CN1479819A - Thermally bonded fabric and method of making the same - Google Patents

Abstract

A method for producing a nonwoven fabric comprises passing a fiber web through a pair of rollers to obtain a thermally bonded fabric with a high percentage of bond areas. The high percentage of bond areas is formed by an engraved pattern on at least one of the rollers. The engraved pattern has a high percentage of bond point areas and wide bond point angles. The nonwoven fabric has increased tensile strength, elongation, abrasion resistance, flexural rigidity, and/or softness.

Description

Thermally bonded fabric and method of making the same

technical field

The present invention relates to a nonwoven fabric made from polyolefin polymers and a method of making such a fabric.

Background of the invention

Fabrics made from fibers include both woven and non-woven fabrics. Nonwoven fabrics are used in hygienic and medical applications including hospital gowns, diaper liners, and hygiene wipes. There are many procedures for making bonded nonwoven fabrics. Non-woven fabrics, for example, can be made to pass through the nip between heated rollers, possibly with a pattern of ridges and grooves on one or both sides, by applying heat and pressure so that in limited areas Combine. During this bonding, depending on the type of fibers constituting the nonwoven, the bonding region can be formed autogenously, that is to say the fibers of the woven fabric are fused by melting them at least at the pattern region, or can be fused by An adhesive is added to fuse. Advantages of these bonded nonwovens include low energy costs and speed of production.

Nonwovens can also be made by several other methods, such as spunlacing or entangling (as disclosed in U.S. Patent No. 3,485,706 and U.S. Patent No. 4,939,016); Bonded staple fibers; bonded continuous fibers by spinning in one continuous operation; or woven fabrics formed by meltblowing fibers into fabrics followed by calendering or thermal bonding.

The various properties of nonwovens determine the suitability of nonwovens for different applications. Nonwovens can be engineered to have different combinations of properties to suit different needs. Variable properties of nonwovens, including liquid retention properties like wettability, spreading, and absorbency, strength properties like tensile strength and tear strength, softness, durability like abrasion resistance, and aesthetics on the nature.

Polypropylene has become the dominant polymer for nonwovens due to its cost, high strength and ease of handling. Polypropylene nonwovens, however, generally do not have a soft, cotton-like feel. In this regard, polyethylene non-woven fabrics have received attention. Polyethylene produces softer fabrics but has considerably lower tensile and abrasion strengths.

While those properties of nonwovens such as liquid retention properties, strength properties, softness, and durability are often of paramount importance in the design of nonwovens, the look and feel of those nonwovens is critical to those forming the exposed parts of the product. Non-woven fabrics are also particularly important. For example, the outer cover of those non-woven fabric products is often desired to have a cloth-like feel and a pleasant decorative design.

Despite the above-described advances in the art, there remains a particular need for improvements in nonwoven fabrics and methods of making them. In particular, nonwoven fabrics need to have improved strength properties, elongation, abrasion resistance, flexural stiffness, and/or softness.

Summary of the invention

Embodiments of the present invention may meet the above needs through one or more features of the present invention. In one feature, the present invention is directed to a method for a nonwoven fabric having increased tensile strength, elongation, abrasion strength, flexural stiffness, and/or softness. The method involves passing a web of fibers through a pair of rollers to obtain a thermally bonded fabric having a high percentage bonded area. This high percentage of bonded area is formed by the relief pattern on at least one of its rollers. This emboss style has a high percentage of joint area and/or a wide joint angle.

In certain embodiments, the fabric has a percent bonded area of at least about 16 percent, at least about 20 percent, or at least about 24 percent, with a bond point angle of about 20° or greater, about 35° or greater , about 37° or more, about 42° or more, or about 46° or more. The relief pattern has at least about 1.55 x ¹⁰⁵ bonds per square meter, at least about 2.31 x ¹⁰⁵ bonds per square meter, at least about 3.1 x ¹⁰⁵ bonds per square meter, at least about 3.44 ×10 ⁵ bonds, at least about 4.6×10 ⁵ bonds per square meter, or at least about 4.65×10 ⁵ bonds per square meter. The fabric may contain polyethylene, which may be a homopolymer of ethylene, or a copolymer of ethylene and a comonomer. The polyethylene can be obtained in the presence of a single site catalyst, such as a metallocene catalyst, or a constrained geometry type catalyst.

In another aspect, the invention relates to a nonwoven fabric made by the method described in this specification. The nonwoven fabric contains a polymer and is characterized by a high percentage bonded area and high abrasion resistance. In certain embodiments, the polymer is polyethylene, which can be a homopolymer of ethylene, or a copolymer of ethylene and a comonomer. The polyethylene can be obtained in the presence of a single site catalyst, such as a metallocene catalyst or a constrained geometry catalyst. In other embodiments, the fabric has a percent bonded area of at least about 16 percent, at least about 20 percent, or at least about 24 percent.

The various features and advantages of the present invention provided by the various embodiments of the present invention will be more apparent from the following description.

Description of drawings

Figure 1 is a schematic diagram of the procedure used to produce fabrics in an embodiment of the invention;

Figure 2A is a fragmentary front view of an engraved cylinder illustrating the arrangement of the joints;

Figure 2B is a schematic diagram of the nonwoven fabric produced by the procedure of Figure 2A and the engraved cylinder of Figure 2A;

Figures 3A-3I are schematic diagrams of binding patterns represented in arbitrary scales used in embodiments of the present invention;

Figures 4A-4I are photomicrographs of non-woven fabrics produced with the bonding pattern in Figures 3A-3I for the PE1 resin used in Example 1;

Figure 5 is a graph of normalized peak load versus temperature for fabrics produced with PE1 resin for the bonding patterns in Figures 3A-3I;

Figure 6 is a graph of percent elongation versus temperature for fabrics produced with the combination patterns in Figures 3A-3I for the PEE resin used in Example 1;

Figure 7 is a graph of typical stress-strain curves associated with the three fabrics produced in Example 1;

Figure 8 is a graph of the abrasion resistance versus temperature for fabrics produced with PE1 resin for the bonding patterns in Figures 3A-3I;

Figure 9 is a graph of flexural stiffness versus temperature for fabrics produced with PE1 resin for the bonding patterns in Figures 3A-3I;

Figures 10A-10I are scanning electron micrographs at a magnification of 80X of the bonding pattern in Figures 3A-3I for the bonding points of non-woven fabrics produced with PE1 resin;

Figures 11A-11C are scanning electron micrographs of the rupture sites of the bonded patterns in Figures 3A-3I for tensile tests of non-woven fabrics produced with various resins; and

Figures 12A-12B are scanning electron micrographs of worn bond sites of nonwoven fabrics produced with the bond patterns in Figures 3A-3I for various resins.

Detailed ways

Embodiments of the present invention may provide a method for producing nonwoven fabrics by thermal bonding. The fabric has a high percentage bond area produced by passing a web of fibers through a pair of rollers, at least one of which has a relief pattern with a high percentage bond area plus a wide bond angle.

The term "nonwoven" as used in this specification refers to a woven cloth or fabric having a structure of individual fibers or yarns that are randomly interwoven but not in an identifiable manner as is the case with woven fabrics. The term "bond" as used in this specification means to apply force or pressure (separate or add to that required or used to draw the fibers to a denier less than or equal to 50 denier) to fuse the molten or softened fibers together, resulting in a Bond strength greater than or equal to 1,500 grams. The term "thermal bonding" as used in this specification means reheating and applying force or pressure (separated or added to those required or used to pull the fibers to less than or equal to 50 denier) to those fibers to melt or fuse the fibers , resulting in a bond strength greater than or equal to 2,000 grams. Those that draw and fuse the fibers together in a single or simultaneous operation, or at either take-up drum (eg, a godet drum), such as spunbonding, are not considered a thermal bonding operation.

A thermal bonding process related to the production of nonwoven fabrics is illustrated in Figure 1. Such procedures, or variations thereof, are described, for example, in the following U.S. Patent Nos.: 5,888,438; 5,851,935; 5,733,646; 5,654,088; Instead, those texts are incorporated into this specification in their entirety. All of these disclosed methods, with or without modification, can be used in the embodiments of the present invention.

Referring to Figure 1, a web forming system 10, such as a carding system, is employed to initially form a fibrous web 12. The fibers, indicated by arrow 13, are primarily aligned in the machine direction of fabric formation. The fabric 12 is guided through a preheating station 14 . The preheated fabric is then passed to a pressure nip through the joining station provided by opposing rollers 20 and 22 . Cylinder 20 is a metal engraved cylinder and is heated to a temperature greater than the melting point of the fibers. Its support roll 22 (ie smooth roll) is heated in a controlled manner to a temperature below the melting point of the fibers, preferably below the sticking point of the fibers. Its bonding operation can form a high percentage of adhesive bonds on its preheated surface 18, while those self-generating bonds formed on its opposing surface 25 are mostly fusions that only partially extend through the thickness of the fabric. combined.

The engraved cylinder illustrated in Figure 2A contains areas, ie, joints, in intimate compressive contact with a flat cylinder. These areas can induce melting, and some areas of adhesion can be established. The dimensions of these regions determine the number of fibers bound at a single point and the total area of non-fibrous integrity that the fabric contains. The number of fibers it has connected to a joint affects its overall strength but also contributes to its overall stiffness. There are three factors in a relief pattern that affect the overall properties of a nonwoven fabric. These include binding area, binding site or sidewall angle, and binding site concentration, usually expressed as number of sites per square unit area.

