This invention relates to antimicrobial fabrics, and more particularly to antimicrobial fabrics or fabric articles such as blankets, bed sheets, fitting sheets, pillow cases, privacy curtains, and others articles suitable for use in environments such as healthcare environments in which articles with antimicrobial properties are desirable.
Fabrics, such as blankets, used in medical healthcare environments, e.g., in hospitals and long-term care facilities, are often formed of woven or knit fabric, e.g., formed of cotton or a blend of polyester and cotton. These blankets can be quite heavy, and generally have only a relatively low value of CLO (a measure of thermal insulation wherein 1 CLO=0.155 m2K/W), and, accordingly, only a low CLO-to-weight ratio. By way of example only, a typical woven hospital blanket formed by standard textile procedures may have a weight of 10.3 oz/yd3, thickness of 0.086 inch, CLO of 0.467, and CLO-to-weight ratio of 0.045. Hospital blankets typically also have only a relatively short useful life, e.g., in some cases only a few months, after which repeated exposure to the harsh conditions of industrial laundering, including high temperatures, bleach, and high pH, causes the blankets to fall apart and disintegrate.
According to one aspect of the disclosure, an antimicrobial fabric, e.g. suitable for use in a medical healthcare blanket, comprises a fabric of micro-denier polymer fibers having at least one raised surface, and an antimicrobial system applied to the fabric, the antimicrobial fabric having durable antimicrobial properties after at least 50 industrial laundering cycles (e.g., at 160° F. with alkali detergent and peroxide).
Implementations of this aspect of the disclosure can include one or more of the following additional features. The polymer of the polymer fibers is selected from among polyester, polypropylene, polyamide, and combinations thereof. The antimicrobial system has durable antimicrobial properties after at least 100 industrial laundering cycles, or after at least 150 industrial laundering cycles, or after at least 200 industrial laundering cycles. The fabric has a double face knit configuration with velour/velour finish surfaces. The antimicrobial system comprises an antimicrobial agent, a rechargeable sequestering agent isolating the antimicrobial agent, and a binding agent binding the sequestering agent to surfaces of the polymer fibers. The antimicrobial agent comprises peroxide. The sequestering agent is a complex of metal oxide, metal salt, metal peroxide, and hydrogen peroxide. The metal is selected from among the group of: zinc, magnesium, and zirconium. The metal salt is selected from among the group of: chloride, nitrate, acetate, and bromide. The rechargeable sequestering agent comprises zinc oxide, or zinc hydroxide, or zinc salt, e.g. zinc oxide and/or zinc salt. The sequestering agent is rechargeable by contact with peroxide antimicrobial agent. The binding agent comprises an acrylate (or polyurethane). The antimicrobial system comprises: an antimicrobial agent, and a rechargeable sequestering agent isolating the antimicrobial agent, the rechargeable sequestering agent being incorporated in the polymer fiber as micro-dimensioned or nano-dimensioned particles. The micro-dimensioned or nano-dimensioned particles of the rechargeable sequestering agent are distributed throughout the cross section of the polymer fibers. The micro-dimensioned or nano-dimensioned particles of the rechargeable sequestering agent are distributed in a relatively greater concentration in an outer layer of the polymer fibers. The micro-dimensioned or nano-dimensioned particles of the rechargeable sequestering agent are exposed on an outer surface of the polymer fibers.
According to another aspect of the disclosure, a method for contributing to sanitary healthcare environment comprises: 1) providing an antimicrobial fabric, e.g. a medical healthcare blanket, as described above, having a predetermined enhanced level of antimicrobial protection, and 2) subjecting the antimicrobial fabric to frequent industrial laundering cycles including contact with an aqueous solution of hydrogen peroxide, thereby to recharge antimicrobial protection provided by the antimicrobial fabrics to at least a predetermined minimum acceptable level, and 3) repeating step 2) for at least 50 industrial laundering cycles.
Implementations of this aspect of the disclosure can include one or more of the following additional features. The polymer of the polymer fibers is selected from among polyester, polypropylene, polyamide, and combinations thereof. The multiple industrial laundering cycles comprises at least 100 industrial laundering cycles, or at least 150 industrial laundering cycles, or at least 200 industrial laundering cycles.
According to another aspect of the disclosure, an antimicrobial fabric material, e.g. a medical healthcare blanket fabric material, comprises a fabric of micro-denier polymer fibers having at least one raised surface, and an antimicrobial system having durable antimicrobial properties after at least 50 industrial laundering cycles. Implementations of this aspect of the disclosure can include one or more of the following additional features. The antimicrobial system has durable antimicrobial properties after at least 100 industrial laundering cycles, or after at least 150 industrial laundering cycles, or at least 200 industrial laundering cycles. The antimicrobial system comprises: an antimicrobial agent, a rechargeable sequestering agent isolating the antimicrobial agent, and a binding agent binding the sequestering agent to surfaces of the polymer fibers.
