Multilayer breathable film and method of its manufacture

 

(57) Abstract:

The invention relates to a method for production of a stretched multilayer breathable film that provides a barrier to microorganisms and a barrier to blood and body fluids, and the film itself. The method involves the simultaneous extrusion of the mouthpiece at least five-layer film having the structure:And:: And:C. In this structure layer In the core is a microporous layer containing at least one thermoplastic polymer and one filler in the form of particles. The outer layers are monolithic layers and consist of a hydrophilic polymeric resin, in which there is no filler in the form of particles. Layers And represent the microporous layers of the binder. After extrusion perform the hood film. Hood creates micropores in the core layer and the binder. After extrusion, the film is cut and delivered. The obtained multilayer films exhibit good transmission rate of wet steam, high ultimate tensile strength, elongation and modulus secant. 4 C. and 25 C.p. f-crystals, 4 Il., 23 table.

The claimed priority to provisional patent application with R is done by, links.

The present invention relates to a multilayer breathable film, and more specifically five - layer breathable films. The invention also relates to a method of manufacturing a multilayer breathable film.

Films that allow the passage of gases at medium and high speeds of transmission, often referred to as breathable. The gases most commonly used for demonstrating breathability of the film, are water vapor, sometimes called wet steam, and oxygen. Test passing wet steam (TID), and the test is passing oxygen (TLC) provides a measurement of mass or volume of gas passing through the cross-section of the film in a given unit of time at a given totality of surrounding conditions. Although the mechanism of passing gas often varies in different films, it is the total amount of gas that passes through the film, making the film breathable.

In the case of close proximity to the skin of the film with high TID naturally allow to cool the body. When a film with a high TIS also provides a barrier for the passage of fluid and (or) microbial transition, there are a variety of applications, largely the creation of this unique combination of properties.

Potential applications include surgical gowns, dressings, soft lining of hospital beds, disposable film, homemade scarves, women's cloths, protective clothing, gaskets, Shoe, packaging material food and gloves.

Breathable films can be classified as either microporous or monolithic, depending on their physical structure and Gating mechanism of gas.

One type of microporous film composed of a mixture of polymers and inorganic fillers, which ekstragiruyut in the film or sheet, using standard manufacturing methods. In the second stage, or during the same continuous process with successive operations of the sheet or film guide or pull in one or two directions at temperatures below the melting temperature of the polymer. The result of the entry of this mechanical energy to the mixture of the polymer with the filler represents the creation of numerous vzaimosoedinenii or near the United pores that allow the passage of the gas molecules. Density and size of these pores can be controlled by the choice of raw materials and the conditions under which appears orientirovaniyu gas, not allowing, at the same time, to pass fluid from which can occur molecules of gas.

Another type of microporous film, sometimes referred to as foamed film contains the same mixture vzaimosoedinenii or near the United pores. Except for the previously described these pores are formed by the release of gases, which are formed under certain conditions of temperature and pressure. These films usually contain as a main component of conventional polyolefin and foaming and/or forming germ substance as minor components. Foaming substance is a substance, which has a much higher vapor pressure than the polyolefin, at the temperature of extrusion. The size and density of the pores can be changed by changing the extrusion conditions and the type or concentration of the foaming and/or forming the embryos substances. These tapes pass gases, using the same mechanism of diffusion, as the microporous film with oriented filler.

Monolithic breathable films are solid homogeneous barriers length of liquids, gases which pass through at least one of the mechanisms of absorption, adsorbed to absorption of water in water-saturated environments. And after the saturation of these tapes pass water molecules to poor moisture environment. This type of breathable film transfers water vapor is much better than oxygen or other gases.

The above-mentioned air-permeable film can be combined for the formation of a multilayer breathable film. Examples of such multilayer breathable film described in the following U.S. patents:

In U.S. patent N 5164258 described multilayer breathable film comprising outer layers of air permeable hydrophobic material (microporous), layer (monolithic) hygroscopic barrier core and binder layers located between the core layer and two outer layers. In this patent it is said that the outer monolithic layers do not work because they absorb water and the outer layer is extended (see column 2, lines 12-20).

U.S. patent N 4828556 discloses a multilayer breathable film comprising a monolithic layer of polyvinyl alcohol, which is located between two microporous layers of non-woven fabric. The binder is not required, because the polyvinyl alcohol acts as an adhesive and as a monolithic layer.

U.S. patent N nepreryvnyi protective film layer, and on the other side of the porous foam bonding layer and the woven substrate.

U.S. patent N 475839 discloses a multilayer breathable film consisting of a water-soluble polymer (solid) layer having on one side of the microporous sheet.

U.S. patent N 5143773 discloses a multilayer film consisting of a water absorbent middle layer (monolithic), one side of which is waterproof layer, and on the other side microporous layer.

