MXPA97009412A - Microporosa film containing adsorbentemicrob - Google Patents

Abstract

The present invention relates to a film that includes a film that includes a microbial adsorbent, the film comprises: a first surface, and a second surface, and with the film defining at least one microporous conduit allowing communication, through the film, between the first and second surfaces, and where a part of the microporous conduit is defined by the microbi absorbent

Description

MICROPOROSA MOVIE CONTAINING MICROBIAL ADSORBENT FIELD OF THE INVENTION The field of the present invention encompasses film materials, which possess antimicrobial characteristics.

BACKGROUND OF THE INVENTION Films have traditionally been used to provide barrier properties in single-use articles including, but not limited to, articles of clothing in general, to protective clothing, to health-related products including surgical drapes, scrubs and sterile wrappings and absorbent products for personal care such as diapers, training pants, incontinence garments, sanitary napkins, bandages, and the like. In absorbent personal care products such as infant diapers and adult incontinence products, films such as outer covers are used for the purpose of preventing body waste from contaminating clothing, bedding and other aspects of the user's surrounding environment. In the area of protective clothing, including hospital gowns, the films have been used to prevent the exchange of microorganisms between the user and the patient.

These films are usually one to two mils in thickness and have a basis weight of about 0.7 to 1.5 ounces per square yard. Polyolefin films are most commonly used in such areas.

One of the significant disadvantages in the use of films, barrier materials in most cases, of these types of products is that the films do not do their job well. That is, they form a complete barrier. Complete barriers of this type completely create a new problem in the sense that they block the exit of the steam water from the person or article that wraps the film. Therefore, garments formed of such materials tend to become quickly very uncomfortable due to the accumulation of water vapor which is produced by the individual but which is not allowed to pass through the film.

The water vapor remains between the individual and the garment or article made of the material. The individual quickly develops a feeling of being "sweaty" or "sticky" as the relative humidity accumulates in those confined areas and water vapor condenses there.

In response to this problem, those skilled in the art have attempted to manufacture protective garments and other articles where the passage of microbes is undesirable from materials that allow the passage of steam water. Such materials include, for example, fabrics and non-woven laminates thereof as described in detail in U.S. Patent No. 4,041,203 issued to Duc et al. This patent is hereby incorporated completely by reference to its entirety.

The icroporous varieties of the films either by themselves or incorporated in laminates have also been used in such products in an attempt to provide articles with attributes other than garment type, such as the ability to reduce the relative humidity below the garment, thus maintaining a higher degree of comfort for the user.

However, the use of non-woven fabrics and / or microporous films in certain protective clothing has not been without difficulties. For example, the use of such materials has raised concerns about their ability to prevent the transfer of microorganisms because the size of such microorganisms such as viruses and bacteria is typically smaller than the pores of the microporous films. The non-woven fabric materials, typically, have also been characterized by conduits therethrough which, while they may delay the progress of the microbes, do not guarantee complete barrier properties with respect thereto. For these reasons, none of these arrangements has proven to be completely satisfactory in view of the fact that these do not form a complete barrier for microbes.

Therefore, there is a definite need for a material that allows the passage of steam water therethrough while effectively forming the barrier to the passage of small pathogens such as viruses, bacteria, cysts and nematodes. If such a material were a film, it should be used as a layer of a laminate with a non-woven material to provide a general material which will have effective microbial barrier properties, respirability, (ie, allowing the passage of an adequate amount of water vapor) and a sense of touch.

OBJECTS OF THE INVENTION It is therefore an object of the present invention to provide a microporous film, which allows the passage of water vapor while still being an effective barrier material for microbes such as viruses, bacteria, cysts and nematodes.

It is a further object of the present invention to provide a microporous film which also allows the passage of water vapor, which is an effective barrier for microbes, such as viruses, bacteria, cysts and nematodes, and on exposure to a generally aqueous liquid, it forms a physical barrier to the passage of such liquid through it in the area limited to such exposure.

It is yet another object of the present invention to provide a laminate of such microporous films with one or more non-woven fabrics.