Other implementation of this aspect of the disclosure can include one or more of the following additional features. The antimicrobial system comprises: an antimicrobial agent, and a rechargeable sequestering agent isolating the antimicrobial agent, the rechargeable sequestering agent being incorporated in the polymer fiber as micro-dimensioned or nano-dimensioned particles. The micro-dimensioned or nano-dimensioned particles of the rechargeable sequestering agent are distributed throughout the cross section of the polymer fibers. The micro-dimensioned or nano-dimensioned particles of the rechargeable sequestering agent are distributed in a relatively greater concentration in an outer layer of the polymer fibers. The micro-dimensioned or nano-dimensioned particles of the rechargeable sequestering agent are exposed on an outer surface of the polymer fibers.
In another aspect, the disclosure features a fabric comprising polymer fibers and an antimicrobial system. The antimicrobial system comprises a sequestering agent and a binding agent binding the sequestering agent on surfaces of at least some of the polymer fibers. In some implementations, at least some of the sequestering agent remains on the surface of the at least some of the polymer fibers after 50 cycles of laundering.
In another aspect, the disclosure features a fabric comprising polymer fibers and an antimicrobial system. The polymer fibers comprise a polymer. The antimicrobial system comprises a sequestering agent dispersed within the polymer of at least some of the polymer fibers.
In another aspect, the disclosure features a fabric comprising yarns and an antimicrobial system. The yarns comprise a polymer and the antimicrobial system comprises a sequestering agent dispersed within the polymer of at least some of the yarns.
Implementations of the above fabrics can incorporate one or more of the following features. The polymer fibers comprise micro-denier fibers and comprise a polymer selected from among polyester, polypropylene, polyamide, nylon, and combinations thereof. The fabric has at least one raised surface, which can include a grid or reverse grid pattern or a jacquard pattern. The binding agent comprises an acrylate or polyurethane. The antimicrobial system comprises an antimicrobial agent having oxidizing property. The fabric comprises 100% polymer fibers. The polymer fibers constitute 50 wt % or more of the fabric. The fabric comprises cotton, and the polymer and fiber weight ratio is 50:50.
Implementations of the above fabrics can also incorporate one or more of the following features. The sequestering agent is dispersed randomly throughout a cross-section of the at least some of the polymer fibers. The polymer fibers comprise extrusion of the polymer and the sequestering agent dispersed throughout an entire cross section of the fibers. The polymer fibers comprise a polymer core and a sheath over the core and the sequestering agent is substantially in the sheath.
Implementations of the above fabrics can also incorporate one or more of the following features. The sequestering agent is dispersed randomly throughout a cross-section of the at least some of the yarns. The yarns are co-spun, comprising the polymer and the sequestering agent. The yarns comprise a core comprising the polymer and a sheath over the core and the sequestering agent is substantially in the sheath.
In another aspect, the disclosure features a curtain that comprises any one or more of the above fabrics.
In another aspect, the disclosure features a bedding sheet that comprises any one or more of the above fabrics. In some implementations, the fabric can be woven or knitted.
In another aspect, the disclosure features a mattress cover that comprises any one or more of the above fabrics.
In another aspect, the disclosure features a pillow case that comprises any one or more of the above fabrics.
In another aspect, the disclosure features a blanket that comprises any one or more of the above fabrics. In some implementations, the fabric comprises a knit with terry sinker loop and at least one raised surface in velour finish. The raised surface of the blanket can have a grid or reverse grid pattern or a jacquard pattern.
In another aspect, the disclosure features a set of fabric articles that comprises a blanket, a pillow case, and a mattress cover, at least one of which comprises one or more of the above fabrics. In some implementations, the set of fabric articles also includes a bedding sheet and/or a curtain, e.g. a privacy curtain.
In another aspect, the disclosure features a method comprising applying an antimicrobial system to a fabric that comprises polymer fibers. The antimicrobial system comprises a sequestering agent and a binding agent. The antimicrobial system can be applied in the form of a slurry. The binding agent comprises an acrylate or polyurethane fabric comprises 100% polymer fibers. The fabric comprises 50 wt % or more polymer fibers. The fabric comprises cotton and the polymer fibers and cotton have a weight ratio of 50:50. At least one raised surface of the fabric is formed before or after the antimicrobial system is applied. The at least one raised surface comprises a grid or reverse grid pattern or a jacquard pattern. The antimicrobial system comprises an antimicrobial agent applied after the sequestering agent and the binder. The antimicrobial agent is applied during a laundering cycle.
