Patent Grant
11091281
The invention pertains to vacuum packaged products and methods of making the same, and more particularly to vacuum packaged nonwoven products and methods that reduce or eliminate the undesirable side effects associated with the sterilization thereof.
Various fields of use require the use of sterilized polyolefin-based fabrics, equipment, and tools. For example, it is well known that the operating environments of medical personnel, dental personnel, chemical research personnel, biotech personnel, and other like areas utilize polyolefin-based products that have been sterilized prior to use (e.g., drapes, gowns, masks, etc.).
Currently, ethylene oxide has been used to sterilize polyolefin-based products such as medical fabrics that are used as surgical gowns and drapes. However, the potentially hazardous nature and high cost of ethylene oxide sterilization have caused the medical community to consider different sterilization methods. One effective method of sterilization has been the use of gamma irradiation and other types of ionizing radiation, such as electron beam irradiation or x-ray irradiation. Although sterilization by gamma irradiation and other methods has been successful for polyolefin-based products and equipment, there remain at least two very undesirable side effects caused by the irradiation process. The first undesirable side effect has been a resulting odor that renders the gamma irradiated polyolefin-based product undesirable for many uses. The second undesirable side effect has been a noticeably decreased strength of the irradiated polyolefin-based products. In fact, the irradiation process has been known to decrease a polyolefin-based product's tear strength by as much as 65% of its non-irradiated tear strength.
It has been shown that the cause for the undesirable odor and the loss in polyolefin-based product strength is a free radical process that occurs when the polyolefins of the product are exposed to gamma radiation in the presence of oxygen. In polyolefin-based products, this process essentially breaks chemical bonds that hold a polyolefin chain together and creates free radicals. This breaking of the polyolefin backbone causes the polyolefin to lose strength proportional to the radiation dosage. The formed radicals are able to recombine with the oxygen in the air, producing short chain acids, oxygenated compounds, such that they become trapped in the product. Butyric acid, one of the acids formed, is a primary suspect in causing the odor.
Although earlier efforts and attempts to eliminate these two undesirable side effects include methods that marginally reduce the odor associated with the gamma irradiation of polyolefin-based products, none has adequately reduced the odor or minimized the reduction in tear strength resulting from the irradiation treatment.
A need therefore exists for a product and method for further minimizing or eliminating the odor that is associated with the gamma irradiation of polyolefin-based products.
Another need exists for a product and method that not only reduces the odor, but also minimizes any decrease in the tensile strength of the polyolefin-based product that is due to the gamma irradiation.
A need also exists for a product and method where the volume of the packaged product is reduced, resulting in the packaged product occupying less space in storage and shipping, thus lowering costs.
In accordance with one embodiment of the present invention, a combination of a product and a film-to-film package is contemplated. The product is vacuum packaged in the film-to-film package. The film-to-film package has an interior and comprises a layer having an oxygen transmission rate equal to or less than about 10 cubic centimeters of oxygen per 100 inches squared per 24 hours. Further, the product is located in the interior of the film-to-film package, and air is removed from the interior of the film-to-film package by applying a vacuum pressure equal to or less than about 250 millibars to the exterior of the film-to-film package and then flushing the interior of the film-to-film package with an inert gas until the interior of the film-to-film package reaches an inert gas flush pressure equal to or less than about 750 millibars. In addition, the film-to-film package and the product are sterilized by ionizing radiation, and the product exhibits a reduction in its tensile strength that is equal to or less than about 18.5% after sterilization.
In one embodiment, the film-to-film package can be thermoformed.
In one particular embodiment, the ionizing radiation can be gamma irradiation, electron beam irradiation, or x-ray irradiation.
In another embodiment, the layer can include ethylene vinyl alcohol or nylon.
In one more embodiment, the product can include a nonwoven polyolefin material.
In still another embodiment, the vacuum pressure can be between about 15 millibars and about 50 millibars, and the inert gas flush pressure can be between about 50 millibars and about 150 millibars. In such an embodiment, the reduction in tensile strength in the machine direction can be equal to or less than about 10% after sterilization, while the reduction in tensile strength in the cross-machine direction can be equal to or less than about 18% after sterilization.
In yet another embodiment, the vacuum pressure can be between about 75 millibars and about 125 millibars, and the inert gas flush pressure can be between about 400 millibars and about 600 millibars. In such an embodiment, the reduction in tensile strength in the machine direction can be equal to or less than about 15% after sterilization, while the reduction in tensile strength in the cross-machine direction can be equal to or less than about 18.5% after sterilization.
