Patent Application
20210324574
This invention relates generally to processes for enhancing the fluid repellant properties of the textiles, and more specifically, to processes for converting textiles into fluid repellant textiles.
Beginning in December 2019 and spreading into a global pandemic extending into 2021, the Coronavirus known as “Covid-19” has resulted in enormous numbers of stricken persons requiring hospitalization. The unforeseen pandemic and resulting needs for healthcare have strained the healthcare community to a point where there is a significant shortage of hand sanitizers and hard surface disinfectants and personal protective equipment (PPE) including but not limited to face masks, isolation gowns, gloves, and face shields, to name a few.
With many of those stricken by the virus requiring hospitalization, and those who are admitted to the hospital being placed into either isolation or intensive care; the demands for PPE are significant. These demands, when coupled with global shortages due to shuttered textile production facilities and travel/shipping restrictions have created a dire situation where alternative means of producing/procuring healthcare supply items have been granted under emergency presidential/governmental order.
Presently, the application of fluid resistant protective chemistries to textiles occurs at a textile mill, most often applied to bolt cloth prior to cutting and sewing. The application of the barrier treatment chemistry may be applied via a padding or spray-on process where in a known volume/quantity of material is applied to a controlled area of dry cloth. Further the applied fluid resistant chemistry may be “cured” onto the cloth by means of a high-heat oven. Protective apparel is manufactured against, or to, written performance standards wherein the application rate is controlled to generate a desired performance attribute.
Chemical treatments which are designed to impart a fluid repellant/fluid resistant property to laundered healthcare barrier gowns are known to those of ordinary skill in the professional laundry marketspace. These treatments are typically merely utilized to refresh fluid repellant/fluid resistant textiles used in the surgical suite including but not limited to surgical drapes, physician gowns and other coverings. Additionally, these barrier treatments have been used to refresh the fluid repellant/fluid resistant properties of isolation gowns, outer coverings used by healthcare workers who administer healthcare to patients in isolation rooms, for example respiratory or enteric isolation. However, this treatment is less than ideal as the improved properties do not last long, and the textile must be retreated frequently.
Accordingly, there is a need to address the general lack of disposable isolation gowns and protective coverings which can be worn by healthcare providers. Additionally, there is a need to provide a process of improving fluid repellent properties of textiles which provides longer lasting improved properties.
The present invention is directed at solving one or more problems noted above. More specifically, it has surprisingly and unexpectantly been discovered that common healthcare textiles can be easily and efficiently treated to enhance the fluid repellent properties thereof. According to the present processes, multiple healthcare textiles that are normally water and oil absorbent, can be made into oil and water repellent after proper treatment. This would allow commonly available clothing items to be converted into materials that could be used as PPE. Additionally, such a treatment is believed to provide a longer lasting improved properties compared with the results of conventional processes. According to the present processes, the fluid repellant properties of the textiles are improved in a laundry process.
In typical commercial or industrial laundry processes, textile materials such as sheets, towels, wipes, garments, tablecloths, etc. are commonly laundered at elevated temperatures with alkaline detergent materials. Such detergent materials typically contain a source of alkalinity such as an alkali metal hydroxide, alkali metal silicate, alkali metal carbonate or other such base component. When the linen is treated with an alkaline detergent composition a certain amount of carryover alkalinity may occur. Carryover alkalinity refers to the chemistry that is contained within the linen (that has not been completely removed) that is available for the next step. For example, when the detergent use solution provides an alkaline environment, it is expected that the detergent use solution will provide a certain amount of carryover alkalinity for a subsequent sour treatment step unless all of the detergent use solution is removed by rinsing.
The residual components of the alkaline detergents remaining in or on the laundered item can result in fabric damage and skin irritation by the wearer of the washed fabric. This is particularly a problem with towels, sheets and garments. Sour materials contain acid components that neutralize alkaline residues on the fabric. In preferred aspects, the present processes convert the textiles and improve the fluid repellant properties of the textiles by adding a fluid repellant into the sour stage of the laundry process.
Accordingly, in one aspect, the present invention may be characterized as providing a process for converting textiles from water and oil absorbent textiles into textiles that are water and oil repellant by: subjecting textiles to a laundry treatment process, wherein the textiles are water and oil absorbent; and, adding a fluid repellant during a stage of the laundry treatment process for the textiles, wherein the textiles are water and oil repellant after the laundry treatment process. The fluid repellant may be a fluoropolymer-based fluid repellant. The fluid repellant may be added during a sour stage of the laundry treatment process. The textiles may include 100% polyester, 80/20 polyester/cotton blends, 65/35 polyester/cotton blends, 55/45 cotton/polyester blends, or a combination thereof. The fluid repellant may be added in an amount between 16 and 64 fluid ounces per one-hundred pounds of cloth (cwt.). A pH of the stage of the laundry treatment process when the fluid repellant is added may be between 3.5 and 6.5, or between 4.5 and 5.5. A temperature of the stage of the laundry treatment process when the fluid repellant is added may be between 100-120° F. The stage of the laundry treatment process may last between 8 and 12 minutes. The process may further include: repeating the adding of fluid repellant; and, drying the textiles after repeating the addition of the fluid repellant at least two times. The addition of the fluid repellant is repeated at least three times.