These and other objects of the wide scope of applicability of the present invention will be apparent to those with ordinary skill in the art of the details given hereafter. However, it should be understood that the detailed description of the presently preferred embodiments of the present invention will be by way of illustration only because various changes and modifications are within the spirit and scope of the invention and will be apparent to those skilled in the art with view to the following detailed description.

SYNTHESIS OF THE INVENTION In response to the aforementioned difficulties encountered by those skilled in the art, we have invented a film which includes a microbial adsorbent and which is capable of providing a barrier to microbes while still being able to allow the passage of steam from Water. The film has the first and second surfaces and defines at least one microporous conduit that allows communication, through the film, between the first and second surfaces. Such communication in some modalities allows the passage of water vapor through the film. In particular, a part of the microporous conduit is defined by the microbial adsorbent so that the microbes attempting to pass through the film by means of a conduit must pass in close proximity to the microbial adsorbent. This arrangement allows the microbial adsorbent to veto the microbe by absorbing it and forbidding its passage through the film.

In some embodiments, the film may be formed of a thermoplastic polymer for example, the thermoplastic polymer may be selected from the group including polyolefins, polyamides, polyesters and copolymers and blends in any combination of these and / or other suitable materials.

For example, the polyolefin can be selected from the group consisting of polypropylenes, polyethylenes, polybutylenes and copolymers and mixtures thereof. The polyethylene can be a linear low density polyethylene. In other embodiments, the film may be a solvent set film formed of any conventional material known to those skilled in the art as being suitable for the formation of such solvent set films.

By specifically making the type of microbial absorbent present in the film, said film can be adapted to adsorb viruses, bacteria, cysts or nematodes or any or all of these. Naturally, the film may be adapted to adsorb specific types of viruses, bacteria, cysts, nematodes, etc. depending on the use to which it is going to be assigned.

In certain embodiments, the film can be designed to not only act as a filter for the microbes as a result of the presence of the microbial adsorbent but also to be designed to act as a physical (mechanical) barrier to the fluids that attempt to pass through the microbial. same For this purpose, the microbial adsorbent used may be one which, in the presence of a generally aqueous fluid, increases its volume by at least 1.5 times in no more than 1.20 seconds. For example, the microbial adsorbent may be one which in the presence of a generally aqueous fluid increases its volume by at least 1.5 times in no more than 60 seconds. More particularly, the microbial adsorbent can be one which, in the presence of a generally aqueous fluid, increases its volume by at least 1.5 times in no more than 15 seconds. Even more particularly the microbial adsorbent can be one which, in the presence of a generally aqueous fluid, increases its volume at least 2 times in no more than one second. In the event that such a microbial adsorbent is used, the adsorbent will increase, when contacted with the aqueous fluid generally, its size and swell. The swelling serves to block the microporous conduit whereby the microbial adsorbent is in close proximity. The blockage of the duct creates a physical barrier within the microporous duct with the consequence that a liquid can not pass.

An alternate way by which physical blockage can be obtained, if the microbial absorbent which is desired to be used does not have the ability to swell (increase in size), is that the film may also include a load of other material particulate which, likewise, swells in the presence of a generally aqueous liquid. In some embodiments, the particulates of the swelling material and the microbial adsorbent may be incorporated within the film in an agglomerated form so that each individual particle contains some non-swelling microbial adsorbent and some swelling material. In any of these modalities the inflatable material is one which can increase its size by at least 1.5 times in no more than 120 seconds. For example, the swelling material may be one which in the presence of a generally aqueous fluid increases its volume by at least 1.5 times in no more than 60 seconds. More particularly, the swelling material may be one which, the presence of a generally aqueous fluid increases its volume by at least 1.5 times in no more than 15 seconds. Even more particularly, the swelling material can be one which, in the presence of a generally aqueous fluid, increases in volume at least twice in no more than 1 second.