In another aspect, the disclosure features a method comprising coextruding a polymer material and an antimicrobial system to form coextruded fibers; and forming a fabric comprising the coextruded fibers. The antimicrobial system comprises a sequestering agent. In some implementations, coextruding comprises forming the coextruded fibers with a core-sheath construction, and the sequestering agent is substantially within the sheath. In some implementations, coextruding comprises forming the coextruded fibers with the sequestering agent dispersed throughout a cross-section of the coextruded fibers.
In another aspect, the disclosure features a method comprising co-spinning a polymer material and an antimicrobial system to form co-spun yarns, and forming a fabric comprising the co-spun yarns. The antimicrobial system comprises a sequestering agent. In some implementations, co-spinning comprises forming the co-spun yarns with a core-sheath construction, and the sequestering agent is substantially within the sheath. In some implementations, co-spinning comprises forming the co-spun yarns with the sequestering agent dispersed throughout a cross-section of the co-spun yarns.
In another aspect, the disclosure features a method comprising: 1) providing a fabric article comprising any one or more of the above fabrics that provides a predetermined enhanced level of antimicrobial protection, 2) subjecting the fabric article to frequent industrial laundering cycles including contact with an aqueous solution of hydrogen peroxide, thereby to recharge antimicrobial protection provided by the fabric article to at least a predetermined minimum acceptable level, and 3) repeating step 2) for at least 50 industrial laundering cycles. In some implementations, the multiple industrial laundering cycles comprises at least 100 industrial laundering cycles.
Implementations of this disclosure can incorporate one or more of the following advantages. For example, antimicrobial fabrics of this disclosure, e.g., in the form of a medical healthcare blanket, can be made of 100% synthetic fibers, such as nylon, polypropylene, and/or polyester or can be made of synthetic fibers blended with absorbing fibers, such as natural fibers (e.g., cotton, wool, etc.) or cellulosic fibers (e.g., rayon, Tencel, etc.). In some implementations, the polyester can be a micro-denier polyester polymer material, e.g., polyester, polypropylene, or polyamide, and the fabrics can have at least one raised surface and can be in a double face knit configuration, with velour/velour finish to offer, e.g.: relatively improved thermal insulation efficiency properties (e.g., a relatively higher CLO-to-weight ratio) as compared to conventional hospital blankets formed of cotton or a blend of polyester and cotton; and/or can retain relatively less water, e.g. about 31% less, as compared to traditional hospital blankets formed of cotton or polyester and cotton blend, resulting in significantly shorter drying times during industrial laundering cycles, e.g. about 70% less, with commensurate reduction in energy costs; and/or can have a relatively longer usable life than traditional hospital blankets formed of cotton or a blend of polyester and cotton.
The fabrics can be antimicrobial so that when used in hospitals or long-term care facilities (in the form of, e.g., bed blankets, bed sheets, pillows cases, curtains, drapes, etc., or others), the fabrics of this disclosure can serve as a first line of defense against transmission of disease and infection. In some implementations, an antimicrobial fabric, e.g. a medical healthcare blanket, of this disclosure can incorporate durable antimicrobial properties that assist patients to avoid contracting germs and/or bacteria, and thus create a more sanitary environment. Fabric articles in other forms, including, but not limited to, e.g., bed sheets, fitted sheets, pillow covers or cases, curtains (e.g., privacy curtains), and other fabric articles of the types typically used in an environment in which antimicrobial properties are desirable, can keep the entire environment surrounding a user at a reduced level, of even free, of infectious disease bacteria.
A chemical system that provides the fabrics with the antimicrobial properties can be applied in various ways and can be readily recharged or reloaded at a user's choice, e.g. at regular, planned intervals. The fabrics can remain antimicrobial after long term use and multiple cycles of industrial laundering. For example, the fabrics can be treated to include a sequestering agent and a binder that binds the sequestering agent to (or near) a surface of the fabrics and/or the fibers, with or without an active antimicrobial agent that is sequestered by the sequestering agent. The aesthetic properties and the thermal properties of the fabrics can be substantially unaffected by the application of the chemical system. In some implementations, the fabrics are treated without the active microbial agent and the user can choose to add the microbial agent at a preferred time or interval to activate the antimicrobial properties of the fabrics. In some implementations, the binder and the sequestering agent cause the active antimicrobial agent to be released at a controlled rate.
In another example, fiber or yarn materials are coextruded or co-spun with sequestering agents, with or without the active antimicrobial agents, to form fibers or yarns for formation of the fabrics. The sequestering agents (with or without the antimicrobial agents) can be distributed, e.g., substantially evenly, throughout a cross-section of a fiber or a yarn, or in a sheath of a fiber or a yarn, and can be secured to the fibers, yarns, and fabrics without binder. Extensive distribution of the sequestering agents at the level of individual fibers or yarns can provide desired antimicrobial properties to the fabrics, which can be activated, recharged, or reloaded in manners similar to those discussed above.