In another aspect, the present invention may generally be characterized as providing a process for converting textiles from water and oil absorbent textiles into textiles that are water and oil repellant by: laundering textiles at an elevated temperature with an alkaline detergent, wherein the textiles are water and oil absorbent; and, adding a sour to the textiles during a sour stage; and adding a fluid repellant during the sour stage, wherein the textiles are water and oil repellant after the sour stage. The fluid repellant may be added in an amount between 16 and 64 fluid ounces per one-hundred pounds of cloth (cwt.) for each cycle. The textiles may include 100% polyester, 80/20 polyester/cotton blends, 65/35 polyester/cotton blends, 55/45 cotton/polyester blends, or a combination thereof. The process may include: repeating the addition of the fluid repellant; and, drying the textiles after repeating the addition of the fluid repellant at least two times. The addition of the fluid repellant may be repeated at least three times.
In some aspects, the present invention, broadly, may be characterized as improving at least one fluid repellant property of textiles by: laundering textiles at an elevated temperature with an alkaline detergent; and, adding a sour to the textiles during a sour stage; and adding a fluid repellant during the sour stage, wherein at least one fluid repellant property of the textile is improved after the sour stage. The fluid repellant may be a fluoropolymer-based fluid repellant. The process may include: repeating the addition of the fluid repellant; and drying the textiles after repeating the addition of the fluid repellant at least two times. The addition of fluid repellant may be repeated at least three times. The fluid repellant may be added in an amount between 16 and 64 fluid ounces per one-hundred pounds of cloth (cwt.) for each time the fluid repellant is added.
Additional aspects, embodiments, and details of the invention, all of which may be combinable in any manner, are set forth in the following detailed description of the invention.
One or more exemplary embodiments of the present invention will be described below in conjunction with the following drawing figures, in which:
With these general principles in mind, one or more embodiments of the present invention will be described with the understanding that the following description is not intended to be limiting.
As noted above, it has surprisingly and unexpectantly been found that textiles that are normally water and oil absorbent, can be made into oil and water repellent after proper treatment. According to preferred aspects of the present processes, application of fluid resistant chemical treatment is made during the final “sour bath” stage of a laundry process. Further still, this process has been found functionally effective on “in-service” textiles which are already in the channel of use and does not require “new/virgin” textiles.
Through application of a known fluid resistant chemical additives normally utilized in the professional laundry process to treat surgical barrier gowns, it has been found that different apparel, that is not fluid resistance, can be successfully treated within the professional laundry setting, to impart a significant level of fluid resistant barrier protection. Thus, with the present processes, a variety of textiles made of varying fiber blends can have improved fluid repellent properties or be converted into water and oil repellant textiles. Further, it has been found that repetitive laundry processing inclusive of “maintenance dosing” of the fluid repellant treatment chemistry can maintain the barrier properties of the treated textiles.
This application and process has been conducted using a fluoropolymer-based fluid repellant laundry treatment manufactured and distributed under the tradename PULSE SHIELD and available from Gurtler Industries of South Holland, Ill. PULSE SHIELD is formulated with a proprietary, partially fluorinated polymer. The polymer is synthesized using alkyl chains which are excluded from the Octyl type, and are considered short chain. PULSE SHIELD, and its formulation components are not considered PFOA/PFOS (perfluorooctyl acid/substances). The formulation components within PULSE SHIELD have been selected to meet “the goals of the EPA 2010/2015 PFOA Stewardship Program.” It is believed that other fluid repellant(s) could be used.
This process invention illustrates that the protective fluid resistant properties can be applied “in-situ” using existing laundry processing equipment and commercially available after-treatment chemistries. Specifically, the present processes add the fluid repellant during one of the stages of a commercial laundry process. Generally, commercial laundry processes are carried out in continuous batch tunnel washers or a washer/extractor. As is known, these types of washers have multiple zones or stages that carry out different functions for the laundry process. For example, a laundry process may include the following stages: pre-wash, wash, rinse, and finishing.
A preferred dose can range between 16 and 64 fluid ounces per one-hundred pounds of cloth (cwt.). A preferred pH of the application bath is between pH 3.5 and 6.5, or between pH 4.5 and 5.5. A preferred application temperature is between 100-120° F. A preferred application duration is between 8 and 12 minutes.
Based on the present processes, fabrics of varying fiber compositions can be enhanced in their fluid resistance. Examples indicated that different fabrics will respond to the treatment to provide a targeted level of fluid repellency. Accordingly, as will be appreciated the exact amount and application conditions may vary based on fabric materials such that may be one targeted application dose rate of the fluid residence chemistry when treating 100% polyester scrubs, a second application when treating 100% polyester doctor coats, a third dosage for treating 65/35 polyester/cotton scrubs, and a fourth application dosage for treating 55/45 cotton/polyester patient gowns. Thus, the application of the fluid repellent may be repeated, for example, two times, or three times, or ten times. One of ordinary skill in the art is able to determine the appropriate number of applications. The number of applications will also depend on whether the application is an initial application or a maintenance (subsequent) application.
