SK100694A3 - Multilayer non woven composite textile - Google Patents

Abstract

The textile comprises the first layer (12) made of the fibrous material chosen from the group comprising thermoplastic, in flowing gas spinned, synthetic fibres, thermoplastic, under the jet joint, synthetic fibres, theromoplastic synthetic shear fibres and their combinations, the area weight of which is between 1.7 to 340 g/m2, advantageously from 8.5 to 68 g/m2, and the second layer (14) from the shear fibres based on cellulose, the area weight of which is between 3.4 to 340 g/m2, advantageously from 34 to 136 g/m2, and the fibres of which have length between 12.7 to 76.2 mm and fineness equivalent to 2 to 5 Micronaire measures, and these two layers (12, 14) are heat-joint together and create integrated structure with joining surface between the layers (12, 14) from 5 to 75 %, advantageously 10 to 30 % of one of the surfaces of the composite textile.

Description

The present invention relates to fibrous fabrics, and in particular to novel composite fabrics consisting of one or more layers of thermoplastic nonwoven material and one layer of cellulose-based fibers (hereinafter cellulose fibers).

BACKGROUND OF THE INVENTION

Non-woven fabrics are defined as planar or non-woven structures made by joining or interweaving short or long fibers or yarns by mechanical, thermal or chemical means or by means of a solvent. These fabrics do not require the fibers to be turned into yarn. Nonwovens are also called spun or technical and are called nonwovens because they are made by processes other than spinning, weaving, or knitting. The basis of all nonwoven fabrics is a fibrous structure which may consist of only one type of fiber. The fibers, which are measured to centimeters or inches or fractions thereof are called Shearing _Star hotels fibers. Very long fibers are called filar ments and are typically measured in kilometers or miles. In fact, they are not easy to measure because their length can be tens or hundreds of yards. For fibers, their length must be much greater than their diameter, e.g. the length to width (diameter) ratio must be at least 100, but is much larger. The length of the cotton fibers may be less than 1/2 inch and may be up to more than 2 inches with a typical length to diameter ratio of approximately 1400. Other natural fibers exhibit the following typical ratios: flax - 1 200, ramia - 3 000 and wool - 3 000 .

In the present application, the terms fiber or fibers will refer to both short and long fibers, i. staple fibers and filaments, unless explicitly stated otherwise in the text. E.g. spunbonded fabrics are made up of filaments, while meltblown fabrics consist of different lengths of fibers, so that we can find both staple fibers and filaments. The individual fibers may be arranged in a non-woven fabric in an organized or random fashion. Each fabric has mechanical, tensile and tactile properties that result from the type of bonding and the degree of cohesion of the fibers as well as the overall reinforcement of the fabric by its components. The nonwoven fabrication technology includes the following primary steps: fibers of different lengths and diameters; structuring textiles according to production and processing methods; bonding the fiber in the structure and reinforcing the individual components. By combining one or more of these elements, it is possible to produce a huge number of types of nonwoven fibrous webs. By selecting the type and length of the fibers and the process of joining them and selecting the optimum production process, it is possible to achieve highly technical, yet extremely flexible combinations of variants.

Nonwovens have so far been used successfully in healthcare as disposable replacements for earlier cotton, reusable medical and surgical gowns, surgical gowns, face masks, shoe covers, sterilizing containers and other items, and are estimated to have a turnover of more than $ 1 billion year. In addition, nonwoven fabrics have found application in the manufacture of medical products, such as e.g. sanitary napkins, sanitary napkins, disposable diapers and other similar articles. One of the advantages of nonwovens compared to woven fabrics has been their relatively low cost. So far, the difference between the price of nonwoven and woven fabrics has been so great that end users could throw away the nonwoven after one use, and yet they were economically worthwhile compared to reusable woven fabrics.

The excellent properties of nonwovens for medical and hygienic applications include their pleasant feel (softness and flowability), wicking capacity, liquid retention capacity, absorbency and strength. End users also appreciate how the properties of nonwovens are close to those of fabrics, especially cotton. In general, nonwoven fabrics are considered not to have many of the characteristics of fabrics, in particular pleasant feel, capillarity, and the ability to absorb and retain liquids.

Blown nonwoven fabrics e.g. they have an air volume of about 85%, spunbonded nonwoven fabrics of about 90 to 95%. In addition, these structures have undesirable chemical properties, e.g. they are hydrophobic and thus not very suitable e.g. for medical use. In addition, the surface of these nonwoven fabrics is smooth so that it is slippery and greasy to look and feel. The fibrous material of prior art nonwoven fabrics generally exhibits a low surface tension, so that it does not attract water, and as a result, these fabrics have a low ability to absorb and retain water-containing liquids. These fabrics are also difficult to impregnate with liquid formulations. Further, with respect to the length of the fibers and the method for producing the fibers, the fibers lie in a structure such that their length is substantially oriented parallel to the plane of the fabric, which results in the fabrics having a low liquid absorption capacity. Therefore, great efforts have been made to improve these properties of nonwovens and to change the technology of their production and / or processing. However, these improvements increase the cost of the nonwoven fabric and may negatively affect its financial advantage over woven fabrics. In addition, nonwoven fibers are made from petroleum and are therefore subject to substantial fluctuations in the price of this raw material and, moreover, their final disposal after use has to be addressed.

SUMMARY OF THE INVENTION

The present invention provides an entirely new multilayer composite fabric, all of which have the same properties as the layers are nonwoven, which exhibits a woven fabric, while maintaining the economic advantage of the nonwoven fabric. The fabric of the present invention is multilayer. Its first layer is of man-made fibrous material selected from the group consisting of thermoplastic blown man-made fibers, thermoplastic spun-man-made fibers, thermoplastic man-made staple fibers and combinations thereof, and is light in a weight per unit area of about 0,05 up to 10 ounces / yard. The second layer consists of cellulose staple fibers with the exception of wood fibers and has a basis weight of between 0.1 and 10 ounces / yard. The second layer fibers have a length in the range of about 0.5 to 3 inches and a fineness (size) between 3 and 5 Micronaire units. The layers are most often thermally bonded to form an integral structure, with the bonding surfaces between the layers making up about 5 to 75% of the area of one of the planar surfaces of the composite fabric. The type of bonding contemplated herein does not adversely affect the tactile and other physical properties of the fabric, e.g. the degree of capillarity and liquid retention. Therefore, the bonding takes place only from one side of the laminate. In an optimum embodiment, the composite fabric has at least one (third) layer of fibrous material selected from the group consisting of thermoplastic blown man-made fibers, thermoplastic spun man-made fibers, thermoplastic man-made staple fibers, and combinations thereof. Thus, the third layer is also lightweight, having a basis weight of between about 0.05 and 10 oz / yd (ounces / yards), touching the second layer on the side facing away from the first layer, and thermally bonding to at least the second layer such that the second layer a layer is sandwiched between the first and third layers (sandwi ch). The composite fabric may further comprise other similar layers of similar materials.

Regardless of the number of layers of the entire structure, the proposed composite fabric should optimally have a total basis weight in the range of about 0.5 and 24 oz / yd, in order to be as close as possible to woven fabrics for touch, drapiness, and other properties. This can be achieved by a responsible selection of individual low basis weight layers. It is also possible to achieve _a more desirable or required properties such as strength, capillarity, the ability to absorb and retain fluids and the ability to create a barrier (the ability to eliminate fluid while permitting or even encouraging transfer of vapors or gases for the entire thickness of the structure).

