MXPA01007640A - High strength nonwoven fabric and process for making - Google Patents

Abstract

A nonwoven fabric sheet comprising a multiplicity of generally parallel elongate strands of inelastic thermoplastic material extending in a first direction in spaced relationship, each of said strands having opposite elongate side surface portions that are spaced from and are adjacent elongate side surface portions of adjacent strands, and each of said strands also having corresponding opposite first and second elongate surface portions extending between said opposite elongate side surface portions, and a first sheet of flexible nonwoven material having spaced anchor portions bonded at first bond sites of the strands along said first elongate surface portions wherein the elongate strands thermoplastic material is oriented at least between adjacent bond sites along the length of the strands.

Description

FIELD OF THE INVENTION The present invention relates to non-woven fabrics of high strength having at least one sheet or sheet of flexible nonwoven material, intermittently joined to inelastic filaments. The invention further relates to methods for producing these reinforced non-woven fabrics in which the low resistance fibrous webs are bonded to high strength filaments as reinforcement elements. Nonwovens having reinforcing elements are well known in the art. Similar canvases or reinforcement webs are often bonded to non-woven fabrics or low resistive webs by one of a variety of bonding methods including binders, adhesives, sonic or heat bonding, hydroentangling or the like. For example, U.S. Patent No. 4,522,863 discloses the basting of a chambray or thin canvas of crisscrossed yarns or fibers covered with a plastisol adhesive which is heat shrunk and which bonds this to a microfiber web, preferably created by meltblowing. . Binders are used in U.S. Patent No. 4,634,621 to bond nonwoven webs to thin fabrics such as Keviar ™ or No ex ™ fabrics. In REF: 131785, U.S. Patent No. 5,691,029, a yarn is attached to a non-woven fabric, preferably in a grid pattern. Heat bonding is used in a pattern for bonding a microfiber nonwoven material to a chambray or thin canvas spun by US Pat. No. 4,041,203. A more complete classification is used in U.S. Patent No. 4,931,355 for attaching a non-elastic, fibrous, non-woven web to a scrim, thin canvas, netting, knitted or woven fabric. Hydroentangling is also used in U.S. Patent No. 4,810,568 to attach a non-woven fabric to a thin weave network fabric. All of the above applications employ relatively high strength materials bonded to low resistance nonwoven webs, resulting in a web that generally has the strength, flexibility, and other bulk or fluff properties that high strength materials have. As such, the desirable properties in low resistance nonwoven webs are generally lost, such as flexibility or formability. This is due to the fact that conventional reinforcing materials are sheet-like materials, as such the properties of the weft or sheet of the composite are dominated by the layer of the reinforcing material. However, the composite material will still have the volume or surface properties of an external non-woven layer, such as the coefficient of friction or absorbency, respectively. U.S. Patent No. 5,705,249 describes the attachment of the filaments to the surface of a nonwoven web. These filaments are joined with a pattern by the union by points. This results in an increase in volume of the composite material in the area between the point attachment sites. This bulking behavior supposedly decreases the volubility or lubricity compared to a previous product where the non-woven material is attached by dots to a product similar to a film. This product is difficult to manufacture and the filaments are filaments of the non-oriented type of relatively low strength. It has also been proposed in U.S. Patent No. 4,048,364. orienting the nonwoven webs as a way to provide increased strength in the orientation direction without effecting softening of the web. The fibers that form the weave line up and provide increased tenacity in this alignment direction. This process, however, has adverse effects on the foaming and tactile properties of the non-woven web and does not provide the strength that is obtained with a high-strength thin canvas or cambray. As well, this process is limited to non-woven wefts that have some interfibrillary joints or integrity, but not so much so that they are similar to films or webs. Thin reinforced canvases or reinforcement sheets have also been incorporated into laminates or non-woven weft structures designed for particular end uses. For example, U.S. Patent No. 5,256,231 describes the creation of a fibrous or non-woven web material by corrugation of either a non-woven web or a series of substantially non-parallel threads at a corrugation fastening point and a subsequent extrusion that joins a thermoplastic film on the specific binding or fixing portions of the sheet of the corrugated fibrous material. U.S. Patent Nos. 5,326,612 and 5,407,439 discloses the formation of loop fastening material from nonwoven materials such as spunbond plies lightly bonded to a structural backing or backing. In U.S. Patent No. 5,326,612 the total bond area (between the fibers of the loop fabric and between the loop fabric and the reinforcement) is between 10 and 35 percent to allow the hooks to penetrate a sufficient open area. The reinforcement could supposedly be a film, a woven or non-woven material but it should not allow the hooks to penetrate. In 5,407,439 the loop fabric (the entanglement zone) was laminated to a material (spacing zone) which allows the hooks to penetrate but preferably does not entangle the hooks with an additional optional reinforcing layer that does not allow the hooks to penetrate. . The spacing zone is generally thicker than the entanglement zone in such a way that a hook will not fully penetrate through it. Low bond levels are desired for these loop fastener applications, such as their dimensional stability. Japanese Patent Publication No. 7-313-213 discloses a loop fastening material created by fusing a face or surface of a nonwoven web or loop. The fabric is formed by embriling fibers of the core-shell composite having a polyethylene shell and a polypropylene core. Generally, the fibers are described as fibers having a diameter of 0.5 to 10 denier with the nonwoven web which has a basis weight from 20 to 200 grams per square meter. The fused surface provides the reinforcement but this also has adverse effects on the softness and flexibility of the fabric.