Patent Application
20130180056
This invention relates to blankets, and more particularly to blankets and similar fabric articles suited for use, e.g., in medical health care environments.
Blankets used in medical health care 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, but generally have only a 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/yd2, thickness of 0.086 inch, CLO of 0.467, and CLO-to-weight ratio of 0.045. Hospital blankets typically also only have a relatively short useful life, e.g., in some cases only a few months, after which the repeated exposure to the harsh conditions of industrial laundering, including high temperatures, bleach, and high pH, cause the blankets to fall apart and disintegrate.
According to one aspect of the disclosure, a medical health care blanket comprises a fabric of micro-denier polymer fibers having at least one raised surface, and an antimicrobial system applied to the fabric and 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 the group of: zinc, magnesium, and zirconium. The metal salt is selected from 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 is 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 of contributing to sanitary health care environment, comprising: 1) providing a medical health care blanket as described above having a predetermined enhanced level of antimicrobial protection, and 2) subjecting the medical health care blanket to frequent industrial laundering cycles including contact with an aqueous solution of hydrogen peroxide, thereby to recharge antimicrobial protection provided by the medical health care blanket 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, a medical health care 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.
Implementations of this disclosure can incorporate one or more of the following advantages. For example, a medical health care blanket of this disclosure, formed of a micro-denier polyester polymer material, e.g., polyester, polypropylene, or polyamide, in a double face knit configuration, with velour/velour finish, can 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.
When used as a hospital or long-term care facility bed blanket, a medical health care blanket of this disclosure can serve as a first line of defense against transmission of disease and infection, e.g., in some implementations, a medical health care blanket of this disclosure can incorporated durable antimicrobial properties that assist patients to avoid contracting germs and/or bacteria, and thus create a more sanitary environment.
Antimicrobial fabrics of the disclosure, e.g. in the form of blankets and/or in the form of bed sheets, pillow covers, etc., can also be a factor in achieving health care objectives such as keeping the entire environment surrounding a medical patient (or other user) free, or at a reduced level, of infectious disease bacteria.
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.
Like reference symbols in the various drawings indicate like elements.
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The fibers of the medical health care blanket polymer material may be treated with an antistatic chemical to reduce electrostatic build up that can be annoying to a user, e.g. due to uncomfortable static discharge, and/or that can interfere with operation of medical and/or communications devices in the vicinity. An example of a commercial antistatic chemical for treating fabric is Lurotex A25 (a nonionic polyamide derivative available commercially from BASF Aktiengesellschaft, of Ludwigshafen, Germany), applied, e.g., at 2% to 4%.
The medical health care blanket 10 of the disclosure offers multiple advantages during use a medical care environment, e.g., as compared to conventional or traditional hospital blankets formed of cotton or a blend of polyester and cotton. For example, the medical health care blanket 10 exhibits improved thermal insulation properties, lower water retention, a longer usable life, and antimicrobial properties for resisting transmission of disease and other medical conditions. All of these features will be discussed in more detail below.
In particular, the medical health care blanket 10 of the disclosure has relatively better thermal insulation efficiency properties than conventional hospital blankets made from cotton or a blend of polyester and cotton. For example, the medical health care 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 medical health care 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). A medical health care blanket 10 of the disclosure is also relatively lighter in weight than traditional hospital blankets, e.g. the medical health care 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. These features in combination contribute to a medical health care blanket 10 allowing a patient increased comfort of a covering of relatively lighter weight, and with increased warmth and insulation of the thicker and thermally more efficient material, while also providing durable antimicrobial properties that contribute to a more sanitary environment through enhanced resistance to contracting germs and/or bacteria.
The medical health care 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 medical health care 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 medical health care 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, has the additional, particularly beneficial, effect of significantly lowering energy consumption and costs for the health care facility.
The micro-denier polymer blanket 10 of the disclosure also exhibits 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 a just a few months of first use. In contrast, the medical health care blanket 10 of the disclosure, formed of micro-denier polymer material, can be expected to have significantly longer usable life, e.g., extending 12 months or longer. Additionally, forming the medical health care blanket 10 of 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.
Also, in order to reduce or minimize transmission of drug resistant germs, e.g. MRSA (Methicillin-Resistant Staphylococcus Aureus), the medical health care 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. For example, in antimicrobial performance tests described in more detail below, a sample medical health 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 medical heath care blanket 10 can serve as a first line of defense in a hospital, health care facility, or other similar environment, protecting the patient from contact transmission, droplet transmission, airborne transmission, etc. The medical health care 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 medical health care blanket 10 in order to reduce transmission of infectious disease in the health care environment where the blanket 10 is employed.
In one implementation, a medical health care 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, 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 medical health care 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 medical health care blanket 10, 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 medical health care 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 melt 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 medical care 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 medical care blanket 10, after this hydrogen peroxide recharging or reloading process, will typically have good antimicrobial properties and with high durability.
During use extended use and repeated industrial laundering cycles, the antimicrobial properties and capabilities of medical health care 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 medical health care 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 medical health care blanket 10. Use of hydrogen peroxide as a disinfecting agent (e.g., rather the bleach) reduces discoloration of colored medical health care 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.
Silver-based antimicrobial agents can also be used in medical health care 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 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 medical health care 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 medical health care 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 surface, 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 medical health care blanket 10 is extended, and thus enhanced. Further enhancement of the durability of the medical health care 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 a antimicrobial agent in medical health care 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 medical health care 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 medical health care 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, referring to
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 blanket fabric 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 to U.S. provisional application No. 61/587,275, filed on Jan. 17, 2012, now pending, and to U.S. provisional application No. 61/604,779, filed on Feb. 29, 2012, now pending. The entire contents of both provisional applications are incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 61587275 | Jan 2012 | US | |
| 61604779 | Feb 2012 | US |