The composite fabric of the present invention is particularly suited for the manufacture of disposable medical products due to its ability to form a barrier, pleasant feel, airiness, strength, capillarity, fluid absorption and retention, and other great properties.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig. 1 is a schematic representation of one embodiment of a fabric incorporating various features of the present invention.

Fig. 2 is a schematic representation of another embodiment of a fabric incorporating various features of the present invention.

Fig. 3 is a schematic representation of a fabric texturing process incorporating various features of the present invention.

Fig. 4 is a schematic representation of another fabric manufacturing process incorporating various features of the present invention.

Fig. 5 is a schematic representation of yet another fabric manufacturing process and fabric manufacturing apparatus included in the process.

Fig. 6 shows an apparatus for measuring the absorbency and retention properties of textiles.

Fig. 7 shows an apparatus for testing the capillarity of textiles.

Figures 8 to 34 show graphs of the wicking capability of the samples according to the data shown in Table X.

Fig. 35 shows a graph of the wicking values of the laminates of the present invention at different weights of the cotton core.

Fig. 36 shows the wicking graph of non-laminate cotton fabrics.

Fig. 37 shows a graphical comparison of the capillarity of cotton core laminates and ramie core laminates.

DETAILED DESCRIPTION OF THE INVENTION

The composite web 10 in Figures comprises a first layer of _R and a second layer 12 .14. As shown in the figure, these layers are connected to each other by diamond-like bonding plates 16 which are substantially the same size and are equidistant from each other. Optimally, these bonding surfaces should extend substantially over the entire surface of the composite fabric, joining the individual layers into a unitary structure. Figure 2 shows another embodiment of the fabric 10, which thus also consists of the first and second layers 12 'and 14 * respectively, and in addition the third layer 20.

At least one layer of the composite fabric of the present invention is of thermoplastic man-made fibers. Therefore, it is possible to perform the bonding of the individual layers of fabric by one of the known thermal bonding methods, e.g. by stretching the superposed layers between the set of heated rollers. At least one of these rollers should have a surface formed by protrusions 30 (see FIG. 3) which form separate bonding surfaces similar to the diamond-shaped surfaces of FIG. 1, formed by a combination of pressure and heat exerted on the fabric as it passes between the rolls. Furthermore, it is also possible to use other methods of thermal bonding, e.g. ultrasonic welding and the like. Other bonding techniques of the composite fabric layers of the present invention may be the physical entanglement of multiple layer fibers, e.g. hydroentanglement, needling and the like. In any case, the optimal way of bonding the individual layers is to provide separate, relatively small bonding areas that extend substantially over the entire surface of the composite fabric and convert the individual layers into a unitary unitary structure without adversely affecting the desired properties of the fabric. When bonding, the bonding surfaces cover about 5 to 75% of the surface of the composite fabric. However, the optimum overall surface coverage of the composite fabric with bonding pads is about 10 to 25%.

In one method of making the composite fabric of the present invention, each of the fabric layers is formed separately. and the layers are laminated. The individual layers of fabric are laid on top of each other and bonded as they were. above. However, it should be appreciated that it is possible to form several layers of the present fabric substantially simultaneously, such as e.g. in an inline manufacturing process, when one of the layers is formed and then a second or further layer is formed on the first or previous layer. In this second example, the joining process can also take place inline and from below to the base layer so that it is possible to form the end layer of the entire structure on both sides. These manufacturing processes are well known to those skilled in the textile industry. Fig. 3 shows a schematic process of laying the previously formed layers 15, 17 and 19 on top of a conveyor 21 moving forward and subsequently joining the layers into an integral structure 10 by passing the fabric through a gap 24 between two heated rollers 26 and 28. In this In the embodiment, the upper roller 28 is provided with surface protrusions 30 which allow the separate bonding surfaces 16 to be formed. It is evident from the figure that the composite fabric 10 is wound onto the roller 32 for storage and subsequent use. The layers 15 and 19 can be made of man-made fibers e.g. by spinning, melt blowing or any other process which ensures the formation of a solid self-supporting fabric.

Fig. 4 schematically illustrates a fabric manufacturing process according to the present invention in which the first synthetic thermoplastic fiber layer 40 is produced by the traditional blown or spinning method 44 and then deposited on a forward moving conveyor 42. The cellulose fiber layer 48, either pre-formed (offline) 5 or at the same time as shown in FIG. 5 is applied to the first layer 40 disposed on the movable belt 42. The third layer 50 of thermoplastic man-made fibers is produced by the traditional blowing or spinning method 51 and applied to the cellulosic layer 48 so as to to form a three-layer structure in which the cellulose fiber layer 48 is sandwiched between the outer layers 40 and 50 of synthetic thermoplastic fibers. In the illustrated process, these multiple layers are passed through a gap between two heated pressure rollers 54 and 56, one of which has protrusions 58 on the outer surface that allow the thermal interconnection of the multiple layers into an integral structure 59. The composite fabric may be collected on a roller 60 for further use. As will become clearer below, one of the layers 40 and 50 (the first and second layers), or both, can be made by traditional blow molding, spinning or similar processes, including thermal bonding of artificial staple fiber structures.

Fig. 5 illustrates another embodiment of a fabric manufacturing process in accordance with the present invention. In this embodiment, the first synthetic fiber layer 64 is made by blowing or spinning by an apparatus 66 included in this process (inline), guided via a guide pulley 65 and positioned on the upper branch of the first conveyor 67. As shown in the figure, the process also includes a carding section 68 in which the cellulosic fiber package 69 is introduced into an inline card 70, from which the carded web 71 is fed directly to the second conveyor 72. From the conveyor 72, the cellulosic layer is laid on the layer 64 on the conveyor 67. Further, a third synthetic fiber layer 74 is formed by another traditional inline blowing or spinning apparatus 75, which is fed through a guide pulley 76 and placed on the surface of the cellulosic layer 71 so that the cellulosic layer 71 is sandwiched between the layers 64 and 74 way. These layers are displaced in the forward direction by a gap 77 between the two heated rollers 78 and 79, of which the upper roll 78 is provided on the outer surface with protrusions 81 to form separate thermal bonds at least between the upper layer 74 and the cellulosic layer 71. which layers combine into a single structure. The tightly bonded composite fabric 83 is wound onto a roll 85 for storage and subsequent use. It is also possible to form an artificial staple fiber layer 87 by means of a conventional air former 89 and insert it into the composite structure 83 between the cellulose layer 71 and one or both of the synthetic fiber layers 64 and 74.

In the present invention, the composite fabric consists of at least two layers. At least one layer must be made of cellulose fibers. For the purposes of the present invention, the term cellulose is understood to be made of staple fibers containing from 25 to 100% cellulose. Cellulose fibers suitable for fiber production include cotton, ramia, hemp, jute, flax, kenaf, pressed sugar cane, eucalyptus, viscose rayon (regenerated cellulose) and combinations thereof, but not wood fibers. The selected cellulosic fiber is typically processed in a known manner so that the resulting product is a clean, clear fiber that readily absorbs liquids. For example, the cotton "is cleaned and whitened to remove grease and the like from the fibers. and that the fiber is compliant and absorbent while not containing any foreign matter and having a bright color (white is considered a color). However, for a number of applications, only partial cleaning is required and no bleaching is necessary, as the degree of fiber absorbency and / or wicking is sufficient for this purpose. Cellulose fibers suitable for the present invention have a length of from about 0.5 to 3 inches. The cotton fibers should be about 0.5 to 1.25 inches long, while the ramie or flax fibers may have a maximum length of 3 inches.