In another embodiment, the layer can have an oxygen transmission rate equal to or less than about 5.0 cubic centimeters of oxygen per 100 inches squared per 24 hours. For instance, the layer can have an oxygen transmission rate between about 0.001 cubic centimeters of oxygen per 100 inches squared per 24 hours and about 2.0 cubic centimeters of oxygen per 100 inches squared per 24 hours.
In one more embodiment, the inert gas can include nitrogen, argon, or a combination thereof.
In still another embodiment, the film-to-film package can occupy less volume than a package not treated with a vacuum and an inert gas flush. For instance, the combination can have a density that is at least 10 percent greater than an identical combination not treated with a vacuum and an inert gas flush. In addition, the combination can have a pre-determined shape and/or a pre-determined stiffness. For example, the pre-determined shape can be substantially planar, and the pre-determined stiffness can be at least 10 percent greater than an identical combination not treated with a vacuum and an inert gas flush.
In accordance with another embodiment of the present invention, a method of packaging a product in a package is contemplated. The method includes the steps of providing a film-to-film package comprising a layer having an oxygen transmission rate equal to or less than about 10 cubic centimeters of oxygen per 100 inches squared per 24 hours, and having an interior and an exterior; providing a product in the interior of the film-to-film package; applying a vacuum to the exterior of the package in a controlled atmosphere until a vacuum pressure equal to or less than about 250 millibars is achieved; flushing the interior of the film-to-film package with an inert gas until an inert gas flush pressure equal to or less than about 750 millibars is achieved; sealing the film-to-film package; releasing the vacuum applied to the exterior of the package in the controlled atmosphere; and sterilizing the package and product with ionizing radiation resulting in the product having a reduction in its tensile strength that is equal to or less than about 18.5% after sterilization.
In one embodiment, the film-to-film package can be thermoformed.
In one particular embodiment, the ionizing radiation can be gamma irradiation, electron beam irradiation, or x-ray irradiation.
In another embodiment, the layer can include ethylene vinyl alcohol or nylon.
In one more embodiment, the product can include a nonwoven polyolefin material.
In still another embodiment, the vacuum pressure can be between about 15 millibars and about 50 millibars, and the inert gas flush pressure can be between about 50 millibars and about 150 millibars. In such an embodiment, the reduction in tensile strength in the machine direction can be equal to or less than about 10% after sterilization, while the reduction in tensile strength in the cross-machine direction can be equal to or less than about 18% after sterilization.
In yet another embodiment, the vacuum pressure can be between about 75 millibars and about 125 millibars, and the inert gas flush pressure can between about 50 millibars and about 150 millibars. In such an embodiment, the reduction in tensile strength in the machine direction can be equal to or less than about 15% after sterilization, while the reduction in tensile strength in the cross-machine direction can be equal to or less than about 18.5% after sterilization.
In another embodiment, the layer can have an oxygen transmission rate equal to or less than about 5.0 cubic centimeters of oxygen per 100 inches squared per 24 hours. For instance, the layer can have an oxygen transmission rate between about 0.001 cubic centimeters of oxygen per 100 inches squared per 24 hours and about 2.0 cubic centimeters of oxygen per 100 inches squared per 24 hours.
In one more embodiment, the inert gas can include nitrogen, argon, or a combination thereof.
In still another embodiment, the film-to-film package can occupy less volume than a package not treated with a vacuum and an inert gas flush. For instance, the step of releasing the vacuum applied to the exterior of the package in the controlled atmosphere can generate a combination of package and product having a density that is at least 10 percent greater than an identical combination not treated with a vacuum and an inert gas flush.
In one particular embodiment, the step of releasing the vacuum applied to the exterior of the package can generate a combination having a pre-determined shape and/or a pre-determined stiffness. For example, the pre-determined shape can be substantially planar, and the pre-determined stiffness can be at least 10 percent greater than an identical combination not treated with a vacuum and an inert gas flush.
In accordance with another embodiment of the present invention, a shipping system comprising a shipping container and a plurality of combinations of a product and a package as described herein is contemplated.
In still another embodiment, a dispensing system comprising: a dispensing container and a plurality of combinations of a product and a package as described herein is contemplated.