The sequestering agents are retained within the fabrics, e.g., through the binders and/or by being dispersed within fiber/yarn materials. The active antimicrobial agent can be recharged or reloaded multiple times to be sequestered by the retained sequestering agents, e.g., over the entire useful life of the antimicrobial fabric, during laundering cycles in which hydrogen peroxide is used, or at other times chosen by the user.
The details of one or more implementations of the disclosure are set forth in the accompanying drawings and in the description below. Other features, objects, and advantages of the disclosure will be apparent from the description and drawings, and from the claims.
Referring to
Over time, the fabrics and fabric articles of the disclosure, e.g., the blanket 10, in use in the environment 11 undergo frequent and repeated industrial laundering cycles under extreme conditions, including of high temperature water, disinfecting agents (e.g., hydrogen peroxide or bleach), and high pH, for reasons of sanitation and in efforts to combat transmission of disease and other unhealthy conditions. The fabrics and fabric articles of this disclosure, although being repeatedly subject to these conditions, have a relative long useful life in which the effectiveness of the antimicrobial properties can be well maintained, recharged, or reloaded. The fabrics and fabric articles of the disclosure are also designed to be energy efficient.
Referring to
As an example, the blanket 10 is formed of a suitable polymer or polymer blend, e.g. 100% or a high percentage of (higher than 50%) polyester, polypropylene, nylon, or polyamide, or combinations thereof. The polymer component of the blanket 10 allows the blanket to absorb less water during laundering and therefore to dry relatively more quickly and with less consumption of heat. The blanket 10 can also have a long use life because the polymer component is durable.
The blanket 10 can have at least one raised surface in a double face knit configuration. In the example shown in
Referring to
The fabric of blanket 10 can also have other constructions. For example, referring to
The fabrics shown in
In some implementations, the antimicrobial fabrics and fabric articles can be woven, e.g., basket weave, twill, satin, simple weave, etc., or knitted, e.g., single jersey, plated jersey, double knit, etc. The fabrics and fabric articles can be stretchable. For example, mattress covers or other fitted sheets can be stretchable for fitting.
Referring again to
In some implementations, suitable sequestering agents may include one or more of, e.g., metal oxide and metal salt, for example, zinc oxide, zinc acetate, zinc chloride, and others. Suitable binders can include acrylate, polyurethane, and others. The active antimicrobial agent can include hydrogen peroxide, Zinc peroxide, and others. Without intending to be bound by theory, it is believed that within the chemical system, one or more binders bind the sequestering agents to surfaces of the individual fibers (such as polyester fibers). The active antimicrobial agents, such as hydrogen peroxide, are sequestered by the sequestering agent to produce an oxidizing agent in the form of an insoluble complex to slowly release the antimicrobial agent in a slightly moist or humid condition. In some implementations, the binders can regulate release of the antimicrobial agent or oxidizing agent by providing required moist or humid release conditions. Again, not intending to be bound theory, it is also believed that the sequestering agent, such as zinc oxide or zinc salt, can react with hydrogen peroxide to produce oxidizing agents, such as zinc peroxide, to act as a disinfectant that kills bacteria. In some implementations, the bound sequestering agents adhere to the fibers or fabrics after long time use, e.g., including 10, 50, or 100 times or more industrial or home laundering cycles. The adhesion of the sequestering agents allows the active antimicrobial agents to be reloaded or recharged, and therefore, maintains the antimicrobial properties of the fabrics or fabric articles for a long time (details explained below).
The fabric 20 containing the chemical system can be made in various ways. For example, in some implementations, referring to
The chemical system applied to the fabric or fabric body can be in the form, e.g., of a dispersion or slurry of the sequestering agents (e.g., zinc oxide, zinc peroxide, and/or insoluble zinc salts) with the binders, and with or without the active antimicrobial agents. In some implementations, the applied chemical system does not include the active antimicrobial agents. Instead, the fabric is inactive until a user or a manufacturer adds the antimicrobial agents to activate the fabrics at a later time. The inactive fabrics can be stored for an extended period, or can be processed (e.g., made into different articles) before being activated. The user or manufacturer can choose to activate the fabrics at a desired time with a selected type and amount of antimicrobial agents, thereby to provide a desired level of antimicrobial properties.
In some implementations, a fabric body containing the binder(s) may resist being raised. In the procedure 30, the chemical system including the binder(s) is added to the pre-finished fabric without affecting the desired physical (e.g., raised surface or surfaces), thermal, and aesthetic appearance of the fabric 20. The antimicrobial agent(s) adheres to individual fibers of the fabric 30 and provides maximum efficacy.
In some implementations, the antimicrobial chemical system can also be applied before any of the fabric surfaces is raised, e.g., when the fabric has the terry sinker loop knit construction or when the fabric is a woven fabric made of coarse yarns that are 100% synthetic or a blend of natural fiber like cotton, rayon and synthetic fibers.
