MXPA94004664A - Sterilization wrapping system of a pasoun - Google Patents

Abstract

The present invention relates to a method for sterilizing an article comprising: providing an article, wrapping the article with a sterilization wrap which comprises: an inner wrap sheet and an outer wrap sheet, and exposing the wrapped article to conditions sterilizers for a sufficient time so that the article has been sterilized, wherein each sheet comprises a laminate, which comprises a first layer joined with spinning, a meltblown layer and a second layer joined with spinning and the sheets are joined together in a plurality of bonding sites which occupy not more than 50 percent of the surface area of any of the sheets, so that said sheets are visually distinguishable as separate sheets, and wherein at least one tension force of one pound is required to separate said leaves together

Description

SINGLE-STEP STERILIZATION WRAPPING SYSTEM INVENTORS: Sonya Nicholson Bourne, Nelson McRay, Wash Campbell Boggs, William Ralph Neff, Charles John Morell and Marsha Lottie Vaughn, all of North American nationality, with addresses at 325 Tyson Circle, Roswell, Georgia 30076; 5955 Canaan Oods Drive, Atlanta, Georgia 30331; 2639 Spencer Trace, Marietta, Georgia 30062; 225 Twinspur Court, Roswell, Georgia 30076, 10480 Turner Road, Roswell, Georgia 30076; 3481 Lakeside Drive N.E. # 1108, Atlanta, Georgia 30326; United States of America.

OWNER: Kimberly-Clark Corporation, of North American nationality, domiciled at 401 North Lake Street, Neenah, Wisconsin 54957-0349, United States of America.

EXTRACT OF THE INVENTION A single-pass sterilization wrapping material suitable for use as, for example, in the wrapper of surgical instruments and supplies for sterilization, transport and storage is described. The material includes separate internal and external wraps, which, unlike previous wrappings, are attached to one another. The common wrapping techniques involve wrapping articles that are to be sterilized with two separate wrapping sheets. The present invention provides separate wraps which can be specially designed to deliver specific properties for each sheet and then join one another as to allow wrapping and opening in a pure single step process that increases efficiency and saves time and money. In special situations the outer casing can be designed with increased strength, the inner casing with increased barrier properties and the inner and outer casings can be made visually different from one another so that inadequate opening or wrapping is not a problem.

BACKGROUND OF THE INVENTION The present invention is directed to sterilization wrapping materials. More particularly the present invention is directed to multi-layer materials made of individual sheets which are fused together to be suitable for use as a sterilization wrap for wrapping surgical instruments and supplies for sterilization and storage in conjunction with surgical procedures and for other applications such as packaging items for bone marrow units.

Personnel in the Central Service Room (CSR) or the Sterile Processing Department (SPD) of the hospitals are commonly assigned with the responsibility to pack surgical supplies to ensure that the sterility of the contents of the packages is maintained in all the way from the point of sterilization to that of reuse. Several activities are involved in the delivery of sterile supplies to the operations room and other units.

Many of the surgical instruments and supplies used in the operating room are reusable. These supplies typically include such things as tweezers, blade handles, retractors, forceps, scissors, surgeon's towels, containers and the like. All these supplies must be collected after each procedure and sterilized before they can be used again in another procedure. For this purpose, supplies are placed in stainless steel tray trays, and soft items such as surgeon's towels, sheets and robes are prepared for packaging. Then the trays and packing contents are each generally wrapped with two sheets of material commonly referred to as sterilization wrap.

The sterilization wrapper is usually a woven or non-woven material which when wrapped around the tray or packing contents in a prescribed prescribed manner will allow the entry of a steam / sterilization gas or other means to sterilize the contents of the container. Tray while denying entry to contaminants such as bacteria and other materials that cause infections or their vehicles after sterilization. Generally, the two primary means for sterilizing instruments are the steam autoclave and sterilization with ethylene oxide.

Using a wrapped tray, as an example, once the wrapped tray and its contents have been sterilized, the wrapped tray is transported to the point of use, typically a room of operations or stored until ready for use. During storage and transfer to the operating room, the wrapped tray can be handled different times. Each time the package wrapped is handled, there is a possibility that the sterile nature of the contents of the package is compromised. The two most common ways that the wrapped packaging can be compromised are a tearing or other breaking of the wrapping material, and moisture or foreign matter identified on the outer wrap, which can guarantee premature unwrap.

In order to promote and maintain the sterility of the packaged contents, the Association of Nurses of the Operating Room (AORN) has developed certain recommended practices for the wrapping and handling of packages processed in the hospital. It is a common practice among many hospitals as it is recommended by the Association of Nurses of Operation Room to "wrap in double form" the packages processed in hospitals. A primary method of the double envelope is "sequential" in nature in the sense that the contents of the package are first wrapped by a sheet of sterilization wrap and then wrapped again by another sheet of sterilization wrap. Another method of double wrapping is "simultaneous" in nature in the sense that the contents of the package are wrapped by two sheets of sterilization wrap at the same time. That is, two sheets of sterilization wrap are aligned one above the other and the article to be wrapped is placed on top of the two sheets. Then the article is wrapped by both sheets of material at the same time.

Studies have been used to track the packages from the initial wrap, all the way through sterilization, storage, handling, transfer, unwrap and reuse. These studies indicate that the frequency at which wrapped articles are compromised due to tears or holes has been reduced due to improved handling and storage techniques and due to the improvement of sterilization packaging products. One of the main thrusts behind such efforts has been the savings. Each time a sterile package is compromised, it must be removed from circulation, unwrapped, rewrapped and resterilized before it is properly reused. This is a waste of time and money.