Typically, multilayer films ekstragiruyut. However, when ekstragiruyut microporous layers containing the filling material, the filling material accumulates on the mouthpiece of the extruder and prevents the extrusion process. Usually, after a period of from 30 minutes to 1 hour of use, the filler is accumulated on the mouthpiece of the extruder to such an extent that it is necessary to shut down the extruder and mechanically remove the filler material from the mouthpiece of the extruder. This operation is costly and takes time. Therefore, there is a great need in the multilayer film, which during extrusion does not cause accumulation of the material of the filler mouthpiece of the extruder.

In nekotoryye by volume. When used in these multilayer films of solid materials of the core layer usually contains a monolithic material. However, the monolithic material has a very high cost compared to microporous materials. Thus, there is a great need in the multilayer material, which is much less monolithic material and which, nevertheless, provides a sufficient barrier to microorganisms and fluids.

Multilayer breathable film having a monolithic layer, used in medical films to ensure microbiological barrier to prevent the penetration of microorganisms through the material and infection of the protected health worker. During some medical procedures such as heart surgery, medical clothes, medical personnel are large amounts of blood and internal fluids. It is very important that these fluids and microorganisms did not penetrate through the material, where they can infect the medical staff.

Thus, there is a great need in the multilayer breathable film, which provides kabwelulu monolithic material and which do not pollute the mouthpiece of the extruder during extrusion.

The present invention is the provision of a multilayer breathable film, which causes significantly reduced contamination of mouthpiece filling material during extrusion.

Another objective of the present invention is to provide a multilayer film which provides good biological and liquid barrier, at the same time greatly reducing the required number of monolithic material.

An additional object of the present invention is to provide a method of manufacturing a multilayer breathable film.

The above and other objectives are obtained as follows.

The invention provides a new multilayer breathable film having the properties:

i) providing a barrier to microorganisms, and

ii) providing a barrier to blood and body fluids

and mentioned breathable film has at least the structure of C: A: B: A: C, where B contains a layer of microporous core containing at least one thermoplastic polymer and at least one filler in the form of particles,

C contains the outer solid layer, the soda is La water and microorganisms, moreover, the said layer C is essentially free of filler particles, and

A contains microporous binder layer for connecting the above-mentioned layers C with the said layer B of the core, in which the said layer C, in essence, prevents the accumulation of material filler in the form of particles on the mouthpiece during the formation of the mentioned multilayer breathable film and in which the said micropores design and features to ensure the passage of gaseous water, but, essentially, to prevent the passage of liquid water.

The invention also provides a new method of manufacturing a stretched multilayer breathable film having the combination of properties (i) providing a barrier to microorganisms and (ii) providing a barrier to blood and body fluids

moreover, the above method comprises steps (a) simultaneously extruding at least five-layer film of the mouthpiece having at least the structure of C::A:B:A:C, where B contains a layer of microporous core containing at least one thermoplastic polymer and at least one filler in the form of particles,

C contains the outer solid layer containing hydrophility and microorganisms, moreover, the layer C is essentially free of filler particles, and

A contains microporous bonding layer for bonding the above-mentioned layers C with the said layer B of the core, in which the said layer C, in essence, prevents the accumulation of the material of the filler particles at the mouthpiece during this stage of extrusion,

b) a hood mentioned extruded five-layer film for the formation thereby of micropores in the above-mentioned layer microporous core and the above-mentioned microporous layer of binder in which is mentioned the stage of extrusion, and the said layer of microporous core and the above-mentioned microporous binder create thus to provide micropores that allow the passage of gaseous water, but, in essence, prevents the passage of liquid water.

Fig. 1 illustrates a plate thread joint extrusion, which can be used in the present invention.

Fig. 2 illustrates a machine for drawing, which you can use to extract the multi-layered material after it is extruded.

Fig. 3 illustrates a standard line relief extruding the m stage.

Fig. 4 illustrates two variants of orientation or drawing multilayer film continuous or sequential manner.

The invention provides a new multi-layer film having the structure C: A: B: A: C, where A contains opisyvaemye here microporous binder,

B contains the described layer microporous core, and

C contains described here monolithic layer.

Found that a suitable thickness of each layer, five-layer film contains:

about 1 to about 40% by volume for each layer A,

from about 1 to about 96% by volume for the layer B, and

about 1 to about 30% by volume for layer C, where the percentage is based on the amount of five-layer film.

Preferably, each layer A is from about 1 to about 10% by volume, the layer B is from about 60% to about 96% by volume, and each layer C is from about 1 to about 10% by volume.

More preferably, each layer A is from about 1 to about 5% by volume, the layer B is from about 80% to about 96% by volume, and each layer C is from about 1 to about 5% by volume.

Alternatively osushestvleniya here monolithic layer and the layer D is microporous layer connecting the core. The binder layer of the core may contain materials used for manufacturing the described binder layer A. the above-Described five-layer film is preferred in comparison with a three-layer film.

In the three-layer film of the value of the layer D may vary between about 2 and about 98% by volume, and the size of each layer C may vary from about 1 to about 49% by volume. Preferably, the value of layer D may vary between about 80% and about 98% by volume, and the size of each layer C may vary from about 1 to about 10% by volume. More preferably, the value of layer D may vary between about 90% and about 98% by volume, and the size of each layer C may vary from about 1 to about 5% by volume.