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides sheets or sheets of high strength, dimensionally stable, inelastic, improved, non-woven fabric comprising a multiplicity of elongated strands of inelastic material that generally extend continuously in at least a first direction and one or more sheets of nonwoven, flexible material intermittently joined along at least a portion of elongated surface of inelastic oriented strands. These non-woven fabric sheets are not easily extensible, in at least the first direction, due to the elongated strands. Preferably, the sheets have joint portions spaced in a regular manner between the nonwoven material and the strands. These intermittently joined mooring or fastening portions are separated by unattached portions where the strands and the nonwoven material face each other, but do not join. These composite materials provide unique advantages such as low cost, breathable, dimensionally stable, flexible or soft non-woven fabric sheets which are relatively simple to manufacture. According to the present invention, there is provided here also a method for forming a non-woven fabric sheet comprising (1) providing a first sheet of flexible nonwoven material (e.g., a non-woven web of polymeric and / or natural fibers). and / or yarns; (2) forming the first sheet of flexible nonwoven material to have arcuate portions projecting in the same direction from the spaced tie portions of the first flexible nonwoven sheet; (3) extrusion or the proportion of elongate yarns spaced generally parallel from the thermoplastic material which is inelastic (eg, polyester, polyolefins, nylons, polystyrenes) on the first sheet of the flexible loop material; (4) providing the inelastic strands as a mass melt at least in the spaced tie portions of the first sheet of flexible nonwoven material to thermally bond the strands to the non-woven material at the uni-site sites. No portions of mooring (the strands extend between the portions of mooring sheet nonwoven flexible with arched first sheet of flexible material projecting from corresponding portions of the elongated surface of the strands portions); and (5) orienting the non-woven fabric sheet in the longitudinal direction of the strands thereby orienting the yarns and reducing or eliminating the argued portions. By this method a new non-woven, sheet-like composite material is provided, comprising a flexible non-woven material, intermittently bonded to a multiplicity of elongated strands, generally oriented in parallel, of the inelastic thermoplastic material extending in one direction in a parallel spaced relationship usually continuous.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will be further described with reference to the accompanying drawings, in which like reference numerals refer to like parts in the various views, and wherein: Figure 1 is a schematic view illustrates a first embodiment of a method and equipment for making a first embodiment of a non-woven fabric sheet according to the present invention; Figure 2A and 2B are perspective views, 2A of a precursor material and 2B of a first embodiment of a nonwoven sheet or sheet according to the present invention made by the method and equipment illustrated in Figure 1; Figure 3A is a fragmentary enlarged sectional view taken approximately along line 3A-3A of Figure 2B; Figure 3B is a fragmentary enlarged sectional view taken approximately along line 3B-3B of Figure 2B; Figure 4 is a schematic view illustrating a second embodiment of a method and equipment for making a second embodiment of a nonwoven sheet according to the present invention; Figure 5 is a perspective view of the second embodiment of the non-woven fabric sheet according to the present invention made by the method and equipment illustrated in Figure 4; Figure 6 is a fragmentary enlarged sectional view, taken approximately along line 6-6 of Figure 5; Figure 7 is a fragmentary front view of a beading die or die included in the equipment illustrated in Figure 1 and 4; Fig. 8 is a fragmentary sectional view similar to that of Fig. 6 in which possible variations in the size and spacing of the strands included in the non-woven sheet are illustrated. Fig. 9 is a schematic view illustrating a third embodiment of a method and equipment for making a third embodiment of the nonwoven sheet or sheet according to the present invention; Figure 10 is a perspective view of the third embodiment of a sheet of non-woven fabric according to the present invention, made by the method and equipment illustrated in Figure 9; Figure 11 is a perspective view of a fourth embodiment of a sheet of non-woven fabric according to the present invention that can be made by the method and equipment illustrated in Figure 9; Figure 12 is a perspective view of a fifth embodiment of a sheet of non-woven fabric as performed in the first embodiment stretched in the transverse direction; Figures 13 and 14 are both plan views of the first non-woven fabric embodiment of Figures 2A and 2B, respectively.

DETAILED DESCRIPTION OF THE INVENTION The composite nonwoven sheet or sheet of the invention is preferably made by extruding inelastic strands over the mooring or securing portions of a first sheet of flexible nonwoven material formed to have arcuate portions extending from the mooring portions followed by orientation to provide a reinforced nonwoven material. The molten strands form arcuate surfaces around the mooring portions creating bonding sites. The melted strands can form bonding sites along all or part of the length of the strands where there are mooring portions, (eg, a flat portion of the non-woven material). The solidified inelastic strands have a generally uniform morphology along their lengths including at the pre-orientation binding sites. The strands can be pressed against the tie-down portions at the joint sites by increasing the width of the strand transverse to the length of the strands (the first direction) which increases the bond strength or bond area between the sheet and the strands. strands along a first portion of the elongated surface of the strands. If the strands have a flexible nonwoven material, adhering only to a portion of the elongated surface, the consequent compression and broadening of the strands also provide a greater surface area for adhesion or bonding of the strands of the non-woven fabric sheet into the strands. the second portions of the surface to be released for an additional substrate. A method for forming a non-woven fabric sheet with arcuate non-woven structures between spaced joining sites comprises a step of forming the arcuate nonwoven material, which may comprise the following steps. (1) First and second generally cylindrical corrugating members are provided, each having an axis and including a multiplicity of spaced ridges defining the periphery of the corrugating members. The flanges have external surfaces and define spaces between the flanges adapted to receive the portions of the flanges of the other corrugating members in mesh relation with the sheet of the flexible material between them. The ridges may be in the form of parallel ridges spaced longitudinally or radially or may be intersecting, defining regular or irregular shapes with the ridges that are linear, curved, continuous or intermittent. (2) The corrugating members are mounted in an axially parallel relationship with the portions of the opposing flanges in meshed or mesh-like relationship. (3) At least one of the corrugating members is rotated. (4) The sheet of the flexible nonwoven material is fed between the mesh portions of the ridges to form the flexible nonwoven sheet at the periphery of one of the corrugating members. This forms arcuate portions of the sheet of the flexible nonwoven material in the spaces between the ridges of a first corrugating member and the mooring portions of the flexible nonwoven sheet along the outer surfaces of the ridges of the first corrugating member. . (5) The sheet or sheet formed from the flexible nonwoven material is retained along the periphery of the first member at a predetermined distance after the movement of the meshing portions in the ridges has been completed. Following the formation of the arcuate nonwoven material, the inelastic strands are extruded in an extrusion phase which includes the provision of an extruder which, through a die with spaced die inlets, extrudes the spaced strands of molten thermoplastic material in the portions of leaf binding of flexible nonwoven