Longer fibers can be broken or chopped to desired length as required. The cellulose fibers used do not convert into yarns or threads. However, they can be processed e.g. by carding and the like so as to be oriented in a certain direction or vice versa randomly to form a self-supporting structure. The fibers can be used directly from the package from the manufacturing process and introduced into the composite fabric as a layer in which the fibers are carded more or less parallel to each other or are randomly oriented. The fineness of the cotton fibers should be between r about 3 and 5 Micronaire units to provide sufficient flexibility and desirable feel quality, drapability, and other properties of the composite fabric of the present invention. Cotton fibers larger than about 5 Micronair are less elastic and the fabrics formed from them tend to be coarse and uncomfortable to feel.

The preferred types of cellulosic fibers for rye fabrics of the present invention are fibers. They do not have a smooth surface and, unlike making a cotton-polyolefin composition having a surface tension (energy) of 31 dynes / cm, the cotton fibers exhibit a surface tension of 44 dynes / cm and thus tend to remain in place after being embedded in the composite fabric of the invention. In addition, cotton fibers multiply the great properties of the composite fabric, e.g. its capillarity, absorbency and liquid retention capacity, volume expansion, water repellency while vapor and gas permeability, and possibly even strength, especially when blown structures have a basis weight of less than 0.5 oz / yd ² (17 g / m 2) ² ).

Regardless of which of the cellulose fibers is used to form the inner layer of the present multilayer composite fabric, the inner layer must be composed of staple fibers and not filaments. Only staple fibers having a relatively small length and often in combination of different lengths, all of which are smaller than 3 inches and optimally 2 inches, guarantee the diversity of their ends. Since these fibers are not spun into yarn, but are present individually in the inner layer and have no stronger orientation than that they are arranged in a structure that is sufficiently compact for the automatic devices to lay on the conveyor or other textile structure on the conveyor, the endings of these fibers tend to extend in the textile structure in all directions. Thus, many fiber ends generally extend longitudinally with respect to the plane of the fabric and even protrude from the planar surface of the fabric. This property of the staple fiber fabric is one of the most important reasons why it is not used in this form in medicine. In accordance with the present invention, this hitherto unacceptable fabric can be attached between two fabrics of artificial nonwoven fibers such that the artificial fibers retain the short cellulosic fibers. However, these synthetic fiber textile layers must be carefully selected so as not to affect the negative tactile and other desirable properties of the resulting composite fabric. Synthetic fiber fabrics are also preferred because they allow the cellulosic fibers of the inner layer to impart desirable feel, capillarity and retention to the composite fabric. This object is achieved in the present invention by using artificial fiber fabrics produced by a technology guaranteeing a sufficient air volume and at the same time of such fine fibers that the fabrics "serve as a barrier to bacteria and the like". and at the same time do not prevent vapor or liquid from entering the inner layer from the cell. fibers, where the liquid is rapidly entrapped and impermeable to the outside.

The ends of the short staple fibers of the inner layer of the composite fabric, which are oriented generally laterally with respect to the plane of the inner layer, serve to delimit areas of liquid transport into the inner layer. The synthetic fiber outer layers are inherently hydrophobic and have a low surface tension. Their fibers are uniformly long and carry liquid poorly. In contrast, the staple fibers of the inner layer are hydrophilic and have a relatively high surface tension, are not smooth, are twisted lengthwise, and are numerous, so that they are capable of draining liquid into the volume of the inner layer. In addition, the plurality of ends of the shear fibers of the inner layer, which extend longitudinally relative to the plane of the inner layer, serve as pathways for transporting the liquid into the inner layer, both because of their affinity for liquids and because the geometry and orientation r in the inner layer form a large number of capillaries which assist in the movement of liquids into the inner layer and the retention of liquids within the inner layer. Cotton fibers also swell when soaked, so that they are suitable for textiles that are designed to absorb liquids and serve as barriers.

As practice shows, cellulose fiber fabrics in which the fibers are not bonded together are unsuitable for most disposable medical products. Firstly, it is not strong enough to be self-supporting, and secondly, the fibers tend to release from the fabric and thus represent unacceptable potential sources of contamination. E.g. loose fibers from surgical gowns that would enter an open wound or incision could be a source of granulomas, and therefore fabrics for these applications must have fibers adequately fastened. According to the present invention, cellulose fibers can be combined with thermoplastic man-made fibers. As will be discussed below, the combination of the cellulosic fiber layer and the thermoplastic synthetic fiber layer, which are thermally bonded to each other by separate bonding pads, results in a coherent composite fabric that exhibits improved properties, in particular wicking, retention and strength. In particular, the synthetic fiber layer imparts strength and abrasion resistance to the composite fabric, and therefore the cellulose fiber layer is sandwiched between the outer synthetic fiber layers.

Previously blown and spun fabrics of thermoplastic man-made fibers required special and additional treatment to be used for the manufacture of disposable medical and sanitary products. However, the present inventors have found that using selected fabrics with cellulose-based layers, it is possible to produce a firmly bonded composite fabric that does not require any special treatment of the synthetic fiber layer and that these fabrics can be directly incorporated into the composite structure. In view of this ability, the present invention has a substantial economic benefit.

r

According to the present invention, the synthetic fiber fabrics are preferably manufactured by blowing or spinning technology. The diameter of the blown man-made fibers should be approximately 0.5 to 10 microns, while the diameters of the fibers in the spunbonded fabrics are between 8 and 50 microns. Generally, the spun fibers are thicker, but stronger than the blown fibers because they acquire a distinct orientation upon cooling. In both cases, the fibers form a self-supporting structure. The optimum basis weight of the meltblown fabric suitable for use in the invention is very low, in the range of about 0.05 to 10 ounces / yard, and preferably from .of _the

0.25 to 2 oz / yd. The optimum basis weight of the spunbonded fabric suitable for use in the present invention is also very low, in the range of about 0.1 to 10 oz / yd ^, and most preferably between 0.3 and 2 oz / yd. Fabrics with a basis weight less than about 0.05 oz / yd generally do not have a sufficiently high fiber density to maintain cellulosic fibers and exhibit sufficient strength and other qualities required for the composite fabric. Fabrics with a higher basis weight,

i above 10 oz / yd, makes it too thick in combination with the cellulosic layer. For a more specific description of the spinning and blowing methods and fabrics produced by these processes, see: Proceedings, Fiber Producer Conference 1983, pp. 12-14. April 1983, pp. 6-1 to 6-11, which is incorporated herein by reference.

As already said, the optimum composite fabric of the present invention comprises an inner layer of cellulose fibers that is sandwiched between the outer layers of artificial fibers. The composite fabric may therefore consist of different combinations of layers. For example, in addition to the desired cellulosic fiber layer, the composite fabric may have a first blown synthetic fiber layer which contacts one side of the cellulosic fiber layer and a third spun synthetic fiber layer which touches the other side of the cellulosic fiber layer. Similarly, the first and third layers may be either blown or spun fibers. Further, it is possible to form multiple layers of cellulose fibers which may or may not be separated by further inner layers of artificial fibers, whether blown or spun. In any case, the cellulosic fibers must be protected by at least one outer layer and more preferably by two outer layers of artificial fibers. It should be appreciated that adding additional layers to the composite fabric increases its cost and may deteriorate its tactile and other qualities.