In yet another embodiment, a stack comprising two or more of a combination of a product and a package as described herein is contemplated.
Other features and aspects of the present invention are discussed in greater detail below.
A full and enabling disclosure of the present invention, including the best mode thereof to one skilled in the art, is set forth more particularly in the remainder of the specification, including reference to the accompanying figures, in which:
Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the present invention.
It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only, and is not intended as limiting the broader aspects of the present invention.
The present invention pertains to a nonwoven-based product. In one particular embodiment, the nonwoven-based product can be a material that includes a polyolefin. Nonwoven materials are materials that are formed without the aid of a textile weaving or knitting process such that it has a structure of individual fibers or threads that are interlaid, but not in any identifiable, repeating pattern. Nonwoven materials have been, in the past, formed by a variety of processes such as, for example, meltblowing processes, spunbonding processes, and bonded carded web processes. The materials of the present invention are generally selected from the polyolefin family. More specifically, the polyolefins may either be homopolymers or copolymers. The preferred homopolymer is polypropylene, and the preferred copolymer is a propylene/ethylene copolymer. The amount of propylene in the copolymer may range from 90% to 100%, and the amount of ethylene in the copolymer may range from 0 to 10%. It should be appreciated that as the amount of ethylene is increased, the flexibility of the material being produced will also be increased. Therefore, the preferred copolymer is 97% propylene and 3% ethylene. Methods for making polyolefin-based fabrics are well known in the art, see for example U.S. Pat. Nos. 4,041,203 and 4,340,563, which are incorporated by reference herein. In one particular embodiment, the polyolefin-based fabric is a spunbond-meltblown-spunbond (SMS) fabric, although it is to be understood that other types of fabrics can be utilized as known in the art.
The weight of the produced material for use in the product, represented in ounces per square yard, is normally determined by the intended use thereof. For example, if the material is to be used as a vehicle cover, the weight of the material should generally be in the range of 7.20 ounces per square yard (osy). If the material is to be used as a diaper liner, the weight of the material should generally be in the range from 0.3 ounces per square yard to 0.8 ounces per square yard. For surgical gowns, the material weight should range from 0.8 ounces per square yard to 3.0 ounces per square yard. A preferred polyolefin-based material for the product of the present invention is a nonwoven polypropylene spunbond/meltblown/spunbond (SMS) material having a basis weight of about 128 osy; another preferred basis weight is about 1.8 osy.
A gamma stabilizer, such as a benzoate ester, may be incorporated into the polyolefin prior to polyolefin extrusion. In the past, it has generally been believed that a gamma stabilizer must be added to the polyolefin in order to stabilize the polyolefin for the gamma irradiation process. This step was taken in an effort to minimize polyolefin strength loss and decrease odors. However, it is known that the use of a gamma stabilizer is not necessary in order to minimize polyolefin strength loss and odor. The present invention has been found to minimize strength loss in polypropylene without a gamma stabilizer. Also, it has been determined that the gamma stabilizer is not needed to reduce the odor associated with the gamma irradiation process. Nevertheless, a gamma stabilizer suitable for intended use herein and known to those of ordinary skill in the art may be incorporated into the polyolefin prior to extrusion.
It is known that when a polyolefin-based product such as the nonwoven material as described above is sterilized via irradiation, such as via gamma, electron-beam, or x-ray irradiation, or any other type of ionizing radiation, some of the bonds in the polyolefin chains are broken and combine with available oxygen, which leads to more chain scission, thereby weakening the product. For instance, when the product of the present invention is irradiated, some of the polyolefin chains are broken. However, there is little or no oxygen to combine with the bonding sites in the broken polyolefin chains due to various features of the packaging in which the product is contained and which are discussed in more detail below. Without intending to be limited by any particular theory, it is believed that the available bonding sites in the polyolefin chains are therefore free to recombine with one another instead of with oxygen in the package such that the majority of the tensile strength of the irradiated product is maintained. The minimization of the potential for the formation of oxygenated compounds, such as short-chain organic acids, with consequent reduction or elimination of odors associated therewith, also comprises a feature of the present invention, as do products which exhibit such characteristics. Other features of the present invention will be discussed in more detail below.