Multilayer films can be made of any thickness for the desired application. Examples of suitable film thickness be between about 0.3 mils (7,6210-3mm) and about 20 Miami (5,0810-1mm), preferably from about 0.5 mils (1,2710-2mm) to about 10 mils (25,410-2mm) and more preferably from about 0.7 mil (1,7810-2mm) to about 3 mils (7,6210-2mm).

Surprisingly, due to the fact that sootvetstvuyushchuyu film, you can do extremely thin, of the order of about 1 mil (2,5410-2mm) or less, which still provide an effective barrier to microorganisms and in body fluids.

Layer microporous core

The microporous layer core contains at least a thermoplastic polymer and a filler in the form of particles for the formation of micropores in thermoplastic polymer during extrusion. You can use any thermoplastic polymer or mixtures thereof, which are suitable for the formation of the film. Examples of suitable thermoplastic polymers are described in U.S. patents NN 4929303 and 5164258, which are included here for reference.

Examples of suitable thermoplastic polymers are polyolefins, polyesters, and polyurethanes. thermoplastic polymer may contain a halogen, such as fluorine. Preferably, thermoplastic polymer includes a polyolefin. Specific examples of suitable polyolefins are polypropylene, copolymers of propylene, homopolymers and copolymers of ethylene and other alpha-olefins having from about 3 to about 20 carbon atoms. Particularly preferred linear low density polyethylene (LDL).

Thermoplastic polymer, preferably sodwee catalyzed by metallocene polyethylene include:

a number exceeding Exxon, in particular H, H, H, H, H, H, EDM-103 and EDM-202;

the exact number of Exxon in particular: 3017, 3022, 3024, 3027, 3030, 3035, 3125, 3128, 3131, 3132, 4003, 4006, 4011, 4015, 4023, 4033, 4041, 4042, 4044, 4049; 4053, 4150, 4151 and 5008;

a number of Dow Engage, in particular: 8003, 8100, 8150, 8180, 8200, 8300, 8400, 8401, 8402, 8403, 8411, 8440, 8441, 8445, 8450, 8452, 8480, 8490, 8499, 8500, 8540, 8550 and 8745;

several tools Dow, in particular: HF1030, NM, PL1840, PL1845, PL1880, PF1140, FW1650, SM1300, GF1550, RT, PL1270, X, SM1350, PL12850, PL1881, SL1170, RT, SE1400 and VP1770, and

the number of BASF Luflexan, in particular: NH, 0322LX and 1712SX.

A useful filler in the form of particles for the manufacture of micropores in the film may be any inorganic or organic material having a low affinity and a lower elasticity than thermoplastic polymer. Specific filler is preferably a rigid material.

Specific examples of inorganic fillers in the form of particles include metal carbonates such as barium carbonate, calcium carbonate and magnesium carbonate; metal hydroxides such as aluminum hydroxide and magnesium hydroxide; metal oxide such as calcium oxide, magnesium oxide, titanium oxide, titanium dioxide and zinc oxide; sulfates of metals, such as barium sulfate, calcium sulfate and Swifty. Preferred is calcium carbonate.

Commercially available suitable concentration of fillers in the form of powders include, for example: Heritag NM-10 (plastic Heritag), and Ampacet LR-88250, 100720 and 100719 (Ampacet). These concentrates contain fillers filler, in this case calcium carbonate, the amount of which is from about 50 to about 75% by weight, and the amount of thermoplastic resin carrier, in this case, LDL, is from about 50 to about 25% by weight.

The average size of the filler particles should be large enough for the formation of micro-cavities, but small enough to avoid the formation of holes or micro-cavities in the adjacent layers during extrusion, which are quite large, to allow the passage of fluids through the adjacent layer. The respective average particle sizes are from about 0.1 μm to about 10 μm, preferably from about 0.5 microns to about 5 microns and more preferably from about 0.8 microns to about 3 microns.

The filler particles should be used in an amount which provides the desired amount of micropores. A suitable amount of filler in VPO weight.

The microporous layer of the core may contain waste from any of the layers of the multilayer film. For example, waste can be mixed with the required materials for the microporous layer of the core, and then ekstradiroval. The amount of filler in the form of particles present in the waste, should be considered when determining the amount to be added of the filler particles to the material layer microporous core.

The outer monolithic layers

The outer monolithic layers contain hydrophilic polymer resin. Thus, the water vapor in contact with outer solid layer can absorb at one side of the monolithic layer, and then decarbonate from the outside of the monolithic layer. Monolithic layer can contain any polymeric resin or blend of polymer resins, which are usually used to create a monolithic layer of desiccant. Examples of suitable materials monolithic layers are disclosed in U.S. patent N 5164258.