material. along the periphery of the first corrugating member within the predetermined distance mentioned above. The strand and the nonwoven composite material are then oriented causing the strand material to undergo a molecular orientation between the spaced binding sites. The dimensions of the strands can be easily varied, by changing the pressure in the extruder from which the strands are extruded (for example, by changing the type or speed of the screw of the extruder); changing the speed at which the first corrugating member, and consequently the first sheet material moves (i.e., for a given extruder exit speed increased the rate at which the flexible nonwoven sheet moves), the diameter of the strands, while the decrease in the speed at which the nonwoven sheet moves, will increase the diameter of the strands); or changing the dimensions of the spaced holes of the die. The die through which the extruder extrudes the thermoplastic inelastic strand material can have a readily exchangeable beading die or die in which the rows of spaced holes are formed through which the strands of the molten thermoplastic material are extruded. Such interchangeable beading dies or dies, with holes of different diameters and different spacing, can be manufactured by electric discharge machines or other conventional techniques. The diameters and / or spacings for the holes along the length of the rows or the beading dies can be used to affect the tensile strength in various places through the composite material, vary the ties or clamps of the material not Woven to the strands increase their surface area in the opposite elongated surface portion of the strands available to join or bond the non-woven fabric sheet to additional substrates. The die can also be used to form hollow strands, strands with shapes other than round ones (eg, squares or + shapes) or two-component strands. The non-woven fabric sheet may additionally include a second sheet or flexible non-woven material having tie-down portions thermally bonded to secondary bond sites. These secondary attachment sites may also be longitudinally spaced along secondary elongated surface portions of the inelastic strands and having arcuate portions projecting from the elongated secondary surface portions of the inelastic strands between the second attachment sites of the membrane. sheet . Using the method described above, such a second sheet of flexible nonwoven material may also have arcuate portions. The second sheet of the arcuate portions of the flexible nonwoven material can also project from the spaced tie portions of the second sheet of the flexible nonwoven material. The spaced tie-down portions of the second sheet of the flexible nonwoven material are then positioned in closely spaced opposition to the spaced tie-down portions of the first flexible nonwoven sheet with the arcuate portions of the first and second sheets of the material non-woven that project in opposite directions. The spaced, generally parallel, elongated strands of the molten thermoplastic inelastic strand material are then extruded between and on the tie portions of both of the first and second sheets of the flexible nonwoven material to form bonds between the inelastic strands and spread them between the portions of the strands. I love both of the first and second sheets of the flexible nonwoven material. In an alternative embodiment, the elongated strands generally spaced in parallel may be preformed and delivered in the tie-down portions along the periphery of the first corrugating member as described above. The corrugating member or a roller opposite the corrugating member, which forms a corrugation fastening point, is heated so that the preformed strands are smoothed or melted and pressed against the tie-down portions at the bonding sites as described above. These preformed strands can be used in any of the contemplated embodiments of the invention wherein the strands are provided by extrusion. The composite non-woven fabric sheets formed by the embodiments described above and elsewhere within this specification are oriented or expanded subsequently in the longitudinal direction of the strands.This is preferably done while heating to soften the strands sufficiently to allow orientation without the cracking of the threads, particularly at the bonding sites. This molecular orientation causes the stretching to occur in the strand material preferably in the unbonded portions of the strands between the binding or binding sites. The height of the arcuate portions becomes smaller as the distance between the joining sites increases due to the orientation of the strands. This can reduce or eliminate the arcuate portions projecting to create a substantially flat nonwoven web sheet with multiple oriented reinforced strands and intermittently attached to the nonwoven material along the length of the oriented strands. Preferably, the length of the flexible nonwoven material between the bonding sites is substantially equal to the distance between the bonding sites following the steps of the orientation. This is done by stretching the composite non-woven material to its allowable stretch (as defined in the examples), however, the composite material can be stretched beyond the allowable stretch as long as the binding sites are not significantly oriented ( example, more than 100 percent, preferably greater than 50 percent). Either one or both of the first and second sheets of the flexible non-woven material (s) in the non-woven fabric sheet can be a conventional weave of non-woven fibers or a multiple composite material. layers of non-woven materials; for example carded frames, spin-linked webs, meltblown webs, Rando webs, or laminates thereof. Also relatively strong nonwoven materials such as spunbonded webs or other highly consolidated webs can be used. The fibers forming the nonwoven material could be formed of synthetic or natural fibers such as polypropylene, polyethylene, polyester, nylon, cellulose, or polyamides, or combinations of such materials, such as a multi-component fiber (e.g., a fiber) core / shell such as a polyester core and a polypropylene shell that provides relatively high strength due to its core material and its easy link to polypropylene strands due to its shell material). The fibers of different materials or combinations of materials can also be used on the same sheet of nonwoven material. A preferred type of non-woven material having random arcing portions is one in which the fibrous webs have been processed to have random arcuate portions by the "Micro-creping process in textile fabrics" using the "Micrex / Microcreper" equipment available by Micrex Corporation, Walpole, MA, which has U.S. Patent Nos. 4,894,169; 5,060,349; and 4,090,385. In the micro-creping process, the non-woven sheet is folded randomly and compressed in a first direction along its surfaces. With a micro-responsive web or similar non-woven web, corrugation steps are not necessary, and the material can be attached directly to the thermoplastic webs. The mooring portions and the arched portions are created by micro-processing processes. Generally, the sheets of the nonwoven material should be of polymeric material that can be bonded or thermally bonded with the thermoplastic material at the temperature of the extrudate or the temperature of bonding. Preferably, the sheets of the non-woven material and the thermoplastic strand material are created from the same type of thermoplastic material to improve the bonding of the non-woven material to the strands, also