Generally speaking, the present invention is directed to a combination of a product and a thermoformed film-to-film package and a method of forming thereof in to improve the various properties of the product (e.g., reduced tensile strength loss, reduced odor, reduced volume for shipping/storage, ability for package to serve as a breach indicator, reduced processing time during manufacturing, etc.). The product is vacuum packaged in the thermoformed film-to-film package. The thermoformed film-to-film package has an interior and exterior and comprises a layer having an oxygen transmission rate equal to or less than about 10 cubic centimeters of oxygen per 100 inches squared per 24 hours. Further, the product is located in the interior of the thermoformed film-to-film package. Air is removed from the interior of the thermoformed film-to-film package by applying a vacuum pressure equal to or less than about 250 millibars to the exterior of the thermoformed film-to-film package and then flushing the interior of the thermoformed film-to-film package with an inert gas until the interior of the thermoformed film-to-film package reaches an inert gas flush pressure equal to or less than about 750 millibars, and the thermoformed film-to-film package and the product are sterilized by ionizing radiation. Further, the product exhibits a reduction in its tensile strength that is equal to or less than about 18.5% after sterilization.
For instance, when the vacuum pressure initially pulled against the exterior of the thermoformed film-to-film package is between about 15 millibars and 50 millibars and the inert gas flush pressure is between about 50 millibars and about 150 millibars, the reduction in tensile strength in the machine direction is equal to or less than about 10%, such was equal to or less than about 9.9%, such as equal to or less than about 9.8% after sterilization, while the reduction in tensile strength in the cross-machine direction can be equal to or less than about 18%, such as equal to or less than 17.75%, such as equal to or less than about 17.5% after sterilization. Further, when the vacuum pressure initially pulled against the exterior of the thermoformed film-to-film package is between about 75 millibars and 125 millibars and the inert gas flush pressure is between about 400 millibars and about 600 millibars, the reduction in tensile strength in the machine direction can be equal to or less than about 13.5%, such was equal to or less than about 13.25%, such as equal to or less than about 13% after sterilization, while the reduction in tensile strength in the cross-machine direction is equal to or less than about 18.75%, such as equal to or less than 18.5%, such as equal to or less than about 18.25% after sterilization.
It should be understood that although the package describe throughout is described as being a thermoformed film-to-film package, the present invention also contemplates a package that is not thermoformed. For instance, the package can be a film-to-film package that is sealed on three sides and has one side that is unsealed, where the product is inserted into the interior of the package via the unsealed end, after which a vacuum is applied and an inert gas flush is carried out in accordance with the methods described herein.
In order to form a combination of a package and nonwoven product contained therein, where the product exhibits minimal reduction in its tensile strength after sterilization by ionizing radiation, the present inventors have found that utilizing a thermoforming process in combination with a vacuum and an inert gas flush results in a product exhibiting improved properties. The use of the inert gas can also reduce the vacuum cycle time required for packaging the product, resulting in a more efficient and economical process. The package can be a film-to-film package that is thermoformed using, for example, a thermoforming packaging machine available from MULTIVAC® Sepp Haggenmüller GmbH & Co KG (Germany), such as the MULTIVAC® R 245 or the MULTIVAC® R 535 or any other suitable thermoforming packaging machine. With such machines, a package can be formed from rolls of packaging film, where the product to be vacuum packaged is loaded into thermoformed pocket formed by an outer member (e.g., film), after which another outer member (e.g., film) is placed on top of the product. Then, the top outer member is sealed under a vacuum, resulting in a vacuum packaged product. By utilizing a film-to-film package as described above, the use of paper-to-film sterilization pouches can be avoided, where the paper can tear easily, resulting in breach of sterility and an overall product that is bulky and takes up significant space.
Turning now to
Next,
Next, as shown in
Then, referring to
After the inert gas flush 120 and turning now to
After the package 10 is sealed, as shown in
According to an aspect of the invention, the step of releasing the vacuum applied to the exterior of the package may be controlled to generate a combination having a pre-determined shape and/or a pre-determined stiffness. For example, the the pre-determined shape desirably is substantially flat and planar. It is contemplated that the pre-determined shape may be curved and planar (e.g., such as a half annular portion or quarter annular portion of a hollow cylinder). It is also contemplated that the predetermined shape may be conical (e.g., such as a hollow cone). The pre-determined shape may be flat, planar having a bend or fold line to generate an acute, obtuse or right angle. These pre-determined shapes may be generated by utilizing a sealing plate 110 have a specific curved, conical or other geometric configuration such that the package has a corresponding shape. Alternatively and/or additionally, these predetermined shapes may be introduced by post-treatment or processing.