Even though the frequency in which envelopes are compromised has been reduced resulting in the saving of time and money, the use of simultaneous wrapping techniques will additionally increase the savings of time in wrapping and opening of packages and therefore will result in even greater cost savings. Simultaneous wrapping takes less time than sequential wrapping and recent research in hospitals has shown that simultaneous wrapping is as effective as sequential wrapping in maintaining sterility absent from a rupture in the wrapping that is generally independent of the way of wrapping .

Even when hospital staff may wish to wrap simultaneously instead of sequentially wrapping, the time it takes to put the outer and inner foil wraps and the difficulty of handling loose wraps during a simultaneous wrapping can offset the expected time savings to be achieved when trying to move out of the envelope sequence. Consequently, if a product existed which provided the appropriate inner and outer leaf combinations and eliminated the difficulty of keeping the two sheets together during the wrapping of the package and the opening processes, then a simultaneous packaging system will deliver the desired benefits including Time savings and operation of inner and outer leaf design objective.

In conjunction with the way in which the packages are wrapped, the material used to wrap is also important. As mentioned above, the two most common wrapping materials are woven materials such as fabric (cotton / polyester), non-woven materials such as KIMGUARDMR sterile wrapper (polypropylene) from Kimberly-Clark Corporation of Neenah, Wisconsin and Bio-shield of CSR Wrap (wood pulp / polyester) from Baxter Healthcare Corporation of Deerfield, Illinois. One version of the Baxter sterilization wrapper is a product called DualWrap ™ sterilization wrap which includes an internal wet-laid paper sheet (cellulose) and a separate outer sheet of hydroentangled pulp / polyester or spin-embroidery. The inner and outer layers are provided in a stack of loose and loose sheets in which the inner and outer sheets are alternated.

Whichever material is being used as a sterile wrapper it should be noted that when two sheets are wrapped at the same time, it is important that the wrapping materials provide good barrier properties to maintain the sterility of the package and good strength properties so that the break or other forms of commitment are kept to a minimum. If the outer and inner sheets of the double wrap will have different properties, then it is important that the system is visually identifiable so that using it can determine which wrapper is the outer sheet and which wrapper is the inner sheet. As a result, there is a need for a new sterilization wrapping system that actually reduces packaging and opening time and delivers a designed performance of exterior and interior sheets in an easy and simple identifiable form of use. Such attributes are provided by the present invention as will be apparent from a further review of the following description, clauses and drawings.

SUMMARY OF THE INVENTION There is described here a single-pass sterilization wrapping system for packaged items which are to be sterilized and maintained in a sterilized condition until they are used such as surgical instruments for use in a hospital operating room. A large number of such articles are currently wrapped with two separate sheets of sterilization wrap. The most common method of wrapping such items is called sequential and double wrap where an article has been wrapped in a first piece of sterilization wrap with the loose ends being closed with tape. Then a second separate sheet of sterilization wrap is used to wrap the article a second time. Once the second wrapping sheet has been wrapped around the article the loose ends of the second sheet are closed with tape and the wrapped article is sent through the sterilization process. After the wrapped article has been sterilized, it is normally placed in storage until the current use at which time the sterilized and wrapped package is removed from storage and transported to the operating room where the sterile wrap is removed and the articles are subsequently used. A second less commonly used method of wrapping is called the simultaneous wrapping method wherein two sheets of sterilization wrapping are placed one on top of the other aligned and then the two sheets are wrapped around the article to be sterilized at the same time. After the wrapping has been completed, the loose ends are closed with tape and the article is sent through the same sterilization process as described above.

The present invention provides improved means for simultaneously wrapping and unwrapping articles which must be sterilized before use. This is achieved through joining or bonding two separate sheets of sterilization wrap together at one or more locations to create a single-pass system where the separate sheets are pre-aligned and linked together to facilitate the wrapping process as well as the unwinding process. As a result of this the amount of time required to wrap and unwrap an article is decreased the ease of wrapping is improved. In addition, each of the individual sheets of the single-pass sterilization wrapping system can be specifically designed to impart different characteristics or special characteristics to the system in general.

The single-pass sterilization wrapping system includes an outer wrap made from a first sterilization sheet which is placed on an inner wrap made of a second sterilization sheet with each of the sheets being independent of one another and joined together to another in one or more union sites. The individual inner and outer shells can be made from a variety of sterilization materials including fibrous materials such as woven and non-woven. The sterilization wrapping system has a first outer surface and a second outer surface formed by the opposite sides of the system with each of the surfaces having the respective surface area and wherein the bonding sites joining the inner and outer shells together occupy not more than 50% of the surface area of any of the first or second outer surfaces of the sterilization wrapping system. The inner and outer sheaths can be joined to one another in a variety of joining patterns including both the long continuous seams and the stitching together. If desired, the sterilization wrapping system can define a first zone and a second zone, with the first zone having a greater number of binding sites than the second zone and wherein the second zone is surrounded by the first zone in a that the sterilization wrapping system has a low density bonding area surrounded by a higher density bonding area.

Each of the individual sheets may be designed to have particular properties which may be the same or different from the other sheet of the single-pass sterilization wrapping system of the present invention. For example, the outer wrapper may be stronger than the inner wrapper as indicated by the outer wrap having a greater resistance to grip stress as compared to the inner wrap. In addition, the barrier properties of the inner wrap can be strengthened to create better bacteria filtering means than the outer wrap.