allowing their recycling. For example, in a preferred embodiment, the flexible nonwoven material should be formed in whole or in part from polypropylene fibers with the strands also made of polypropylene allowing the increase of mooring between the strands and the fibers., forming the flexible nonwoven material. Generally, both, the strands and at least a portion of the flexible nonwoven fibers are polyolefin materials, preferably compatible polyolefins. Figure 1 schematically illustrates a first embodiment of a method and equipment for making a first embodiment of a non-woven fabric sheet 10 according to the present invention, which is illustrated in Figures 2B and 3. Generally, the method illustrated in Figure 1 involves providing a first sheet 12 of flexible nonwoven material. The first sheet 12 of flexible nonwoven material is folded to have multiple arcuate portions 13 projecting in the same direction as the spaced tie portions 14 of the first sheet 12 of the flexible nonwoven material. The elongated strands 16a, generally spaced apart in parallel from the molten thermoplastic inelastic material, is extruded into the tie-down portions 14 of the first sheet 12 of the flexible nonwoven to form inelastic strands 16. The inelastic strands are thermally bonded to the tie portions 14. forming bonding sites and extending in the areas of the arcuate portion between the tie-down portions 14 of the first sheet 12 of the flexible nonwoven. As such, the multiple arcuate portions 13 of the first sheet 12 of the flexible nonwoven material project from the portions 18 of the elongated surface of the strands 16 as shown in Figure 2A. The strands are then cooled, solidified, and oriented to provide a non-woven, flexible, high-strength sheet of fabric 10 as shown in Figure 2B. The orientation step is usually done with applied heat to soften the strands during orientation. The arcuate portions 13 have flattened due to the orientation of the strands 16 between the roller 15 and the roller 17, both of which can be driven. The roller 17 is over-actuated relative to the roller 15 to orient the sheet 10 of non-woven fabric. As illustrated in Figure 1, the equipment for performing the above method includes first and second corrugating members 20 and 21 in general cylindrical, each having an axis including a multiplicity of spaced ridges 19 defining the periphery of the corrugating members 20 or 21. The flanges 19 have external surfaces with defined spaces between the flanges 19 adapted to receive portions of the flanges 19 of the opposing corrugating members in gear relation therebetween, with the first sheet 12 of the non-woven material flexible among them. A means is provided for mounting the corrugating members 20 and 21 in an axial parallel relationship with portions of the flanges 19 in gear relation. A means is provided for rotating at least one of the corrugating members 20 and 21. A sheet 12 of flexible nonwoven material is fed by the corrugating members rotating 20 or 21 between the meshing portions of the flanges 19 of the sheet 12. The flexible nonwoven material will generally conform to the periphery of one of the corrugating members (e.g., 20). This forms the arcuate portions 13 of the first sheet 12 of the flexible material in the spaces between the flanges 19 of this first corrugating member 20 and also forms the mooring portions 14 along the outer surfaces of the flanges 19 of the first corrugating member. 20. A means is also provided for retaining the formed sheet 12 of the flexible material along the periphery of the first corrugating member 20 for a predetermined distance after the sheet has moved past the gear portions of the opposite flanges 19. This method could include the surface of the first corrugating member 20 that has been crimped or corrugated, for example, by sanding or polishing by applying sand under pressure or by etching chemically, or vacuum, or by heating to a temperature above the temperature of the first sheet 12 of the flexible nonwoven material, generally in the range of 25 to 150 degrees Fahrenheit above the temperature of the nonwoven material. An extruder feeds a die 22, which can be provided with a row of flanging die 23 (see Figure 7) with spaced through openings 40. The extruder and flanging die form a multiplicity of elongated molten strands generally parallel to the thermoplastic material (eg, polyester, polystyrene, polyolefins, nylons, co-extruded materials or the like as discussed above) continuously extended in a generally spaced relationship in parallel. The extruder and the die are further positioned so that the melted strands 16a are extruded into the tie portions 14 of the first sheet 12 of the flexible material along the periphery of the first corrugating member 20 within the predetermined distance mentioned above. Also, the equipment further includes a generally cylindrical cooling roller 24 having an axis with means for rotatably mounting the cooling roller 24 in an axially parallel relationship with the corrugating members 20 and 21. The periphery of the cooling roller 24 was narrowly spaced from the periphery 'of the first corrugating member 20 defining a fastening point. At a second predetermined distance, a means (e.g., a holding roller 25) is provided to move the non-woven fabric sheet 10 for the second predetermined distance around the periphery of the cooling roller 24 past the attachment point. The strands 16 in this area are brought into contact with the cooling roller 24 and the strands 16 are solidified. The nonwoven fabric sheet is fed to an orientation station, which may be a tension roller 15 and a clamping driven roller. 17 operated at a faster speed than the cooling roller 24. to orient the strands 16 at least in an unbonded portion 11 between the bonding sites 27. Alternatively, the nonwoven fabric sheet could only be selectively oriented at the regions as described in U.S. Patent No. 5,424,025, the substance of which is incorporated by reference in its entirety. The structure of the nonwoven sheet 10 made by the method and equipment illustrated in Figure 1 is best seen in Figures 2A, 2B, 3A and 3B. The sheet 10 of nonwoven fabric comprises a multiplicity of generally parallel elongated strands 16 of the inelastic thermoplastic material continuously extending in a parallel spaced relationship. Each of the strands 16 are generally cylindrical and have opposite elongated side surface portions 26 (see Figure 3A) that are spaced apart and adjacent to the opposing, elongated side-portion portions 26 (see Figure 3A) that are spaced apart from each other. from adjacent elongated side surface portions 26 of adjacent threads. Each of the yarns 16 also has its respective first and second opposed elongated surface portions 18 and 28 extending between the portions of the opposite elongated side surface 26. The spaced tie portions 14 of the sheet '12 of the material not flexible fabric are thermally bonded to the binding sites of the sheet 27 to the longitudinally spaced portions of the strands 16 along the portions of the first elongated surface 18. The arched portions 13 of the flexible nonwoven material have been flattened and laid in contact, but not joined to the first portions 18 of the elongated surface of the inelastic strands 16 oriented in the unbonded regions 11 between the first binding sites 27 of the sheet. In Figures 2A and 2B, the binding sites 27 of the sheet are spaced approximately the same distance apart and generally aligned in parallel rows extending transversely in the strands 16.