The step of releasing the vacuum applied to the exterior of the package may be controlled to generate a combination having a pre-determined stiffness. The pre-determined stiffness is at least 10% greater than an identical combination not treated with a vacuum and an inert gas flush. This results in a package 10 that is stiffer, such as at least about 20%, such as at least about 30%, such as at least about 40%, such as at least about 50%, stiffer than a package not treated with a vacuum and an inert gas flush. Generally speaking, the increase in stiffness may range from at least about 10% up to about 75%. For example, the increase in stiffness may range from about 20% up to about 60%.
Once the product 24 has been sealed within the thermoformed package 10 as discussed above with respect to
In one aspect of the present invention and turning now to
The package 10 as contemplated by the present invention and formed by the methods described herein may be used for packaging individual or multiple products such as, by way of example only, surgical or other type gowns, gloves, masks, drapes, packs, covers, and the like. The package 10 has an exterior 23 and comprises outer members 12, 14 which are oxygen impermeable films that are sealed, for example, by means of heat seal lines 16, 18, and 20, thereby forming interior 22 in package 10. Members 12, 14 can be a single layer of material, or a laminate of more than one layer of the same or different material, and can include a layer for purposes of oxygen impermeability. For instance, referring to
Meanwhile, product 24, which can be a nonwoven material such as a SMS polyolefin material, is placed in interior 22, and then package 10 is sealed along periphery 28. If desired, notches 26 may be cut in package 10 to facilitate product removal.
The materials and methods used in carrying out the present invention may be more fully understood by reference to the following examples, which examples are not intended in any manner to limit the scope of the present invention.
The ability to reduce tensile strength loss of spunbond-meltblown-spunbond (SMS) polyolefin-based nonwoven fabrics was determined for various vacuum, inert gas (nitrogen) flush, and gamma irradiation conditions. Samples of SMS fabrics were sealed in thermoformed film-to-film packages using a thermoforming packaging machine as generally described above. The film-to-film packages included top and bottom layers, where the resulting packages had various oxygen transmission rates (OTR) as described below in Table 1.
Individual packages of SMS fabric were created using a thermoforming packaging machine via a form-fill-seal process. Generally, the bottom layer of the package (outer member 14 as shown in
Gamma irradiation was done for tight control (+/−10%) of the radiation dose. A target dose of 25, 45, or 50 kGy was used for the various samples as illustrated below in Table 3. For the manufacturing process used to generate these samples, 50 kGy is considered the worst case radiation exposure necessary to ensure a 10−6 sterility assurance level and was therefore chosen to illustrate the invention. Previous work has demonstrated a strong correlation between the radiation dose applied to polypropylene spunbond samples and the amount of tensile loss that occurs.
For all samples, the tensile testing was conducted following ASTM D-5034 test method entitled: “Standard Test Method for Breaking Strength and Elongation of Textile Fabrics (Grab Test)”. Details of the testing method can be found below in Table 2.
For each sample listed below in Table 3, the samples were tested for tensile strength in both the machine direction and cross-machine direction. The control samples were then used to calculate the percent loss in tensile strength for the samples that were subjected to gamma irradiation.
The % loss in tensile strength in the machine direction or cross-machine direction due to gamma irradiation exposure was then calculated using the following formula:
The machine direction and cross-machine direction % tensile strength loss is shown for the various samples processed at various vacuum levels, nitrogen gas flush levels, and gamma irradiation exposure levels in packages formed from films with varying oxygen transmission rates (see Table 1) is shown in Table 3 below, and the 45 kilogray gamma irradiation exposure samples are also compared in the bar charts shown in
Table 3 shows the effects of varying the initial vacuum level, the nitrogen gas flush pressure level, and the oxygen transmission rate of the packaging material on the loss in tensile strength of polyolefin-based SMS fabrics that have been exposed to gamma radiation (γdose=25, 45, or 50 kGy). Generally, the samples that included a nitrogen gas flush (samples 1-4 and 7-10), despite having an increased OTR of 1.5 cubic centimeters of oxygen per 100 inches squared per 24 hours, exhibited reduced loss in tensile strength compared to the samples that did not include a nitrogen gas flush (samples 12-13), which had an OTR of 0.2 cubic centimeters of oxygen per 100 inches squared per 24 hours. Thus, despite allowing increased oxygen transmission, the samples contemplated by the present invention that included a nitrogen gas flush generally maintained their tensile strength better than samples that allowed less oxygen transmission. Such a distinction is not trivial, as film layers that have an increased OTR are less expensive than those having a reduced OTR.