The inner wrapper and the outer wrapper can both be made from the non-woven laminate such as the spin-bonded / melt-blown / spin-bonded laminates wherein the inner melt-blown layer provides barrier properties and the bonded layers by external spinning provide resistance. By using a heavier weight basis layer formed by melt blowing in the inner wrapper compared to the outer wrap, the inner wrap will have a better barrier property than the outer wrap in which case the inner wrap will have a rate of dry spore penetration lower than the outer shell and higher bacterial filtering efficiency than the outer shell. Conversely, the melt blown layer of the inner wrapper can be lowered to such an extent that the bacterial filtering efficiency of the inner wrapper is less than the outer wrap. In addition, the strength of the inner and outer shells can be varied by varying the basis weight and the types of polymers that are being used to form the fibers that make up the individual layers of the respective laminates. As a result of this, a sterilization wrapping system can be designed wherein the peak energy of the outer wrapper is greater than that of the inner wrapper.

In situations where the inner wrapper has design properties different from those of the outer wrapper, it is important that the end user be able to determine which of the two wrappers (inner or outer) should be placed on the side of the item being wrapped. wrapped and subsequently sterilized. For this purpose, the inner and outer envelopes may be designed to be visually distinct from each other as by printing or other indicia as well as the use of different colors or shades with respect to the individual sheets of sterilization wrap.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a perspective view of a single-pass sterilization casing according to the present invention with a ready-to-wrap sterilization tray placed on top of the sterilization casing.

Figure 2 is a cross-sectional side view of a single pass sterilization casing according to the present invention.

Figures 3 to 6 are top plan views of additional single-pass sterilization casings according to the present invention with different attachment patterns for joining the separate sterilization wrapping sheets together.

DETAILED DESCRIPTION OF THE INVENTION Described herein is a sterilization system suitable for use with simultaneous wrapping procedures for wrapping, sterilizing, storing and using sterilized articles such as surgical supplies. While the present invention will be described in conjunction with its use in surgical and hospital room procedures, the sterilization system of the present invention is intended to be used when there is a need for sterilized materials. Consequently, the following description of the present invention should not be considered a limitation in relation to the scope of the use of the present invention.

Referring to Figures 1 and 2 of the drawings, there is shown a sterilization system or wrap to contain and maintain the sterility of surgical supplies and the like. The sterilization system 10 includes an outer wrap 12 also referred to as a reinforced barrier woven laminate and an inner wrap 14 also referred to as a barrier fabric laminate. As can be seen from Figure 1, the outer casing 12 and the inner casing 14 are placed in a face-to-face relationship with one another, one on top of the other in a vertical juxtaposition. Each of the wraps are of the same general shape and size. More typically the wrappers will be square or rectangular in shape. As a result of this, each envelope will have at least two edges generally parallel to, a 'and b, b' located around its peripheries 16.

To facilitate the wrapping of an article 18 as shown in Figure 1, the outer shell 12 and the inner shell 14 are fastened to each other in a manner so as to hold the two shells together while still retaining their visual distinctiveness. so that the end user can visually see that the item is being wrapped by two separate sheets of sterile wrap. Generally the two wraps will be bonded around all or a portion of their peripheries 16. As specifically shown in FIGS. 1 and 2, the two wraps are attached to one another along the entire length of two generally parallel edges of the wrapping. wrapping a, a 'and b, b'. The edges may be joined to each other by any number of suitable means including, but not limited to, adhesives, stitches, heat bonding and ultrasonic joint collectively mentioned, as a joint. As shown in Figures 1 and 2, the bonding sites 20 are perfected by ultrasonic bonding, are continuous, and run to the full length of the edges just inside and / or along the periphery 16 on opposite sides of the edges. leaves 12 and 14.

In addition to or as an alternative to the continuous seams or seams 20, a second set of seams 22 can be used to secure the two wraps together. The joints 22 in Figure 1 are a series of points spaced apart and spaced apart in the form of two rows of spaced-apart rectangles and parallel or other shapes with the rectangles in one row being off-center from the other row so that they are offset. in an overlapping relationship if system 10 were to be viewed from the edge. This attachment pattern has been used to sew sleeves in disposable surgical coats manufactured by the registry assignee, Kimberly-Clark Corporation of Neenah, Wisconsin. The joints 22 may be just inside the continuous joints 20 and serve to further join the two separate wraps 12 and 14 together when used alone or in conjunction with the continuous joints 20.

It is also possible to make connections between the two casings 12 and 14 in a variety of other ways which are exemplified, at least in part, in Figures 3 to 6. As indicated in Figures 3 to 6, the inner casings and external are superimposed and joined to one another by one or more joining sites which may be long continuous joining lines as shown in Figures 3 to 5 or a plurality of localized bonding points as shown in the figure 6. In figure 3, which is a top plan view, the outer casing 12 and the inner casing 14, the system 10 are joined together by crossing intersecting lines 28 and 30 forming an "X" pattern. through the surface of the system 10. In Figure 4, the outer casing 12 and the inner casing 14 of the system 10 are joined to each other by a series of parallel links 32 extending all the way to a part of the length or the width of the system 1 0. In Figure 5, a series of sinusoidal junctions 34 are provided.

In addition to or in conjunction with the relatively long seams or joints shown in Figures 3 to 5, the outer shell 12 and the inner shell 14 of the system 10 can be joined by a plurality of localized discontinuous junction points 36 as shown in FIG. Figure 6. These junction points may be evenly spaced across the surface of the system 10 or they may be broken in two or more zones with each of these zones having varying degrees or densities of binding sites. Specifically referring to Figure 6, the system 10 is divided into a first zone 38 and a second zone 40 which for the purposes of illustration are shown in Figure 6 as being separated by an imaginary dotted line 42. The first zone 38 has a larger number of general plurality of joining sites per unit area than the second area 40. In addition, the first zone 38 completely surrounds the second zone 40 thereby creating a system 10 wherein the periphery of the system 10 has a generally greater degree of union that the central part of the system 10.