Because the strands 16 have been extruded in molten form on the tie down portions 14 of the sheet 12 of the flexible nonwoven material, the strands can be pressed onto the tie down portions 14 of the sheet 12 by adjusting the attachment point corrugation spaced between the dies 19 in the first corrugating member 20 and the periphery of the cooling roller 24. The compressed, molten strands 16 can be formed around and are indented by the convex arched surfaces of the tie-down positions 14. The joints between the strands 16 and the tie-down portions 14 in the first binding sites 27 of the sheet may extend outwardly depending on the compression of the melted strands in the tie-down portion. As illustrated in FIG. 3B, the surface of the strand at the attachment site 27, which is closely adjacent to the tie-down portions 14, is enlarged by the indentations of the strands 16. FIG. 4 illustrates a second embodiment of a strand. method and equipment for making a second embodiment of a sheet 30 of non-woven fabric according to the present invention, which sheet 30 is illustrated in figure 5 and 6. The method illustrated in figure 4 is somewhat similar and is widely used of the same equipment as illustrated in figure 1, and the same numerical references have been given to the similar portions of the equipment and performing the same functions as in the equipment illustrated in figure 1. In addition to the steps of the general method described above with respect to Figure 1, the method illustrated in Figure 4 further includes in a general manner the steps of providing a second sheet of nonwoven material 32. The second sheet 32 of the non-woven material is formed to have several arcuate portions 33 projecting in the same direction of the spaced-apart fastening portions 34 of the second sheet 32 of the non-woven material. The spaced tie portions 34 of the second sheet 32 of the nonwoven material are placed in closely spaced opposition to the spaced tie portions 14 of the first sheet 12 of the flexible nonwoven material with the arcuate portions 13 and 33 of the first and second sections. sheets 12 and 32 of the nonwoven material projecting in the opposite directions. The die of the extruder 23 extrudes the elongate strands 16a generally spaced in parallel from the molten thermoplastic inelastic material between and in the tie portions 14 and 34 of both of the first and second sheets 12 and 32 of the nonwoven material to form the inelastic strands. 16 joined together and extending between the portions 14 and 34 of both, the first and second sheets 12 and 32 of the non-woven material. The arched portions 13 and 33 of the first and second sheets 12 and 32 of the nonwoven material projecting in the opposite directions from the corresponding first and second portions 18 and 28 of the opposite elongated surface of the strands 16 prior to the orientation of the sheet of fabric that flatten the arched portions between the binding sites in the mooring portions. The equipment illustrated in Figure 4, in addition to the first and second corrugating members 20 and 21, and the extruder 22, which are operated in the manner described above with reference to Figure 1, additionally includes a third and fourth corrugating members 36 and 37 generally cylindricals which operate as described above in relation to the corrugating members 20 and 21. The third corrugating member 36 is positioned in a spaced relation from the first corrugating member 20 so that the die 22 of the extruder positions the melted strands 16a in the tie portions 14 and 34 of both of the first and second sheets 12 and 32 of the tie material along the peripheries of the first and third corrugating members 20 and 36 within the predetermined distance mentioned above. The air ducts 39 provide cold air blow streams against opposite sides of the sheet 30 of non-woven fabric to solidify the threads 16a and the bond between the strands 16a and the lanyard portion 14 and 34 of the sheets 12 and 32. The solidified cloth sheet was then oriented between the tension roller 15 and the driven roller of clamping 17 for orienting the strands at least in the unbonded regions 11 between the joining sites 27 and 47 as described in relation to the first embodiment of the method and equipment illustrated in figure 1. The structure of the second embodiment of the sheet 30 of nonwoven fabric made by the method and equipment illustrated in Figure 4 can best be seen in Figures 5 and 6. The sheet 30 of non-woven fabric comprises the multiplicity of elongated strands 16 generally parallel to the inelastic thermoplastic material, which extend in a relationship spaced generally parallel. Each of the strands 16 have opposite, elongated lateral surface portions 26 (see Figure 6) that are spaced from, and are adjacent to, the portions 26 of the elongated side surface of the adjacent strands. Each of the strands 16 also have their corresponding first and second opposed elongated surface portions 18 and 28 extending between their elongated, opposite side surface portions 26. The spaced mooring portions 14 of the first sheet 12 of flexible nonwoven material are thermally bonded to the bonding sites 27 of the first sheet to the longitudinally spaced portions of the strands 16 along their first elongated surface portions 18, and the arched portions 13 of the first sheet 12 of the flexible material are flattened in the unbonded region 11 where the strands have elongated. The second sheet 32 of the non-woven material has its spaced tie portions 34 thermally bonded at the bonding sites 47 on the second sheet spaced at the longitudinally spaced portions of the strands 16 along the portions 28 of the second elongated surface, and have their bowed potions 33 flattened in the unbonded region 11 where the strands have been stretched. The attachment sites (27 and 47) of the first and second sheets are opposite each other, are spaced approximately the same distance apart, and are aligned in generally parallel rows extending transversely in the strands 16. Because the strands 16 they have been extruded in molten form on the tie-down portions 14 and 34 of both, the first and second sheets 12 and 32, the fused strands 16 can form around and be serrated in the portions of the opposite elongated surface, by the adjacent convex surfaces of the tie-down portions 14 and 34. The junctions between the strands 16 and the portions 14 and 34 at the attachment sites (27 and 47) of the first and second sheets, as above may extend outwards into the adjacent area of the tie portions 14 and 34 as shown in Figure 3B. Alternative structures that could be provided for the sheet 30 of the non-woven fabric (in addition to the alternative structures mentioned above for the sheet of the non-woven fabric 10) include the spacing of the tie-down portions 14 of the first sheet 12 and the tie-down portions 34 of the second sheet 32 at different spacing along the strands 16 and / or causing the continuous rows of the arcuate portions 13 and 33 to project at the different distances from the first and second portions. and 28 of the elongated surface of the strands 16; or causing one of the sheets 12 or 32 to be discontinuous along its length, or across its width. Figure 7 illustrates the face or surface of the die 22 through which the molten strands 16a of the thermoplastic material are extruded. The die 22 has spaced holes 40 (eg, 0.762 millimeters or 0.03 inch diameter holes with spaces of 2.54 millimeters or 0.1 inches center to center) in its beading trogue 23 preferably formed by electrical discharge machining techniques. The flanging die 23 was retained in place by the bolts 41, and can be easily replaced with a beading die or die with differently sized holes, the holes are spaced in different and varied centers to produce a desired pattern of strands from the die 22. Figure 8 illustrates a nonwoven fabric sheet 30b similar to that illustrated in Figure 5 and 6 and in which like parts are identified with similar numerical references except for the addition of the suffix "b". Figure 8 shows one of many possible variations in the spacing of the diameters of the wires 16b. The strands can be round, square, rectangular, oval, and in any other way. The elongated surface portions of the strands attached to the oriented non-woven sheet material generally comprise from 2 to 70 percent of the cross-sectional surface area of the sheet of the non-woven fabric, preferably from 5 to 50 percent. This allows the area of the surface to be sufficient for the nonwoven sheet to be bonded to a substrate and still have the required tensile strength as well as breathability, flexibility and other volume properties of the nonwoven material. Generally, the non-woven fabric sheet should have a tensile strength in the longitudinal direction of the strands of at least 2000 grams / 2.54 on width, preferably at least 4000 grams / 2.54 cm-width. Low tensile strengths decrease dimensional stability. Figure 9 illustrates a third embodiment of a method and equipment that can be used for the elaboration of a third and fourth embodiments of a sheet of non-woven fabric 90 and 100 according to the present invention, illustrated respectively in Figures 10 and 11. The equipment illustrated in Figure 9 includes first and second generally cylindrical connecting rolls 82 and 83 each having an axis and a periphery around it. of that axis defined by the ridges 85 circumferentially spaced, generally parallel to the axes of the