The microbial adsorbent can be any of such adsorbents, which are compatible with the film material that is being used. In some embodiments, the microbial adsorbent can be derivatized silane such as, for example, 3- (trimethoxysilyl) propyldimethyloctadecyl ammonium chloride [(CH 3) 3 Si (CH 2) 3 N + (CH 3) 2 C, g H 37 Cl]. This material was previously available from Dow Corning under the brand name Dow Corning 5700. This is now available from Aegis Environmental. In other embodiments, the microbial adsorbent is a heavy metal. For example, heavy metal can be silver.

In other embodiments, the microbial adsorbent may be a metal salt. For example, the metal salt can be a polyvalent metal salt insoluble in water. The water-soluble, polyvalent metal salt can be a salt of a metal selected from the group including the metals of Group IB, Group IIA, Group IIB, Group IIIA, Group IVB and Group VIB. More particularly, the metal can be selected from the group including iron, aluminum, lead, magnesium, silver, calcium and alloys of one or more or more of iron, aluminum, lead, magnesium, silver and calcium. The salt can be selected from the group including hydroxides, phosphates, chromates, oxides and peroxides. For example, the salt may be selected from the group including one or more of ferric hydroxides, ferrous hydroxides, aluminum hydroxides, magnesium hydroxide, magnesium oxide, magnesium peroxide, lead chromate and calcium hydroxide.

In other embodiments, the microbial adsorbent can be selected from the group including colloidal clays.

For example, the colloidal clay can be a bentonite such as a sodium bentonite and / or a calcium bentonite. Colloidal clay can, in some modalities, be hectorite.

The microbial filter film of the present invention can be advantageously formed in a wide variety of articles where it is desired to have a material which allows the passage, for example, of water vapor but which prohibits the passage of microbes to through it. For example, the article may be a garment, such as a surgical gown, foot protectors, face masks, hair or head covers, aprons, sacks, pants, gloves, coveralls and generally speaking all the costumes of quarter of operations.

Alternatively it may be a product such as, for example, a sterile wrapping material which is used to keep the sterile field around the doctor's instruments until they are used in an operation.

Similarly, the film of the present invention can be conveniently formed in a surgical drape for use on a patient during an operation.

DEFINITIONS As used herein, the term "respirable" refers to any material which has a water vapor transmission rate (WVTR) of at least 300 grams per square meter per 24 hours when measured in accordance with the standard ASTM E 96-80.

As used herein, the term "adsorbent" refers to any material which has the ability to retain and / or inactivate microbes such as, for example, viruses, bacteria, cysts and / or nematodes on or near its surface.

As used herein, the term "microporous conduit" refers to any conduit which, at some point along its length, has a diameter of fifty (50) microns or less.

As used herein, the term "microporous film" refers to a film having a plurality of microporous passages therethrough to make the film breathable. The microporous film will also have a hydro head of at least 25 centimeters of water when its hydro head is measured according to method 5514 - Standard Test Methods Standard No. 191A. For example, the microporous film can have a hydro head of at least 50 centimeters of water when measured.

As used herein, the term "generally aqueous liquid" refers to any liquid which has water as its main component. All body fluids, including, without limitation, blood, saliva, menstrual fluids, mucosa, limbal fluid and urine, are expressly included within this definition.

Whether a material is "swelling" was determined by first providing 100 ml of water contained in a cylinder with a 100 ml capacity glass stopper. Then a first portion of two grams of the material was put on the surface of the water and the settling was left completely. Then, a second portion of two grams of the material being approved was placed on the surface. After two hours, the volume occupied by the material at the bottom of the cylinder was observed. For the material to be "swollen" the material at the bottom of the cylinder must have an apparent volume of not less than about 6 ml.

As used herein, the term "non-woven fabric" refers to a fabric having a structure of individual fibers or filaments which are interleaved, but not in a repetitive and identifiable manner.

As used herein, the term "spunbond fibers" refers to the fibers which are formed by extruding a melted thermoplastic material as filaments of a plurality of usually circular and fine capillaries of a spinning organ with the diameter of the fibers. extruded filaments then being rapidly reduced as indicated, for example, in U.S. Patent No. 4,340,563 issued to Apel et al. and in U.S. Patent No. 3,692,618 issued to Dorshner et al., in the United States of America Patent No. 3,802,817 issued to Matsuki et al., In US Pat. No. 3,338,992 and 3,341,394 issued to Kinney, US Pat. Nos. 3,502,763 and 3,909,009 granted to Levy and the United States patent. United States No. 3,542,615 issued to Dobo and others, all of which are incorporated herein by reference.