The engraved pattern on the cylinder is created through those joints. The points extend from the engraved cylinder and, upon contact with the flat cylinder, create a bonded area. The bond points generally create a pattern on the nonwoven fabric as seen in Figure 2B. The joints of a relief pattern are usually expressed in terms of joints per square area. In a preferred embodiment, the relief pattern has about 1.55×10 ⁵ bond points per square meter (100 bond points per square inch), preferably about 2.31×10 ⁵ bond points per square meter (100 bond points per square inch). 149 joints per square inch), more preferably about 3.10×10 ⁵ joints per square meter (200 joints per square inch), or about 3.44×10 ⁵ joints per square meter (222 joints per square inch joints), or about 4.60 x ¹⁰⁵ joints per square meter (297 joints per square inch), or about 4.65 x ¹⁰⁵ joints per square meter (300 joints per square inch). More bonding points per square meter, such as 5.42×10 ⁵ , 6.20×10 ⁵ , 7.75×10 ⁵ , 9.30×10 ⁵ , or more, (per square inch, such as: 350, 400, 500, 600, or more) is also feasible.

The junction is made by a junction angle and junction area. Referring to Figures 3A-I, different bond angles and bond areas are shown for various bond styles. Its joint angle refers to the angle at which its joint extends from the engraved cylinder. The joint angle is about 20° or more, preferably about 35° or more, more preferably about 37° or more, more preferably about 42° or more, and especially about 46° or more. Figure 3A is about bonding pattern 1, which has a 46° angle, 20 percent bonding area, 3.44×10 ⁵ pts/m ² (222 pts/in ² ), basic width 1.7×10 ^-3 m (0.067 inches), Base height 4.32×10 ^-4 m (0.017 inch). And point width 7.62×10 ^-4 m (0.03 inches). Figure 3B is about bonding pattern 2, which has a 20° angle, a bonding area of 16 percent, 3.44×10 ⁵ pts/m ² (222 pts/in ² ), a basic width of 1.7×10 ^-3 m (0.067 inches), Base height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 6.86×10 ⁻⁴ m (0.027 inch). Figure 3C is about bonding pattern 3, which has a 20° angle, 24 percent bonding area, 3.44×10 ⁵ pts/m ² (222 pts/in ² ), base width 1.7×10 ^-3 m (0.067 inches), Base height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 8.38×10.4 m (0.033 inch). Figure 3D is about bonding pattern 4, which has a 20° angle, 20 percent bonding area, 2.31×10 ⁵ pts/m ² (149 pts/in ² ), basic width 1.7×10 ^-3 m (0.067 inches), Base height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 9.30×10 ⁻⁴ m (0.0366 inch). Figure 3E is for bond pattern 5, which has a 20° angle, 20 percent bonding area, 4.60×10 ⁵ pts/m ² (297 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 inch), Base height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 6.60×10 ⁻⁴ m (0.026 inch). Figure 3F is for bond pattern 6, which has a 42° angle, 16 percent bond area, 3.44×10 pts/m ² (222 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 inches), base height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 6.86×10 ⁻⁴ m (0.027 inch). Figure 3G is for bond pattern 7, which has a 37° angle, 24 percent bond area, 3.44×10 ⁵ pts/m ² (222 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 inches), Base height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 8.38×10 ⁻⁴ m (0.033 inch). Figure 3H is for bond pattern 8, which has a 46° angle, 20 percent bond area, 2.31×10 ⁵ pts/m ² (149 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 inches), base Height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 9.3×10 ⁻⁴ m (0.0366 inch). Fig. 3I is for bonding pattern 9, which has a 35° angle, 20 percent bonding area, 4.60×10 ⁵ pts/m ² (297 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 inches), Base height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 6.60×10 ⁻⁴ m (0.026 inch).

Those bonded regions and unbonded regions will make up the nonwoven fabric described above. Those bonded areas can be defined as the percentage of the surface area of the nonwoven described above covered by the bond created by that bonded area. The bonding area in embodiments of the invention is preferably at least 16 percent, more preferably at least 20 percent, and especially preferably at least 24 percent, 30 percent, 35 percent, 40 percent, 45 percent, 50 percent or more . Manufacture of fibers and nonwovens

A fabric forming system typically includes a number of procedures that can be used to produce fibers that can be thermally bonded to form a fabric including dry twisting, wet twisting, and polymer twisting, or any other procedure. In certain embodiments, the fibers are produced by processes such as spunbond, meltblown, or carded staple fibers. This procedure is further described in the following US Patent Nos. 3,338,992; 3,341,394; 3,276,944; 3,502,538; 3,978,185; and 4,644,045, the entire contents of which are incorporated herein by reference. Typically, the spunbonding process uses a high powered vacuum chamber to increase the velocity of the fiber, thereby reducing the diameter of the fiber and producing a continuous fiber. The meltblowing process blows air from top to bottom and uses surface forces to drag the fibers to higher velocities to produce very low denier non-continuous fibers.

Those conventional spunbonding procedures are described in US Pat. Nos. 3,825,379; 4,813,864: 4,405,297; 4,208,366; and 4,334,340, all of which are incorporated herein by reference. This spunbonding procedure is well known in the art of fabric production. Typically, those continuous fibers are extruded, placed on an endless belt, and then bonded to each other and often sometimes to a second layer like a meltblown layer etc., which is often passed through a Heat calender roll, or add a binder. An Overview of One-Spin Integration, Available from the Sponsorship of The Textiles and Nonwovens Development Center (hereinafter "TANPEC"), Tennessee State University, Knoxville, Tennessee, 1990 Nonwovens by L.c. Wadsworth and B.C. Goswami in Proceedings of the 8th Annual Nonwovens Symposium, July 30-August 3: "Spunbonded and Melt Blown Processes".

The term "melt blown" is used in this specification to refer to fibers that are formed by extruding a molten thermoplastic polymer composition through a plurality of thin, usually circular, die capillaries, with some molten yarn or filament, into a converging high-velocity gas stream (eg, air) that functions to attenuate the yarn or filament to a reduced diameter. Thereafter, the filaments, or yarns, are carried by the high velocity gas stream and deposited on a collecting surface to form a web of randomly scattered meltblown fibers typically having an average diameter of less than 10 microns.

The term "spunbond" is used in this specification to refer to fibers that are formed by extruding a molten thermoplastic polymer composition through a plurality of spinnerets having the diameter of the extruded filament and then shrinking sharply. Fine, generally circular die capillaries, and subsequent deposition of these filaments on a collecting surface to form a weave of randomly dispersed melt-blown fibers usually having an average diameter between about 7 and about 30 microns .

Those nonwovens can be produced by many methods. Most methods generally involve the same basic procedures: (1) material selection; (2) fabric formation; (3) fabric consolidation; and (4) fabric completion. Material selection can provide properties suitable for its application. The fabric is formed from the fibers of the chosen material. The woven fabrics are then combined to form a fabric that can be processed to produce a final product that can be cut and folded.

The diameter of the fiber affects its fabric properties including strength and flexural stiffness. The diameters of those fibers can be measured and recorded in a variety of ways. Typically, fiber diameter is measured in denier per filament. Denier is a textile term defined as grams of fiber per 9000 meters of fiber length. Monofilament generally refers to an extruded strand having a denier per filament greater than 15, usually greater than 30. Fine denier generally refers to a fiber having a denier of about 15 or less. Microdenier (ie, microfiber) generally refers to a fiber having a size no greater than 100 microns. In the case of the fibers disclosed in this specification, the diameter can vary widely with little impact on the fiber's elasticity. However, its fiber denier can be adjusted to suit its ability to handle finished products, etc., or preferably: from about 0.5 to about 30 denier per filament for meltblowing; from about 1 to about 30 denier; and from about 1 to about 20,000 denier per filament for continuous coiled filaments.

Fiber diameter in deniers can be converted to meters according to the following equation:

Other final fiber properties that affect the fabric include: fiber orientation, crystallinity, diameter, and cooling rate. Its bond strength is a limiting factor in the strength of nonwoven fabrics. Lower fiber orientation allows a greater amount of melting during bonding, resulting in a stronger bonded area. In addition, the high amount of orientation induced by drawing a polymer will cause a high amount of shrinkage during thermal bonding, making its handling difficult.

The crystalline portion of a fiber is particularly important for the fusion-induced thermal bonding process that occurs. The extent to which it melts and flows significantly impacts its bond strength. The less stable crystals will melt first; if sufficient heat is transferred to the polymer, the more stable or oriented crystals will follow. Only a portion of the crystals will melt due to this short period of heat transfer to their bonded area.

After the fabric has been loosely formed, the individual fibers need to be bonded together. Fabric consolidation provides strength and stiffness to the fabric. Those methods of consolidating fabrics include: mechanical, chemical, and thermal bonding. Mechanical consolidation is accomplished by winding fibers at various points in the weave, including needling, stitching, spun lace, or any other mechanical consolidation process. Chemical bonding involves spraying or saturating the fabric with an adhesive such as latex. Thermal bonding of woven fabrics is a common bonding technique, including spot calendering, ultrasonic and radiant thermal bonding. In certain embodiments, point calender bonding is used, which involves passing the web through two heated rollers in intimate contact. One of the cylinders is positive relief, and the other cylinder is a flat cylinder. The fibers melt and flow onto each other. On cooling, the fabric is formed.

When a web of fibers is drawn into a calender, many thermal processes of various scales occur. These procedures include: conductive heat transfer; thermal deformation; flow of molten polymers; diffusion; and the Clapeyron effect.

Conductive heat transfer is transmitted across the steel drum, fabric interface. The amount of heat transferred by conduction is directly proportional to the temperature of the steel drum, and the amount of time the fabric spends under the bonding needle point (roller speed). Also, the heat added to its system is the heat of its deformation. Due to the high pressure between the steel rollers, the fabric will very quickly form a different shape and perform mechanical work on this system. This mechanical work will be converted into heat. These two forms of heat will raise the temperature of the fabric between the cylinders and highest at the point where it joins the needles. The equation assuming that all mechanical work is transferred to heat is given by:

[F(s)ds]α=VρC _P ΔT+fΔH _f XρV

where F(s)ds is the force applied to the fabric over a distance ds. α is the mechanical work component converted into heat, V is the weaving capacity, X is its crystallinity, and f is the component of crystal melting. The first term on its right side is the amount of heat it uses to increase the temperature, and the second term describes the amount of heat it uses to melt the polymer crystals.