Specific examples of suitable hydrophilic polymer resins include polyesters, polyamides and grades of polyvinyl alcohol and etilenovogo alcohol, which are essentially insoluble in water at ambient's polymer resins include a number of resins Pebax, representing polyethers comprising amide units, sold under the name Elf Atochem, type 3533, 4033, MV1074, MH, MV3000, MV1041, MV6200, H and MN; a number of resins Hytrel sold by DuPont, type 8206, HTR8171, G4778, or Eastman 14766. The monolithic material layer preferably contains Hytrel 8206 or Pebax MV1074.

The outer monolithic layers preferably include the substance of smoothing to improve the qualities of the surfaces of the film during extrusion. Commercial examples of such substances planarization include a number of Viton (registered in the Patent office of the USA) fluoroelastomer made the company "DuPont". To bring to minimum agglomeration and gel formation these forecaster should be diluted in a resin carrier, which are similar or identical component of most resins in this layer. These types of consumable substances can be used in amounts up to about 10,000 parts per million parts, preferably from about 200 to about 2000 parts per million parts by weight of the materials in the layer.

These free consumable substances can also be used in the layers of a microporous microporous core and binder. Certain p the em LR-86769 (3% of Viton And in 97% of hexene LDL) and Ampacet LR-88249 (3% of Viton And 97% octene LDL), which makes the firm "Ampacet".

To ensure effective barrier present in the body fluid (including blood) and the microorganism is preferably a sufficient choice of a monolithic material and the choice of thickness of the outer monolithic layers. Professionals in this field know how to test the resistance of the film barrier to liquids and microorganisms. On the basis of provided here disclosure specialists in the art will easily have the ability to select the desired monolithic material and the desired thickness of the outer monolithic layers. To bring to a minimum value of the thickness of the outer monolithic layers should be as close as possible to the minimum thickness, which still provides an effective barrier to liquids and microorganisms.

Microporous binder layer

Binder layers can be made from any polymeric material capable of binding a monolithic layer with microporous layer. The choice of the binder layer depends on the type of polymeric materials used for monolithic and microporous layers. Based on the above disclosure here specialists in the art will easily have the ability will determine what you eat.

Bonding layer, which connects the outer monolithic layers with a microporous layer of the core, should be allowed to pass through the water vapor. This can be done by adding filler particles to be used as the binder polymer material, so when the hood multilayer film binder becomes microporous same way as the microporous layer of the core.

Commercial examples of suitable polymeric materials for binding the outer monolithic layers with the core layer include: Lotader 3210, 3420 and 3410 (Elf Atochem); Orevac 18302 and 18305 (Elf Atochem); Plexar RH, RH and RH (quantum).

The binder may contain a mixture of polymers used in the core layer and the monolithic layers. The binder preferably includes a mixture of recycled or waste materials microporous and monolithic layers that combine ekstragiruyut. More preferably, the binder can be manufactured from reusable multilayer films. In this way, the binder contains material Napo Prov. ü binder polymers.

Thanks to the use as binders waste or reusable layers of monolithic or microporous material is achieved considerable efficiency. Moreover, a multilayer film is much easier to reuse.

The choice of materials used for microporous and monolithic layers, depends on the amount of stretching, which is subjected to multi-layer film. Ventilation must be sufficient to obtain a mixture of microporous thermoplastic polymer with a filler and a binder material, but not too large to form the gaps and holes in the monolithic layer. Specialists in the art will know how to do microporous layer containing the desired amount of stretching for the formation of micropores. On the basis of provided here disclosure specialists in the art will easily be able to determine what materials should be selected for monolithic layer used for a specific mixture of thermoplastic polymer with a filler and a binder material so that when the hood multilayer material, the core layer was microporous and outer monolithic layers maintained their celebrationtime, using standard industrial methods of extraction. The film preferably extend only in the direction (hereinafter referred to as "uniaxial"). The direction represents the direction in which the film during its formation.

The porosity value is permanently stretched film is determined by four factors:

1) the number, type and size of filler particles,

2) the type of polymer layered film

3) the quantity of volatile substances present in the material film to akrotiriani, and

4) the degree of stretching.

Usually, the greater the number of filler particles, the greater the number of micropores, which can be formed during extrusion. Thermoplastic polymer material forming the micropores around greater part of the filler particles in the form of particles.

Volatile substances present in the material prior to extrusion, can be released during extrusion film forming micropores. Examples of typical volatile substances are water and/or volatile organic substances. If the quantity of volatile substances is too large, the layer may be foam or it can be formed large, easily visible hole that is niania microplastics films of thermoplastic resins are typically very hydrophobic and, therefore, thermoplastic raw materials will not have a significant amount of water. However, such fillers in the form of particles such as calcium carbonate, are hydrophilic. For example, the concentrates of calcium carbonate before drying contain from about 800 to about 900 parts per million of water. This amount of water is usually too large under normal conditions of extrusion.

Another source of volatile substances is usually available in the fillers in the form of particles coating. For example, for coatings of calcium carbonate is usually used stearic acid. During extrusion film of stearic acid can evaporate, forming thanks to microplates. The amount released from the organic coating on the filler particles of volatile substances can be controlled by degassing of the mineral during compounding.