As used herein, the term "meltblown fibers" means fibers formed by extruding a melted thermoplastic material through a plurality of capillaries, usually circular and thin as melted threads or filaments into a usually heated gas stream. at high speed (for example air) which attenuates the filaments of the melted thermoplastic material to reduce its diameter. Then, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collector surface to form a meltblown fabric of fibers randomly discharged. Melt blowing is described, for example, in U.S. Patent No. 3,849,241 issued to Buntin, in U.S. Patent No. 4,307,143 issued to Meitner et al., And in the patent of the United States of America. United States of America No. 4,707,398 issued to Wisneski and others, all of which are incorporated herein by reference.

DESCRIPTION OF THE DRAWINGS Figure 1 is a highly amplified and schematic cross-sectional view of a breathable microbial barrier film designed in accordance with the teachings of the present invention.

Figure 2 is a highly enlarged and schematic cross-sectional view of a form of a breathable microbial barrier film designed in accordance with the teachings of the present invention and wherein the film also forms a physical barrier to the passage of liquids in the contact site of the film by means of such liquid. Figure 2 illustrates the mode in the configuration where the physical barrier has been formed.

Figure 3 is a highly amplified and schematic cross-sectional view of another embodiment of a breathable microbial barrier film designed in accordance with the teachings of the present invention and wherein the film also forms a physical barrier to the passage of liquids in the contact site of the film for a liquid.

Figure 4 is a schematic representation of a process for forming a laminate having the respirable microbial barrier film of the present invention incorporated therein.

Figure 5 is a highly enlarged and schematic cross-sectional view of a laminate of a non-woven fabric and the breathable microbial barrier film of Figure 1.

DETAILED DESCRIPTION OF THE INVENTION Turning now to the drawings in which the like reference numbers represent equivalent or equal structures or equal processes, an improved microporous film 10 of the present invention is shown. Typically, the film will be formed of a sheet 12 of a thermoplastic material. For purposes of simplicity and clarity the film 10 is shown as having only a microporous conduit 14. However, those of ordinary skill in the art will readily recognize that typical microporous films possess a multitude of such conduits 14 per square inch. The film 10 is configured so that a particle 16 of a material which is a microbial adsorbent is positioned at some point along the length of the conduit between the first surface 18 of the film 10 and the second surface 20 of the film 10. In most cases, the ducts 14 will be dimensioned in a manner such as to allow the passage of water vapor through the film 10. That is, the film 10 is breathable. In particular, a part of the microporous conduit 14 is defined by the microbial adsorbent 16 so that the microbes (not illustrated) attempting to pass through the film 10 through the conduit 14 must pass in close proximity to the microbial adsorbent 16. This arrangement allows the microbial adsorbent 16 to prohibit microbes by adsorbing them and prohibiting their passage through the film 10 while still retaining the breathability of the film 10.

In some embodiments, the thermoplastic material 12 may be selected from the group including polyolefins, polyamides, polyesters, and copolymers and blends in any combination thereof and / or other suitable material. For example, the polyolefin can be selected from the group consisting of polypropylenes, polyethylenes, polybutylenes and copolymers and mixtures thereof. The polyethylene can be a linear low density polyethylene.

By specifically making the type of microbial adsorbent 16 present in the film 10, the film 10 can be adapted to absorb a wide variety of pathogens. For example, the film 10 can be made to act as a filter for viruses, bacteria, cysts and / or nematodes. Naturally, the film 10 will be adapted to adsorb specific types of viruses, bacteria, cysts and / or nematodes depending on the use to which it is to be assigned. The use of the pathogen-specific adsorbent quickly achieves this result.