When its temperature reaches its melting point, the high pressure under the junction pin will cause the melt to flow outward to a region of lower pressure. Also, in the molten state, the polymer will self-diffuse. On leaving the calender roll, the melt will solidify and will mechanically lock the fibers at their bond points. These two phenomena cause several fibers to fuse together at a joint and transform the weave into a fabric. The relative diffusion penetration distance of those polymers during the bonding procedure is almost negligible. Its penetration distance is obtained from:

R＝[t(2×D)] ^

Among them, R is the penetration distance, t is the time, and D is the self-diffusion coefficient. Typically, most polymers have a diffusion coefficient of 10 ^-15 and will take 10 to 40 milliseconds at the binding pin site. Using these approximations, it will be possible to calculate that the penetration distance is only between 45 Å and 100 Å. Considering that most of the fibers used in thermal bonding are approximately 20 microns in diameter, the fibers spread only 0.00000225 percent of those total diameters. Therefore, the mechanical interlocking of its polymer melt around the fiber in the bonding region is likely to be the dominant force holding the fiber together at its bonding point.

This, combined with increased pressure under the pinpoint, will result in an increase in melting temperature otherwise known as the Clapeyron effect. The pressure effect increases the melting point of polypropylene by 38K/kbar or 0.38°C/Mpa. Using typical pressures at a bond point, the melting point of polypropylene will increase by about 10°C. The melting temperature of polyethylene, at typical bonding pressures, will increase by approximately 5°C.

The above points combined with several factors of the thermal calendering procedure will affect those final fiber properties, including temperature, pressure, speed, roll diameter, and relief pattern. The choice of temperature is primarily a function of its material, but it should be noted that the total energy transferred to the fabric is a function of temperature, pressure, drum diameter, and line speed. If its temperature is selected too low, the woven fabric will be insufficiently bonded, so the strength of its fabric will be weak. If the drum temperature is too high, the web will become overbonded so that the resulting fabric will be too stiff, or the web will completely melt and stick to the drum.

The effect of the pressure it applies to the fabric is small but not negligible. At low pressures, the fabric bonds poorly and thus has poor strength. As pressure increases, the strength of the fabric is a function of combined temperature and pressure. At very high pressure, though, the fabric strength will reach a maximum and then begin to decrease as the pressure increases. Below this pressure, the strength will continue to increase upward to the melting point of the polymer.

This, combined with the speed and diameter of the drum, will affect the total time for heat transfer to the fabric. Larger bonded roller diameters allow closer contact with the heat roller than those of smaller rollers. Therefore, it will have more heat transfer to the fabric. In the same way, a slowly rotating drum will have less contact time than a faster rotating drum.

The amount of time a fabric spends in the gap (intimate contact area) can be expressed as:

t＝AC ₀ ^1/2 R ^1/2 V ¹

t = time

R = Radius of combined roller 7

V = the speed of the combined roller $A=\sqrt{\frac{C_o-C_{\mathrm{no}}}{C_o}}$ $+\sqrt{\frac{C_R-C_{\mathrm{no}}}{C_o}}$

Wherein, C _o is the original fabric thickness, C _N is the thickness between the combining rollers, and C _R is the thickness after compression in the combining rollers.

The shape of the fibers is not limited and may be of any suitable shape. For example, typical fibers have a circular cross-section, but sometimes those fibers have a different shape, such as a trilobal shape. Or a flat (ie, "ribbon") profile.

After the thermally bonded fabric has been released from the bond pin, the bonded area will cool and solidify. The quenching rate of the fabric, and more specifically the bonded area, may impact its final fabric properties.

Those important fabric properties include: strength, elongation, peak load, abrasion strength, and flexural stiffness. The strength or tenacity and elongation of nonwoven fabrics are important both to the subsequent production process and to the consumer. The greater the strength and elasticity of a fabric, the faster it can be combined with other materials into a final consumer product. Another property of nonwoven fabrics is their ability to resist abrasion. When a rough surface is applied to a nonwoven fabric, those fibers will be pulled from the surface and form fuzz or pills on the surface. In this connection, high abrasion resistance is advantageous for nonwovens. Another important property of materials worn by humans and placed against the skin is their hardness. This property can be measured by bending stiffness or touch assessment. fiber forming polymer

Any fiber-forming polymer, particularly those capable of thermal bonding, may be used in embodiments of the present invention. By way of example, those suitable polymers include, but are not limited to, alpha-polyolefin homopolymers and interpolymers, those including polypropylene, propylene/ _C4 - _C20 alpha-polyolefin copolymers, polyethylene , and ethylene/C ₃ -C ₂₀ α-polyolefin copolymers, the interpolymers may be heterogeneous ethylene/α-polyolefin interpolymers, or uniform ethylene/α-polyolefin interpolymers, those include Substantially linear ethylene/alpha-polyolefin interpolymer. Also included are those aliphatic alpha-polyolefin interpolymers having from 12 to 20 carbon atoms and containing dipole groups. Examples of suitable aliphatic alpha-polyolefin monomers that can introduce dipole groups into the polymer include ethylenically unsaturated cyanides like acrylic cyanide, methacrylic cyanide, ethacrylic cyanide, and the like; Unsaturated anhydrates like maleic anhydride; ethylenically unsaturated amines like acrylamide, methacrylamide, etc.; ethylenically unsaturated carboxylic acids (mono- and difunctional) like acrylic acid, methacrylic acid, etc.; like isobutylene Ethyl unsaturated carboxylic acid methyl ester, ethyl acrylate, hydroxyethyl acrylate, n-butyl acrylate or methacrylate, 2-ethyl-hexyl acrylate, or ethylene-vinyl acetate copolymer, etc. Esters of acids (especially lower, e.g. C ₁ -C ₆ , alkyl esters); similar to N-alkyl or N-arylmaleimides, similar to N-phenylmaleimides Ethylenically unsaturated dicarboxylic acid imides. These monomers including dipole groups are preferably acrylic acid, vinyl acetate, vinyl acetate, maleic anhydride and acrylic cyanide. The polymers derived from aliphatic alpha-polyolefin monomers may contain halogen groups including fluorine, chlorine and bromine; these polymers are preferably some chlorinated polyethylene (CPE). Polymers such as polyester and nylon can also be used.

Those heterogeneous interpolymers are distinguished from homogeneous interpolymers in that substantially all of the interpolymer molecules in the latter have the same ethylene/comonomer ratio within their interpolymer, whereas heterogeneous interpolymers Polymers are those interpolymer molecules that do not have the same ethylene/comonomer ratio. The term "broad composition distribution", as used in this specification to describe the comonomer distribution associated with heterogeneous interpolymers, means that those heterogeneous interpolymers have a "linear" component, and that the heterogeneous interpolymers have Multiple melting peaks (ie, exhibiting at least two distinct melting peaks) as measured by DSC. The heterogeneous interpolymer, within about 10 percent (weight ratio) or more, preferably greater than 15 percent (weight ratio), more preferably greater than 20 percent (weight ratio), has a A degree of branching of 2 methyl groups/1000 carbons. The heterogeneous interpolymer, within about 25 percent (by weight) or less, preferably less than 15 percent (by weight), more preferably less than 10 percent (by weight), has a Branching degree of 25 methyl groups/1000 carbons.

Its heterogeneous polymer composition may be an α-polyolefin homopolymer preferably polyethylene or polypropylene, or more preferably an α-polyolefin with at least one C ₃ -C ₂₀ and/or C ₄ - Ethylene interpolymer of C ₁₈ diene. Heterogeneous copolymers of ethylene with propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene are particularly preferred.

Linear low density polyethylene (LLDPE) is produced in a solution or a fluid bed process. Its polymerization is a catalytic reaction. Ziegler-Natta and single-site metallocene catalyst systems have been used to produce LLDPE. The resulting polymer characteristically has a substantially linear backbone. Density is controlled by the level of comonomer incorporated into the otherwise linear polymer backbone. Various alpha-polyolefins, typically copolymerized with ethylene to produce LLDPE. The alpha-polyolefin, preferably having four to eight carbon atoms, is present in the polymer in an amount up to about 10 weight percent. Its most typical comonomers are butene, hexene, 4-methyl-1-pentene and octene. The comonomer will affect the density of its polymer. The density range associated with LLDPE is quite broad, typically from 0.87-0.95 g/cc (ASTM D-792).

The LLDPE melt index is also controlled by the introduction of a chain terminator such as hydrogen or a hydrogen donor. A linear low density polyethylene with a melt index measured in accordance with ASTM D-1238 condition 190°C/2.16kg (formerly known as "Condition E" and also known as "I ₂ "), ranging from about 0.1 to about 150g /10min. For the purposes of the present invention, the LLDPE should have a melt index, for spunbonded filaments, greater than 10, and preferably 15 or greater. Particularly preferred LLDPE polymers have a density of 0.90 to 0.945 g/cc, and a melt index greater than 25.

Examples of commercially available suitable LLDPE polymers include: LLDPE polymers sold by The Dow Chemical Company, USA, such as the ASPUN ^™ series of fiber grade resins, Dow LLDPE 2500 (55 MI, 0.923 density), Dow LLDPE type 6808A (36 M1, 0.940 density), and the EXACT ^™ series of low density polyethylene polymers sold by Exxon Chemical Company, such as EXACT ^™ 2003 (31 M1, 0.921 density).