The amount of water and/or volatile organic substances present in the components prior to the extrusion of the film must be such that, essentially, is low enough to prevent large holes or gaps in the layer during the stages (phases) of the extrusion. The amount of water and/and the s, having a diameter of from about 1/8 to about 1/2 the thickness of the stretched film. The required amount of water and/or volatile organic substances can be easily determined by adjusting the amount of water and/or volatile organic substances present in the raw materials used for production of film, to obtain the micropores of the desired size. Found that a suitable total content of volatile substances in the case of the filler particles should be between about 100 millions of parts and about 500 millions of parts, more preferably between 100 million and 300 parts millions of parts based on the total weight of the filler particles. If the total content of volatile substances is too low, the number of micropores formed at escape in the film during extrusion, may be sufficient to optimize the permeability of the stretched film.

The amount of volatilization is influenced by the melting temperature of the film during extrusion. Generally, the higher the melting temperature, the greater the size of the escape, which take place during extrusion, and the greater the number formed by micropores.

JV for the implementation in practice of the present invention can be easily modified conventional methods of manufacturing multilayer films. For example, the present invention can be applied in practice, using the method of extruding a film cast from a solution, and a method of extruding a film obtained by extrusion-blow process.

A method of manufacturing a multilayer breathable film will be described with reference to the drawings. The invention is not limited to particular methods described with reference to the drawings.

In the corresponding present invention method, a multilayer film can be ekstradiroval and cool, and then later to warm up and stretch for the formation of a breathable multilayer film. Preferably, immediately after extrusion of the multilayer material to pull it cool (one-step method). Extruded film can be pulled by any conventional method, including biaxial and uniaxial. Extruded film is preferably uniaxial pull method in the direction of extrusion.

A preferred example of the multilayer film is a 5-layer film containing microporous core layer, two outer monolithic layers and two link layer, which connect the outer layers with the core layer.

In Fig. 4A-4C pocketstudio the present invention a one-step method.

As shown in Fig. 4B, in the embodiment 1 shown in position 10 5-layer film extruded from the mouthpiece 1 and passes through the vacuum duct 2, where it is in contact with the primary cooling drum 3 and breathtaking rolling roller 4 output 5-layer material extend between the primary cooling drum 3 and the secondary drum 5 cooling. The section drawing shows position 6.

In the form shown in Fig. 4C version 2, the polymer film 21 is extruded from the mouthpiece 20 and passes through the vacuum duct 30 where the film comes into contact with the primary drum 25 cooling and breathtaking rolling roller 26 output. The polymeric film is extended between the primary drum 25 cooling and the secondary drum 27 cooling. Breathtaking swath 28 holds the material of the film relative to the secondary drum 27 cooling. The section drawing shows the position 29. While the polymer film 21 is in contact with the primary drum 25 cooling, rubber roller or silicon roller 24, which is covered with water, in contact with the film 21 to facilitate the cooling and lowering of the film from the primary drum 25 cooling. Rubber roller 24 is provided by water in the bowl 2E, than one stage, for example two, three, four or more stages.

The invention also concerns a multilayer film containing the described two outer monolithic layers described here microporous layer core and described herein binder layers, which connect the outer monolithic layers with a microporous layer of the core.

Multilayer breathable film is a film suitable for use in the manufacture of surgical gowns, dressings, soft linings for hospital beds, disposable diapers, homemade scarf, feminine wipes, protective clothing, lining material for shoes, packaging materials food and gloves, but not limited to.

Next, an explanation is given of the invention using the following non-limiting examples.

Example 1. Three different compositions of the resins in the form of unmelted solid granules were loaded into three different extruder: the extruder A, extruder B and C. extruder Specific composition of the resin, which took place in each extruder, shown in the following table 1.

Heritag NM-10 is a material consisting of 75% calcium carbonate and 25% linear icrel G4778 (company "DuPont") is a monolithic elastomeric polyester.

Thus, A layer is a link layer, layer B - microporous layer and the layer C - monolithic layer.

Extruders transformed unmelted solids in the liquid state, using the heat and action. The filler using auger, loaded resin in the section of the hopper of the extruder. Resin is forcibly directed through the extruder using a screw. The area of the drum of the extruder was divided into areas or zones. Each zone was heated so that was an additional melting of the resin as it passes through the extruder.

The molten resin was passed through the area of the unit mesh of the filter. Each land unit has a temperature zone. The purpose of the unit mesh of the filter was filtering all unmelted materials that could pass through the extruder, such as cardboard, sludge, coal and so on. The greater the density of the molten resin, the smaller the grid cell and the more used, the discharge pressure and melting temperature.

From the screws of the extruder the molten resin is passed through the connecting pipes in the block extrusion. Block extrusion is located on the top of the mouthpiece. Block extrusion is where CX is usii, which is often called the plate expires. The plate expires shown in Fig. 1. As shown in Fig. 1A-1D, three of the molten resin of the connecting pipes missed in three separate holes, indicated by the positions A, B and C. Then, the molten resin out of the five holes on the bottom plate of expiration in the form of extrusion C:A: B: A: C with the following percentage amounts: 10/20/40/20/10. Used mouthpiece had seven heating zones. To change the thickness can be adjusted values of heat on the mouthpiece.