In certain embodiments, the film 10 can be designed to not only act as a filter (adsorbent) to the microbes as a result of the presence of the microbial adsorbent 16, it is also designed to act as a physical (mechanical) barrier to the fluids that are intended the pass through it. For this purpose, the microbial adsorbent 16 used can be a swelling which, in the presence of a generally aqueous fluid, will increase its volume by at least 1.5 times in no more than 120 seconds. For example, the microbial adsorbent 16 can be one which in the presence of a generally aqueous fluid increases its volume by at least 1.5 times in no more than 60 seconds. More particularly, the microbial adsorbent 16 can be one which, in the presence of a generally aqueous fluid, increases its volume by at least 1.5 times in no more than 15 seconds. Even more particularly, the microbial adsorbent 16 may be one which, the presence of a generally aqueous fluid increases in volume at least twice in no more than one second. In the event that such microbial adsorbent 16 is used, the adsorbent 16 will increase, upon contact with the generally aqueous fluid, its size and swell. The swelling serves to block the microporous conduit 14, which is in close proximity to the swelling adsorbent 16. The blocking of the conduit 14 creates a physical barrier within the microporous conduit 14 with the consequence that no liquid will pass therethrough. Therefore, a physical or mechanical barrier (dam) is formed in the conduit 14 which closes the conduit 14. Figure 2 illustrates an embodiment of the present invention wherein the microbial adsorbent 16 is swellable and has swollen to seal or make the dam in conduit 14. This arrangement results in an "intelligent" film in the sense that said film 10 reacts to being contacted by a liquid only in the area where the liquid contact occurs. Therefore, the film 10 remains breathable due to the presence of numerous other micropores 14 which may not be blocked. A specific example of a swelling microbial adsorbent is bentonite and, in particular, sodium bentonite.

An alternate form by which the physical blockage of the conduit 14 can be obtained, if the microbial adsorbent 16 which is desired to be used does not have the ability to swell (increase in size) is that the film 10 can also include a loading of another particulate material 22 which in itself swells in the presence of a generally aqueous liquid. In some embodiments, the swell material particles 22 and the microbial adsorbent 16 can be incorporated in the film in an agglomerated form so that each individual particle contains some of a non-swelling microbial adsorbent 16 and some of the swelling material 22. In any of these modalities the 22 hinchabie material is one which can increase its volume by at least 1.5 times in no more than 120 seconds. For example, the swelling material 22 can be one to which, the presence of a generally aqueous fluid increases its volume by at least 1.5 times in no more than 60 seconds. More particularly, the swelling material 22 can be one which, in the presence of a generally aqueous fluid, increases in volume by at least 1.5 times in no more than 15 seconds. Even more particularly, the swelling material 22 can be one which, in the presence of a generally aqueous fluid, increases in volume at least twice in no more than one second. Specific examples of such inflatable materials 22 will be used in conjunction with a non-swelling microbial adsorbent 16 include, without limitation, kaolins, and diatomaceous earth. The diatomacea earth can be treated, as it is known in the art, as being positively charged. A restriction in this design is that the microbial adsorbent 16 and the swelling material 22 must both be exposed to the conduit 14 for each to carry out their respective functions. Such a design is illustrated schematically in Figure 3.

The microbial adsorbent 16 can be any adsorbent 16 which is compatible with the film material 12 that is being used. In some embodiments, the microbial adsorbent is a heavy metal. For example, heavy metal can be silver.

In other embodiments, the microbial adsorbent 16 may be a metal salt. For example, the metal salt can be a polyvalent metal salt insoluble in water. The water-insoluble polyvalent metal salt can be a salt of a metal selected from the group metals including Group IB, Group IIA, Group IIB, Group IIIA, Group IVB and Group VIB. More particularly, the metal can be selected from the group including iron, aluminum, lead, magnesium, silver, calcium and alloys of one or more of iron, aluminum, lead, magnesium, silver and calcium. The salt can be selected from the group including hydroxides, phosphates, chromates, oxides and peroxides. For example, the salt may be selected from the group including one or more of ferric hydroxides, ferrous hydroxides, aluminum hydroxides, magnesium hydroxide, magnesium oxide, magnesium peroxide, lead chromate and calcium hydroxide.