The homogeneous polymer composition may be preferably an α-polyolefin homopolymer of polyethylene or polypropylene, or more preferably an α-polyolefin having at least one C ₃ -C ₂₀ and/or C ₄ - Ethylene interpolymer of C ₁₈ diene. Homogeneous copolymers of ethylene with propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, and 1-octene are particularly preferred.

The recent introduction of metallocene-based catalysts required for the polymerization of ethylene/α-polyolefins has led to the creation of new ethylene interpolymers, known as homogeneous interpolymers.

The homogeneous interpolymers that can be used to form the fibers described in this specification have some uniform branch distribution. That is, the polymer system wherein the comonomer is randomly distributed within a given interpolymer molecule and wherein substantially all interpolymer molecules have the same ethylene/comonomer ratio within the interpolymer By. The isomorphism of the polymer is typically described by SCBDI (Short Chain Branch Distribution Index) or CDB1 (Composition Distribution Branch Index), and is defined as having a median total molar comonomer The weight percent of polymer molecules of the comonomer content within the content. The CPBI of a polymer can be easily calculated from data obtained by techniques known in the art, for example, as described by Wild et al., in PolymerScience, Poly.Phys.Ed., Vol. 20, p. 441 (1982) , as described in U.S. Patent No. 4,798,081, or as described and exemplified in U.S. Patent No. 5,008,204, the temperature rising elution fractionation method (this specification will be abbreviated as "TREF"), those disclosures are hereby incorporated by reference incorporated into this manual. The technique for calculating the CDBI is described in USP 5,322,728, and in USP 5,246,783, or in US Patent No. 5,089,321, all disclosures of which are incorporated herein by reference. Preferably, the SCBDI or CDB1 of the homogeneous interpolymers used in the present invention is greater than about 30 percent, especially greater than about 50 percent, 70 percent, or 90 percent.

The homogeneous interpolymers used in the present invention substantially lack a measurable "high density" component as measured by the TREF technique (i.e., the homogeneous ethylene/α-polyolefin interpolymers do not contain a polymer fraction with branching less than or equal to 2 methyl groups/1000 carbon atoms). The homogeneous interpolymer also does not contain any highly short-chain branched components (ie, those that do not contain a polymer component having a degree of branching equal to or greater than 30 methyl groups per 1000 carbon atoms).

The substantially linear ethylene/α-polyolefin polymers and interpolymers, also homogeneous interpolymers, but further in this specification as defined in U.S. Patent No. 5,272,236 and U.S. Patent No. 5,272,872 , the entire contents of which are incorporated into this specification by reference. However, these polymers are unique due to those excellent processability and unique rheological properties and high melt elasticity and resistance to melt fracture. These polymers can be successfully prepared in a continuous polymerization procedure using the constrained geometry metallocene catalyst system.

The term "substantially linear" ethylene/α-polyolefin interpolymer means that the polymer backbone is branched by about 0.01 long chain branches/1000 carbon atoms to about 3 long chain branches/1000 carbon atoms, preferably from about 0.01 long chain branches/1000 carbon atoms. Chain branches/1000 carbon atoms to about 1 chain branch/1000 carbon atoms, and especially from about 0.05 long chain branches/1000 carbon atoms to about 1 long chain branch/1000 carbon atoms for substitution.

Long chain branching is defined in this specification as a chain length of at least one carbon atom less than two carbon atoms from the total carbon atoms in the comonomer, for example, a substantially linear ethylene/octene ethylene interaction The long chain branches of the polymer are at least seven (7) carbon atoms long (ie, 8 carbon atoms minus 2 equals 6 carbon atoms plus one equals the seven carbon atoms long chain branch length). The long chain branches can grow to a length about the same as the backbone of their polymer. Long-chain branching was determined using 13C nuclear magnetic resonance (NMR) spectrometry and quantified using the Randall method (Macromol. Chem. Phys., C29(2&3), pp. 285-297), which revealed that It is incorporated into this specification by reference. Of course, long-chain branches are to be distinguished from short-chain branches, which result solely from incorporation of comonomers, so that, for example, the short-chain branches of a generally linear ethylene/octene polymer are six-carbon Atoms long, while the long-chain branches of the same polymer are at least seven carbon atoms long.

Other suitable polymers are disclosed in the following U.S. Patent Nos.: 6,316,549; 6,281,289; 6,248,851; 6,194,532; 6,190,768; 6,140,442;

Examples of commercial fiber forming polyethylenes include: ASPUN ^™ 6806A (melt index: 105.0 g/10 min; density: 0.930 g/cc), ASPUN ^™ 6842A (melt index: 30.0 g/10 min; density: 0.955 g/cc), ASPUN ^TM 6811A (melt index: 27.0g/10min; density: 0.941g/cc), ASPUN ^TM 6830A (melt index: 18.0g/10min; density: 0.930g/cc), ASPUN ^TM 6831A (melt index: 150.0g/cc 10 min; density: 0.930 g/cc), and ASPUN ^™ 8635A (melt index: 17.0 g/10 min; density: 0.950 g/cc), all sold through The Dow Chemical Company, Midland, MI. These linear low density polyethylenes can be blended with a uniform generally linear ethylene polymer, such as the AFFINITY ^™ resins sold by The Dow Chemical Company, USA.

Examples of commercial fiber forming polypropylenes include: Copolypropylene designated 5A10 (melt flow rate: 1.4 g/10 min; flexural modulus: 1585 MPa (230,000 psi)); 5A28 (melt flow rate: 3.0 g/10 min; Flexural modulus: 1585MPa (230,000psi)); 5A66V (melt flow rate: 4.6g/10min; flexural modulus: 1654MPa (240,000psi)); 5E17V (melt flow rate: 20.0g/10min; flexural modulus: 1344MPa (195,000psi)); SE40 (melt flow rate: 9.6g/10min; flexural modulus: 1378MPa (200,000psi)); NRD5-1258 (melt flow rate: 100.0g/10min; flexural modulus: 1318MPa ( 191,300psi)); NRD5-1465 (melt flow rate: 20.0g/10min; flexural modulus: 1344MPa (195,500psi)); NRD5-1502 (melt flow rate: 1.6g/10min; flexural modulus: 1347MPa ( 195,500psi)); NRD5-1569 (melt flow rate: 4.2g/10min; flexural modulus: 1378MPa (200,000psi)); NRDS-1602 (melt flow rate: 40.0g/10min; flexural modulus: 1172MPa ( 170,000psi)); SRD5-1572 (melt flow rate: 38.0g/10min; flexural modulus: 1298MPa (188,400psi)); SRD5-1258 (melt flow rate: 25.0g/JOmin), and INSPIRE ^TM resin (melt Flow rates range from 1.8 to approximately 25 g/10 min), all sold through The Dow Chemical Company, USA. Its melt flow rate is measured according to ASTM D1238 (230° C./2.16 kg), and its flexural modulus is measured according to ASTM D 790A. It should be understood that resins from other companies, such as Exxon, Bassel, Mitsui, etc., may also be used.

Those like antioxidants (e.g. barrier phenolics like 1RGANOX ^™ 1010 or 1RGANOX ^™ 1076 supplied by Ciba Geigy), phosphites (e.g. 1RGAFOS ^™ 168 also supplied by Ciba Geigy), adhesion additives (e.g. PIB ), pigments, colorants, fillers, etc., can also be included in the fiber materials disclosed in this specification.

Likewise, the polymers disclosed in this specification may be blended with other polymers to modify properties such as elasticity, ease of handling, strength, thermal bonding, or adhesion so that these modifications do not adversely affect the range of desired properties.

Some useful materials that can be used to modify this polymer include other substantially linear ethylene polymers plus other polyolefins such as high pressure low density ethylene homopolymer (LDPE), ethylene vinyl acetate (EVA), Ethylene-carboxylate copolymers, ethylene-acrylate copolymers, polybutylene (PB), including high-density polyethylene (HDPE), medium-density polyethylene, polypropylene, ethylene-propylene interpolymers, ultra-low-density polyethylene (ULDPE), plus some ethylene/α-polyolefin polymers involving graft-modified polymers exemplified by anhydrates and/or dienes or mixtures of those.

Still other polymers suitable for modifying polymers include several synthetic and natural elastomers and rubbers known to exhibit varying degrees of elasticity. AB and ABA blocks or graft polymers (where A is a thermoplastic end block similar to, for example, a styrocene half-body, and B is an elastic middle block derived from, for example, a conjugated diene or lower olefin ), chlorinated elastomers and rubbers, ethylene propylene diene monomer (EDPM) rubber, ethylene propylene rubber, etc., and mixtures thereof, are some known prior art elastic materials contemplated as being suitable for modifying the elastic properties disclosed in this specification Examples of materials.

Polypropylene can be blended with a low melting polymer like polyethylene to increase the strength of its bonded areas. In the same way, LLDPE can be blended with a low melt/low density polyethylene to produce the same result.

The initial chemical structure of the polymers used to produce the nonwoven has an influence on the fabric properties. The chemical structure of a polymer will impact the density/crystallinity, velocity, and molecular weight distribution of the polymer. Also, adding two or more polymers to make a blend will significantly impact the properties of the nonwoven. Fabric strength can increase with increasing molecular weight distribution. An increase in MWD will reduce the orientation of the fibers during spinning and cause greater melting during calendering.