Samples of the composite fabrics of the present invention were made as shown in Fig. 3. The cellulose-based fibers were fed into a tumbling and blending machine where the fibers from the package were loose and uniformly mixed. From this machine, the fibers were fed to a carder, where a fabric was formed by carding, which was taken directly (without winding) from the carder and then laid on a layer of thermoplastic man-made fibers on a conveyor. The staple used in the manufacture of these samples had an output unit for random fiber orientation attached so that the fibers were randomly arranged with little or no orientation in the machine direction. Then, the cellulose fiber layer was covered with a third thermoplastic synthetic fiber layer so that the cellulose layer was sandwiched between the two outer layers of thermoplastic synthetic fibers. The laminate was then moved through a gap between a set of heated rollers, one of which had a smooth surface and the other was covered with separate diamond-shaped cross-sections. Tables I and II provide further details on the operating parameters used to manufacture these samples and to assemble the various samples.

TABLE I

Parameters and their levels

parameter Number of levels Hodnotv Blown fabrics 1. Live ca 2 Himont Valtec 442 dating in Exxon PD 3495G 2. Area weight text, 2 0.7 oz / yd ^Z 0.5 oz / yd ^z Staple fiber fabrics 1. Ploš. mass 1 1.0 oz / yd ^z 2. Contained fibers 2 cotton (C),

polypropylene (PP)

3. Fiber denier - cotton denier 1 1.75 (Veratec 'Easy Street') - PP denier 2 2.2 (Hercules T-185) 3.0 (BASF bico 'Merge 1080') 4. Length of fiber - cotton fiber 1 1 inch - PP fiber 1 1.5 inch

Thermal bonding

1. Engraved flat shape 1 diamond Second Area of elevated sample 1 16,6% * Third Gap pressure 1 250 PLI (lbs / linear inch) 4th , Temperature - upper cylinder 4 128 ° C, 133 ° C 134 ° C, 135 ° C - lower cylinder 4 127 'C, 129' C 131 C, 132 'C 5th Surface speed of calender rolls 1 29 ft / min

* Kuster calender bonding area used in the production of samples in Table II.

TABLE II

Technological conditions for the production of blown / cotton / blown laminate samples o

Vz. Surface mass layer no. _ (Oz / E ^) _

Top / The middle / lower

Layer composition

Upper Middle Lower

1 0.7 / 1.0 / 0.7 UT-1-24 ³ 100% cotton UT-1-24 2 0.7 / 1.0 / 0.7 UT-1-24 100% cotton UT-1-24 3 0.7 / 1.0 / 0.5 UT-1-24 100% cotton UT-1-17 4 0.7 / 1.0 / 0.7 UT-1-24 100% PP ⁵ UT-1-24 5 0.7 / 1.0 / 0.5 UT-1-24 100% PP ⁵ UT-1-17 6 0.7 / 1.0 / 0.5 UT-1-24 100% BF pp6 UT-1-17 7 0.7 / 1.0 / 0.7 UT-1-24 100% BF pp6 UT-1-24

Continuation of TAB II

Vz. no. Coupling temperature cylinders (“C) Composition of composite fabric Cotton (%) PP (%) top lower 1 128 129 41.8 58.2 2 134 129 41.8 58.2 3 134 129 45.4 54.6 4 135 132 0 100 5 135 132 0 100 6 135 132 0 100 7 135 132 0 100

production of 40-inch textiles.

outer layers composed of fibers of different lengths of blown polypropylene (PP) and a middle layer of staple fibers.

Himont blown polypropylene (0.7 oz / yd ^x ). Hercules resin blow molded polypropylene (0.5 oz / yd ^z ) Hercules Grade T-185 polypropylene.

bicomponent fiber BASF.

The following characteristics of the samples produced according to the data in Tables I and II were tested as follows:

Barrier - A barrier means the ability of a substance to withstand the penetration of fluid and micro-organisms. Creating a barrier protects the theater staff and patients from infection.

Test The test procedure used

Hydrostatic pressure test method AATCC

127-1985

Grease repellency rate AATCC test method

118-1983

Water penetration test method AATCC

42-1985

Water shatter penetration rate by the AATCC test method

22-1985

Strength - Non-woven fabrics used in health care must also be strong enough not to tear or puncture at all times from production to use of the finished product.

Test

Test procedure

Burst load IST ¹ 110,0 - 70 (82) Tear strength (Elmendorf) GO 100,0 - 70 (R 82) Punching strength (Mul1 en) GO 30,0 - 70 (R 82) Elongation at tension GO 110,0 - 70 (82)

Standard Test of INDA (Association of Nonwovens Fabrics Industry)

Drapability and comfort - the drapability of a nonwoven fabric means the ability to adapt to the shape of the object it covers. These objects are understood to be e.g. patients, operating tables and equipment. Convenience means airiness, proper material selection and product design.

Test

Test procedure

Breathability (Frazier)

Length for bending when hanging on the beam

IST 70.1 - 70 (R82)

ASTM D 1388-64

The results of these tests are shown in Tables IIIA and IIIB.

TABLE III

Results of testing of laminate textiles without surface treatment

Vz. no. Bend length (cm) strength in overprint. (psi) (kPa) strength in previous year (e) breathability Nedza fortress FKG / cm) (ft ^ / min / ft ^) (m ^ / sec / m ^) ND CD ND CD ND CD 1 7.22 5.63 11 75.79 98 174 32.00 0.16 0.83 0.54 2 7.91 5.97 9.4 64.77 84 126 30.51 0.16 0.90 0.49 3 7.02 5.27 7.7 53,05 68 114 32.84 0.17 0.80 0.43 4 7.4 5.14 19.1 131.60 158 694 30.90 0.16 0.97 0.50 5 6.98 5.20 17.3 119.20 126 488 36.70 0.19 0.88 0.40 6 7.37 5.14 19.4 133.67 166 248 36.42 0.19 1.46 0.45 7 7.53 5.49 19.1 131.60 112 292 30.17 0.15 1.39 0.54 8 3.68 4.04 39.5 272.16 853 1209 26.37 0,132 1:42 1.59 9 3.93 2.70 39.3 270.78 613 660 16.77 0,083 1.49 1.35 10 4.62 4.88 40.3 277.67 1179 1755 13.66 0,068 1.32 1.66 11 3.90 2.94 42.5 292.83 641 746 11.9 0,059 1.59 1.33

Continuation of TABLE III

Vz. no. tensibility (¥) Hydros. pressure (Cm) Pren. water. drift Penetration at impact of water (G) Reputation rate. grease ND CD 1 14 21.2 34 90 0.43 0 2 11.6 20 32 80 0.37 0 3 10.4 22.8 24 70 0.9 0 4 20 24.8 39 70 0.83 0 5 22.4 21.6 57 80 4.33 0 6 24.8 24.4 42 80 1.73 0 7 26 24 48 70 0.33 0 8 35.6 34.4 50 90 0 0 9 22 28.4 62 70 0 8.0 10 31.2 35.2 77 90 0 0 11 24.8 27.6 58 70 0 7.5

note:

Sample # 8 = 1.8 oz / yd ^ textured SMS (spun / blown / spinned) uncoated Sample # 9 = 1.8 oz / yd textured SMS

ABOUT

Sample No.10 = 2.3 oz / yd SMS textiles without surface treatment n

Sample # 11 = 2.3 oz / yd SMS coated textured fabric

The data in Table III show that the lightweight laminates of the present invention exhibit strength values that fully entitle them to replace the previously produced synthetic fiber materials, i. of existing SMS textiles, which have so far been popularly used in health care. In addition, the present laminates have good tactile (bending length) and barrier properties as opposed to laminates which are not provided with a layer of cellulose fibers. As will be seen later, the laminates of the present invention have excellent liquid absorption, retention and absorbency properties, making them more suitable for medical applications.