In some embodiments the microbial adsorbent 16 can be selected from the group including colloidal clays. For example, the colloidal clay can be a bentonite such as a sodium bentonite and / or a calcium bentonite. In some embodiments, the colloidal clay can be a hectorite.

The microbial filter film 10 of the present invention can advantageously form in a wide variety of articles where it is desired to have a material which allows the passage of, for example, water vapor but which prohibits the passage of microbes to through it. For example, the article may be a garment such as a surgical gown, foot pads, face masks, head or hair covers, aprons, sacks, gloves, pants, overalls and generally speaking all clothing for the quarter of operations.

Alternatively, the film 10 can be incorporated into a product such as, for example, a sterile wrapping material which is used to keep the sterile field around the doctor's instruments until they are used in the operation.

Similarly, the film 10 of the present invention can conveniently be formed or incorporated into a surgical drape for use on a patient during an operation.

The film 10 of the present invention can be made from a wide variety of methods known to those skilled in the art. A method for forming the film 10 is described in detail in the United States patent application Serial No. 08 / 254,207 entitled "Thinned-Stretched Film and Nonwoven Laminate" and filed on June 6, 1994 on behalf of Ann Louise McCormack, Lance James Garrett, Jr. and Karen Lynn English. This application is specifically incorporated herein by reference in the present application in its entirety. It is known that the films can be made respirable by adding filler particles such as calcium carbonate to the film during the film forming process.

Once the film filled with particles has been formed by conventional methods, it is then stretched or crushed to create conduits therethrough. This action results in the creation of a breathable film. This particular method also results in a configuration wherein at least one of the particles defines a part of essentially each conduit. Therefore, this method is very suitable for the formation of articles 10 according to the present invention. These films 10 can be easily manufactured by replacing the particles of the microbial adsorbent 16 with the filler material. All the other process steps remain essentially the same. Of course, the desirably selected microbial adsorbent 16 will not chemically interfere or adversely affect the extruded film 10 and will have the ability to be relatively uniformly dispersed throughout the film 10. For example, the moisture content of the microbial absorbent 16 should be maintained at 1 percent, by weight or less for a satisfactory extrusion to occur. Generally speaking, the particles of the microbial adsorbent 16 will have an average particle size in the range of from about 0.1 to about 7 microns. Of course, the maximum particle size which can be used is related to the ultimate thickness (thinness) of the film 10. Typically, the film 10 will contain at least about 30 percent, by weight of the film, of the absorbent 16.

As previously stated in some embodiments, it may be desirable to form a laminate of the film 10 of the present invention and one or more non-woven fabrics. Such a laminate can have a cloth-like appearance and a fabric feel, be breathable like fabrics and still be able to prevent microbes from passing through it.

Figure 4 schematically illustrates a process for forming such a laminate by forming a thinned and stretched film 10 and a non-woven fabric 24 in a laminate 26. The film 10 is formed using any type of conventional film-forming equipment such as film. blowing or melting equipment. Prior to extrusion, the film-forming material is filled into the microbial adsorbent 16 in particulate form. After conventional formation of the film 10, it is sent through a film stretching apparatus to stretch and thin the film to an appropriate thickness which is in the order of 0.55 mils or less. The thinning-stretching step also creates the micropores or conduits 14 through the film 10 as well as is known to those of ordinary skill in the art. One type of apparatus for such stretch-slimming is a machine direction orienter 27 (MDO) Model Unit No. 7200 from the Marshall and Williams Company of Providence, Rhode Island.

Figure 4 also illustrates that while the film layer 10 is being formed and thinned, the fibrous nonwoven fabric 24 can also be formed 24. A conventional fibrous nonwoven fabric forming apparatus 24 such as that of the fabric 24 can also be used to form the fabric 24. as a spinning machine. The essentially continuous and long spunbonded fibers 30 are deposited on a forming wire 32 as an unbonded mat 34 and the unbonded mat 34 is then sent through a pair of bonding rollers 36a and 36b to join the fibers together 30 and increasing the tear strength of the resultant fabric 24. One or both of the rollers 36a and 36b are frequently heated to aid in bonding. Typically, one of the rollers 36a is also patterned so as to impart a discrete bond pattern with a prescribed bonding surface area to the fabric 24. The other roll 36b is usually a smooth anvil roll but this roll 36b may also be with pattern yes that's the way you want it.