The nonwoven fabrics according to embodiments of the present invention have utility in a variety of applications. Those suitable applications include, but are not limited to, disposable personal hygiene products (for example, baby pants, diapers, absorbent underwear, incontinence products, feminine hygiene products, etc.), disposable garments (for example, industrial clothing, coveralls, hoods, underpants, pants, shirts, gloves, socks, etc.), and infection control/room cleaning products (for example, surgical gowns and drapes, face shields, heads, surgical hats and hoods, shoes, boots and slippers, wound dressings, bandages, antiseptic wraps, wipers, lab coats, coveralls, pants, aprons, jackets, bedding products, and sheets).该无纺织物，亦可在下列诸美国专利中所揭示说明的方式中被使用：6,316,687；6,314,959；6,309,736；6,286,145；6,281,289；6,280,573；6,248,851；6,238,767；6,197,322；6,194,532；6,194,517；6,176,952；6,146,568；6,140,442； 5,919,177; 5,912,194; 5,900,306; 5,830,810; and 5,798,167, the entire contents of which are incorporated herein by reference. Example

The following examples are presented to illustrate certain embodiments of the invention. It is not intended to limit the present invention, except as otherwise stated and within the scope of the patent application of this specification. All numbers in the examples are approximate values. In the following examples, various nonwoven fabrics are characterized in a number of ways. Performance data for these fabrics can also be obtained. Most methods or tests are performed according to ASTM standards, if applicable, or known procedures. Preparation of polymer mixture

A HAAKE twin-screw extruder was used to produce the polymer mixture. This extruder has the following characteristics:

● 6 heating zones with temperatures of 110°C, 120°C, 130°C, 135°C, 135°C, and 135°C respectively.

● Two 19mm diameter screws.

●L/D＝30

● Melting temperature＝146℃

● Die pressure＝2.64×10 ⁶ Pa(383psi)

● Torque＝3.44×10 ⁷ Pa(5000psi)

● Speed = 200rpm for the preparation of polymer fibers

Fibers were produced by extruding the polymer using a 1 inch diameter extruder fed to a gear pump. The gear pump pushes the material through a spin pack containing a 40 micron (average pore size) sintered flat metal filter and a 108 hole spinneret. The spinneret holes had a diameter of 400 microns and a land length (ie, length/diameter or L/D) of 4/1. The gear pump was operated to squeeze approximately 0.3 grams of polymer per minute through each hole of the spinneret. The melting temperature of the polymer varies depending on the molecular weight of the polymer being spun. Usually the higher its molecular weight, the higher its melting temperature. Quenching air (slightly above room temperature (about 24°C)) is used to help cool the melt-spun fibers. This quenching air is located just below the spinneret and can be blown through the above-mentioned extruded fiber strands. The quenching Air velocity, low enough to be felt only in the fiber region below the loom. The fibers are collected on godet rollers that are approximately 0.152 m (6 inches) in diameter. The speed of the godet rollers System can be adjusted, but with regard to the demonstrated experiment of this specification sheet, the speed system of this godet drum is about 1500 rev/mins.This godet drum is positioned at about 3 meters below the die of this spinneret.Close to this weaving process Finally, all fibers will be cut into 0.0381m (1.5 inches) long fibers. Preparation of non-woven fabrics

Nonwoven samples were produced according to the procedure described in this specification on a laboratory calender equipped with a hardened, chrome embossed steel roll. A relief pattern contains a total bond area of 20 percent, and 3.44 x ¹⁰⁵ bonds per square meter (222 bonds per square inch). Figures 3A-3I schematically show various bonding patterns plus dimensions used in embodiments of the present invention.

For each pattern design, follow the procedure below. All fibers are 3 denier. The fiber will then be fed into a card. The fiber will be drawn into the RotorRing by vacuum and passed through a series of cross needles. The fibers are then aligned for further carding in a high-speed centrifuge. This procedure will be repeated for each sample. Next, the fiber will be evenly distributed on a steel plate measuring 10cm by 40cm, and a paper feed card will surround the front end of the fiber weave. This would yield a fabric with a basis weight of 33 g/m ² or 1 oz/yd ² . The fiber web is placed between the moving heated calender rolls where the web is combined into a nonwoven fabric. Its initial combination drum condition system is as follows:

● Top (relief) drum temperature - from about 110°C (230°F) to about 121.1°C (250°F)

● Bottom (smooth) rolling temperature - from about 110°C (230°F) to about 121.1°C (250°F)

● Water pressure - from about 4.82×10 ⁶ Pa (700psi) to about 1.03×10 ⁷ Pa (1500psi)

● Drum speed/dial setting = from about 3 to about 5m/min. test method

The fabrics produced above contain, for the most part, a machine direction alignment. There are very few fibers arranged in the transverse direction. The characterization of those fabrics and fiber orientation was performed using the following techniques:

1. Optical micrographs are of randomly selected fabrics from this experiment. The top and bottom of the fabric, both were photographed at 40X magnification. Those optical micrographs were also obtained in the same manner from commercial spunbonded PP fabrics made by TANDEC.

2. Convert the photomicrograph into Scion imaging software and divide into quarters.

3. The angle of the fibers in each quarter of the photomicrograph, measured with the machine direction as vertical (0°) and the cross-sectional direction as horizontal (90°).

Once all fibers have been measured, the following equation will be used to quantify their orientation:

Fp＝2*avg(cosθ) ² -1

θ is the angle of the fiber and Fp is its orientation parameter, where a value of 0 corresponds to random orientation and a value of 1 corresponds to perfect alignment in one direction.

The tensile strength of each fabric sample was checked using an Instron 4501 Tensile Tester. Linear jaw jaws were used to secure the fabric to the Instron. "Standard Test Method for Breaking Force and Elongation of Fabrics" (ASTM D5035-90) was used with one exception. The strip was not cut into 0152m (6 inch) strips; it was cut into 0.101m (4 inch) strips.

A standard abrasion procedure was developed which included the following steps using a Taber Abraser model 503 with an 8-compartment sample holder (rotating platform dual-head method):

1. The fabric is cut into 0.0762 x 0.0762 m (3 x 3 inch) pieces and marked.

2. Apply an adhesive backing to the edge of its abraded surface to prevent tearing at the edge.

3. Samples are individually weighed to 4 digits.

4. The sample is placed in the sample holder to determine not to cause any wrinkles or loose areas. The samples are arranged in the machine direction, pointing toward the center of the sample holder, and with the embossed side facing upwards.

5. Fabric samples are made with CO ₂ rubber friction wheels for a determined amount (100) of one cycle. Masking tape, made by American Tape, was applied to the abrasive surface and removed in one steady but quick motion.

6. The fabric is again weighed and recorded.

Any samples that were torn or completely degraded during abrasion were discarded and removed from further testing.

Bending stiffness is measured according to the design specifications of ASTM method D1388-64. Before taking measurements, place a leveling bubble on top of its leveling platform to ensure consistency. The projected length and basis weight of the fabric are then used to calculate its flexural stiffness. While the Protrusion Test, is a way to easily measure the stiffness of all fabrics, it is important to be able to correlate its results with consumer opinion. The tactile feel of a fabric in one's hand may have properties different from those found in a mechanical test. In addition, the surface of the fabric should also have a soft feel to the touch.

All hand feel evaluations were performed by a 12-person research team selected to evaluate the texture and stiffness of the fabrics. All research team members follow the following procedures:

1. Each research team member was given 4 anchor samples, and those corresponding numbers ranging from 1 for the least grainy or hardest to 15 for the most grainy or hardest. The anchors and their corresponding numbers are indicated in Table 10.

2. The research team member lays the sample flat on the table with the embossed side of the fabric facing up. Place the wrist on the table and move those index and middle fingers across the entire surface of the sample. This procedure will be repeated for all four directions of the sample. Those texture identification grades will be recorded.

3. The research team member lays the sample flat on the table so that the dominant hand is placed on top of the sample. The fingers are positioned such that the fingers point to the top of the sample. The sample is collected by moving the fingers towards the palm while the other hand guides the sample into the cupped hand. The sample is repeatedly squeezed and released.

4. Those certified grades will be recorded for their hardness.

All samples were evaluated before being assigned a rating for each. Due to the availability of members of the research team, only a selected set of samples were tested. Example 1

Those polyethylene (PE) polymers were obtained from The Dow Chemical Company, USA. The polyethylene polymers have varying densities and melt indices. A polypropylene (PP) polymer is also available from Dow Chemical Company, USA. The properties of the polymers are shown in Table 1.

Table 1: Polymers used in the experiments polymer grade Density(g/cc) Melt index (g/10min) Melting point (°C) PE1 0.955 29 131 PE2 0.941 27 125 PE3 0.950 17 129 PE4 0.870 1 55 PP1 0.910 35 165

Polyethylenes representative of PE1 include ASPUN ^(TM) 6842A sold by The Dow Chemical Company, Midland, Michigan. Polyethylenes representative of PE2 include ASPUN( ^TM) 6811 sold by The Dow Chemical Company, Midland, Michigan. Polyethylenes representative of PE3 include ASPUN ^(TM) 6835A sold by The Dow Chemical Company, Midland, MI. Polyethylenes representative of PE4 include AFFINITY ^™ EG8100 sold by The Dow Chemical Company, Midland, MI. Polypropylenes representative of PP1 include H500-35 sold by The Dow Chemical Company, Midland, Michigan. Four samples were formulated from these polyethylene polymers. Three homopolymers and a 95 percent/5 percent blend of PE1 and PE4 were tested. The composite system of the mixture is as described above. 4.75 kg of PE1 pellets combined with 0.25 kg of PE4 were placed in the hopper of the above twin screw extruder. After leaving the extruder, the polymer was drawn through a cooling bath maintained at 5°C. The solid polymer is then fed to a Berlyn Clay Group chipper where it is cut into pellets. The polymer will be washed for 15 minutes, and the pellets will be collected for 100 minutes.

Those fibers were produced using the spinning conditions indicated in Table 2 and the procedure described above.