Repellent finish

Laminate samples were provided with a surface fluorochemical layer to improve their repellency against water, oils, blood, alcohol and other water-containing liquids and their ability to form a barrier.

Surface fluorochemical treatment was carried out by traditional method of surface treatment - so-called. padding. This impregnation is accomplished by immersing the sample in a chemical mixture and then moving it through a gap between a set of rollers that pressurized excess chemicals from the impregnated laminate by pressure. The gap pressure can be controlled to achieve the desired degree of extrusion (Vet Pick Up Percentage, VPU%). The embossing step is the amount of the surface solution absorbed by the laminate sample. Untreated samples were weighed after cutting. Fullar drawn samples for fluorochemical impregnation were weighed after finishing. The degree of printing was determined using the following formula:

Weight impr. samples - weight unimpr. Sample x 100 VPU% = -Weight of impregnated sample

The embossing values for the different laminate samples are given in Table IV.

TABLE IV

Degree of extrusion of laminate samples of MSM

Sample no. Degree of printing (%)

7

152.10 145.50 149.43 157.96

157.90

140.91

140.11

Fluorochemical impregnation of the laminate specimens was performed on 18 inch wide filaments. The fluorine chemical used was 5% Zonyl PPR from Dupont. An extrusion rate of 140% was planned. The specimens were fluorochemically impregnated with a two-well fissure with two gaps at 30 psi pressure. The impregnated samples were then treated in a convection oven on a spike frame at 250 degrees Fahrenheit for 3.5 minutes. The following chemical mixture was used for impregnation:

Klocování (planned degree of subsidy 140%)

Weight ratio (%)

Zonyl PPR Water Ce1 k om

3.6

96.4

100.0

Fluorochemically coated with the abovementioned test procedures, ability to form a barrier, their strength and strength. The results of the impregnated tests are shown in Table V.

the samples were tested to determine their drape and cool laminate samples

TABLE

Test results of impregnated laminate textiles

Vz. Length for strength strength breathability Strength limit no. bend (cm) in overprint. in previous year (e) (ft ^ / min / ft ^) (m ^ / s / n²) IKE / cm) MD CD (psi) (kPa) ND CD MD CD

1 6.92 5.60 10.08 74.41 76 108 28.28 0.14 0.80 0.48 2 6.67 5.34 10.65 73.38 66 104 27.93 0.14 0.76 0.46 3 6.87 5.65 10.45 72,00 62 100 32.24 0.16 0.69 0.39 4 6.48 5.06 17,05 117.47 146 664 29.91 0.15 0.91 0.46 5 5.98 5.67 16.2 111.62 122 388 29.14 0.15 0.86 0.41 6 6.58 5:41 18.7 128.84 136 354 29.65 0.15 1.35 0.46 7 6.45 5.24 18.85 129,88 114 404 28:19 0.14 1.41 0.51

Continuation of TABLE

Vz. no. tensibility (%) Hydros. pressure (Cm) Pren. water. drift Water penetration (G) Reputation rate. grease MD CD 1 16 22 45 90 0.23 8 2 14 14 44 90 0.27 8 3 14 26 40 80 0.33 8 4 38 22 39 80 0.13 7 5 16 20 32 90 0.27 8 6 30 26 35 80 0.17 6 7 30 32 40 70 0.13 6

The hydrostatic pressure required to push the liquid through the samples was very high for the untreated samples, indicating a good ability of the blown fabric to form a barrier. However, impregnated samples 1, 2 and 3 having only cotton staple fibers in the middle layer showed much higher hydrostatic pressure values than the corresponding unimpregnated samples and generally higher values than impregnated samples which contained only polypropylene fibers in the middle layer. On the other hand, the hydrostatic pressure in most samples containing only PP in the core was significantly reduced by performing a repellent coating. It was found that the water sheath penetration rate of most impregnated samples increased due to fluorochemical impregnation. The greatest advantage of said fluorochemical coating was, according to the results obtained, an increase in the grease repelling rate from 0.0 (for unimpregnated samples) to excellent 6.0 to 8.0 (for fluorochemically impregnated samples). Summing up the results, we find that the greatest value for repelling the grease 8 is fluorochemically impregnated samples containing only cotton in their core.

Another series of samples, designated 8 to 15 in the following tables, was prepared for comparison. Except for Sontara, which contained wood pulp, none of the samples contained a cellulose fiber layer but one or more artificial fiber layers. Table VI shows the composition and method of manufacture of each sample.

TABLE VI

Structure and type of surface treatment of nonwovens

no. Type of fabric Fiber content structure Surface. .úprava * 8 Tyvek 1422A 100% PE ¹ spun no • 9 Tyvek 1422R 100% PE spun treat r.Coronou 10 Sontara 50% polyester reinforced no 50% dr.buničina spinning 11 Sontara 50% polyester reinforced DuPont RF ⁴ 50% dr.buni or na spinning m 12 SMS (1.8 oz / yd ² ) 100% PA ² Lam-SMS ³ no one 13 SMS (1.8 oz / yd ² ) 100% PP Lam-SMS KC RF ⁵ 14 SMS (2.3 oz / yd ² ) 100% PP Lam-SMS no 15 SMS (2.3 oz / yd ² ) 100% PP Lam-SMS KC RF

IpE - Polyethylene ² PP - Polypropylene

Lam-SMS - thermally bonded laminate of spun / blown / spunbond nonwoven ⁴ DuPont RF - DuPont Repellent ³ KC RF - Kimberly-Clark Repellent.

These samples were tested for various properties that were of importance to the use of laminates as fabric substitutes. The results of these tests are shown in Table VII.

TABLE VII

Basis weight, thickness, bending length, breathability, water shatter penetration, impact penetration and grease repellent of both conventional and Corona treated Tyvek textiles and non-impregnated and repellent impregnated Sontara and SHS textiles ¹

N ' Tvvek Sontara SHS 1422 1422R neim- impreg- ΝΡΗΛ.8 oz / E ^of NPH ³ 2.3 oz / E ² common. treated. What- pregno- novaná neim- impregnated. neim- impreg. neimpreg - rona, ne- vaná repelen- preg- repe- preg- repe- defined impregnate. that defined lentom lented

Average basis weight (oz / yd ^z ) 1.30 1.23 2.11 Average thickness (Mils) 6.60 5.90 11.20 Diameter, bend length front (cm) 3.92 4.13 5.28 back side (cm) 4.16 5.10 7.14 Avg, breathability (ft / min / ft) Water shatter penetration rate (0-100) 0 0 52.6 first set 90 76 0 second set 90 80 0 2 Water penetration on impact (g) Grease repellant (0-8) 0 0 23.7 first set 2 0 0 second set Punching strength (psi) Hydrostatic pressure (cm) Tear strength (g) Tensile strength (kg / cm) Ductility (%) 2 0 0