Once the film 10 has been sufficiently thinned and oriented and the non-woven fabric 24 is formed the two layers are put together and laminated to one another using a pair of lamination rolls or other means 38a and 38b.

As with the connecting rollers 36a and 36b, the rolling rollers 38a and 38b can be heated. Also, at least one of the rollers 38a may be patterned to create a discrete bonding pattern with a prescribed bonding area for the laminate 26. Generally, the surface area of the maximum bonding point for a given area of The surface on one side of laminate 26 will not exceed about 60 percent of the total surface area.

After the laminate 26 has been formed, it is wound onto a roll 40 for subsequent processing. Alternatively, the laminate 26 can continue online for additional conversion to other articles or products.

It should be noted that this process can be altered in a number of ways without departing from the spirit and scope of the present invention. For example, a different apparatus can be used for stretching - thinning the film 10.

A nonwoven fabric / different film forming equipment such as a bonded and melt blown fabric equipment can be used in place of the yarn bonding equipment. In addition, other means for joining and laminating can be used as long as the resulting laminate has the required properties described herein. Finally, the training processes to make the film and the support layers can be done at a remote site and the rolls of the two materials can be unrolled in the process.

The process shown can also be used to create a three layer laminate. By modifying the previously described process to feed a supply 42 of a second fibrous nonwoven fabric 44 into the lamination rolls 38a, 38b on one side of the film 10 opposite to that of the first fibrous nonwoven fabric 24. As shown in Figure 4, the material supply for the second fibrous woven fabric 44 is in the form of a preformed roll 42. As with the other layers 10 and 24, the layer 42 can be formed directly in line or this can be preformed and then fed into the process from a supply roll. In either case, the second nonwoven fabric 44 is fed into the lamination rolls 38a and 38b and laminated to the film 10 in the same manner as the non-woven fabric 24.

Figure 5 is a highly enlarged and schematic cross-sectional view of a two-layer laminate of a non-woven fabric 24 and a film 10 made in accordance with the present invention. For purposes of clarity and simplicity, only one microduct 14 is illustrated in the film 10. Those of ordinary skill in the art will recognize that conventional microporous films will contain a multitude of such conduits per square inch or per square centimeter basis. For example, from about 100 to 100,000 or more ducts per square centimeter may be present.

It should be understood that variations and modifications of the present invention can be made without departing from the scope of the invention. It should also be understood that the scope of the present invention should not be construed as limited to the specific embodiments described herein but only in accordance with the appended claims when read in the light of the foregoing description.

Claims (36)

1. A film that includes a film that includes a microbial adsorbent, the film comprises: a first surface; Y a second surface; Y with the film defining at least one microporous conduit allowing communication, through the film, between the first and second surfaces; Y wherein a part of the microporous conduit is defined by the microbial absorbent.

2. The film as claimed in clause 1, characterized in that the film is formed of at least one material selected from the group consisting of polyolefins, polyamides, polyesters and copolymers and mixtures in any combination thereof.

3. The film as claimed in clause 2, characterized in that the polyolefin is selected from the group consisting of polypropylenes, polyethylenes, polybutylenes and copolymers and mixtures thereof.

4. The film as claimed in clause 3, characterized in that the polyethylene is a linear low density polyethylene.

5. The film as claimed in clause 1, characterized in that the microbial adsorbent is adapted to adsorb at least one type of virus.

6. The film as claimed in clause 1, characterized in that the microbial adsorbent is adapted to adsorb at least one type of bacteria.

7. The film as claimed in clause 1, characterized in that the microbial adsorbent is adapted to adsorb at least one type of cyst.

8. The film as claimed in clause 1, characterized in that the microbial adsorbent is adapted to adsorb at least one type of nematode.