Table 2: Spinning conditions related to various fibers fiber polymer Extruder temperature (℃) Wire guide roller speed(rpm) Guide wire roller speed(m/min) Expected Fiber Diameter (microns) Total mass of sample (g) 1 PE1 190 1800 900 twenty one 540 2 PE2 190 1800 900 twenty one 180 3 PE3 190 1800 900 twenty one 180 4 PE1+PE4 190 1800 900 twenty one 180 5 PP1 230 1800 900 twenty one 180

Fabrics were produced using the fibers in Table 1, produced by the procedure described above, coded in the following manner. There is a three-number series assigned to each sample. Its first digit indicates the polymer used. Its second number indicates its binding pattern number, and its third number indicates its binding temperature. Refer to polymer numbers according to Table 2 and binding pattern numbers according to Figures 3A-3I. For convenience, this marking system is used to identify samples.

Figure 3A is for bond pattern 1 with a 46° angle, 20 percent bond area, 3.44×10 ⁵ pts/m ² (222 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 inches), base Height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 7.62×10 ⁻⁴ m (0.03 inch). Figure 3B is for bond pattern 2 with 20° angle, 16 percent bond area, 3.44×10 ⁵ pts/m ² (222 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 in), base Height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 6.86×10 ⁻⁴ m (0.027 inch). Figure 3C is for bond pattern 3 with 20° angle, 24 percent bond area, 3.44×10 ⁵ pts/m ² (222 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 inches), base Height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 8.38×10 ⁻⁴ m (0.033 inch). Figure 3D is for bond pattern 4 with 20° angle, 20 percent bond area, 2.31×10 ⁵ pts/m ² (149 pts/in ² ), base width 1.7×10 ^-3 m (0.067 inch), base Height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 9.30×10 ⁻⁴ m (0.0366 inch). Figure 3E is for bond pattern 5 with 20° angle, 20 percent bond area, 4.60×10 ⁵ pts/m ² (297 pts/in ² ), base width 1.7×10.3 m (0.067 inches), base height 4.32 ×10 ⁻⁴ m (0.017 inch), and spot width 6.60×10 ⁻⁴ m (0.026 inch). Figure 3F is for bond pattern 6 with 42° angle, 16 percent bond area, 3.44×10 ⁵ pts/m ² (222 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 inches), base Height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 6.86×10 ⁻⁴ m (0.027 inch). Figure 3G is for bond pattern 7 with 37° angle, 24 percent bond area, 3.44×10 ⁵ pts/m ² (222 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 inches), base Height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 8.38×10 ⁻⁴ m (0.033 inch). Figure 3H is for bond pattern 8 with 46° angle, 20 percent bond area, 2.31×10 ⁵ pts/m ² (149 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 inches), base Height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 9.3×10 ⁻⁴ m (0.0366 inch). Figure 3I is for bond pattern 9 with 35° angle, 20 percent bond area, 4.60×10 ⁵ pts/m ² (297 pts/in ² ), base width 1.7×10 ⁻³ m (0.067 inches), base Height 4.32×10 ⁻⁴ m (0.017 inch), and spot width 6.60×10 ⁻⁴ m (0.026 inch).

Next, fabric pieces are cut for tensile testing, abrasion testing and protrusion testing. All samples were cut from the center due to inconsistencies in the processing temperature at the fiber weave and at the edges.

The fabric is evaluated visually. Temperature, pressure, and choice of resin had no effect on the visual appearance of the fabric. Incorporating a drum pattern has a dramatic effect on the visual properties of the fabric. Figures 4A-4I are photomicrographs at 20X magnification of a nonwoven fabric produced from resin 6824A at 119.4°C (247°F) showing the visual difference in the fabric. The darker diamond-shaped areas are the bonded areas of the fabric, while the lighter areas are those unbonded fibers.

A comparison of Figures 4A, 4F, 4G, 4H, and 4I with Figures 4B, 4C, 4D, and 4E shows that sidewall angles of 20° will produce less bonding than those patterns containing larger sidewall angles area. The bond area of the fabric is shown in Table 3. This data shows a greater percentage bonded area than the roll pattern which produced bond patterns 1, 6, 7 and 8 fabrics. This is due to the melt flow of the polymer below its transient bonding pins, and also due to the increased heat transfer due to the compaction of the fibers in the void areas between the bonding pins. The fibers contain less free space and their heat transfer system via conduction is higher. All patterns that included a 20° sidewall angle showed a fabric with a percent bonded area that was less than that of the drum pattern. Shrinkage of the polymer fibers is a possible cause. During the spinning process of the fibers, the fibers are solidified under tension in an oriented state. When the fiber is exposed to higher temperatures under the bonding pinpoints, the polymer molecules will loosen or shrink back to a more stable state.

Table 3: Bonded areas measured for nonwoven fabric samples resin style Temperature °C (°F) mean percent binding area PE1 1 119.4 (247) 33.7 PE1 2 119.4 (247) 16.5 PE1 3 119.4 (247) 30.8 PE1 4 119.4 (247) 19.0 PE1 5 119.4 (247) 20.7 PE1 6 119.4 (247) 17.7 PE1 7 119.4 (247) 31.8 PE1 8 119.4 (247) 24.7 PE1 9 119.4 (247) 24.1 PE2 1 116.1 (241) 31.1 PE2 2 116.1 (241) 14.0 PE2 3 116.1 (241) 20.7 PE2 4 116.1 (241) 17.6 PE2 5 116.1 (241) 17.5 PE2 6 116.1 (241) 17.1 PE2 7 116.1 (241) 28.6 PE2 8 116.1 (241) 22.2 PE2 9 116.1 (241) 23.1 PE3 1 119.4 (247) 33.0 PE3 2 119.4 (247) 13.8 PE3 3 119.4 (247) 23.5 PE3 4 119.4 (247) 15.5 PE3 5 119.4 (247) 17.3 PE3 6 119.4 (247) 16.3 PE3 7 119.4 (247) 28.4 PE3 8 119.4 (247) 23.2 PE3 9 119.4 (247) 19.8 95% PE1+5% PE4 1 119.4 (247) 30.8 95% PE1+ 2 119.4 (247) 13.4 5 percent PE4 95% PE1+5% PE4 3 119.4 (247) 19.0 95% PE1+5% PE4 4 119.4 (247) 17.0 95% PE1+5% PE4 5 119.4 (247) 16.5 95% PE1+5% PE4 6 119.4 (247) 15.3 95% PE1+5% PE4 7 119.4 (247) 26.8 95% PE1+5% PE4 8 119.4 (247) 21.8 95% PE1+5% PE4 9 119.4 (247) 20.0

The 20° sidewall angle pattern also exhibited fibers with some less compact or higher porosity. Bonding styles 4, 5, 7 and 8 have the same percentage bonded area but different dot densities per square meter. The distance between each joint point is larger for the pattern with lower point density per square meter.

The analysis of its fabric weight is shown in Table 4. Thin spots appeared in the fabric due to variations in the carding procedure and handling of the fiber web. The variability in its thickness has a strong impact on the mechanical properties. The weight of a one square inch sample within the fabric has extremely low variability.

Table 4: Analysis of fabric weight within and between samples resin style Average weight (g) PE1 1 0.021 PE1 2 0.023 PE1 3 0.023 PE1 4 0.020 PE1 5 0.019

Figures 4A-4I are photomicrographs of the changing bonding pattern of PE1 resin at 119.4°C (247°F) which was also used to assess fiber orientation. A study of the picture shows that most of the fibers are arranged in one direction (up and down). This is the machine direction (MD) of the fiber. Most spunbonded and fused fabrics contain more randomly aligned fibers such that the fabric contains both cross direction (CD) strength and machine direction strength. Evaluation of those randomly selected fabrics showed that commercial spunbonded fabrics were associated with lower fabric orientation ( _fp ) values than the samples produced and tested in these Examples. The commercial spunbond fabric is made from polypropylene under TANDEC. The results are shown in Table 5. The _fp value at the bottom of the fabric is higher than at the top, which means that the fibers are more aligned in the machine direction on the bottom. Bonding pinpoints on the top push the fibers into a more random state, while the bottom fibers bonded to a flat roller keep the fabric aligned.

Table 5: Data collected from fiber orientation measurements the fabric f _p (1) f _p (2) f _p (3) mean f _p PE (top) 0.56 0.54 0.53 0.54 PE (bottom) 0.7 0.82 0.69 0.75 Spun bonded PP 0.22 0.19 0.25 0.22 Spun bonded PP 0.16 0.18 0.22 0.19

Tables 6 through 9 show various properties of the nonwoven fabrics tested for each polymer fiber at various temperatures using various bonding patterns. A three-number series is assigned in each sample. Its first digit indicates the polymer used. The second number indicates its binding style number, and its third number indicates its binding temperature in °F. Refer to Table 2 for polymer numbers and to Figures 3A-3I for binding style numbers. For convenience, this marking system is used to identify samples. For example, 1-1-116.1 represents a fabric made with PE1 resin using bond pattern 1 (Figure 3A) at a bond temperature of 116.1°C (241°F). Tensile properties of all samples were measured for peak load and elongation at break using an Instron 4501 and procedure ASTM D5035-90 as previously described. Six tensile samples were tested due to inter-fabric variability produced under the same conditions. The average abrasion (ABR) observed for each treatment condition is tabulated. For flexural rigidity (FR), the sag length and basis weight of each fabric will be measured to determine FR according to ASTM D 1388-64 as described above. The average FR measured by each treatment condition for each resin is listed in the table.