2.14 1.78 1.84 2.32 2.38 12,60 14.50 11.80 17,00 14.60 3.46 3.67 4.04 4.54 4.90 4.74 4.34 3.73 3.59 4.38 58.7 17.6 10.9 10.1 5.1 90 90 70 90 70 90 90 70 90 70 0.2 0 0 0 0 8 0 8 0 7.4 8 0 8 0 7.6 39.5 39.3 40.3 42.5 50.0 62.0 77.0 58.0

HD CD HD CD

853 1209 613 660 1179 1755 641 746

1.42 1.59 1.49 1.35 1.32 1.66 1.59 1.33

35.6 34.4 22.0 28.4 31.2 35.2 24.8 27.6

29 ¹ each value is an average of 35 samples »

due to the large number of samples required for this test, only one set of samples with five pieces of ³ NPH was tested at a time - nominal basis weight

As can be seen from Table VIII, several different woven fabrics differing in the type of fibers contained, basis weight and surface treatment were obtained from commercial sources for further comparison. 100% cotton denim is used to make trousers. Poplin is used for trousers and shirts. The denim fabric had a nominal basis weight of 10, 12 and 14.5 oz / yd. The indigo denim was made of unbleached and uncoloured greige material, desglued and partially cleaned material, and desglued, partially cleaned and fluorochemically impregnated material. White denim and ash were stripped, cleaned and bleached. Part of the white denim was also fluorochemically impregnated. The ash was assessed after desizing, cleaning and bleaching, durability coating and fluorochemical impregnation. All surface treatments and impregnations were carried out using commercial equipment already at the factory. See Table IX for more details on these substances.

TABLE VIII

Number and structure of yarns and yarns of denim and ash

Number Description of the substance

Nominal basis weight of yarn (oz / yd) warp attack

Thread count_ Structure in warp / inch in weft / inch fabric

100% cotton denim 13-A-B1 ¹ neodšlichtované 10,0 6.20 9.49 65 48 2x1 twill 13-B-B1 12.0 5.77 7.39 72 45 3x1 twill 13-C-B1 14.5 4.52 5.58 61 43 3x1 twill 14-AV ² odšlichtované 10,0 8.80 7.35 76 44 3x1 twill 124-A-B1 ³ and cleaned 10,0 8.13 10.56 65 42 2x1 twill 14-B-B1 12.0 8.02 7.84 73 41 3x1 twill 14-C-W 14.5 6.74 5.75 68 42 3x1 twill 14-C-B1 14.5 5.28 5.59 61 40 3x1 twill 15-A-W odšlichtované. 10,0 9.21 6.92 75 43 3x1 twill 15-A-B1 cleaned and 12.0 7.79 8.85 73 41 3x1 twill 15-C-W 14.5 6.57 5.25 66 41 3x1 twill 15-C-B1 14.5 6.29 5.84 62 39 3x1 twill

100% cotton poplin

16-V D + S + D ⁴ D + S + D + DP ⁵ D + S + B + D + FC ⁶ 16.10 13.89 64 56 easy 17-V 15.60 13.08 66 56 easy 18-V 15.15 11.54 66 54 easy Pooelin 75% cotton. 25% do1vester 19-V D + S + B 66 56 easy 20-V D + S + B + DP 67 55 easy 21-V D + S + B + DP + FC 66 56 easy

³ BI means indigo denim

V denotes white denim (stripped, cleaned and bleached) and

indigo denims have been partially despatched and cleaned ⁴ despatched, cleaned and bleached despatched, cleaned, bleached and durable surface treated descharged, cleaned, bleached, durable surface treated and fluorocarbon impregnated

TABLE IX

The basis weight, thickness and permeability of denim and popines

Number substances description Face. pl. weight (oz / yd ² ) Actual basis weight thickness (Mils) breathability (ft ^ / min / ft ² ) (m ³ / s / m ² ) (oz / yd ^from ) (g / m ^W ) 100% cotton denimv 13-A-B1 ³ neodšlichtované 10,0 10.55 357.74 31.53 16.55 0,085 13-B-B1 12.0 12.67 429.72 35.90 23.52 0,119 13-C-B1 14.5 14.92 505.81 39,36 16,11 0,082 14-AV ⁴ odšlichtované 10,0 9.77 331.33 25.74 7.06 0,036 124-A-B1 ⁵ and cleaned 10,0 8.24 279.45 21.96 13.81 0,070 14-B-B1 12.0 9.63 326.35 26.85 13.47 0,068 14-C-W 14.5 11.38 385.92 28.89 7.73 0,039 14-C-B1 14.5 11.54 391.24 30.20 9.59 0,049 15-A-W odšlichtované. 10,0 9.88 334.86 25.43 6.57 0,038 15-A-B1 cleaned and 10,0 8.23 278,88 32.01 13.86 0,070 15-C-W impregnated 12.0 9.67 327,97 26.31 11.73 0,060 15-C-B1 fluórkarbánom 14.5 11.47 388.90 28.30 8.18 0,042 14.5 11.67 395.68 30,08 8.98 0,046

100% cotton poplin

16-V D + S + D ⁶ D + S + B + D ⁷ D + S + B + D + FC ⁸ 5.53 187.47 15.63 37,15 0,189 17-V 5.74 194,65 15.68 37.91 0,193 18-V 5.82 197.37 15.67 Poplin 75% cotton, 25% polyester 39,13 0,199 19-V D + S + B 5.52 186.99 16.14 27.54 0,140 20-V D + S + B + DP 5.78 196,08 15.87 26.58 0,135 21-V D + S + B + DP + FC 5.85 198.45 15.78 26.53 0,135

values for individual samples are mean values of 2 times measured for 50 samples values for individual samples are mean values measured for 50 samples BI means indigo denim

V denotes white denim (descaled, cleaned and whitened5 indigo denim were partially desiccated and cleaned desiccated, cleaned and whitened desiccated, cleaned, bleached and durable surface stripped, cleaned, whitened, durable surface treated and impregnated fluorocarbon

The tactile and drape values of the composite fabrics of the present invention were close to those of fabrics which have been used to date for the manufacture of surgical gowns and similar medical equipment.

The permeability values of these composite fabrics, i. about 25-37 ft / min / ft (feet / min / ft) are comparable e.g. with the values of shirt fabrics and their ability to form a barrier and their airiness are the same as those of woven materials. Due to the presence of the fibrous layer in the present composite fabric, the filtration efficiency of the fabric is higher than that of previously manufactured single-layer woven fabrics, thereby increasing the suitability of the present composite fabric for applications where barrier-forming capability is required.

The absorbency and retention properties of some of the prior art fabrics, cotton mats and laminates made in accordance with the present invention were investigated. Absorption capacity was determined by a procedure developed by the Swedish Institute for Textile Research (TEFO) and evaluated in the TAPPI Journal in July 1987 (Shishoo). 6 shows a test apparatus consisting of a large funnel 80 with a glass frit 82 and a graduated measuring cylinder 84 with a scale. A 100 cm spherical sample 86 was placed overnight at 21 ° C and 65% relative humidity. It was then placed face up on a glass frit. A hundred milliliters of 7 mm / s liquid from a height of 2.54 cm was used to saturate it. Then, the saturated sample was rapidly loaded with a circular load 88 with an area of 100 cm and a weight of 100 g and allowed to lie for 10 minutes. The amount of liquid trapped in the cylinder was then measured and the absorbency (C) of the sample was calculated as follows:

C = a - b, where a = total amount of liquid delivered (100 ml), b = liquid (ml) not absorbed under 100 Pa.

