein the inner layer is absorbent and moisture permeable.

14. 2. The sterilization wrap of any one of the preceding claims, wherein the sterilization wrap is permeable to a sterilizing agent, such as steam.

15. 2. The sterilization wrap of any one of the preceding claims, wherein the sterilization wrap exhibits microbial barrier properties and is impermeable to bacteria.

16. 10. The sterilization wrap of any one of the preceding claims, wherein the sterilization wrap meets the requirements of European Standard EN 868 Part 2 as a sterile barrier system.

17. 10. The sterilization wrap of any one of the preceding claims, wherein the sterilization wrap meets the requirements of international standard ISO 11607 Part 1 as a sterile barrier system.

18. the outer layer has a basis weight of about 35 grams per square meter (gsm) to about 85 gsm; and / or 4. The sterilization wrap of any one of the preceding claims, wherein the inner layer has a basis weight of from about 35 grams per square meter (gsm) to about 85 gsm.

19. 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; 2. The sterilization wrap of any one of the preceding claims, wherein the cellulosic fibers comprise at least one of hardwood fibers, softwood fibers, annual plant fibers, or cotton fibers.

20. 2. The sterilization wrap of any one of the preceding claims, wherein the inner layer comprises at least one of mercerized or non-mercerized cellulosic fibers, or a combination thereof.

21. 2. The sterilization wrap of any one of the preceding claims, wherein the inner layer is Micrex or Microcreped.

22. the inner layer comprises synthetic fibers, preferably polyester staple fibers, more preferably polyethylene terephthalate (PET) fibers; 2. A sterilization wrap according to any one of the preceding claims, wherein the inner layer comprises synthetic fibers in an amount of 5% to 60% by weight, preferably 15% to 30%, the percentages being based on the dry weight of the fibers in the inner layer, and any synthetic binder fibers, if present, are included in this percentage.

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

24. 10. The sterilization wrap of any one of the preceding claims, 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 15-30% by weight, more preferably 18-28% by weight, and even more preferably 20-25% by weight.

25. the inner layer comprises a surfactant, the surfactant comprises 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, 2. The sterilization wrap of any one of the preceding claims, wherein the inner layer comprises a surfactant in an amount of 0.5-5%, preferably 1-3%, more preferably 1-2% of the binder mixture.

26. 10. The sterilization wrap of any one of the preceding claims, wherein the outer layer secured and joined to the inner layer by at least the first weld area has a bond strength according to standard method ASTM F88 of 80 cN / 15 mm or more, preferably 100 cN / 15 mm or more.

27. 6. The sterilization wrap of claim 5, wherein at least one of the first welded area or the second welded area comprises a plurality of continuous and / or non-continuous weld lines and / or weld spots.

28. 2. The sterilization wrap of any one of the preceding claims, wherein the outer layer is treated with an antistatic composition.

29. 1. 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; fixing and joining the outer layer to the inner layer by at least a first weld area; A method comprising:

30. 30. The method of claim 29, wherein the outer layer is directly secured and directly bonded to the inner layer by at least the first weld area.

31. the outer layer defines a thickness of a thermoplastic material and the inner layer defines a thickness of a wet laid nonwoven material; 31. The method of claim 29 or claim 30, wherein 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.

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

33. The method of any one of claims 29 to 32, wherein the outer layer and the inner layer are each free of added adhesive material.

34. 34. The method of any one of claims 29 to 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, even more preferably the outer layer comprises SMS polyolefin fibers, such as SMS polypropylene fibers.

35. 33. The method of claim 32, wherein at least one of the first weld area or the second weld area is an ultrasonic weld.

36. 36. The method of any one of claims 29-35, 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.

37. The method of any one of claims 29 to 36, wherein the wet laid nonwoven material comprises cellulose, synthetic fibers, a binder, and optionally a surfactant.

38. 38. The method according to any one of claims 29 to 37, wherein the outer layer fixed and joined to the inner layer by at least the first weld area has a bond strength according to standard method ASTM F88 of at least 80 cN / 15 mm, preferably at least 100 cN / 15 mm.

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