Table 6: Information of resin PE1 sample Average percent elongation Normalized Average Peak Load (g) Average abrasion (mg/cm ² ) Average FR(mg*cm) 1-1-116.1 43.17 1974 0.76 29.1 1-1-117.7 52.20 2026 0.71 33.8 1-1-119.4 70.00 2161 0.55 45.9 1-2-116.1 16.77 920 1.02 17.6 1-2-117.7 17.40 882 1.01 20.3 1-2-119.4 31.61 1186 0.83 22.0 1-3-116.1 17.00 927 0.77 30.4 1-3-117.7 20.06 1032 0.71 28.8 1-3-119.4 27.81 1330 0.53 33.6 1-4-116.1 20.73 956 1.08 17.8 1-4-117.7 19.66 915 0.92 19.6 1-4-119.4 27.64 1141 0.64 19.6 1-5-116.1 93.69 806 0.99 17.9 1-5-117.7 0.89 25.3 1-5-119.4 19.37 1073 0.66 32.4 1-6-116.1 32.08 1253 0.93 28.4 1-6-117.7 49.86 1393 0.89 38.4 1-6-119.4 76.48 1619 0.75 50.8 1-7-116.1 41.15 1511 0.72 48.0 1-7-117.7 52.51 1821 0.66 51.4 1-7-119.4 93.13 2149 0.54 70.1 1-8-116.1 48.27 1517 0.97 41.4 1-8-117.7 75.35 1666 0.83 46.2 1-8-119.4 70.34 1865 0.61 56.0 1-9-116.1 24.08 1193 0.94 45.7 1-9-117.7 28.04 1335 0.85 55.6 1-9-119.4 53.75 1493 0.64 85.2

Table 7: Information of resin PE2 sample Average percent elongation Normalized Average Peak Load (g) Average abrasion (mg/cm ² ) Average FR(mg*cm) 2-1-112.7 24.62 1646 0.94 31.8 2-1-114.4 31.54 1912 0.80 43.3 2-1-116.1 45.24 2075 0.68 66.2 2-2-112.7 49.30 1228 1.20 30.1 2-2-114.4 60.96 1336 0.92 36.7 2-2-116.1 36.26 1188 0.75 50.3 2-3-112.7 63.42 1370 1.00 35.9 2-3-114.4 62.79 1544 0.74 41.8 2-3-116.1 33.12 1336 0.59 55.1 2-4-112.7 81.15 1482 1.06 20.2 2-4-114.4 90.96 1525 0.78 24.2 2-4-116.1 39.15 1316 0.65 35.9 2-5-112.7 54.37 1409 0.97 35.0 2-5-114.4 64.09 1508 0.84 40.1 2-5-116.1 19.75 1344 0.61 51.5 2-6-112.7 74.57 1530 1.06 39.6 2-6-114.4 56.29 1438 0.93 52.8 2-6-116.1 38.05 1057 0.75 57.4 2-7-112.7 68.12 1583 0.96 43.0 2-7-114.4 64.24 1743 0.78 54.3 2-7-116.1 50.48 1858 0.58 72.5 2-8-112.7 95.53 1594 1.04 35.5 2-8-114.4 91.61 1617 0.75 40.3 2-8-116.1 33.78 1122 0.65 48.6 2-9-112.7 60.33 1685 0.95 54.6 2-9-114.4 78.11 1705 0.83 54.1 2-9-116.1 73.58 1950 0.61 60.8

Table 8: Information about resin PE3 sample Average percent elongation Normalized Average Peak Load (g) Average abrasion (mg/cm ² ) Average FR(mg*cm) 3-1-11 17.74 1447 0.92 40.0 3-1-11 21.50 1702 0.61 41.0 3-1-11 27.82 1919 0.55 46.3 3-2-11 13.53 1242 1.09 41.4 3-2-11 23.23 1785 0.97 40.1 3-2-11 32.40 1992 0.79 46.0 3-3-11 21.65 1992 0.89 36.8 3-3-11 28.69 2021 0.62 44.8 3-3-11 40.03 2274 0.56 44.9 3-4-11 22.66 1721 1.06 27.7 3-4-11 26.83 1845 0.89 38.7 3-4-11 38.57 2035 0.69 42.1 3-5-11 12.33 1248 1.05 28.8 3-5-11 16.31 1582 0.87 35.4 3-5-11 28.89 1975 0.70 40.3 3-6-11 18.79 1138 1.03 60.4 3-6-11 28.29 1677 0.88 88.4 3-6-11 41.52 1980 0.80 98.0 3-7-11 24.87 1597 0.94 82.9 3-7-11 41.28 1879 0.66 90.1 3-7-11 51.97 2376 0.55 125.5 3-8-11 26.63 1255 0.97 74.1 3-8-11 43.24 1806 0.81 79.9 3-8-11 36.78 2017 0.68 88.4 3-9-11 16.56 904 0.90 80.7 3-9-11 16.83 1279 0.84 103.7 3-9-11 20.26 1456 0.65 116.4

Table 9: Data for resins containing 95% PE1 and 5% PE4 sample Average percent elongation Normalized Average Peak Load (g) Average abrasion (mg/cm ² ) Average FR(mg*cm) 4-1-116.1 54.03 2065 0.96 22.9 4-1-117.7 81.32 2288 0.75 35.8 4-1-119.4 31.72 1988 0.50 39.0 4-2-116.1 20.23 1322 1.09 32.6 4-2-117.7 33.20 1659 1.00 42.0 4-2-119.4 33.48 1676 0.72 53.4 4-3-116.1 27.46 1485 0.95 35.3 4-3-117.7 36.27 1735 0.71 32.6 4-3-119.4 51.98 2192 0.53 49.0 4-4-116.1 27.59 1452 1.33 26.5 4-4-117.7 39.67 1756 1.05 30.3 4-4-119.4 42.27 1928 0.77 29.4 4-5-116.1 19.75 1344 1.28 31.0 4-5-117.7 34.79 1800 1.03 47.7 4-5-119.4 41.19 2017 0.70 48.7 4-6-116.1 34.41 1590 0.97 56.9 4-6-117.7 60.42 1812 0.84 71.0 4-6-119.4 28.85 1589 0.63 91.0 4-7-116.1 49.89 1920 0.93 67.9 4-7-117.7 75.67 2241 0.73 82.0 4-7-119.4 32.57 1861 0.48 102.7 4-8-116.1 54.02 1862 0.99 46.5 4-8-117.7 45.77 2076 0.85 62.4 4-8-119.4 46.92 1884 0.64 77.9 4-9-116.1 29.05 1362 03 67.7 4-9-117.7 53.70 1737 0.85 80.7 4-9-119.4 57.83 1862 0.58 109.6

Those peak load values range from 800g up to 2400g. These values are much smaller for typical PP samples. Using Style 2 at 136.6°C (278°F), PP1 will produce a peak load of 4875g. In general, its normalized peak load increases with temperature, bond area, and bond angle. For resin PE2 and a mixture of 95 percent PE1 and 5 percent PE4, when the temperature is from 114.4°C (238°F) to 116.1°C (241°F) for PE2 and when the temperature is from 117.7°C for the mixture (244°F) to 119.4°C (247°F), its peak load will decrease. This may be a factor contributing to the change in its rupture mechanism. A pairwise comparison of those samples showed a higher peak loading for 24 percent bound area compared to 16 percent bound area. As shown previously, the binding angle has a significant effect on the actual binding area on the sample. Figure 5 is a graph of normalized peak load versus temperature for PE2 resin at different temperatures and using various bonding styles. Its peak load is linearly normalized to a basis weight of 33 g/m ² (1 oz/yd ² ), since peak load is a powerful function of basis weight.

Figure 6 is a graph of percent elongation versus temperature for PE1 resin at different temperatures and using various bonding styles. The elongation of those PE nonwovens ranges from 10 percent to as high as 95 percent. At 136.6°C (278°F), using Style 2, the elongation of PP was only achievable at 31 percent, and 37 percent was the highest achievable under either treatment condition. A decrease in the concentration of those junctions will significantly increase the elongation. In fact, resin PE2 at 114.4°C (238°F) decreased the concentration at those junctions from 4.60×10 ⁵ pts/m ² to 2.31×10 ⁵ pts/m ² (from 297 pts/in ² to 149 pts/in ² ), the elongation almost doubles. One of the exceptions was the 95% PE1 and 5% PE4 resins, where the elongation did not appear to differ with a decrease in the concentration of those bond sites. This can be explained by the highly elastic nature of PE4 where the effect is more pronounced than that of the bound form. Temperature control is important. A temperature difference of 1.6°C (3°F) can have as much as a 100 percent decrease in elongation.

Figure 7 shows three examples of resin PE1 with respect to typical stress-strain curves. The samples were made using Bonding Style 3 using PE1 resin at temperatures of 116.1°C (241°F), 117.7°C (244°F), and 119.4°C (247°F). This peak load will increase as the temperature increases. At a maximum temperature of 119.4°C (247°F), the elongation of the fabric will decrease. Also, the initial modulus of the fabric produced at 119.4°C (247°F) was higher than that produced at the lower temperature. This is typical for all fabric samples.

Figure 8 is a typical graph of PE1 resin on abrasion versus temperature. In general, their data show that their elongation is a function of all treatment variables. The increase of its interrelated bonding area and bonding angle will increase the elongation of the fabric. In general, its abrasion resistance is roughly a function of temperature, although significant differences can be seen between those bonded styles. This can be explained by its rupture mechanism. When the surface is rubbed, the fiber will be pulled from the joint. Due to its abrasion-related fracture mechanism, the amount of fine hairs on its surface will depend more on the bond strength than its bond size. Its abrasion-related values range from 0.48 mg/cm ² to more than 1 mg/cm ² . At 136.6°C (278°F), the PP sample combined with style 2 has an abrasion value of 0.15 mg/cm ² , which is more than 3 times less than that of PE.

Figure 9 shows a graph of PE2 related to flexural rigidity ("FR") versus temperature. This is a typical graph and represents trends found in other resins. A high length protrusion indicates a stiff fabric. Also, a high basis weight is a factor contributing to the increased stiffness because the fabric can support a greater weight when hung at the end edges. The average of the overhang of the fabric with its engraved cylinder side up and down is considered the total overhang associated with the individual pieces of fabric. The average value of each will be obtained. This is believed to be a better indicator of the overall stiffness of the fabric, since the fabric will flex in both directions during wear. Each sample was measured four times in this manner.