Other combinations of binding patterns can also be used. For example, indicia, logos and other printed matter can be used as the joining pattern to join the outer wrap 12 to the inner wrap 14. Therefore the tie pattern can be indicated as "KIMBERLY-CLARK" or "KIMCUARD" "". .

An important feature of the present invention is that the user of the single-pass sterilization wrapping system of the present invention can visually perceive that the system in fact includes two separate sheets of sterilization wrapping. Being able to see this reinforces the comfort level of the user that the wrapped item is protected by not one but two sheets of sterilization wrap. Therefore the two sheets of the sterilization wrap must be joined to each other with a sufficient amount of joint so that the two sheets do not separate, but with a sufficient joint so that the two sheets appear to be one. For this purpose, the sterilization wrapping system 10 can be seen as having a first outer surface 44 and a second outer surface 46 on the opposite sides of the system 10. See Figure 2. To maintain the visual distinctiveness of the two areas of The respective surface area is advantageous if the surface area of the bonding sites does not occupy more than about 50% of the surface area of either the first or second outer surfaces 44 and 46 of the sterilization wrapping system 10.

Even if it is desired to maintain the visual distinctiveness of the outer casing 12 and an inner casing 14, the two casing sheets must be sufficiently joined to each other so that they do not easily separate from each other through the process of removal of the outer casing. the sterilization wrapping of its original packaging, wrapping the articles to be sterilized with the wrapping and unwrapping the articles sterilized for use. Accordingly, it is desirable that there be at least one tension force of one pound needed to separate the sheets attached to one another.

Generally bound envelopes come in various sizes to wrap items of various sizes and trays. Typical sizes include 18, 24, 30, 36, 40, 45, 48 and 54 square inches as well as rectangular wraps of 54 by 72 inches. For wrapping an article in this case a sterilization wrapping tray 18 as shown in Fig. 1, the article is placed on the upper part of the system 10 in contact with the inner wrapping 14 so that the counter-wraps of the wrapping can Be bent over the pack one at a time. Once the folding has been completed, the wrap is sealed with tape and the wrapped package is ready to be sterilized.

Each of the wrappings can have its own special characteristics. The main function of the inner wrapper 14 is to act as the primary filtering barrier while the primary function of the outer wrapper 12 is to provide strength with a secondary function of also providing a barrier to bacteria and other contaminants.

Both the outer wrap 12 and the inner wrap 14 can be made from a number of materials. Sterilization casings are generally characterized as falling into two main classes, reusable and disposable. Reusable materials are materials which, as the name suggests, can be reused, typically by washing or other cleaning. Disposables, on the other hand, are usually single-use items which are discarded or recycled after initial use. Generally, fabric, linen or other woven materials fall within the category of reusable, while disposables normally include nonwoven materials made of either or both natural or synthetic fibers such as paper, fibrous polymeric fabrics as well as films which are capable to pass sterilants and slow the transmission of bacteria and other contaminants.

Non-woven sterilization casings have become particularly attractive due to their barrier properties, savings and quality consistency. Non-woven materials can be made from a variety of processes including, but not limited to air laying processes, wet laying processes, hydroentanglement processes, spin bonding, melt blowing, carding and short fiber bonding, and solution spinning. The fibers themselves can be made from a variety of both natural and synthetic materials, including, but not limited to cellulose, rayon, polyesters, polyolefin and many other thermoplastic materials. The fibers may be relatively short short length fibers, typically less than 3 inches, or longer continuous fibers such as are produced by spinning and meltblowing processes. Whatever materials are chosen, the resulting wrap must be compatible with the particular sterilization technique that is being used and must also provide both resistance and barrier properties to maintain the sterile nature of the contents wrapped up to use.

It has been found that the polyolefin-based fibers and their resulting nonwovens are particularly well suited for the production of a sterilization wrap. The polypropylene spunbonded nonwovens as produced by the registration assignee, Kimberly-Clark Corporation, can be used to impart sterilization wrap resistance characteristics and in particular, to the outer wrap 12. In more refined embodiments , the outer casing 12 can be made of laminates such as a meltblown and meltblown laminate or meltblown spunbonded, spunbonded to impart both strength and barrier properties to the outer casing 12.

A spin-bonded yarn-formed meltblown material is made of three separate layers which are laminated to one another. The method for making these layers is known and described in the patent of the United States of America number 4, 041203 commonly assigned to Brook et al. Which is hereby incorporated by reference in its entirety. The Brook and others material is a three layer laminate of spunbonded / meltblown / spunbonded, which is also commonly referred to by the term SMS. The two outer layers of the SMS are a spin-bonded material made of extruded polyolefin fibers placed in a random pattern and then bonded together. The inner layer is a meltblown formed layer also made of extruded polyolefin fibers generally of a smaller diameter and sometimes having a more discontinued length than that of the fibers in the spunbonded layers. As a result of this, the meltblown layer provides increased barrier properties due to its fine fiber structure which allows the sterilizing agent to pass through the fabric while preventing the passage of bacteria and other contaminants. Conversely, the two outer spunbonded layers provide a greater part of the strength factor in the overall laminate.

A particular feature of the present invention is the specific construction available for each of the layers in the respective outer wrap 12 and in the inner wrapper 14. While the two wrappers may be identical to one another, in more refined embodiments of the present invention the outer wrap 12 is designed to have superior strength properties to those of the inner wrapper 14. This is to provide a stronger barrier to tearing and other possible breakages of the wrapped article from the outer objects. Conversely, in more refined embodiments of the present invention, the inner shell 14 is designed to have barrier properties superior to those of the outer shell 12. The adjustment of the barrier and strength properties can generally be achieved by adjusting the basis weights of the outer and inner sheaths as well as the base weights of each of the individual layers within each of the shells. The proper base weight for each of the wraps varies between about 0.5 and about 3.5 ounces per square yard (osy).