9. The film as claimed in clause 1, characterized in that the microbial adsorbent is adapted, in the presence of a generally aqueous fluid, to increase its volume by at least 1.5 times in no more than 120 seconds.

10. The film as claimed in clause 1, characterized in that the microbial adsorbent is adapted, in the presence of a generally aqueous fluid, to increase its volume at least 1.5 times in no more than 60 seconds.

11. The film as claimed in clause 1, characterized in that the microbial adsorbent is adapted, in the presence of a generally aqueous fluid, to increase its volume by at least 1.5 times in no more than 15 seconds.

12. The film as claimed in clause 1, characterized in that the microbial adsorbent is adapted, in the presence of a generally aqueous fluid, to increase in volume at least twice in no more than one second.

13. The film as claimed in clause 1, characterized in that the film also comprises a swelling material which defines a part of the duct and is adapted, in the presence of a generally aqueous fluid, to increase its volume by at least 1.5 times in no more than 120 seconds.

14. The film as claimed in clause 1, characterized in that the film also comprises a swelling material which defines a part of the duct and which is adapted in the presence of a generally aqueous fluid, to increase its volume by at least 1.5 times in no more than 60 seconds.

15. The film as claimed in clause 1, characterized in that the film also comprises a swelling material which defines a part of the duct and which is adapted in the presence of a generally aqueous fluid, to increase its volume by at least 1.5 times in no more than 15 seconds.

16. The film as claimed in clause 1, characterized in that the film also comprises a swelling material which defines a part of the duct and which is adapted in the presence of a generally aqueous fluid, to increase its volume by at least 2. times in no more than a second.

17. The film as claimed in clause 13, characterized in that the microbial adsorbent is attached to the swelling material.

18. The film as claimed in clause 1, characterized in that the microbial adsorbent is a heavy metal.

19. The film as claimed in clause 18, characterized in that the heavy metal is silver.

20. The film as claimed in clause 1, characterized in that the microbial absorbent is a metallic salt.

21. The film as claimed in clause 20, characterized in that the metal salt is a polyvalent metal salt insoluble in water.

22. The film as claimed in clause 21, characterized in that the water-insoluble polyvalent metal salt is a salt of a metal selected from the group consisting of the metals of Group IB, Group IIA, Group IIB, Group IIIA, Group IVB, Group VIB.

23. The film as claimed in clause 22, characterized in that the metal is selected from the group consisting of at least one of iron, aluminum, lead, magnesium, silver, calcium and alloys of one or more of iron, aluminum, lead, magnesium, silver and calcium.

24. The film as claimed in clause 21, characterized in that the salts selected from the group consisting of hydroxides, phosphates, chromates, oxides and peroxides.

25. The film as claimed in clause 24, characterized in that the salt is selected from the group consisting of one or more ferric hydroxides, ferrous hydroxides, aluminum hydroxides, magnesium hydroxide, magnesium oxide, magnesium peroxide, chromate lead and calcium hydroxide.

26. The film as claimed in clause 1, characterized in that the microbial adsorbent is selected from the group consisting of colloidal clays.

27. The film as claimed in clause 26, characterized in that the colloidal clay is selected from the group consisting of bentonite and hectoarite.

28. The film as claimed in clause 27, characterized in that the bentonite is sodium bentonite.

29. The film as claimed in clause 27, characterized in that the bentonite is calcium bentonite.

30. An article comprising the film as claimed in clause 1.

31. The article as claimed in clause 30, characterized in that the article is a pledge.

32. The garment as claimed in clause 31, characterized in that the garment is suitable for operating room clothing.

33. The garment as claimed in clause 31, characterized in that the garment is selected from the group consisting of a surgical gown, foot protectors, face masks, head or hair covers, aprons, sacks, pants, gloves and coveralls.

34. The article as claimed in clause 30, characterized in that the article is a sterile wrap.

35. The article as claimed in clause 30, characterized in that the article is a surgical drape.

36. A laminate of the film as claimed in clause 1 and a non-woven fabric.