In some implementations, the process 30 can also be applied to fabrics having components different from those of the fabric 20. For example, the chemical system can be applied to traditional blankets, e.g., used in healthcare environments, that contain a blend of polyester and cotton at a weight ratio of 50:50. The blankets can be woven with coarse yarns that are not brushed. However, the blankets may have an abraded surface, e.g., occurred during use or laundering, that becomes similar to a raised surface discussed above. The blankets can also be brushed before laundering to form one or more raised surfaces. Such traditional blankets treated with the chemical system can have one or more advantages discussed for the fabric 20 and other fabric articles. For example, among others, the binders bind and retain the sequestering agents on the blankets during use and laundering cycles, and the antimicrobial agents can be recharged by adding active agents at selected times.
Alternatively, the fabric 20 can also be made using a process 40 shown in
The fibers and/or yarns can be made by coextruding or co-spinning one or more fiber/yarn materials (e.g., synthetic polymers) and components of the chemical system. For example, the sequestering agents in the form of metal oxide particles or powders (e.g., zinc oxide particles or powders) are added into polymer chips (e.g., polyester chips) that are used for forming the fibers. Alternatively, the sequestering agents can be added directly into an extrusion machine when the fibers are being extruded. The antimicrobial agents can be added with the sequestering agents, or at a later time, as discussed previously. In some implementations, it is not necessary to include any binding agent to bind the sequestering agents to the fibers or yarns. Instead, when co-spun or coextruded, the sequestering agents and the fiber/yarn materials are well mixed or integrated, examples of which are schematically shown in
Referring to
The fibers, yarns, fabrics, and fabric articles described above can incorporate a chemical system, including one or more sequestering agents, with or without the binder or the antimicrobial agent, in the form of particles, e.g., nano or micro-sized particles, on surfaces and/or in bodies of individual fibers. The materials can provide antimicrobial properties by releasing the antimicrobial agent and/or an oxidizing agent over an extended period of time and maintaining the properties under harsh laundering conditions. In addition, the materials can be recharged with antimicrobial agents (and the oxidizing agents) after initial use. For example, hydrogen peroxide is a common oxidizer or bleach disinfectant used in industrial laundering cycles. Accordingly, during each laundering cycle, the antimicrobial agent (and the oxidizing agent) is automatically recharged or reloaded (to be sequestered by the sequestering agents in the fibers, yarns, fabrics and fabric articles), commercially or at a consumer level. In some implementations, after initial use, additional antimicrobial agents can be added during the laundering cycles, or at other times. Other disinfectant oxidizing agents, such as Para acetic acid, can also be added to reload or recharge the antimicrobial agents or oxidizing agents.
In some implementations, the fibers of the fabrics or fabric articles, e.g., as shown in
The fabrics and fabric articles, such as the medical healthcare blanket 10, in the environment 11 described above can provide advantages, e.g., when compared to conventional or traditional medical healthcare blankets formed of cotton or a blend of polyester and cotton. For example, the blanket 10 (and/or other fabric articles of the disclosure) exhibits improved thermal insulation properties. The fabric articles of the disclosure can also have relatively low water retention, a relatively long usable life, and antimicrobial properties for resisting transmission of disease and other medical conditions. All of these features are discussed in more detail below, using the medical healthcare or other blanket 10 as an example. The other fabric articles, such as bedding (top or fitted) sheet 22, privacy curtain 26, floor covering 28, and others (shown or not shown in the figures) can also have one or more of the features/advantages described below.
The blanket 10 of the disclosure has relatively better thermal insulation efficiency properties than conventional blankets (e.g., traditional hospital blankets) made from cotton or a blend of polyester and cotton. For example, the blanket 10 of the disclosure has CLO of 0.812 (compared to CLO of 0.467 for a traditional hospital blanket) and a CLO-to-weight ratio of 0.140 (compared to 0.045 for traditional hospital blankets). The blanket 10 is also thicker, e.g. having a thickness, T, of about 0.154 inch (as compared to a thickness of about 0.086 inch for a traditional hospital blanket). The blanket 10 of the disclosure is also relatively lighter in weight than traditional hospital blankets. For example, the blanket 10 of the disclosure may weigh about 5.8 ounces/yard2 as compared to about 10.3 ounces/yard2 for a traditional hospital blanket. In combination, these features allow the blanket 10 to provide a user with increased comfort. The blanket has a relatively light weight, provides increased warmth and insulation with the thicker and thermally more efficient materials, while also providing durable antimicrobial properties that contribute to a relatively more sanitary environment through enhanced resistance to contracting germs and/or bacteria.