A particular example of a single-pass sterilization wrapping system comprises an outer wrap made of a resistance barrier fabric laminate and an inner wrap made of a barrier fabric laminate with the strength barrier fabric laminate and the laminate of barrier fabric being placed side by side in an imposed or face-to-face relationship generally with the laminates being joined to one another at one or more attachment sites. Each of the layers is made of a spin-bonded / melt-blown / spin-bonded laminate as taught, for example, in US Pat. No. 4,041,203. Thus the strength barrier fabric laminate may comprise a first reinforcement layer made of randomly deposited fibers, a second resistance layer made of randomly deposited fibers and an intermediate barrier layer made of fibers randomly deposited with the fibers in the intermediate barrier layer having an average fiber diameter which is less than the average fiber diameter in the fibers in either the first or second strength layers. In addition, the intermediate barrier layer is positioned between and bonded to the first and second reinforcing layers. This laminate of resistance barrier fabric will generally form the outer shell 12. The inner shell 14 can be made of a laminate of barrier fabric comprising a third layer of strength made of randomly deposited fibers and a fourth layer of strength made of deposited fibers. randomly with a second layer of intermediate barrier made of fibers deposited at random. Here again the fibers of the second intermediate barrier layer have an average fiber diameter which is smaller than the average fiber diameter of any third or fourth resistance layers and the second intermediate barrier layer is placed between and attached to the third and fourth resistance layers. To provide added strength, the outer sheath composed of the strength barrier fabric laminate may have a greater grip strength than the inner sheath and the inner sheath made of the barrier fabric laminate may have a spore penetration rate dry that is lower than the outer wrapper and a bacterial filtering efficiency which is greater than that of the outer wrap.

When designing the inner and outer sleeves with different properties it is usually important that the system 10 be positioned so that the appropriate wrapping surface is facing the article to be wrapped and that the other wrapping surface is facing outwardly from the wrapping. article wrapped. Typically this will mean that the inner wrapper 14 is in contact with the article 18 to be wrapped and the outer wrapper 12 will be placed out of the wrapped article 18. For this purpose it may be desirable to produce the inner and outer wrappers which are visually distinguishable a of other. By "visually distinguishable" it is meant that a majority of people who routinely use such materials will be able to tell the difference between the first outer surface 44 and the second outer surface 46 of the system 10 based on the visual observation of the two surfaces. One means to achieve this would be by coloring or toning the inner wrapping 14 differently from the outer wrapping 12. In addition, printing or other indications can be used to differentiate the two wrappings from one another.To demonostrate the attributes of the present invention, various sterilization wrapping systems 10 were prepared and then tested against currently available sterilization wraps. Several of these wraps including samples of the present invention were wrapped around the sterilization packs and then sent through a representative management process in the hospital after which the tray contamination rate was measured. In addition, the attributes of certain components of the present invention were compared to the components of other available products.

Kimberly-Clark Corporation, the registration assignee, manufactures a series of single-sheet sterilization wrapping materials made from spin-layered / melt-blown / spin-bonded laminates. These materials are available in a variety of base weights as indicated below in Table I.