connecting rollers 82 and 83. The connecting rollers 82 and 83 define the corrugation fastening point. The Compaction devices 86 and 87 (for example, the devices commercially designated "Micrex / Microcreper" equipment available by Micrex Corporation, Alpole, MA, which wrinkle and compress the fibers or sheet material to form a sheet that is compacted in a first direction along its surfaces) are adapted to receive a sheet 88 or 89 of flexible nonwoven material having opposed major surfaces. These compaction devices compact sheets 88 or 89 in a first direction parallel to their main surfaces (for example, along their direction of movement through device 86 or 87) so that the first and second compacted sheets 91 and 92 have opposite surfaces and can be extended in the first direction along those surfaces in the range of 1.1 to more than 4 times their compacted length in the first direction. The means are provided to feed the first and second compacted sheets 91 and 92 of flexible nonwoven material at the corrugation fastening point formed by the first and second nip rolls 82 and 83. An extruder 83 which is essentially the same as the extruder 22 described above, extrude the strands of the inelastic thermoplastic material in a generally parallel spacing relationship and are positioned between the opposed surfaces of the first and second compacted sheets 91 and 92 of the flexible material at the point of clamping between the first and second rolls of junction 82 and 83. The strands 95 extending in the first direction along the first and second compacted sheets 91 and 92, are thermally bonded to the first and second compacted sheets 91 and 92 at the spacing sites 96 a along the strands 95 due to the joint pressure applied by the flanges 85. The sheet of the non-woven fabric 90 is retained along the length of the pe ripple of the nip roll 82 by a guide roll 97, and the nip roll 82 is cooled (eg, to 100 degrees Fahrenheit) to help solidify the strands 95. The non-woven fabric 10 is oriented between the nip roll 15 and the drive roller 17 clamped as described in relation to the first embodiment of Figure 1. The nonwoven fabric sheet 90 made by the mechanism illustrated in Figure 9 was illustrated in Figure 10. That sheet of non-woven fabric 90 comprises a multiplicity of extruded strands, generally elongated in a parallel fashion, of inelastic thermoplastic material extending in a generally parallel spacing relationship. Each of the yarns 95 having opposite elongate side surface portions that are spaced apart and adjacent to the opposite side surface portions of the adjacent yarns 95, and each of the yarns 95 also have a first and second corresponding portions of opposing elongated surface between the portions of the opposite elongate lateral surface. The first and second extended and compacted sheets 91 and 92 of flexible nonwoven material have mainly opposite surfaces. Those first and second compacted and extended sheets 91 and 92 are respectively thermally bonded to the first and second elongated surface portions of the wires 95 to the closely spaced joining sites 96.

The equipment illustrated in Figure 9 can be operated with only one of the sheets 88 or 89 of the flexible nonwoven material, in which case a sheet of nonwoven fabric similar to the nonwoven sheet 100 illustrated in Figure 11 will be made. Alternately, one of the sheets of the non-woven material 88 or 89 in the equipment of figure 9 could be replaced by a chambray or thin canvas 99 linked by spinning, or breathable, swiveling material of low foaming, which could be fed without feeding through of a compaction device 86 and 87. The strands 16 illustrated in the above embodiments are essentially continuous and parallel in the longitudinal or machine direction of the nonwoven composite. Additionally, the strands could extend substantially non-parallel, each with respect to the other provided that the inextensibility of the whole frame is not significantly affected. In addition, the arcuate portions of the flexible material sheet formed by the methods illustrated above could be in the form of circles, diamonds, rectangular shapes or other regular or irregular patterns through the use of suitable interenganing corrugating members with rigid elements. Preferably, the attachment sites of the tie-down portions are spaced from each other along the length of the inelastic thread materials by a distance of an average from 2 mm to 200 mm, preferably from 5 mm to 100 mm previous to the orientation and from 4 to 100 mm, preferably from 5 to 500 mm after orientation of the sheet of the composite material. The inelastic strands 16 could also be provided as preformed strands that could be unwound from multiple coils or other wound rolls and fed into a comb or similar structure to distribute the strands along the width of a heated holding point that would join thermally preformed elastic fibers to flexible non-woven material. For example, in the embodiment described in Figure 1, the flange members 19 on the first corrugating member 20 could be heated or serve as an anvil for an ultrasonic linker for thermally bonding the preformed strands to the mooring portions of the nonwoven material. flexible 12. With any of the modalities described above, the layers could be incorporated. For example, in the embodiment described in Figure 9, any of the compaction devices 87 or 86 could be omitted, instead of being replaced by the supply of a non-compacted sheet of film or web or a variety of easily extensible material including extendable non-woven wefts lightly bonded. These additional weft materials could also be printed on one or both sides to provide adequate informational or aesthetic messages. The impression could also be made on the nonwoven sheet formed by printing the flexible nonwoven material on any surface, it is joined either before or after it is joined to the inelastic strand material 16. In the embodiment of the figure 12, the material of Figure 2B has been stretched transversely (T) in the longitudinal direction (L) of the oriented inelastic yarn 16. This result in the non-woven material which contracts in the longitudinal direction (L) by narrowing. The strands 16 are deformed between the binding sites 27 of the spaced tie-down portions, causing the strands to bend outward in the unattached regions 11. The length of the strand 16 between the attachment sites is greater than the length of the strands 16. the flexible non-woven fabric, contracted or compacted between the binding sites. These folded loop portions 116 provide a straight projection extending from the surface of the substantially flat flexible nonwoven material 12. These strand projections 116 can be used to create a spacer element to separate the nonwoven material 12 from a surface in which the composite material is in contact. The strand projections 116 may also provide significantly greater material or may involve mechanically suitable fasteners. The nonwoven material for this modality should be reducible, this means that it must shrink in size in the direction transverse to the direction in which it is lengthened. Suitable reducible nonwoven webs include spunbonded webs, bonded carded webs, meltblown webs and the like. The composite of the nonwoven material of the invention has particular use advantages such as medical gowns, interwoven, absorbent, geotextiles, cloths or napkins or the like. The material has high strength in the mechanical direction but still retains its breathable nature and conformability in both the transverse direction and that of the machine. The orientation steps result in a molecular orientation of the molecules of the inelastic strand material thereby significantly increasing the tensile strength of the composite material. The phenomenon of molecular orientation on orientation is well understood. Since the fiber portions are bowed prior to their orientation they do not undergo substantial deformation during the orientation steps if the level of orientation is maintained in the proportion where the arcuate portions are tensed substantially laid. The non-woven material can be easily folded and aligned and withstand the bending forces. The process of the invention actually decreases the percent of the joint area by increasing the permeability and opening. In a particular preferred embodiment, the sheet of the non-woven fabric material could be supplied in the form of a cutting incision roll with appropriate shapes in a continuous production line and integrated into an assembly with suitable joining methods including ultrasonic bonding, bond by heat, fusion by heat, or bond by pressure-sensitive adhesive. Generally, it is desired to have stretching of binding sites of less than 100 percent and more preferably less than 50 percent. With non-woven fabrics the stretch is relatively high (eg, stretching by sorting or similar joints) this is possible because the stretching of the bonding site is less than 5 percent (for example, non-woven fabrics joined by spinning). The strand of the material between the bonding sites is generally oriented at at least 15 percent, preferably at least 50 percent, and more preferably at least 90 percent, resulting in a molecular orientation of the strand of the thermoplastic material. The strand of material between the binding sites should be significantly more oriented than the strand of the material at the binding sites. Generally at least 15 percent more, more preferably at least 50 percent more.

