This application relates generally to barrier fabrics and, more specifically, to coated barrier fabrics for use in reusable medical products.
Barrier fabrics are generically characterized as being resistant to penetration by liquids. Because of this property, barrier fabrics are especially suited for use in the medical field to prevent or control the spread of infectious microorganisms, such as viruses and bacteria found in blood, and other potentially infectious material (“OPIM”) associated with, for example, surgical procedures.
Barrier fabric properties are critical for medical products such as surgical drapes that are used to maintain sterile surgical or procedure fields and protective apparel such as surgical or isolation gowns. Particularly where there is a possibility of coming into contact with bodily fluids, every effort is made to protect the health professional and the patient. Health professionals routinely use medical barrier fabrics during surgery, the drawing of blood, or while working with specimens containing contaminated fluids to both protect themselves and to avoid cross or secondary contamination of subsequent patients through the inadvertent transmission of infectious materials.
Generally, there are two types of medical barrier fabrics: (1) single use, i.e., disposable, fabrics, and (2) reusable fabrics. Performance of the single use or disposable fabrics in terms of liquid resistance is generally acceptable; however, these fabrics often fail to provide the spectrum of properties deemed necessary to achieve desirable protection in many medical applications. Additionally, single use items contribute significantly to the volume of medical waste and are inconsistent with accepted principles of environmental sustainability. Reusable medical barrier fabrics, on the other hand, can offer equivalent or better performance with respect to liquid resistance, better fabric drape, wearer comfort, and lower cost per use. However, it is also known that reusable barrier fabrics are commonly associated with diminished protective performance over the course of the usable service life.
Importantly, reusable medical gowns, surgical drapes, and other non-disposable medical barrier fabric products have requirements that distinguish them from other products or garments that incorporate barrier fabrics. To wit, after each use, a reusable surgical gown, for example, must be washed, dried, and sterilized for subsequent reuse. These procedures often involve harsh detergents and high temperatures which can quickly degrade the barrier properties of the gown and limit the number of times the gown can be reused.
A typical, institutional laundering/autoclaving cycle for such reusable medical products generally comprise one or more initial flushes in which the products are soaked in water at 90°−100° F. for two to five minutes. Following the one or more flushes, the products are soaked in an alkali bath at approximately 120°−160° F. for three to ten minutes to loosen dirt. Next the products are placed in a detergent bath at approximately 160° F. for approximately five to ten minutes. This is followed by one or more rinsings at temperatures that may be progressively reduced from about 140° F. to ambient temperature. The products are mechanically agitated in some, if not all of these baths. Also, following each bath, there is a drain to minimize the liquid carried over to the succeeding process. Finally, there is an acid sour bath in which the pH is adjusted to the 4.0 to 7.0 range, and in which a softening agent may also be employed. After washing, the products are extracted (spin or hydraulic press) to remove as much water as possible prior to drying. The products are then dried in a tumbling dryer at an average temperature of 160° F. Typical drying times for products are in the order of 15 to 30 minutes. It is to be noted that there can be hot spots in such dryers, which can subject the products to temperatures in excess of 400° F. After drying, the products are placed in an autoclave and sterilized by pressurized steam at a temperature of approximately 270° F. for at least four minutes in a commercially available pre-vacuum steam sterilizer. Parameters for sterilization will differ for a gravity steam sterilizer.
These harsh conditions are several orders of magnitude greater than those that exist in the laundering or dry cleaning of barrier fabrics incorporated in ordinary garments. In fact, many of the barrier fabrics intended for use in normal (e.g., non-medical) garments, such as foul weather gear, become unusable after a single, or relatively few, institutional laundering/autoclaving cycles.
While the efforts to produce reusable barrier fabrics with required liquid and microorganism resistance for use in medical applications have seen some success, fabric coatings known in the art tend to degrade the feel of the fabric and give the coated fabric a rubberized finish, which is not appealing for many fabric uses, particularly garments. Moreover, heavy abrasion or multiple harsh institutional laundering/autoclave cycles often result in breakdowns in the protective properties of some known reusable barrier fabrics, which can significantly shorten the potential useful life of the fabrics.