TABLE I WEDDING TIDY Class Base-total weight By layer? (s / m / s) SPUNGUARDMR 1 Light 1.05 osy (3.35) / .35 / .35) Sterile packaging. SPUNGUARD "" Regular 1.2 osy /.375/.45/.375) Envol.de sterile. SPUNGUARD "* Working 1.5 osy (.525 / .45 / .525) Heavy Sterilization Wrap SPUNGUARDMR Super 1.85 osy (.7 / .45 / .7) Sterilization Work Wrap SPUNGUARD ** Regular 1.4 osy /.45/.5/.45) Sterile Wrap SPUNGUARD8 * Average weight 1.8 osy (.65 / .5 / .65) Sterile Wrap SPUNGUARD "* Work 2.2 osy /.85/.5/.85) Sterile Heavy Wrap SPUNGUARD Ultra 2.6 osy (1.05 / .5 / 1.05) Sterile Wrap Two sterilization wrapping systems 10 were prepared according to the present invention. One of the two systems had a lower general basis weight and therefore was mentioned as a regular class. The second sterilization wrapping system had a higher general basis weight, and therefore, it was mentioned as a heavy class. The outer casing 12 of the regular class system 10 was a spin-bonded / melt-blown / spunbonded laminate with an average overall basis weight of 1.4 ounces per square yard. The two outer layers of the outer wrap 12 each had a basis weight of 0.55 ounces per square yard and the inner layer of the melt blown had a basis weight of 0.3 ounces per square yard. The inner wrapper 14 of the regular class system 10 had an average overall basis weight of 1.4 ounces per square yard including the individual outer spun bonded base weights of 0.45 ounces per square yard and a base melt weight of internal melt 0.5 ounces per square yard. The outer shell 12 and the inner shell 14 were ultrasonically joined together in the same manner as the joint shown in Figure 1 including two continuous joints along two opposite parallel edges of the system and a series of spaced-spaced apart links just interior to each other. each of the continuous seam links or seams. The opposing edges found were not joined. The heavy-class sterilization wrapping system 10 has an outer wrap 12 made of a spin-bonded / melt-blown / spin-bonded laminate with an average overall basis weight of 2.6 ounces per square yard. The outer casing 12 was made of two layers of spunbonded each of which tube a basis weight of 1.05 per square yard and a medium melt-blown layer having a basis weight of 0.5 ounces per square yard. The inner casing 14 of the heavy duty class sterilization casing system 10 was also made from a meltblown / meltblown / spunbond and tube blown laminate an overall average basis weight of 1.8oz per square yard. This wrapper 14 included two outer spunbonded layers each of which had a base weight of 0.65 ounces per square yard and an inner meltblown layer having a basis weight of 0.5 ounces per square yard. The outer casing 12 and the inner casing 14 were joined to each other in the same manner as the regular class sterilization system described above. These two systems according to the present invention were tested against two sheets of the non-subject sterilization wrap produced by Baxter Healthcare of Deerfield., Illinois and sold as DualWrap ™ sterilization wrap. The DualWrap "* sterilization wrapping is sold to customers in a loose-leaf box with an entangled hydro-outer sheet and an alternate paper-based inner sheet in the box and with the individual sheets being not attached to each other. DualWrap sterilization has a general basis weight including both leaves of 3.57 ounces per square yard.This wrapper included a heavier outer leaf with a base weight of 2.02 ounces per square yard and a lighter inner leaf with a base weight of 1.55 ounces per square yard Each of the individual sheets of the samples were tested in the transverse and machine directions for resistance to grip stress in pounds and peak energy in inches-pounds The samples were also tested for penetration of dry spores in parts by thousands and the efficiency of bacterial filtering as a percentage.Each of the samples were also tested with respect to the Frazier porosity in a cubic foot per square foot per minute. Grip tension resistance and peak energy measurements were carried out according to the standard federal test method 191A, Method 5100 as modified by the 1992 protocol. The dry spore talc filtration efficiency test measures the ability of a cloth to resist the penetration of bacteria on the dry talc particles. A stream of air moving to a cubic foot per minute and carrying talc particles with a range of average diameters from 1 to 9 microns was pumped through the sterilization casing to the petri dishes filled with agar below. The Bacillus subtilis, var. Globgii. The dishes were grown at 37 ° C (plus or minus 2'C) for 24 hours. The bacterial colonies were then counted to determine the filtering efficiency and the efficiencies were then reported as the number of particles per one thousand penetrating particles. This test was carried out on the individual sheets according to the standard operating procedure ARO-003.

The bacterial filtering efficiency test is a measure of the ability of a material to prevent the passage of bacteria completely through it. To determine this, a culture of Staphylococcus aureus was diluted in 1.5% peptone water at a precise concentration. The culture suspension was pumped through a "Chicago" nebulizer at a controlled flow rate and fixed air pressure. The delivery of constant challenge to a fixed air pressure formed aerosol droplets with a main particle size (MPS) of approximately 3.0 um. The aerosol gostas were generated in a glass aerosol chamber and pulled through an Anderson sample of 6-phase viable particles that contained single sheets of the various casings that were being tested. The collection flow rate through the test sample and the Anderson sample were maintained at 28.3 LPM (1 CFM). Test controls and test samples were challenged for a 2-minute interval. A total of five samples were run for each of the tested materials.

The challenge delivery rate also produced a consistent level of 2200 ± 500 colonial forming units (CFU) on the test control plates. A test control was run by not using filter media in the air stream. In requirement for the control of test was that the average of control fell within the range of 1700-2700 units formed of colony (EFU). The test controls were run 4 to 5 times a day. A reference material was included after each set of test samples. The standard reference material used had filtering efficiencies of 97.5% ± 1.0.

The Anderson sampler, a sieve sampler, tapped the spray droplets onto the six agar plates based on the size of each drop. The agar medium used was soybean casein digestion agar (SCDA). The agar plates were incubated at 37 * C ± 2 ** C for 48 hours and the colonies formed for each bacterial-laden aerosol droplet were counted and bumped into "probable hit" values using the hole conversion chart provided. by Andersen. These converted accounts were used to determine the level of challenge delivered to the test samples. The distribution ratio of the colonies for each of the six agar plates was used to calculate the main particle size (MPS) of the challenge aerosol. Filtering efficiencies were calculated as a percentage difference between the test sample runs and the control average using the following equation: BFE% - C -T x 100 C Where: C - Average of control values. T = Total account for test material.

Frazier porosity was measured in accordance with Federal Test Method 5450 (Revised March 18, 1992).

As can be seen from Table II, the inner and outer casings of the heavy class sterilization system of the present invention provided a general system with peak energy and grip voltage values better overall than the Baxter DualWrap sterilization casing in addition. , the heavy class system of the present invention had a lower dry spore penetration rate and therefore a bacterial filtration efficiency higher than that of the Baxter material.

TABLE II Test Parameter DualWraD "" Ki suard One Steo "" HG1 Internal External Internal Holding Voltage, lbs MD 14.4 27.5 37.1 45.4 CD 13.2 16.0 26.8 35.7 Peak Energy, in-lbs MD 1.1 11.8 37.2 46.8 CD 1.6 18.4 32.4 46.1 Spore Dry, ppt2 10.6 18.4 2.6 1.4 BFE3,% 73 56 78 73 Porosity Frazier Pie / cube foot / cubic / min.21.0 43.4 44.2 44.0 Base weight, ounces per yard2 1.55 2.02 1.89 2.49 1 Heavy class - contains 0.5 ounces per square yard of fiber formed by blowing melted, the remaining weight is fiber joined by spinning. 2 Particles per one-thousand 3 Efficiency of Bacterial Filtration Referring to Table III, the regular class sterilization wrapping system of the present invention when compared to the Baxtger DualWrap "* sterilization wrapper provided comparable grip tension values and better peak energy values. Regular class sterilization wrapper had a lower dry spore penetration rate and therefore a higher bacterial filtering efficiency due to the nature of the individual components than what the DualWrap sterilization wrapper did ".