The blanket 10 of the disclosure also retains much less water during laundering, e.g. as compared to traditional hospital blankets formed of cotton or a blend of polyester and cotton. For example, the blanket 10 of the disclosure retains about 31% less water as compared to a traditional hospital blanket formed of cotton or a blend of polyester and cotton. As a result, the drying time for the blanket 10 following laundering is approximately 70% of that required for drying a traditional hospital blanket of cotton or a blend of polyester and cotton. The reduced water retention properties, resulting in shorter drying times, have the additional, particularly beneficial, effect of significantly lowering energy consumption and costs.
The blanket 10 of the disclosure can include micro-denier polymers materials and can have relatively greater longevity (i.e., longer useful life), e.g. as compared to traditional hospital blankets formed of cotton or a blend of polyester and cotton, through repeated industrial laundering cycles under harsh conditions, including high water temperatures and exposure to bleach and high pH environments. For example, a traditional hospital blanket made of cotton or a blend of polyester and cotton can be expected to degrade and disintegrate to a point of being unusable within just a few months of first use. In contrast, the blanket 10 of the disclosure, formed of micro-denier polymer material, can be expected to have significantly longer usable life, e.g., extending to 12 months or longer. Additionally, forming the blanket 10 with a polyester material allows the blanket to be provided in a range of colors that remain stable (e.g., will not substantially fade or become discolored) during repeated industrial laundering cycles. As an example of providing antimicrobial properties, the blanket 10 is made to reduce or minimize transmission of drug resistant germs, e.g. MRSA (Methicillin-Resistant Staphylococcus Aureus). For example, the blanket 10 of the disclosure has been developed with a capacity for killing GRAM-positive and/or GRAM-negative bacteria, even after numerous industrial laundering cycles. In the antimicrobial performance tests described in more detail below, a sample blanket of the disclosure continued to show an acceptable level of antimicrobial performance after 50 industrial laundering cycles. Similar performance is projected for antimicrobial fabrics of the disclosure, e.g., after at least 100 industrial laundering cycles, or after at least 150 industrial laundering cycles, or after at least 200 industrial laundering cycles. The blanket 10 can serve as a first line of defense in a hospital, healthcare facility, or other environments, protecting users, and potentially others working in or visiting the environment, from contact transmission, droplet transmission, airborne transmission, etc. The blanket 10, having a raised surface of, e.g., polyester fiber, and containing antimicrobial agents for killing GRAM-positive and/or GRAM-negative bacteria, can provide an important enhancement to reducing nosocomial infections, such as MRSA and/or klebsiella pneumonia.
Examples of types of antimicrobial agents are described, e.g., in “Disinfection, Sterilization, and Preservation”, edited and partially written by Professor Seymour S. Block, Fourth Edition, published 1991 by Lea & Febiger, Pennsylvania, and in “Recent Advances in Antimicrobial Treatments of Textiles”, Y. Gao and R. Cranston, TEXTILE RESEARCH JOURNAL Vol. 78(1), p 60-72 (2008), a review of antimicrobial treatment of textiles. The complete disclosures of both references are also incorporated herein by reference. Described below are examples of a few categories of antimicrobial agents that can be applied to polyester and other polymeric fibers of the fabric articles to reduce transmission of infectious disease in the environment where the fabric articles are employed. In the discussion above and below, the blanket 10 is used as an example. The other fabrics and fabric articles in the environment 11 of
In one implementation, a blanket 10 of the disclosure is treated with zinc oxide, zinc hydroxide, zinc peroxide, and/or zinc salt (which has very low solubility and, by itself, has mild antimicrobial properties), e.g. zinc oxide and/or zinc salt, to create a system for providing a peroxide antimicrobial agent, e.g. as described in Toreki et al. U.S. Patent Publication No. 2011/0171280, published Jul. 14, 2011 (U.S. Pat. No. 8,277,827, issued Oct. 2, 2012), and assigned on its face to Quick-Med Technologies, Inc., of Gainesville, Fla., the complete disclosure of which is incorporated herein by reference. In particular, during spinning of the polyester fibers that will be formed, e.g., by knitting, into the blanket 10 of the disclosure, sequestering agents, e.g. zinc oxide, zinc hydroxide, zinc peroxide, and/or zinc salt, e.g. zinc oxide and/or zinc salt, are added to the polymeric blend, along with a binding agent, e.g. an acrylate (or polyurethane). The sequestering agent can be a complex of metal oxide, metal salt, metal peroxide, and hydrogen peroxide. The metal can be zinc (or magnesium or zirconium). The metal salts can contain chloride or nitrate (or acetate or bromide). The complex has low solubility and it is deposited on the textile fabric or entrapped within the binder. In the blanket 10 (or other article), the binding agent on the surfaces of the polyester or other polymeric fibers then serves to secure the sequestering agents, e.g. against early dislodgement during repeated industrial laundering cycles. The binder, based, e.g., on acrylate, can entrap peroxide and contributes to the antimicrobial property. The binder binds the metal oxide, metal peroxide, and/or metal salt to increase antimicrobial durability to withstand industrial laundering cycles. The sequestering agents, in turn, serve to sequester (or immobilize) the antimicrobial agent, i.e. the peroxide, on the surfaces of the blanket fibers, thereby to provide durable antimicrobial protection.