It thus would be beneficial to provide an improved coated barrier fabric, such as for use in a reusable medical product, that achieves excellent liquid resistance without sacrificing the comfort or the feel of the fabric. Further, the fabric should be able to sustain said barrier properties after at least 10 institutional laundering/autoclaving cycles without sacrificing the comfort or the feel of the fabric.
The present invention relates generally to barrier fabrics and, more specifically, to coated barrier fabrics for use in reusable medical products.
In one embodiment, a coated barrier fabric is provided that includes a first ply and a second ply each comprising a coated side and a non-coated side, wherein the first ply and the second ply are peripherally joined together to form the barrier fabric, wherein the coated side of the first ply and the coated side of the second ply face each other and define an interior of the barrier fabric, with each coated side able to come into direct contact with one another but remain movable thereagainst and able to form a gap therebetween, and wherein the non-coated side of the first ply and the non-coated side of the second ply face opposing directions and define an exterior of the barrier fabric.
In another embodiment, a reusable medical product is provided that includes a two-ply barrier fabric having a first ply and a second ply each comprising a coated side and a non-coated side, wherein the first ply and the second ply are peripherally joined together to form the barrier fabric, wherein the coated side of the first ply and the coated side of the second ply face each other and define an interior of the barrier fabric, with each coated side able to come into direct contact with one another but remain movable thereagainst and able to form a gap therebetween, and wherein the non-coated side of the first ply and the non-coated side of the second ply face opposing directions and define an exterior of the barrier fabric. In one example, the reusable medical product can be a surgical gown, isolation gown, or surgical drape. In another example, the two-ply coated barrier fabric is provided within a critical zone(s) of the reusable medical product.
In another embodiment, a method for making a two-ply barrier fabric for use in a reusable medical product is provided and includes applying, via a single pass, a non-fluorine containing polymer coating to a side of each of two separate plies of a woven or knitted fabric, wherein the coating is applied at a rate of from 1 g/m2 to 75 g/m2. Next, the coating on the fabric is cured, by a single cure process and then the coated first ply and second ply are peripherally joining together to form the barrier fabric, wherein the coated side of the first ply and the coated side of the second ply face each other and define an interior of the barrier fabric, with each coated side able to come into direct contact with one another but remain movable thereagainst and able to form a gap therebetween, wherein the non-coated side of the first ply and the non-coated side of the second ply face opposing directions and define an exterior of the barrier fabric, and wherein the barrier fabric is suitable for use within or as a reusable medical product. In one example, the polymer coating is silicon and applied at a rate of from 10 g/m2 to 50 g/m2. In another example, the content of the first and second ply comprise at least 25% polyester or at least 25% polyamide.
The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with a Detailed Description of the embodiments given below, serve to explain the principles of the invention.
The exemplary embodiments described herein are provided for illustrative purposes and are not limiting. Other exemplary embodiments are possible, and modifications may be made to the exemplary embodiments within the scope of the present disclosure. Therefore, this Detailed Description is not meant to limit the scope of the present disclosure.
Use of descriptive terms hereinbelow such a left, right, top, bottom, front, back, or vertical as the terms pertain to or describe the gown 10 are to be interpreted from the viewpoint of a wearer of the gown 10, when properly donned, unless otherwise noted.