In order to maintain a desired level of fluid repellency, for example that detailed in AATCC Method 118 or 193, a specific maintenance dose is likely needed to be re-applied on each subsequent laundering and wear cycle. The experimental data has revealed that such maintenance dosages differ significantly from historical norms for treated synthetic surgical barrier fabrics.
Five (5) classifications of healthcare textile items were collected for study. These healthcare textiles included: new 100% polyester scrubs; in-service 100% polyester scrubs; in-service blended cotton/polyester scrubs; in-service blended cotton/polyester patient gowns; and, in-service 100% polyester laboratory coat.
All textiles were laundered and treated in a commercially available washer/extractor from Pellerin Milnor of Kenner La. The laundry process conditions for some of the various stages are outlined in TABLE 1.
Dry Conditions: Dry garments to full-dry based on fiber/fabric composition. Typically, this is a high-heat setting. Extending the dry cycle will aide in developing the full-cure of the components of the water repellant to the fabric.
Performance Evaluations: The efficacy of the application of PULSE SHIELD to normal daily healthcare wear was measured via the following test methods to determine water repellant properties of the treated textiles: AATCC Method 79: Absorbency of Textiles; AATCC Method 118: Oil Repellency: Hydrocarbon Resistance Test; and, AATCC Method 193: Aqueous Liquid Repellency: Water/Alcohol Solution Resistance Test.
Impact of Repeated Laundering & Treatment Cycles: Each of the above textile classifications were repeat laundered for several wash-and-dry cycles. TABLES 2 and 3, below, display the test solutions from each AATCC test method that was used to evaluate the textiles for various fluid repellent properties.
Results of Repetitive Laundering & After-Treatment: The treatment of 32 oz/cwt of repellant was applied to every cycle beginning with the initial treatment and continuing through the following wash & treatment cycles as shown in the TABLES below.
The results of the foregoing experiments shown in the above TABLES reveal that multiple types of healthcare textiles that are normally water and oil absorbent, can be made into oil and water repellent textiles after they are treated with 32 oz/cwt of PULSE SHIELD. After three (3) cycles of 32 oz/cwt of PULSE SHIELD being added to the sour bath, all five textile classifications displayed dramatic increase in fluid repellant properties. After three wash cycles of 32 oz/cwt of PULSE SHIELD, the textiles went from instantly absorbing water and oil to showing a sustainable water repellency of 40% water/60% isopropyl, and a sustainable oil repellency of n-decane.
Through the data collected, garments treated with a dosage of PULSE SHIELD at 32 oz/cwt show significantly enhanced repellency, and after three washes, textiles that were previously water and oil absorbent have the ability to become water and oil repellent. Cotton/Polyester blend patient gowns were also treated with a lower dosage of PULSE SHIELD (4 oz/cwt, & 6 oz/cwt), which was proven to be ineffective at displaying the desired degree of water and oil repellency that would be needed for a repurposed healthcare textile. The exact “maintenance dose” required during subsequent laundering cycles would need to be determined based on fabric composition.
In second set of experiments, five sets of different textiles were tested according to AATCC TM127-2017(2018)e: Water Resistance: Hydrostatic Pressure Test to measure the resistance of a fabric to the penetration of water under hydrostatic pressure. The textiles that were tested under AATCC TM127-2017(2018)e included: a smock with a 80/20 polyester/cotton blend; scrub pants with a 55/45 cotton/polyester blend; scrub pants with 100% polyester; a patient gown with a 55/45 cotton/polyester blend; and a patient gown with 100% polyester. One of each type of textile was subjected to a treatment in which fluid repellant treatment was added into two different sour bath stages of a laundry process. The first treatment was dosed at 64 oz/cwt and the second treatment, or maintenance dose, was dosed at 32 oz/cwt.
In the TABLES, below, the results of the testing under AATCC TM127-2017(2018)e. As would be appreciated by one of ordinary skill in the art, compared to the untreated textiles, the treated textiles had a much high resistance to the penetrate of water.
Accordingly, by using the present processes, normal healthcare textiles can be enhanced in their fluid repellant properties either converting them to fluid resistant textiles, or providing a longer lasting maintenance application. This is believed to be particularly beneficial in times when there is a shortage of suitable fluid resistance textiles in hospitals, such as the shortages of PPE attributed to the Covid-19 pandemic.
While at least one exemplary embodiment has been presented in the foregoing detailed description of the invention, it should be appreciated that a vast number of variations exist. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. Rather, the foregoing detailed description will provide those skilled in the art with a convenient road map for implementing an exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements described in an exemplary embodiment without departing from the scope of the invention as set forth in the appended claims and their legal equivalents.
This application claims priority to U.S. Provisional Patent Application Ser. No. 63/011,918 filed on Apr. 17, 2020, the entirety of which is incorporated herein by reference.
| Number | Date | Country | |
|---|---|---|---|
| 63011918 | Apr 2020 | US |