In another implementation, the blanket 10 is formed of polyester, polypropylene, or polyamide (or other suitable polymer or polymer blend) fibers that incorporate particles of sequestering agent, e.g. zinc oxide and/or zinc salt, of small characteristic dimension, e.g. particles of micro or nano dimension. The zinc oxide and/or zinc salt particles may be added to feed of polymer chips or polymer melts during extrusion of the polymer fibers. In this manner, the zinc oxide and/or zinc salt particles are distributed (e.g., randomly) throughout the cross section of the fiber.
Alternatively, a relatively greater distribution or concentration of particles of sequestering agent (zinc oxide and/or zinc salt) can be preferentially provided in an outer (sheath) layer of the polymer fibers, and/or even exposed on the outer surface of the polyester fibers. For example, the polymer fibers formed, e.g., using core/sheath spinning technology may have the form of bicomponent fibers having an outer sheath with a relatively high concentration of zinc oxide and/or zinc salt particles, and an inner core with a relatively lower concentration of, or little or no, zinc oxide and/or zinc salt particles.
As described above, the blanket 10 having polyester polymer fibers incorporating particles of zinc oxide and/or zinc salt, e.g., on the surface, in the outer layer, and/or distributed throughout the cross section, can be treated with a disinfecting agent, such as hydrogen peroxide or percarboxylic acid, to produce a complex system of zinc oxide and/or zinc salt, zinc peroxide (generated by exposure of the zinc oxide and/or zinc salt to the hydrogen peroxide), as well as the hydrogen peroxide sequestered at a controlled pH on the surface of the textile fabric, e.g. the fibers of a raised surface blanket or linen. For example, the disinfecting agent may be applied to the fabric, e.g. in a textile mill, during an industrial laundering cycle, or as a separate step before or after the industrial laundering cycle. The treated blanket 10, after this hydrogen peroxide recharging or reloading process, will typically have good antimicrobial properties and with high durability.
During extended use and repeated industrial laundering cycles, the antimicrobial properties and capabilities of the blanket 10 can be expected to degrade as the antimicrobial agent becomes depleted, e.g. is washed or worn away. However, according to the present disclosure, industrial laundering of the blanket 10, with application of an aqueous solution including hydrogen peroxide, which is routinely used as a disinfecting agent, including processing in a textile mill (during industrial laundering, or separately, before or after laundering), serves to recharge the sequestering agents with peroxide from the laundering solution, thus restoring the antimicrobial properties of the blanket 10. Use of hydrogen peroxide as a disinfecting agent (e.g., rather the bleach) reduces discoloration of colored blankets during repeated industrial laundering cycles. Industrial laundries of the type discussed are also moving away from use of chlorine as a disinfectant (for example, for environmental reasons) and moving to peroxide as an alternative.
Other types of disinfectant chemicals include, e.g., peracetic acid, ozone, etc., which can recharge the metal salt or metal oxide to generate the complex containing metal peroxide as an antimicrobial agent.
The antimicrobial agents discussed above have broad “killing” capacity, targeting no specific moiety in the cell metabolism, and, as a result, will not generate bacteria resistance to antibiotic agents (so-called “super bug”). Transmission of drug resistant bacteria (like MRSA) can occur by contact transmission (direct or indirect), as well as by airborne transmission.
Silver-based antimicrobial agents can also be used in blankets 10 of the disclosure. The silver can be in the form of, e.g. silver ions, silver ions embedded in Zeolite, and/or silver deposited on the surface of polyester or other suitable polymeric fibers by reduction-oxidation process.
Any of these silver treatments can be combined with a polymer, e.g. polyester, nylon, and/or acrylic, during fiber manufacture. The silver-loaded fibers can then be blended with untreated synthetic yarn in simple form to make blended spun yarn, or can be blended in filament form to be commingled with untreated synthetic filament yarn. The silver-loaded fibers can also be added to the knit construction with untreated synthetic filaments.
The silver ions loaded into the fibers leach out of the fiber material over time, migrating towards bacteria to react with its cell DNA and/or during repeated industrial laundering cycles. Binders may be added to the silver ion during application in order to control, i.e. reduce, the level of leaching during laundering. Selection of a binder is crucial to improvement of the durability and longevity of the blanket 10 through repeated cycles of industrial laundering. The binder, mixed with the antimicrobial agent, can be applied by pad as is, or with an added cross-linking agent. After application, the treated fabric is dried and cured at 375° F. for 60 seconds. The binder must be stable under the conditions of industrial laundering, e.g. temperatures of 160° F., alkaline PH 10±1, and bleaching chemicals (peroxide, Clorox, ozone). A preferred binder is based on acrylate, but other binders based on polyurethane, silicon, etc. will be effective as well.