EXAMPLES Example 1 An inelastic sheet material composite similar to the sheet-like composite illustrated in FIGURE 2A was made using equipment similar to that illustrated in Figure 1. A thermoplastic ethylene-propylene impact copolymer commercially available under the designation 7C50 of the Union Carbide Corporation of Danbury, Connecticut, was placed in the extruder 22 to form substantially parallel inelastic strands 16 in approximately 4.7 strands per centimeter. The strands, at a basis weight of 40 grams per square meter, were applied by the equipment to a first corrugated sheet 12 of the carded non-woven material formed of 6 diener basic or cut polypropylene fibers commercially available under the Amoco J01 name. Fabric and Fibers Company of Atlanta, Geo. The carded non-woven sheet has a basis weight of 55 grams per square meter after corrugation. The non-woven sheet 12 was corrugated in the transverse direction between the corrugating rolls 20 and 21 to form approximately 3 linear corrugations per centimeter, then bonded to the extruded strands 16 at the point of attachment between the corrugating roll 20 and the cooling roll. 24. Corrugation roll 21 was at about 149 ° C, and cooling roll 24 was at about 21 ° C. The coating speed was about 18 meters per minute, and the melting temperature in the extruder 22 was about 260 ° C. The composite material of the resulting inelastic nonwoven sheet produced had arcuate non-woven portions of approximately 2mm in height projecting from the strands. The strands 16 between the binding sites were then oriented longitudinally with the application of heat and tension. A 7.6 cm wide by 10.2 cm long sample was stretched approximately 91% while heating with a Master Heat Gun Model HG-751B available from Master Appliance Corp. of Racine, Wisconsin to soften the inelastic strands. The heat gun was placed at a high point and remained approximately 25 centimeters from the sample while it was stretched. The temperature of the hot air during stretching was approximately 50 ° C, when measured with a thermometer in close proximity to the sample. During the stretching operation, the inelastic strands between the longitudinally oriented bonding sites result in the arcuate non-woven portions becoming flat as shown in Figure 2B. The strands are not oriented in the regions of the binding site to any appreciable degree providing that the strands are not stretched beyond the point where the arcuate non-woven portions become flat, also referred to as a percentage (%) of allowable stretch . The allowable stretch percentage of the composite of non-woven fabrics before the orientation phase of the strand was calculated by measuring the arc of length AQ of the arcuate non-woven portions between two binding sites of the composite material of the non-woven fabric sheet. woven, subtracting the length of the strands between the two SD binding sites of the result, dividing the result by the length of the strand Ss between the two binding sites, and then multiplying by 100 to convert the result to a percentage. The percentage of orientation or stretching was calculated by measuring the length of the inelastic strands between the binding sites S0 and S ', before and after the orientation. The increase in the length of the strand was divided by the length of the original unoriented strand and the result was multiplied by 100 to convert it to a percentage. The percentage of orientation and the percentage of stretch available is shown in Table 1 below. The lengths of binding sites B0 and B 'are shown in FIGS. 13 and 14, also measured before and after stretching to determine if the composite material has been stretched beyond the point at which the non-woven portions discussed are they come back flat. The results are shown in Table 2 below. Following the longitudinal orientation, the oriented composite material was tested for its tensile strength as described in "Test Methods" below. The data obtained are shown in Table 3.

Example 2 An inelastic nonwoven fabric sheet composite was prepared similarly to the composite material in Example 1 except that the polypropylene staple fibers commercially available under the name J01 from Amoco Fabric and Fibers Company of Atlanta, Georgia, was used. to form the corrugated non-woven sheet at a basis weight of 55 grams per square meter. A strand count of 9.4 strands per centimeter was used at a basis weight of 50 grams per square meter. The sheet-like inelastic composite has stripped non-woven portions 13 of approximately 1.6 mm in height projecting from the strands. The strands between the binding sites were then oriented approximately 92% using the same procedure as in Example 1. The lengths of the binding sites were also measured after and before the stretch. The inelastic composite was tested for its tensile strength before and after the orientation stage.

Comparative Example 1 A composite material similar to an inelastic nonwoven sheet was prepared as in Example 2 and the strands between the binding sites were oriented using the same procedure as in Example 1 except that the strands were oriented approximately 330% to demonstrate the effect of stretching the compound significantly beyond the point where the arcuate non-woven portions become flat. This material has high tensile strength due to the high level of orientation in the strands, however the binding sites have also been stretched considerably (approximately 130%) resulting in broken and / or minimally bonded, unbound fibers, which compromise the appearance, homogeneity and integrity of the plot. One of the bonding areas was substantially reduced due to orientation, the fibers have a minimum width and the compound has an undesirable non-uniform appearance. The lengths of the binding sites were also measured before and after stretching. The composite material was tested for its tensile strength before and after the orientation stage.