TABLE II Test Parameter DualW: rap. "Ki suard One SteDH * HG1 Internal External Internal Exerna Holding Tension, lbbss MD 14.4 27.5 22.4 26.7 CD 13.2 16.0 14.2 20.2 Peak Energy, in-lbbss MD 1.1 11.8 17.3 24.4 CD 1.6 18.4 13.8 23.2 Spore Dry, ppt2 10.6 18.4 0.8 1.2 BFE3,% 73 56 72 75 Porosity Frazier Pie / cub ft / 2 / min 21.0 53.4 47.8 73.0 Base weight, ounces per yard2 1.55 2.02 1.44 1.43 1 Regular Class - the inner wrap contains 0.5 ounces per square yard of meltblown fibers and the outer wrap contains 0.3 ounces per square yard of meltblown fibers with the weight of fiber bonded by spinning constituting the difference in weight total. 2 Particles per one-thousand 3 Efficiency of bacterial filtering.

The effectiveness of the product in actual use is the ultimate test of whether a product works. To determine the functionality of the sterilization wrapping system of the present invention to protect the contents of a package from contamination was carried out under study on three sterilization wrapping systems all of which were used to wrap packages which were subsequently sterilized using steam. For each of the three systems, 120 samples were prepared and tested in an effort to determine the overall effectiveness of the present invention in relation to each of the controls. As can be seen from Table IV, the first set of samples used the system of the present invention. Outer sheath 12 was a spin-bonded / melt-blown / spin-bonded laminate of 1.4 ounces per square yard including an inner melt blown layer with a basis weight of 0.3 ounces per square yard and two layers bonded together. outer yarns, each having a basis weight of 0.55 ounces per square yard. The 1.4 oz. Per square yard 14 wrap was also a spin-bonded / melt-blown / spin-bonded laminate including a melt blown layer having a basis weight of 0.5 oz. Per square yard and two plies joined by outer yarns, each having a basis weight of 0.45 ounces per square yard. The outer casing 12 was ultrasonically joined to the inner casing 14 in a manner similar to that shown in Figure 1. The ultrasonic bonding techniques and equipment are well known.

Control I was two unclamped sheets of a polypropylene sterilization wrap from current Kimberly-Clark Corporation that has historically shown less than 3% contamination when using sequential wrapping techniques. Each of the unclamped sterilization wrap sheets made of a spin-bonded / melt-blown / spin-bonded laminate has an approximate overall basis weight of 1.4 ounces per square yard including a melt blown layer of 0.4. - 0.5 ounces per square yard and two layers bonded per yarn of approximately 0.45 ounces per square yard.

The control II was made of two sheets of unclipped muslin fabric with each sheet being made of two layers of a muslin fabric of 140 count beads sewn together. The wrapping of packages sterilized with two sheets of muslin cloth not historically fastened showed around 10% - 26% contamination.

All 120 packages for each of the sample controls were prepared using a double sequential wrapping method, that is, folding a sheet around the package followed by repeating the process by folding a second sheet of wrap around the package. These packages were wrapped in this manner to represent the most commonly used method of wrapping (sequential, double wrapping). The 120 samples of the invention were wrapped simultaneously with two wrapping sheets which were ultrasonically joined together. All packages, including controls, were sterilized using steam. Once sterilized, the packages were sent from the sterilization-processing department of a hospital to the operating room and from the operating room returned to the warehouse to simulate a canceled procedure and then back to the operating room within a period of time. two days The package contents were then grown microbiologically to determine the percentage of contaminated packages. The results of this study are given in Table IV.

TABLE IV STUDY RESULTS OF STERILITY EFFECTIVENESS IN RELATION TO EVENTS % of Packages No. of Coated Contaminated Packages Single Step Sterilization Wrap System (Ultrasonically Molten Polypropylene Wrap Sterilization) 1/120 0.83 I Control - Kimberly-Clark 0/120 0 Control II Polypropylene Sterilization Wrap - 140 Thread Count Fabric 12/120 10.0 As can be seen, the premilization envelope system of the present invention only had one contaminated packet of 120 total packets, for a packet contamination percentage of 0.83%. Control I had no contaminations and Control II (cloth) of yours 12 contaminations per 120 packages for a package contamination percentage of 10%. At a confidence level of 95%, the contamination level of the sterilization wrapping system of the present invention and Control I were not statistically different. The same 95% confidence level, both the sterilization envelope system of the present invention and Control I had significantly lower contamination rates than Control II. As a result of this, it can be seen that using two sheets of sterile wrapping in a simultaneous wrapping function will protect the package contents as well as the double sequential wrapping with unclamped sheets.

The amount of time required to wrap and open a package is another important feature of the present invention and is particularly important in hospitals in relation to labor costs for the preparation and opening of hospital goods. To demonstrate the packaging and opening time savings incurred when using the present invention, a time study was conducted in a hospital to compare the time it takes to wrap and open the system of the present invention discussed in Table IV and the Control I system and the Control II system which were sequentially double and open enveloped and also discussed in Table IV. As previously noted, the Control I and Control II systems were composed of two sheets of sterilization wrap that were not attached to each other. The method of simultaneous wrapping with the present invention and the double sequential method with the Control I and II wraps were carried out on a variety of articles including towel packs, vessels and instrument trays. The results are shown in Table V given below.