The test was repeated seven times with each sample and the results were rounded to milliliters. After determining the absorbances, the retention capacity was determined. After determining the amount of liquid not absorbed within 10 minutes in the absorbency test, the sample was still loaded with 2.9 kilograms to apply a pressure of 3 kPa (100 Pa was already developed on the sample for the absorbency test), and the sample was left under 5 minutes. After this time, the amount of liquid in the cylinder was recorded and the sample was loaded with an additional 2 kilograms so that the resulting pressure was 5 kPa. The wet sample was subjected to this pressure for an additional 5 minutes and the amount of liquid collected in the cylinder was again recorded. The amount of liquid (C _rm and C ' _rm ) remaining in the sample below two different pressure values was calculated as follows:

C _rm = C - c where C = absorption capacity c = liquid not absorbed under 3 kPa

C ' _rm = C - c' where C = absorption capacity c '= liquid not absorbed at 5 kPa

The test was repeated seven times with each sample and the results were rounded to milliliters. The results are shown in Table XI. A further comparison concerned the absorption and retention capacity of 100% carded cotton fabrics under different loads and is shown in Table XII. Samples Nos 37 to 40 in Table XI do not contain a layer of cellulose fibers. Their absorption and retention capacities are negligible. From these data and the data in the preceding tables, it is apparent that the laminates of the present invention are in many physical respects better than the prior art nonwoven fabrics used primarily in health care and the like. The present fabrics are also very lightweight and it is known that fabrics having a lower content (by weight) of blown material have better liquid-absorbing and retention properties and hence greater economic benefits. In addition, although 100% cotton fabrics have been found to lose part of their retention capacity with increasing weight, such cotton fabrics have been incorporated into the laminate structure of the present invention, surprisingly, the resulting laminate exhibited a surprisingly high retention capability even with a higher inner cotton layer weight.

TABLE X

Fiberglass fabrics bonded on Kuster calender (1)

Vz. Name of the sample Polymer composition Name of the sample Polymer composition Area weight no. (upper layer) exhaust, fabric (bottom layer) textiles fabric core (upper layer) (bottom layer) (oz / yd ² )

²¹ 3

22 ³

23 ³

OC-13-88-5 1.5 oz / yd ² EVA OC-13-88-5

JA-12-88 1.0 oz / yd; ENA JA-12-88

Hay 1-90-3 1.0 oz · Nylon 6 Hay 1-90-3

OC-25-90-2 1.0 oz / yd ² Eastman OC-25-90-2

PET 12270

AU-20-91-2 1.0 oz / yd ² Celanese AU-20-91-2

PBT 1300A

1.5 oz / yd ² EVA 1.0 cotton ²

1.0 oz / yd ² EMA 1.0 cotton ²

1.0 oz / yd ² Nylon 6 1.0 cotton ²

1.0 oz / yd ² Eastman 1.0 cotton ²

PET 12270

1.0 oz / yd ² Celanese 1.0 cotton ² PBT 1300A

24 ^J

25A, 25B NO-15-90-1B 1.0 oz / yd ² PE NO-15-90-1B 26A, 26B "5 OC-11-89-3 0.25 oz / yd ² PP OC-11-89-3 OC-12-89-5 1.0 oz / yd ² Blue PP 0.7 oz / yd ² PP OC-12-89-5 28A, 28B, 28C ³ UT-1-24 UT-L-24 29A, 29B UT-1-24 0.7 oz / yd ² PP UT-1-24

29C ³

1.0 oz / yd ² PE 0.25 oz / yd ² PP

1.0 oz / yd ² Blue PP 0.7 oz / yd ² PP 0.7 oz / yd ² PP

1,0 cotton ² 1,0 cotton ²

1,0 cotton ² 2,0 cotton ² 3,0 cotton ²

30A, 30B, UT-1-24 0.7 oz / yd ² PP

30C ³

31A, 31B, UT-1-24 0.7 oz / yd ² PP

31C, 31D

32A, 32B, UT-1-24 0.7 oz / yd ² PP

32C, 32D

UT-1-24 0.7 oz / yd ² PP

UT-1-24 0.7 oz / yd ² PP

UT-1-24 0.7 oz / yd ² PP

UT-1-24 0.7 oz / yd ² PP

UT-1-24 0.7 oz / yd ² PP

UT-1-24 0.7 oz / yd ² PP

OC-11-89-3 0.25 oz / yd ² PP

UT-1-24 0.7 oz / yd ² PP

100% PP SB 0.9 oz./yd ² PP

100% PP SB 0.9 oz./yd ² PP

100% PP SB 0.6 oz./yd ² PP

100% PP SB 0.6 oz / yd ² PP thermally bonded 0.6 oz / yd ² TBS ^ ² PP

100% PP SB 0.6 oz / yd ² PP thermally bonded 0.6 oz / yd ² TBS ³ PP

UT-1-24 0.7 oz / yd ² PP 4,0 cotton ' UT-1-24 0.7 oz / yd ² PP 1,0 cotton ' UT-1-24 0.7 oz / yd ² PP 1,0 Ramie 100% PP SB 0.6 oz / yd ² PP 0.6 oz / yd ² PP 3,0 cotton ' 100% PP SB 1,0 Ramie 100% PP SB 0.6 oz / yd ² PP 2,0 Ramie 100% PP SB 0.6 oz / yd ² PP 3,0 Ramie UT-1-24 0.7 oz / yd ² PP - UT-1-24 0.5 oz / yd ² PP -

OC-11-89-3 0.25 oz / yd ^of PP

100% PP SB 0.6 oz / yd ² PP

100% PP SB 0.9 oz / yd ² PP 2.0 cotton ² 100% PP SB 0.9 oz / yd ² PP 1.0 cotton ² 100% PP SB 0.6 oz / yd ² PP 2.0 cotton ² 100% PP SB 0.6 oz / yd ² PP 1.0 cotton ² heat-bonded 0.6 oz / yd ² TBS ³ PP 1.0 cotton ² heat-bonded 0.6 oz / yd ² TBS ³ PP 1.0 cotton UT-1-24 (MB) 0.7 oz / yd ² PP 4.0 cotton ¹ Laminated and heat-bonded on Kuster calender with 1.7% diamond-bonded area. Samples 20 and 21 were bonded under 150 PLI pressure using a top patterned cylinder at 41 ° C and a bottom smooth cylinder at 41 ° C and at a fabric speed of 10 yards / min (9.1 m / min). Samples 25A and 25B were joined using a 88 ° C upper roller and a 90 ° C lower roller under a pressure of 250 PLI and a fabric speed of 10 yards / min (9.1 m / min). Samples 26A and 26B were joined using a top roller at 105 ° C and a bottom roller at 100 ° C under a pressure of 250 PLI and at a fabric movement speed of 10 yards / min (9.1 m / min). Samples 22, 23, 24, 27, 28A, 28B, 28C

29A, 29B. 29C, 30A, 30B, 30C, 31A, 31B, 32A, and 32B were joined using a 134 ° C upper cylinder and a 129 ° C lower cylinder under a pressure of 250 PLI and a fabric speed of 10 yards / min (9.1 m / min). The remaining samples, unless otherwise indicated, were laminated under the same conditions except for the upper and lower roll temperatures (125 and 122 CC respectively).