Using this method, was extruded 5 layer nevitta film. After performing extrusion 5-layer devicenote film was annealed by passing through shown in Fig. 3 heated rolls. In Fig. 3 also shows how you can modify the extrusion line for extruding and drawing multilayer films on a single stage, using the above options 1 or 2.

Then devicenote film had in shown in Fig. 2 separate machine for drawing. As shown in Fig. 2, showing the position 30 a roll navatanee films were unwrapped and the film was introduced into a processing device MPE (mechanism direction Araucania two rolls, marked positions 41 and 42. Then the film was passed between the roller 43 and the capture and roller 44 and grip. Stretching occurs between the rollers 43 and 44. Roller 43 is rotated slower than the roller 44. The ratio of the speeds of the two rolls is known as the ratio of impregnation. The greater the distance between the rollers 43 and 44, the greater the magnitude of the contraction, which you will see. Narrowing represents the amount of reduction in film thickness during her hood.

After drawing the film is annealed. Roller 45 is where are the start of the process tigania. Usually Tigana is a way in which dimensional stability is achieved after a process of extrusion. Annealing was performed by first heating the film by passing it through a roller 45, and then cooling the film by passing it through a roller 46. Heating and cooling cause the elimination of stresses in the film and achieving balance. During annealing on the film you can apply the pattern embossing by pressing the film under high pressure to origaudio Valka, who engraved the required pattern.

Then the film was cut in the apparatus shown position 50, and was reeled on the final product shown in position 60 ostroy 2.

Narrowing represents the difference between the width of the multilayer material inlet and a width of the multi-layered material at the exit.

Inevitaly multilayer material was transparent. However, after extraction, the material was taken opaque white with a beautiful view. Due to the fact that the material has two outer monolithic layer, no filling material, the extrusion mouthpiece was not visible accumulation of filler.

Due to the fact that the material has two outer monolithic layers, the material provides an effective barrier against microorganisms.

Example 2. It was produced by repeating example 1, except for using the materials shown in table 3. The parameters used for drawing the extruded films, shown in table 4.

Listed in the tables titled "Trials 1-4" the results show that generated in accordance with the present invention a multilayer film finds a good bandwidth wet steam. All films showed a transmission rate of wet steam, equal 115-380 g/m2/24 h

The film also found good mechanical characteristics. The tensile strength of the hood, the authorized surgical service. In particular, the tensile stretching, elongation and modulus were significantly higher than the same parameters of conventional materials, such as polyethylene, which are used for the surgical service.

The film showed high resistance to puncturing, as measured by the test transmission of the seam. High resistance to puncturing desirable because during surgery, if there is perforation of the material, the microorganisms will be able to pass through the material and to infect the medical staff.

The test light transmission showed that the film blocks more than about 60% of the light, from which it is desirable to protect the person or object close this film material.

The film showed the clipping module in the range that provides sufficient softness, drape and comfort.

Test biological penetration was made by a company "TRI/CE, Inc." on one sample of the film produced in accordance with example 1 and one sample of the film produced in accordance with example 2, using the test aim (American society for testing and materials) ES21 and aim ES22. Were providse a penetration testing artificial blood. Test ES22 is a penetration testing of living organisms. Due to the fact that the film material has passed both tests, the film material can be used for surgical service.

Examples 3-7. Was repeated in example 1, except that the test used materials are shown in tables 5-9. The parameters used for drawing the extruded films, shown in table 10.

Devicenote multilayer materials of examples 3-5 were translucent. But after drawing the material took opaque white with a beautiful view. Due to the fact that the material has two outer monolithic layer, no filling material, the extrusion mouthpiece was not visible accumulation of filler. Due to the fact that the materials of examples 3-5 were two outer monolithic layers, the materials did not provide an effective barrier to microorganisms.

The presence of two outer monolithic layers, separated by a microporous layer provides additional assurance that the penetration must be made through all three layers before microorganisms can pass through. Conversely, in multilayer materials having only the passage of microorganisms, that can pass through the microporous film.

Was used for measurement of properties created in examples 3-7 multilayer films (devicenote and elongated). The results are shown in tables 11 to 20.

The results in tables 11 - 20 labeled examples 3-5 demonstrate that established in accordance with the present invention multilayer films exhibit good transmission rate of wet steam. All films showed a transmission rate of wet steam in the range from 270 to 4077 g/m2/24 h

The films also exhibit good mechanical characteristics. The tensile stretching, elongation and modulus were high enough so that the material can be used as a component of enhanced surgical service. In practice, strength, stretching, elongation and modulus were significantly higher than the same characteristics of conventional materials, such as polyethylene, which are used for the surgical service.

The film showed high resistance to puncturing, as measured by the test for transmission of the seam. High resistance to puncturing desirable because during the surgery, in case of perforation of the material, the microorganisms will be the W light showed that film has blocked more than 60% of the light, from which it is desirable to protect the person or the subject covered by the film material.