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One or more of the terminal cuffs 36, in other embodiments, may be absent altogether, with the long sleeves 28, 30 simply defining an opening that is hemmed at a distal end of each sleeve 28, 30. In another example, the long sleeves 28, 30 may be short sleeves or they may be no sleeves at all, if so desired. In other embodiments, the terminal cuff 36 may be replaced with long sleeves 28, 30 having thumb loops, for example. Moreover, although the central body 26 and the sleeves 28, 30 are shown as one piece in
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It will be appreciated that alternative embodiments can take forms other than a reusable surgical gown 10. For example, the fabric 12 may be alternatively embodied in other reusable medical products such as a surgical drape, stand or table covers, wrappers, or other protective apparel. In the case of an isolation gown, the AAMI PB70 Standard dictates that the critical zones 11 are the entire gown, including the seams, but excluding the cuffs, hems, and bindings. In the case of a surgical drape, the critical zone 11 can be defined as the area of the drape generally surrounding the fenestration. Regardless of the embodiment, it is to be understood that the critical zones 11 of embodiments (e.g., gowns, drapes, etc.) may be fabricated from a coated, two-ply barrier fabric 12. However, the fabric 12 may be used in other embodiments (besides in the critical zones 11 of gowns and drapes). In this way, the fabric 12 is not limited in use to any specific reusable medical product.
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The material for the coating 42 can be applied to one side of each of the first and second plies 44, 46 via conventional coating technologies to impart a solid, semi-solid, liquid, or vaporized (e.g., sublimation) chemistry to coat one side of the fabric 12, as is known in the industry. For example, the coating 42 may be applied to the fabric 12 using a knife coat, spray coat, foam coat, or similar methodology. It will be understood that alternative methodologies, as generally known in the art, besides those specifically listed can be used to apply the coating 42 to one side of each of the first and second plies 44, 46 of the fabric 12. Upon application, the material for the coating 42 can interact with the surface of the ply 44, 46 in any number of ways, as would be understood in the industry, to provide the coating 42. For example, the applied coating material can adhere to the surface of the ply 44, 46, and may form a layer thereover, such as by binding to surface fibers (e.g., via covalent and/or non-covalent bonds, etc.) or the coating material can become entrapped within the fibers of the ply 44, 46. Further, a combination of some of all of polymerization, bonding, and physical entrapment can be used to adhere the coating 42 to the plies 44, 46.
Further, when applying the coating 42, it is desirable to limit the penetration of the coating 42 through the ply 44, 46. It is known in the industry that applying a coating to a side of one ply 44, 46 can result in an undesirable “bleed-through” effect in which the applied coating may penetrate therethrough and appear on the other side of the ply 44, 46. It will be understood that the term ‘coated’ as used herein excludes the bleed-through of the coating 42. It will also be understood that the term ‘non-coated’ is inclusive of the bleed-through of coating 42 material. For example, if a coating 42 is applied to one side of a ply 44, 46, then the side of the ply 44, 46 that the coating 42 was applied to would be considered ‘coated’; however, the opposing side of the ply 44, 46, to which a coating 42 was not applied, could be considered ‘non-coated’, even if it exhibits bleed through effects from the coating 42 on the opposing side of the ply 44, 46.
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When the coating 42 is applied to a ply (first or second ply 44, 46 of the fabric 12), the coating 42 can be applied at a rate of from 1 grams per square meter (“g/m2”) to 75 g/m2. More specifically, in one embodiment, the coating 42 can be applied at a rate of from 10 g/m2 to 65 g/m2. In another embodiment, the coating 42 can be applied at a rate of from 15 g/m2 to 50 g/m2. In another embodiment, the coating 42 can be applied at a rate of from 15 g/m2 to 35 g/m2. In a further embodiment, the coating 42 can be applied at a rate of from 20 g/m2 to 30 g/m2. Even more specifically, in an embodiment, the coating 42 can be applied at a rate of approximately 1, 2, 5, 10, 15, 20, or 25 g/m2. Further, in an embodiment, the total, cumulative weight of the coating 42 across both the first ply 44 and second ply 46, combined, can be 100 g/m2 or less. In another embodiment, the total, cumulative weight of the coating 42 across both the first ply 44 and second ply 46, combined, can be 75 g/m2 or less. In yet another embodiment, the total, cumulative weight of the coating 42 across both the first ply 44 and second ply 46, combined, can be 50 g/m2 or less. For example, the coating 42 on the first and second plies 44, 46 may be 20 g/m2 each—for a total of 40 g/m2 across both plies 44, 46, and performed in a single pass. Alternatively, the coating rate on each ply 44, 46 may vary. For example, the coating 42 on the first ply 44 may be 20 g/m2 and the coating 42 on the second ply 46 may be 25 g/m2—for a total of 45 g/m2 across both plies 44, 46, and performed in a single pass.