Veratec Easy Street - stripped, cleaned and bleached cotton carded on a 40-inch carding machine (Hollingsworth - On - Vheels) with a combination of flat and semi-grain fabrics. The fabrics were wound on a roll having a width of 18 cm and a circumference of 1.5 m.

neka1 and rované

Λ thermally bonded nonwoven staple fibers from Veratec

note:

(a) Samples 31C and 31D, and 32C and 32D were bonded using a Ramisch Kleinewefers calender on an area of 21.6% under a pressure of 250 PLI, at a top roller temperature of 134 ° C and a bottom roller 129 ° C at a fabric movement speed of 10 yards / min. (9.1 m / min).

(b) Samples 26D, 26E and 26F, 28D, 28E and 28F, 29D, 29E and 29F, and 30D, 30E and 30F were also bonded using a Ramisch Kleinewefers calender on an area of 21.6% under a pressure of 250 PLI at an upper roller temperature. 134 ° C and the lower roller 129 ° C and at a fabric movement speed of 10 yards / min (9.1 m / min).

TABLE XI

Absorption and retention capacity

Sample no. Absorption capacity (100 Pa) ¹ Retention capacity (3 kPa) ² Retention capacity (5 kPa) ³ Tyvek 1422A 5 5 5 Tyvek 1422R 6 5.5 5 Sontara (not impregnated) 8 7 7 SMS (not impregnated) (1.8 oz / yd ² ) 8 8 8 SMS (non-imp.) (2.3 oz / yd) 5 5 5 * 20 12 10 9.5 * 21 9.5 9 8.5 * 22 14 12 12 25A, 25B * 7.0 6.0 6.0 26A, 26Β » 8.5 8.0 8.0 * 27 8.5 8.0 8.0 * 28 11 9.5 9.0 * 29 14.5 12 11.5 30 « 17 14.5 14 31A.31B * 8 7 6.5 32A.32B * 7.5 6.5 6.0 * 33 18 15 14 34th 7 6.5 6.0 * 35 12 11 11 * 36 17 14 13 * 37 4 4 4 * 38 7 7 7 * 39 8 7.5 7.5 * 40 7 7 7 41 16 14 13.5 42 9 7.5 7 43 14 11 10.5 44 10 9 8 45 12 11 11 46 8.5 7 7 47 28 18 17

»Description of samples see. Tables VI and X (sample numbers correspond to the numbers in Tables VI and X) calculated by subtracting the quantity of liquid discharged into the graduated cylinder after 10 minutes from the original 100 ml batch calculated by subtracting the amount of liquid not sampled at 3 kPa from the absorption capacity. not absorbed by the sample at a pressure of 5 kPa from the absorption capacity

TABLE XII

Sample no. Absorption capacity (100 Pa) ¹ Retention capacity (3kPa) ² Retention capacity (5 kPa) ³ 1.0 oz / yd2 24 20.5 19.5 2.0 oz / yd ² 33 20.0 19.0 3.0 oz / yd ² 34 18.5 16.5 4.0 oz / yd ² 46 23 21.0

calculated by subtracting the quantity of liquid discharged into the measuring cylinder after 10 minutes from the initial 100 ml batch calculated by subtracting the amount of liquid not sampled at 3 kPa from the absorption capacity calculated by subtracting the amount of liquid not sampled at 5 kPa from the absorption capacity

The capillarity of the sample was tested using the apparatus shown in Fig. 7. It consists of a scale 90 with a connected printer 92, a laboratory jack 94, a water tank 95 for the test liquid 96, a funnel 98 with a thick (40-60 micron) glass frit 100. a rubber hose 102 for connecting the funnel 98 to a water tank 94, 100g round weights 106 (100 cm area) and stems (not shown). The funnel 98 is vertically adjustable mounted on the ring stand 110. Roughly seven circular samples of 100 cm area were cut from each test fabric stored overnight at 65% relative humidity. In the test, the water tank was lifted until the surface of the glass frit was wet (but water did not stand on it). Then a sample with a 100 gram circular load was placed on the frit. The stopwatch was started at the time the load was placed on the sample, and every 10 seconds for 3 minutes the weight of the test liquid was removed and transferred from the water tank to the sample. Thus, the liquid soaked into the sample had enough time to stabilize. The result was plotted in a plot of the amount of liquid versus time. This test was repeated seven times for one test fabric. Data for each sample can be found in Table X. Graphs of the amount of liquid versus time observed during the tests are shown in FIG. 8 to 34. FIG. Figures 8 to 34 clearly show that the capillary action values of the prior art synthetic fiber laminates are very low. However, when these fabrics are combined with a layer of natural cellulose fibers, the resulting laminates exhibit excellent capillarity, making them suitable for use in healthcare and other areas.

While the present invention has been demonstrated by specific examples, it will be appreciated by those skilled in the art that various modifications may be made thereto. E.g. it is possible to use non-diamond bonding patterns that have been described. Further, various fluorochemical impregnation methods that are commercially available and well known can be used. You can find them eg. in the publication

Handbook of Fiber Science and Technology, Volume II: Chemical Processing of Fibers and Fabrics, Functional Finishes, Part B, published by Menachem Lewin and Stephen B. Sello, and listed in the bibliography of this report at p. 172-183.

Claims (6)

Multilayer nonwoven composite fabric, in particular as a replacement for woven fabrics, characterized in that it comprises a first layer of fibrous material selected from the group consisting of thermoplastic blown man-made fibers, thermoplastic spun man-made fibers, thermoplastic man-made staple fibers and combinations thereof, is in the range of about 0.05 10 to about 10 oz / yd, and preferably from about 0.25 to about 2 oz / yd, and a second cellulose staple fiber layer having a basis weight of from about 0.1 to about 10 oz / yd. yd and preferably from about 1 to about 4 oz / yd, and wherein the fibers have a length in the range of about 0.5 to about 3 inches and a weight in the range of about 2 to about 5 micronair, and the two layers are thermally bonded to each other to form a coherent a structure having an air permeability of from about 25 to about 37 ft / min / ft, with a bond area between layers of from about 5 to about 75% of one of the composite fabric areas, and optimally between about 10 and 30% of the composite fabric area. 2. The composite fabric of claim 1 comprising a third layer of fibrous material selected from the group consisting of thermoplastic blown man-made fibers, thermoplastic spun man-made fibers, thermoplastic man-made staple fibers, and combinations thereof, having a basis weight ranging from about 0.05 to about 10 oz / yd and the optimum interval is about 0.10 to 2.0 oz / yd and which is disposed on the side of said second layer facing away from said first layer and thermally bonded to at least said second layer such that a second layer was interposed between said first and said third layers. Composite fabric according to claim 1 or 2, characterized in that said layers are joined to each other at separate points over the entire flat surface of said fabric, such that the joint surfaces form a substantially uniformly arranged pattern. The composite fabric of claim 1 or 2, wherein the first and third layers have an air volume above about 85%. 5. A composite fabric as claimed in claim 1 or 2, characterized in that it has a wicking rate of from about 0.01 g / s to about 0.05 g / s and a water retention value at a pressure of 3 kPa of about 7 to about 15. 6. A composite fabric according to claim 1 or 2, characterized in that it has an extrusion strength of from about 40 to about 225 kPa.