TABLE V STERILIZATION WRAPPING SYSTEM SINGLE PASSAGE SAVING TIMES VS WRAPPING OPENING Control I 49% 48% Control II 47% 42% Based on the related time study, the sterilization system of the present invention provided 49% savings in wrap time compared to the Control I system and a 47% time saving compared to the Control system II. With respect to the opening of the sterilized packages, the sterilization system of the present invention provided a 48% reduction in opening time compared to the Control I system and a 42% saving in time compared to the opening with with respect to the Control II system. Consequently, the joint connection of the outer casing 12 and the inner casing 14 of the sterilization casing system of the present invention provides a real improvement in time savings with respect to handling / wrapping and unwinding of sterilized packets in the hospital. As a practical matter, an article can be wrapped and unwrapped in almost half the time it takes with a conventional double sequential wrap. Consequently, the present invention can and does provide cost savings and real time to the end user.

Having described the invention in detail, it should be evident that various modifications and changes can be made without departing from the spirit and scope of the present invention. For example, a wide variety of individual sterilization casings have been described there. Therefore, a wide variety of combinations of internal and external wraps are

Claims (16)

Possible including combinations of both sheets of reusable and disposable sterile wrapping. The inner and outer wrappings can be made of the same or different base weight materials to design specific properties within each of the wraps. In addition, a wide variety of binding techniques are also discussed which can be used alone or in combination with one another to impart variable binding patterns to the sterilization wrapping system of the present invention. Consequently, these and other modifications are contemplated to be within the spirit and scope of the following clauses. CLAIMS Having described the invention is considered as a novelty and therefore the content of the following clauses is claimed as property:

1. A single pass sterilization system comprising: an outer envelope made of a first sterilization sheet superimposed on an inner envelope made of a second sterilization sheet each sheet will be independent of one another and joined to the other in one or more attachment sites.

2. The sterilization wrapping system as claimed in clause 1, characterized in that said first sterilization sheet is formed of a first fibrous sheet, and said second sterilization sheet is formed of a second fibrous sheet.

3. The sterilization wrapping system as claimed in clause 1, characterized in that said sterilization wrapping system has a first outer surface and a second outer surface each defining a respective surface area and wherein said joining sites occupy not more than 50% of the surface area of either the first or second outer surfaces of said sterilization wrapping system.

4. The sterilization wrapping system as claimed in clause 1, characterized in that said sterilization wrapping system defines a first zone and a second zone, said first zone having a greater number of said union sites per unit area than said second zone.

5. The sterilization wrapping system as claimed in clause 4, characterized in that said second zone is surrounded by said first zone.

6. The sterilization wrapping system as claimed in clause 1, characterized in that said plurality of joining sites comprises two continuous seams joining said outer wrapping to said internal wrapping.

7. The sterilization wrapping system as claimed in clause 1, characterized in that said outer sheath and said inner sheath each have a resistance to the grip tension and the resistance to the grip tension of said outer sheath is greater than the one of said internal envelope.

8. The sterilization wrapping system as claimed in clause 7, characterized in that said internal wrapping has a dry spore penetration rate which is lower than that of said outer wrapping.

9. The sterilization wrapping system as claimed in clause 8, characterized in that said internal wrapping has a bacteria filtering efficiency that is greater than that of said outer wrapping.

10. The sterilization wrapping system as claimed in clause 8, characterized in that said internal wrapping has a bacterial filtering efficiency that is lower than that of said outer wrapping.

11. The sterilization wrapping system as claimed in clause 9, characterized in that said internal envelope has a peak energy and said outer envelope has a peak energy, said peak energy of said outer envelope being greater than that of said internal envelope.

12. The sterilization wrapping system as claimed in clause 1, characterized in that said inner and outer shells are visually different from one another.

13. A single pass sterilization wrapping system comprising: an outer wrap made of a laminate of resistance barrier fabric and an inner wrap made of a woven barrier laminate. Said resistance barrier fabric laminate and said barrier fabric laminate being positioned adjacent to each other in a generally face-to-face relationship, said laminates being joined to one another at one or more attachment sites; said laminate of resistance barrier fabric comprises a first resistance layer made of randomly deposited fibers, a second resistance layer made of randomly deposited fibers, and an intermediate barrier layer made of randomly deposited fibers, said fibers in said intermediate barrier layer having an average fiber diameter which is smaller than the average fiber diameter of the fibers in any of the first and second strength layers, said intermediate barrier layer being placed between and bonded to the first reinforcing layers and second, said laminate of barrier fabric comprises a third resistance layer made of randomly deposited fibers, a fourth resistance layer made of randomly deposited fibers, and a second intermediate barrier layer made of randomly deposited fibers, said fibers in said second layer. intermediate barrier layer having an average fiber diameter which is smaller than the average fiber diameter in any of the third and fourth resistance layers, said second intermediate barrier layer being placed between and attached to said third and fourth resistance layers; said outer casing having a grip strength greater than that of said inner casing, said inner casing having a dry spore penetration cup that is lower than that of the outer casing and said inner casing has a bacterial filtration efficiency that is greater than that of the outer envelope.

14. The sterilization wrapping system as claimed in clause 12, characterized in that said outer sheath and said inner sheath are joined to one another along the entire length of two generally parallel edges of said sterilization sheath.

15. The sterilization wrapping system as claimed in clause 14, characterized in that said sterilization wrapping system has a plurality of separate and spaced junction points joining said outer wrapping to said internal wrapping just inside of both of said two generally parallel edges of said sterilization wrapping system.

16. The sterilization wrapping system as claimed in clause 15, characterized in that said outer wrapping is visually distinguishable from said inner wrapping. In testimony of which I sign the present in Mexico, D.F., the KUHH 195 ^