EXAMPLE 3 A composite material similar to an inelastic non-woven fabric sheet was prepared as in Example 1 except for 18 diener polypropylene staple fibers commercially available under the name J01 from Amoco Fabric and Fibers Company of Atlanta, Georgia, used to form the corrugated non-woven sheet. A strand count of 9.4 per centimeter was used at a basis weight of 50 grams per square meter. The corrugation periodicity was approximately 4 corrugations per centimeter. The composite material similar to a produced sheet had arcuate non-woven portions approximately 1.60 mm in height projecting from the strands. The strands between the binding sites were then oriented approximately 104% using the same procedure as in Example 1. The lengths of the binding sites were also measured before and after stretching. The inelastic compound was tested for its tensile strength before and after orientation. EXAMPLE 4 A composite material similar to an inelastic nonwoven sheet was prepared as in Example 1, except that a spunbonded nonwoven fabric, of the polypropylene type, of 30 gram basis weight per square meter available from Amoco was used. Fabrics and Fibers Company of Atlanta, Georgia, under the name "RFX", instead of the non-woven weft carded. A strand count of 9.4 strands per centimeter was used at a basis weight of 50 grams per square meter. The composite material similar to a produced sheet had arcuate non-woven portions approximately 2.0 mm in height projecting from the strands. The strands between the binding sites were then oriented approximately 100% using the same procedure as in Example 1. The lengths of the binding sites were also measured before and after stretching. The compound was tested for its tensile strength before and after orientation. Example 5 A composite material similar to an inelastic nonwoven sheet was prepared as in Example 1except that hexagonal pattern embossing rolls were used in place of the corrugating rolls as described in PCT Application No. WO 98/06290. The commercially available denier 18 polypropylene staple fibers were used under the name J01 of the Amoco Fabric and Fibers Company of Atlanta, Georgia, to form the carded nonwoven fabric in which a hexagonal pattern was embossed with each side of the hexagon which is about 3 mm long. A 50 gram basis weight yarn per square meter was used. The sheet-like composite produced had stripped non-woven portions of approximately 1.34 mm in height projecting from the strands. The strands between the binding sites were then oriented using the same procedure as in Example 1. The compound was tested for its tensile strength before and after the orientation phase. Example 6 A composite material similar to an inelastic nonwoven sheet was prepared as in Example 4 and subsequently the strands between the binding sites were oriented approximately 100% using the same procedure as in Example 1. The resultant oriented compound after 10% was stretched in the transverse or cross direction which resulted in the 11 oriented strands projecting upwards from the non-woven layer to form arcuate portions of approximately 0.85 mm in weight as shown in FIGURE 12. TEST METHODS For To evaluate the tensile strength of the inelastic composites of this invention, a stress test was performed using a modified version of ASTM D882 with a constant speed of Instron Model 5500R machine of extension tension. A composite sample of 2.54 cm wide by 10.16 cm long was cut, the lengthwise direction in the machine or the longitudinal direction. The sample was mounted on the jaws of the test machine with an initial jaw clearance of 2.54 cm. The jaws were then rated at a speed of 5 cm / min and the point of the yield point was recorded. Three replicates were tested and averaged for each test result. Table 1 Table 2 Table 3 It is noted that in relation to this date, the best method known to the applicant to carry out the aforementioned invention, is the conventional one for the manufacture of the objects or products to which it refers.

Claims (15)

1. CLAIMS - Having described the invention as above, the content of the following claims is claimed as property: 1. A sheet of nonwoven fabric characterized by comprises: a multiplicity of generally parallel elongated strands of inelastic thermoplastic material, extending in a first direction in a spaced relation, each of said strands has lateral, elongated, opposite surface portions, which are spaced apart and adjacent to the elongated side surface portions of adjacent strands, and each of said strands also have the first and second portions. of corresponding opposite elongated surface, extending between said portions of opposite elongated lateral surface; and a first sheet of flexible nonwoven material having spaced tie-down portions, attached to a first binding site of the strands along said portions of the first elongated surface wherein the thermoplastic material forming the strands is oriented at least between the adjacent binding sites along the length of the strands.
2. 2. The non-woven fabric sheet of claim 1, characterized in that the non-woven fabric sheet has a tensile strength in the elastic limit, in the first direction, of at least 2000 grams / 2.54 cm in width.
3. 3. The non-woven fabric sheet of the claim 1, characterized in that the non-woven fabric sheet has a second weft attached to a second elongated surface portion.
4. 4. The non-woven fabric sheet of claim 1, characterized in that the non-woven fabric sheet has a tensile strength in the elastic limit, in the first direction, of at least 4000 g / 2.54 cm in width.
5. The non-woven fabric sheet of claim 1, characterized in that the strands are oriented at the binding sites less than between the binding sites of the fibrous web
6. 6. The non-woven fabric sheet of claim 1, characterized because the bonding sites are from 2 to 70 percent of the cross-sectional area of the non-woven fabric sheet.
7. 7. The non-woven fabric sheet of claim 1, characterized in that the binding sites are oriented at less than 100 percent.
8. 8. The sheet of non-woven fabric of claim 7, characterized in that the binding sites are oriented at less than 5 percent.
9. 9. The sheet of non-woven fabric according to claim 1, characterized by having regions with oriented strands and adjacent regions without oriented strands.
10. The non-woven fabric sheet according to claim 1, characterized in that the length of the strand between the bonding sites is greater than the length of the flexible nonwoven material between the bonding sites, creating portions of straight strand loop .
11. The sheet of non-woven fabric according to claim 8, characterized in that said strands have a greater width between said elongated, opposite side surface portions at the joining sites of the first sheet.
12. The sheet of non-woven fabric according to claim 1, characterized in that the strands and at least a portion of the fibers forming the flexible non-woven material are polyolefins.
13. The non-woven fabric sheet according to claim 12, characterized in that the strands and at least a portion of the fibers forming the flexible non-woven material are compatible polyolefins.
14. The sheet of non-woven fabric according to claim 12, characterized in that the strands and at least a portion of the fibers forming the flexible non-woven material are compatible polypropylene.
15. 15. A disposable diaper or other garment including a sheet of non-woven fabric, the sheet of non-woven fabric characterized in that it comprises: a multiplicity of generally parallel elongated strands of inelastic thermoplastic material, which extend in a spaced relation, each of said strands have opposite elongate side surface portions that are spaced from, and adjacent to, the adjacent elongated side surface portions of adjacent strands, and each of said strands also have the corresponding first and second opposed elongated surface portions that are extend between said opposite elongated side surface portions; and a first sheet of the flexible nonwoven material having tie-down portions thermally bonded to the first sheet of the bonding sites of the strands along said first elongated surface portions wherein the thermoplastic material forming the elongated strands is oriented at least between the adjacent bond sites along the length of the strands. NON-WOVEN FABRICS OF HIGH STRENGTH AND PROCESS TO MANUFACTURE THEM SUMMARY OF THE INVENTION A sheet of non-woven fabric comprising a multiplicity of generally parallel elongated strands of inelastic thermoplastic material, extending in a first direction in a spaced relationship, each of said strands having opposite, elongated, side surface portions that are spaced apart from and are adjacent to the elongated side surface portions of adjacent strands, and each of said strands also have the first and second corresponding opposite elongated surface portions, extending between said portions of opposite elongate side surface; and a first sheet of flexible nonwoven material having spaced mooring or fastening portions, attached to a first binding site of the strands along said portions of the first elongated surface where the thermoplastic material forming the strands orients at least between adjacent junction sites along the length of the strands.