The film found a clipping module in the range that provides sufficient softness, drape and comfort.

Test biological penetration was made by the firm "Nelson Laborers, Inc. "in salt lake city, Utah) on some of the films of examples 3 and 5, using the test aim ES22 (now aim F1671). Tests were carried out with three portions of each sample film. Test ES22 is a penetration testing of living organisms.

Two films of example 3, elongated with respect to the pulling 4:1 and 4.95:1, tested by test aim ES22 on the barrier for blood.

Test biological penetration was made by the firm "Nelson Laborers, Inc. "in salt lake city, Utah) on some of the films of examples 3-5 using the test aim ES21 (now aim F1670). Tests were carried out with three portions of each sample film. Test ES21 is a penetration testing blood.

Stretched film of example 3 with respect to the pull of 4.5:1 and 4.95:1 passed test ES21. Stretched film of example 4 with otim for these films of example 4, and therefore, large particles penetrated through the surrounding layers. Stretched film of example 5 with respect to the pull of 4.5:1 and 4:1 passed the test.

From the above data were calculated percentage composition of micro-cavities using the following formula:

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The results of the calculations are shown in tables 21-23 indicated by the examples 3 to 5, to demonstrate that the microporous layers can be pulled with a much higher relationship broaching

1. A method of manufacturing a stretched multilayer breathable film having the combination of properties (i) providing a barrier to microorganisms and (ii) providing a barrier to blood and body fluids, and the said method comprises steps (a) simultaneously extruding at least five-layer film of the mouthpiece having at least a structure With:A:Q:A:C, where b contains a layer of microporous core containing at least one thermoplastic polymer and at least one specific filler, contains the outer solid layer containing a hydrophilic polymer resin, able to absorb and adsorb moisture and to provide a barrier to aqueous liquids and microorganisms, and referred to in the subsequent substances for binding the above-mentioned layers With the said core layer, in which the said layer With essentially prevents the accumulation of the material of the filler particles at the mouthpiece during this stage of extrusion, b) hood mentioned extruded five-layer film for the formation thereby of micropores in the above-mentioned layer microporous core and the above-mentioned layer microporous binder in which is mentioned the stage of extrusion, and the said layer of microporous core and said layers of microporous binder are formed in such a manner as to provide micropores that allow the passage of gaseous water, but, in essence, prevents the passage of liquid water.

2. The method according to p. 1, characterized in that it further includes the step of combining the component parts used in the core layer, with a part of the components used in the monolithic layer, to form a mixture of binder, and the step of simultaneously extruding includes extruding at least one layer of binder containing the above-mentioned mixture of the binder.

3. The method according to p. 1, characterized in that it further includes the step of collecting waste mentioned mnie at least one layer of binder And, contains mentioned the collected waste.

4. The method according to p. 1, wherein the step of simultaneously extruding layers includes the extrusion of the layers in the following volume ratio of the total volume of the multilayer breathable film: each layer is from about 1 to about 40% by volume, the layer is from about 1 to about 96% by volume, each layer is from about 1 to about 30% by volume.

5. The method according to p. 1, wherein the step of simultaneously extruding layers includes the extrusion of the layers in the following volume ratio of the total volume of the multilayer breathable film: each layer is from about 1 to about 10% by volume, the layer In the range from about 60 to about 96% by volume, each layer is from about 1 to about 10% by volume.

6. The method according to p. 1, wherein the step of simultaneously extruding layers includes the extrusion of the layers in the following volume ratio of the total volume of the multilayer breathable film: each layer is from about 1 to about 5% by volume, the layer is from about 80 to about 96% by volume, each layer is from about 1 to about 5% by volume.

7. The method according to p. 1, is within a thickness of approximately 2,5410-2mm or less.

8. The method according to p. 1, characterized in that it further includes the steps of determining the content of volatile substances in materials intended for the manufacture of microporous layer core and layers of microporous binder, and control the amount of volatile substances in the above-mentioned materials to provide micropores having an average diameter of from about 1/8 to about 1/2 the thickness of the extruded layer of microporous core or extruded layers of microporous binder.

9. The method according to p. 1, characterized in that it comprises the steps of determining water content in the filler in the form of solid particles for the manufacture of microporous layer core and layers of microporous binder and regulate the amount of water in the above-mentioned materials to provide micropores having an average diameter of from about 1/8 to about 1/2 the thickness of the extruded layer of microporous core or extruded layers of microporous binder.

10. The method according to p. 8, wherein the step of regulating includes regulating the amount of volatile substances in the filler in the form of particles ranging from about 100 wt. hours on different topics the step of regulating includes regulating the amount of volatile substances in the filler in the form of particles ranging from about 100 wt. hours per million by weight.h. to about 300 wt.h. per million by weight.h. the above-mentioned filler.

12. The method according to p. 1, characterized in that at least one of the layers of a microporous microporous core and the binder contains catalyzed by metallocene linear low density polyethylene.