Specifically, samples 1-4 and 7-10 (nitrogen gas flush) exhibited a percent loss of tensile strength in the machine direction ranging from 9.5% to 12.8%, while samples 12 and 13 (no nitrogen gas flush) exhibited a percent loss of tensile strength in the machine direction ranging from 12.3% to 15.6%. Meanwhile, samples 1-4 and 7-10 (nitrogen gas flush) exhibited a percent loss of tensile strength in the cross-machine direction ranging from 13.5% to 18.1%, while samples 12 and 13 (no nitrogen gas flush) exhibited a percent loss of tensile strength in the cross-machine direction ranging from 14.5% to 19.6%. Moreover, when comparing the samples utilizing the same vacuum levels (either 20 millibars or 100 millibars), the samples with the nitrogen gas flush and higher OTR films performed better and showed less tensile strength loss in the machine direction. For example, at 20 millibars of vacuum, samples 3-4 and 9-10 only exhibited a percent loss of tensile strength in the machine direction ranging from 4.8% to 9.7%, while sample 13 exhibited a percent loss of tensile strength in the machine direction of 12.3%. In addition, at 100 millibars of vacuum, samples 1-2 and 7-8 only exhibited a percent loss of tensile strength in the machine direction ranging from 8.6% to 12.8%, while sample 12 exhibited a percent loss of tensile strength in the machine direction of 15.6%.
Turning now to
Nonwoven materials (e.g., drapes, gowns) were placed in thermoformed film-to-film packages and then tested for oxygen content within the packages over a time period spanning 32 days. One of the goals of Example 2 was to determine if various packages met the barrier requirement goal of maintaining an oxygen-reduced environment inside the package for up to 5 years pre-sterilization. The various samples tested are shown below in Table 4. It should be noted that the sample packages were formed with either a draw depth of 45 mm unless otherwise noted.
During the oxygen content study, an OpTech® oxygen reader from MOCON was used to read re-usable platinum sensors that were sealed into the bottom of the sealed package samples. The sensors enabled measurement of the % oxygen in each package over time. The oxygen content of the samples listed in Table 4 was measured at the time of package sealing (time 0) and over the course of the following 32 days. Testing was performed every 2 to 4 days early on, then once per week for the final two readings.
Based on the results shown in
P(t)=Pd+(Pi−Pd)e(RT(TR′)t)/V
where Pd=driving force partial pressure (%), Pi=initial partial pressure in the package (%), R=gas constant, T=temperature, TR′=measured oxygen transmission rate at 100% oxygen, V=headspace volume, and t=time.
For these calculations, a headspace volume of 10 cubic centimeters was assumed. Also, for the packages using the low oxygen transmission rate barrier (high barrier) (combos 4-6), the average slope of 0.0016% of the oxygen transmission rate/day was used (average slope of data for combos 4-6). Based on these assumptions, combo 1 would be expected to equilibrate at 21% oxygen in less than 100 days, combo 2 would be expected to equilibrate at 21% oxygen in about 220 days, combo 3 would be expected to equilibrate at 21% oxygen in about 415 days, and combos 4-6 would only reach 4-6% oxygen in 5 years, and would require over 50 years to equilibrate at 21% oxygen.
In conclusion, Example 2 shows that a thermoformed film-to-film package can be produced that serves as a barrier to increased oxygen levels over time, which increases the stability of the package and also limits the volume or size of the package, while also maintaining the package in a rigid state, which can enable for efficient shipping and storage of packages formed as described in the present disclosure. In addition, the low oxygen content over a period of 5 years or greater can prolong the time during which packaged products can be stored with reduced odor upon sterilization, as any ingress of oxygen between the time of packaging and the time of sterilization can produce a strong odor upon sterilization of the package.
In Example 3, thermoformed film-to-film packages containing a product (e.g., surgical gowns) made according to the methods of the present disclosure were provided to 80 study participants. In the study, 100% of the participants found the aseptic donning of the surgical gown to be acceptable. In addition, a majority of the participants found the packaging with respect to donning to be the same as, a little better, or much better than their current packaging and would accept the packages for use at their facility. Further, no comments were received with respect to any odor being emitted from the opened packages. Moreover, it was noted that the vacuum packaging of the present invention, which had a thickness half that of the comparison packaging, was preferred by some participants because it gave the added confidence of knowing if the packaged had been breached and was therefore unsterile. In addition, the participants perceived the thermoformed film-to-film packaging concepts as beneficial to their facilities in terms of storage and logistics management.