It can be observed that those binding patterns 6-9 with larger binding angles have higher values than those of patterns 2-5 with a binding angle of 20°. The flexural stiffness of all PE samples ranged from a low of 20 to a high of 125 mg*cm for sample 3-7-119.4. These values are quite low considering that a typical PP fabric has an fr value above 200 mg*cm. Resin PE2 showed the least hardness compared to other resins under the same processing conditions. This may be due to the low density of this polymer. Its highest FR value is obtained with PE3 and can be attributed to a higher polymer density. Adding PE4 to FE1 will produce a higher FR value. This may be caused by increased melting and/or shrinkage of the fibers and fabric in their bonded regions. Regarding its binding pattern, low binding area, low sidewall angle and low binding site density were shown to yield the lowest FR values. It should be noted that low bond area, sidewall angle and bond density can affect other properties, namely abrasion. Therefore, due to the low modulus of PE, its FR value may not be as important as other properties.

The effects of the combined drum pattern on the stiffness (ST) of the fabric and the grain (GR) of its surface were evaluated by hand touch tests. The 12-member research team scaled the two properties on a scale of 1 to 15. Anchor samples (used as a baseline) were provided as listed in Table 10. Resin PE1 processed at 119.4°C (247°F) for each bonding pattern was used as a sample. Table 11 summarizes the mean values of the two-handed calibrations for each combination pattern.

Table 10: Anchor materials and their corresponding values test type anchor material Anchor number texture Bleached mercerized cotton poplin 2.1 texture Bleached Military Carded Sateen 4.9 texture cotton momie fabric 9.5 texture Natural cotton canvas 13.6 hardness Polyester/cotton 50/50 single weave 1.3 hardness Bleached mercerized cotton printed cloth 4.7 hardness Bleached mercerized cotton poplin 8.5 hardness cotton organdy 14.0

Table 11: Data collected from hand feel survey sample hardness texture 1-1-119.4 2.5 5.6 1-2-119.4 0.9 2.9 1-3-119.4 1.8 3.9 1-4-119.4 1.6 4.0 1-5-119.4 1.1 2.8 1-6-119.4 1.7 3.5 1-7-119.4 3.0 5.4 1-8-119-4 1.5 4.0 1-9-119.4 2.5 4.9 5-2-140 5.3 6.4

Scanning electron microscopy (SEM) was used to analyze the effect of treatment conditions on the nonwoven surface, bond perimeter, cross-section, and rupture mechanism. Those treatment conditions show that the feel and strength of the fabric can be achieved. This section discusses the relationship between the fabric surface and its properties, and also identifies the fracture mechanism as a function of treatment conditions.

Arial views and section views are obtained using the following methods:

1. A section of the fabric was cut by placing it between two sheets of paper and placing the sample in liquid nitrogen for about 1 minute, followed by cutting perpendicular to the machine direction with a razor blade.

2. Place the sample on top of a platform with a conductive tape, the edges of which are lined with conductive graphite paint.

3. A Denton vacuum Hi-Res 100 high resolution cadmium spraying system was used to coat the fabric as a 100-120 Å thick film.

4. The sample is placed in its sample compartment, which is evacuated to 1.3×10 ⁵ Pa (10 ⁷ torr).

5. The available 20Kev was used to 5Kev because of the problem of charge buildup on the surface of the fabric.

6. Micrographs were obtained at various magnifications.

7. Scion imaging software is used to observe and measure the photomicrograph.

All samples tested were photomicrographed at a low magnification between 60X and 100X, focusing on the junction. Since there were no significant surface differences between temperatures, all photographs were taken of samples 1.6°C (3°F) below those sticking points. This temperature was 119.4°C (247°F) for all samples except resin PE2 which was at 119.4°C (247°F). All nine binding patterns, made from resin PE1, are shown in Figure 10A-IOI. All joints consist of a large flat surface in the center which is raised towards the edges. Styles 1, 6, 7, and 8, all include large sidewall angles. This effect is less pronounced with PE1 resin than with other resins, probably due to its high melt index. The pattern with smaller sidewall angles will produce a bond that includes a smaller flat area, and a geometrically more rounded bond point. Since the joints created by the 20° sidewall angle are round in shape and will cover a smaller surface area than previously described, the space between each joint will be larger. This larger space can give the fabric a softer feel due to the increased exposed area of the fibers. This system correlates with its hand feel evaluation data. Conversely, smaller bond surface coverage will result in less entangled fibers and will reduce the strength of the fabric. This has been seen in previous tension data.

The effect of processing conditions on nonwoven fabrics is the breaking mechanism during destructive tests like tensile and abrasion tests. There are three types of breaks that can occur. The fiber will be pulled outside of the bond scene and break at its bond perimeter, or outside of the bond point. SEM micrographs were also used to determine the fracture mechanism of selected nonwoven samples. Figures 11A-C show one embodiment of a fracture mechanism during a tension rupture test. Obviously, most of the processing conditions will cause the polyethylene fabric to break due to the fibers pulling away from a weak bonding point. In some of the higher temperature cases it was apparent that the bond was strong enough to break the fibers at their bonded perimeter. Adding 5 percent of PE4 resin to PE1 resin will increase its bond strength, at 119.4°C (247°F), enough to cause some fibers to break at their bond perimeter. As such, there is evidence of two fracture mechanisms, those involving fracture at the fiber pulling away from the bond and the fiber at its bond perimeter.

Analysis of the fracture mechanism due to abrasion did not show signs of fracture at the bond perimeter. Figures 12A-B show two examples of abrasion-induced fracture joints. Its thin ribbon-like strips are remnants of its previous thermal junctions. Even those samples that did break during the tensile test as the weak fibers broke at their bonded perimeter, did not show the same failure mechanism. After the fabric is abraded, it breaks due to the destruction of the bonding points. This phenomenon can explain why the wear resistance fails to reach a peak and then, like its toughness and elongation, decreases with the increase of its processing temperature. Its wear strength depends only on its bonding force.

As demonstrated above, embodiments of the present invention can provide a nonwoven fabric with relatively increased tensile strength, elongation, abrasion strength, flexural stiffness, and/or softness. Additional features and advantages provided by embodiments of the present invention will be readily apparent to those skilled in the art.

While the invention has been described with reference to a limited number of embodiments, alterations and modifications exist. For example, the fabric composition need not be a mixture within the compositions given above. It may contain any amount of those compositions as long as the desired properties of the fabric composition are met. It should be noted that the application example of the fabric composition is not limited to hygiene articles, and it can be used in any environment requiring a thermally bonded nonwoven fabric. The appended claims are intended to cover all changes and modifications within the scope of the present invention.

Claims (28)

1. method of making non-woven fabrics fabric, it comprises:

Make a fiber weaving cloth by a pair of cylinder, obtaining having the thermal fabric of high percentage bonded area,

Wherein said high percentage bonded area is to form by embossment pattern above the cylinder therein, and this embossment pattern has the binding site area of high percentage.

2. method according to claim 1, wherein said embossment pattern have the binding site zone and the wide binding site angle of high percentage.

3. method according to claim 1, the percentage of wherein said bonded area is about at least 16 percentages.

4. method according to claim 1, the percentage of wherein said bonded area is about at least 20 percentages.

5. method according to claim 1, the percentage of wherein said bonded area is about at least 24 percentages.

6. method according to claim 2, wherein said binding site angle are about 20 ° or bigger.

7. method according to claim 2, wherein said binding site angle are about 35 ° or bigger.

8. method according to claim 2, wherein said binding site angle are about 37 ° or bigger.

9. method according to claim 2, wherein said binding site angle are about 42 ° or bigger.

10. method according to claim 2, wherein said binding site angle are about 46 ° or bigger.

11. method according to claim 1, wherein said embossment pattern has about 1.55 * 10 for every square metre at least ⁵Individual binding site.

12. method according to claim 1, wherein said embossment pattern has about 2.31 * 10 for every square metre at least ⁵Individual binding site.

13. method according to claim 1, wherein said embossment pattern has about 3.1 * 10 for every square metre at least ⁵Individual binding site.

14. method according to claim 1, wherein said embossment pattern has about 3.44 * 10 for every square metre at least ⁵Individual binding site.

15. method according to claim 1, wherein said embossment pattern has about 4.6 * 10 for every square metre at least ⁵Individual binding site.

16. method according to claim 1, wherein said embossment pattern has about 4.65 * 10 for every square metre at least ⁵Individual binding site.

17. according to claim 1,4,7 or 14 described methods, wherein said fiber weaving cloth contains polyethylene.

18. method according to claim 17, wherein said polyethylene is an Alathon.

19. method according to claim 17, wherein said polyethylene are the copolymers of ethene and comonomer.

20. method according to claim 17, wherein said polyethylene obtains in the presence of metalloscene catalyst.

21. method according to claim 17, wherein said polyethylene obtains in the presence of confinement geometry type catalyst.

22. method according to claim 17, wherein said polyethylene obtains in the presence of single site catalysts.

23. a non-woven fabrics fabric that contains a kind of polymer, wherein said fabric are characterised in that bonded area and the high abrasion resistance strength with high percentage.

24. nonwoven fabric thermal fabric according to claim 23, wherein said polymer is a polyethylene.

25. method according to claim 23, the percentage of wherein said bonded area is about at least 16 percentages.

26. method according to claim 23, the percentage of wherein said bonded area is about at least 20 percentages.

27. method according to claim 23, the percentage of wherein said bonded area is about at least 24 percentages.

28. fabric by the described method preparation of claim 1-22.

Images