13. A method of manufacturing a stretched multilayer breathable film having the combination of properties (i) providing a barrier to microorganisms and (ii) providing a barrier to blood and body fluids, and the said method comprises steps (a) simultaneously extruding at least a three-layer film of the mouthpiece having at least a structure C:D: C, where C contains the outer solid layer comprising a hydrophilic polymer resin, which is able to absorb and decarbonate moisture and to provide a barrier to aqueous liquids and microorganisms, and in the above-mentioned layer With essentially no filler in the form of particles, and D contains a layer of microporous core binders, designed to link povide particles on said mouthpiece during this stage of extrusion, b) a hood mentioned extruded three-layer film for the education of micropores in the above-mentioned layer microporous core and the above-mentioned layer microporous binder, in which the said stage of the extrusion is carried out, and the said layer of microporous core and said layers of microporous binder form so as to provide micropores that allow the passage of gaseous water, but, in essence, prevents the passage of liquid water.

14. Multilayer breathable film having the properties (i) providing a barrier to microorganisms and (ii) providing a barrier to blood and body fluids, and referred to a breathable film represents at least a five-layer film having at least a structure With:A:Q:A:C, where b contains a layer of a microporous core which includes at least one thermoplastic polymer and at least one filler in the form of particles, contains the outer solid layer comprising a hydrophilic polymer resin, able to absorb and decarbonate moisture and to provide a barrier to water and microorganisms, and in the layer With essentially no who I associate mentioned layers with the above-mentioned layer In the core, in which the said layer With essentially prevents the accumulation of material filler in the form of particles on the mouthpiece during the formation of the mentioned multilayer breathable film and in which the said micropores are constructed and located in such a way as to prevent the passage of gaseous water, but, essentially, to prevent the passage of liquid water.

15. Film under item 14, characterized in that at least one of the layers of microporous binder contains a thermoplastic polymer mentioned microporous layer core and a hydrophilic polymer resin mentioned Monomeric layers.

16. Film under item 14, characterized in that the layers in the film have the following dimensional relationship to the total volume of the multilayer breathable film: each layer is from about 1 to about 40% by volume, the layer is from about 1 to about 96% by volume, each layer is from about 1 to about 30% by volume.

17. Film under item 14, characterized in that the layers in the film have the following dimensional relationship to the total volume of the multilayer breathable film: each layer is from about 1 to about 10% by volume, the layer In the range from about 60 to p is the lasting themes what layers in the film have the following dimensional relationship to the total volume of the multilayer breathable film: each layer is from about 1 to about 5% by volume, the layer is from about 80 to about 96% by volume, each layer is from about 1 to about 5% by volume.

19. Film under item 14, characterized in that the said breathable film has a thickness of about 2,5410-2mm or less.

20. Film under item 14, characterized in that the layer of microporous core and layers of microporous binder manufactured through steps of determining the content of volatile substances in materials intended for the manufacture of the respective layers and control the amount of volatile substances in the above-mentioned materials to provide micropores having an average diameter of from about 1/8 to about 1/2 the thickness of the extruded layer of microporous core or extruded layers of microporous binder.

21. Film under item 14, characterized in that the layer of microporous core and layers of microporous binder manufactured through steps of determining water content in the above-mentioned filler particles for the manufacture of the respective layers and reimeria 1/8 to about 1/2 the thickness of the extruded layer of microporous core or extruded layers of microporous binder.

22. Film under item 14, characterized in that at least one of the layers of a microporous microporous core and the binder contains catalyzed by metallocene linear low density polyethylene.

23. Film under item 14, characterized in that the hydrophilic resin selected from the group comprising polyesters, and polyamides.

24. Film under item 14, characterized in that thermoplastic polymer includes a polyolefin.

25. Film under item 14, wherein thermoplastic polymer contains a linear low density polyethylene.

26. Multilayer breathable film having the combination of properties (i) providing a barrier to microorganisms and (ii) providing a barrier to blood and body fluids, and referred to a breathable film is at least three-layer film having at least a structure C:D:C, where C is the outer solid layer containing a hydrophilic polymer resin, which is able to absorb and decarbonate moisture and to provide a barrier to water and microorganisms, and in the layer With essentially no filler in the form of particles, and D is the layer of microporous core binder pedestrian filling material in the form of particles at the mouthpiece during the formation of the mentioned multilayer breathable film and in which the said micropores design and have so, to ensure the passage of gaseous water, but, essentially, to prevent the passage of liquid water.

27. Film under item 26, characterized in that the layers in the film have the following dimensional relationship to the total volume of the multilayer breathable film: layer D is from about 1 to about 98% by volume, and each layer is about 1 to about 49% by volume.

28. Film under item 26, characterized in that the layers in the film have the following dimensional relationship to the total volume of the multilayer breathable film: layer D is from about 80 to about 98% by volume, and each layer is about 1 to about 10% by volume.

29. Film under item 26, characterized in that the layers in the film have the following dimensional relationship to the total volume of the multilayer breathable film: layer D is from about 90 to about 98% by volume, and each layer is about 1 to about 5% by volume.

 

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