Applying such a light coating 42 to the first and second plies 44, 46 of the fabric 12 results in plies 44, 46 with a desirable comfort and feel. Some known coated fabrics used in reusable medical products feature thick coatings. As such, these fabrics have an unpleasant rubber-like feel. Specifically, medical apparel made from such thickly coated fabrics are uncomfortable to wear, especially for long durations of time (such as during a medical procedure). In contrast, applying a light coating 42 on the first and second plies 44, 46 (as opposed to a thicker coating on a single ply) results in a finished fabric 12 that is similar in feel and comfort to an uncoated fabric, but with the desirable barrier properties of a coated fabric 12. As such, the fabric 12 achieves the desirable properties of a reusable barrier fabric without sacrificing on comfort or feel.
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Because only the interior-facing sides of the first and second plies 44, 46 are coated, it is understood that the coating 42 of the first ply 44 will rub, but still move freely due to coating characteristics, against the coating 42 of the second ply 46. Such is preferable to the coated side of either ply being directly exposed to the outside or exterior environment. Coatings 42 are generally abraded and/or degraded when they come into contact with any number of environmental factors. For example, if the coated side of the ply were on the exterior 50 of the fabric 12 as opposed to the interior 48, then the coating 42 would be exposed during the institutional laundering/autoclave cycle where the coating 42 could be damaged by the harsh detergents, agitation during a washing phase, or heat during a drying phase. Such abuse could severely diminish the useful life of the fabric 12 as a barrier fabric by degrading the coating 42.
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Advantageously, the coated, two-ply barrier fabric 12 described herein avoids problems of other barrier fabrics known in the art. For example, the two-ply construction of the fabric 12, where the coated side of the first ply 44 and coated side of the second ply 46 are interior 48 facing, enhances the durability of the fabric 12. By protecting the coating 42 from environmental factors (e.g., institutional laundering/autoclave cycles) the useful life of the fabric 12 is extended. Other known barrier fabrics often utilize chemical hydrophobic finishes, containing fluorocarbons, that are known to diminish through repeated processing and use cycles. Leaving the coating exposed can drastically reduce the lifespan of the barrier fabric. Furthermore, the construction of the fabric 12 offers a more reliable barrier without sacrificing the feel of the fabric 12. By utilizing two plies 44, 46 with thin coatings 42, the fabric 12 can achieve the barrier properties of a fabric with a much thicker coating without compromising on the feel of the fabric. Whereas fabrics known in the art with thicker coatings typically have an uncomfortable, undesirable rubber-like feel, the fabric 12 described above maintains the feel and comfort of a woven or knitted fabric because the coated sides of the plies 44, 46 are not exposed to a user or wearer. Moreover, the two coated plies 44, 46 of the fabric 12 offer a barrier redundancy not offered by coated barrier fabrics known in the art. The two-ply configuration of the fabric 12 yields a higher hydrostatic resistance than either of the two plies 44, 46 would yield individually or would be yielded by a single layer or ply that was coated with the same quantity of coating 42 utilized cumulatively for the two individual plies 44, 46. These, other features, and combinations thereof (as described in the preceding paragraphs) improve upon the shortcomings of reusable barrier fabrics known in the art. Other advantages and technical effects of the embodiments of this invention will become evident to one skilled in the art from the preceding description.
While the present invention has been illustrated by the description of various embodiments and while these embodiments have been described in some detail, it is not the intention of the Applicant to restrict or in any way limit the scope of the invention to such detail. Additional advantages and modifications will readily appear to those skilled in the art. The invention in its broader aspects is therefore not limited to the specific details and illustrative examples shown and described. Accordingly, departures may be made from such details without departing from the scope of the general inventive concept.