The family of quaternary ammonium silane (QAS) chemicals can also be used as antimicrobial agents in blankets 10 of the disclosure. One suitable antimicrobial agent of this family is 3-(trimethoxysilyl)propyldimethyl octadecyl ammonium chloride. Trimethoxy silyl reacts with another trimethoxy silyl, or with the hydroxyl, carboxylic, amine, or amide on the fiber surfaces, and the octadecyl with the quaternary ammonium will puncture and rupture the outer wall of a bacteria cell. This antimicrobial agent type does not leach out of the fibers in order to penetrate the bacteria, so the effective useful life of the blanket 10 is extended, and thus enhanced. Further enhancement of the durability of the blanket through repeated industrial laundering cycles (e.g. at 160° F. with high PH and exposure to disinfecting agents, such as peroxide or bleach) may be obtained by addition of a chemical binder, with or without a cross-linking agent.
Polyhexamethylene bigunide (PHMB) can also be used as an antimicrobial agent in blankets 10 of the disclosure. This agent may be applied to polyester or other suitable polymeric fabric by patting with addition of binder, and with or without cross linking agent.
Other types of disinfectant chemicals include, e.g., peracetic acid, ozone, etc., which can recharge the metal salt or metal oxide to generate the complex containing metal peroxide as an antimicrobial agent.
The antimicrobial agents discussed above have broad “killing” capacity, targeting no specific moiety in the cell metabolism, and, as a result, will not generate bacteria resistance to antibiotic agents (so-called “super bug”). Transmission of drug resistant bacteria (like MRSA) can occur by contact transmission (direct or indirect), as well as by airborne transmission.
Several standard testing methods are available for evaluation of the effectiveness of antimicrobial treatment of the blankets as described herein. For example, ISO 2073 is a standard quantitative test method for determining antimicrobial activity of immobilized antimicrobial agents. Other or additional testing methods may also be utilized. For example, ATCC 147 is a form of qualitative testing, and ASTM E 2149-01 (“Shake Flask” test) tests antimicrobial activity of immobilized antimicrobial agents under dynamic contact conditions.
A sample of the blanket 10 of this disclosure (Material Sample Reference No. 082411B) was treated with the zinc-based peroxide antimicrobial agent system discussed above. Testing of antimicrobial properties was conducted on an unlaundered sample, and on a sample that had undergone 100 industrial laundering cycles of 160° F. for 10 minutes each cycle. The samples were tested according to ISO 20743, AATCC 100, and JIS L 1902, with two different bacteria in different inoculum concentrations (shown in Table 1).
Both the treated unlaundered and the treated laundered test samples were found to have good antimicrobial properties. Test results for the samples are provided below in Table 2.
Staphylococcus aureus, 6538
Klebsiella pneumonia, 4352
Staphylococcus aureus, 6538
Klebsiella pneumonia, 4352
As shown in these test results, the treated laundered sample maintained good antimicrobial properties and performed nearly as well as the treated unlaundered sample, even after undergoing 100 industrial laundering cycles.
A number of embodiments of the disclosure have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the disclosure. For example, the zinc oxide or low solubility zinc salt of the rechargeable sequestering agent can be substituted by, e.g., magnesium oxide, zirconium oxide, or low solubility salt of magnesium or zirconium.
Also, in other implementations, the yarn or fibers of the textile fabric may be chemically treated, e.g. with 4% Lurotex A-25 (available from BASF Aktiengesellschaft, of Ludwigshafen, Germany), a nonionic polyamide derivative that improves moisture transport in textiles composed of synthetic fibers, to increase the moisture content on the face of the fabric, to impart antistatic and soil release properties, as well as absorbing moisture from the air, e.g., to release hydrogen peroxide from sequestration on the surface of the fabric.
Use of the antimicrobial fabrics of the disclosure in other environments, e.g., in nursing homes, correctional facilities, hospitality environments (e.g., hotels, motels, cruise ships, etc.), dormitories, military facilities, schools, daycare facilities and kindergartens, private homes, and the like, is also contemplated. Referring again to
Accordingly, other embodiments are within the scope of the following claims.
This application claims priority from U.S. Ser. No. 61/587,275, filed Jan. 17, 2012, and from U.S. Ser. No. 61/604,779, filed Feb. 29, 2012. The entire contents of U.S. Ser. No. 61/587,275 and U.S. Ser. No. 61/604,779 are incorporated herein by reference.
Number | Date | Country | |
---|---|---|---|
61587275 | Jan 2012 | US | |
61604779 | Feb 2012 | US |