As mentioned above, as a result of the particular film-to-film packaging and packaging/sterilization conditions contemplated by the present invention, a nonwoven material such as a sterile drape, gown, etc. can exhibit various improved properties such as minimal tensile strength loss, reduced odor after sterilization, etc. In addition, because of the use of film-to-film packaging in conjunction with a vacuum for packaging the products of the present invention, the film-to-film packaging can fit the shape of folded drapes, gowns, etc. such that the packaging can collapse uniformly, thus avoiding the formation of crinkles, bends, and folds, which, in turn, provides for a package having a flat, planar shape. Because the packaging has a flat, planar shape, the combination of the packaging and product stored therein can be shipped and stored more efficiently, as the flat, planar shape is relatively stiff and occupies much less volume than conventionally packaged products and/or has greater stability. Accordingly, the present invention encompasses a system for shipping a quantity of folded drapes, gowns, etc. that includes: (i) a shipping container such as, for example, a shipping carton; and (ii) a plurality of packaged products arranged in the shipping container such that the plurality of packaged products occupies less volume, such as at least about 20%, such as at least about 30%, such as at least about 40%, such as at least about 50%, less volume than an identical plurality of package not treated with a vacuum and an inert gas flush (for example, from about 10% up to about 75% less volume; as another example, from about 20% up to about 60% less volume). The above described system for shipping such products also encompasses a system for stacking, storing and/or dispensing such packaged products (folded drapes, gowns, etc.) that includes a plurality of the packaged products arranged in a stack or arranged in a storage and/or dispensing container—particularly when the packaged products have a pre-determined shape and/or pre-determined stiffness at least 10% greater than an identical packaged product not treated with a vacuum and an inert gas flush. This results in a package that is stiffer, such as at least about 20%, such as at least about 30%, such as at least about 40%, such as at least about 50%, stiffer than a package not treated with a vacuum and an inert gas flush. Generally speaking, the increase in stiffness may range from at least about 10% up to about 75%. For example, the increase in stiffness may range from about 20% up to about 60%. Such stiffer products are more stable in a stack (e.g., for storage) or are more stable in a shipping container or dispensing container. Such stiffer products desirably have a pre-determined shape that is substantially flat and planar—which is generally thought to increase stability in a stack, in a storage container or dispensing container. It is contemplated that the pre-determined shape may be curved and planar (e.g., such as a half annular portion or quarter annular portion of a hollow cylinder). It is also contemplated that the predetermined shape may be conical (e.g., such as a hollow cone). The pre-determined shape may be flat, planar having a bend or fold line to generate an acute, obtuse or right angle. These alternative shapes may also impart stability and/or ease of dispensing.
Such a shape also enables the packaged product to be stacked with more stability (for example, in a sterilizer, as part of a kit and/or on a procedure tray) and the flat, stiff nature of the package product can also make it easier to open the package. Moreover, the collapsed package can function as a breach indicator to alert a user that the product contained therein is not sterile because the collapsed package will inflate if there is a breach and may also make an inflation noise under certain conditions to alert the user that sterility has been breached.
Moreover, the present invention allows for control of the volume of the inert gas flush to be controlled to provide for different amounts of compression or collapse of the packaged product in order to address the level of rebound encountered when the package is opened, as some drapes or gowns can “fluff up” when the package is opened.
These and other modifications and variations of the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole and in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims.
The present application is the national stage entry of International Patent Application No. PCT/US2017/061231 having a filing date of Nov. 13, 2017, which claims priority to U.S. Provisional Patent Application Ser. No. 62/422,806, filed on Nov. 16, 2016, both of which are incorporated herein in theft entirety by reference thereto.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2017/061231 | 11/13/2017 | WO | 00 |
| Publishing Document | Publishing Date | Country | Kind |
|---|---|---|---|
| WO2018/093700 | 5/24/2018 | WO | A |
| Number | Name | Date | Kind |
|---|---|---|---|
| 2790284 | Hultkrans | Apr 1957 | A |
| 4041203 | Brock et al. | Aug 1977 | A |
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