DE68908468T2 - Web-like material for producing the loop part of a surface zipper. - Google Patents

Description

Technical area

The present invention relates to sheet materials adapted to be cut into pieces to form loop portions for fasteners of the type comprising releasable, engaging hook and loop portions, and a method for producing sheet materials.

Background of the invention

Many sheet materials are known which are adapted to be cut into pieces to form loop portions for fasteners of the type which include releasable, engaging hook and loop portions. Such sheet materials comprise a backing and a plurality of loops anchored in the backing and projecting beyond a front surface of the backing so as to be releasably engaged with the hooks on the hook portion of such fastener and can be manufactured by many processes including conventional weaving and knitting techniques. Such sheet materials in which the loops are stitched into the backing are described in US-A-4,609,581 and US-A-4,770,914. Another such sheet material described in EP-A-0 289 198 which illustrates the prior art in accordance with Art. 54(3) of the European Patent Convention is made by providing a reinforcement in an unstable state with respect to one direction (i.e. the reinforcement is stretched or capable of shrinking in that direction), placing threads on the reinforcement and securing the threads to the reinforcement at the spaced locations and then causing the reinforcement to move or shrink to a stable state so that the portion of the threads between the attachment points form loops. While the loop fastener parts made from many such sheet materials work well with many different hook fasteners can, the processes by which they are made can be more costly or unpredictable than desired, particularly when the loop portions are intended for a limited number of applications such as attaching a throw-away angle to an infant or for attaching an abrasive sheet to a reinforcement member by which it is driven. US-A-3 869 764 and US-A-3 533 871 describe methods of forming sheet material which comprise forming a sheet to have curved portions which protrude in the same direction from the spaced-apart anchor portions of the sheet; and bonding the spaced-apart anchor portions of the sheet to the front surface of a reinforcement, the curved portions protruding from the front surface of the reinforcement. While the process described in US-A-3,869,764 produces sheet material adapted to be cut into pieces to form fastener parts, this sheet material can only engage itself in alignment and is not suitable for use in hook and loop fasteners. The sheet material provided by the process described in US-A-3,533,871 is a blanket rather than a sheet material from which loop fastener parts for hook and loop type fasteners can be cut.

Disclosure of the invention

The present invention provides a sheet material adapted to be cut into pieces for forming loop members for fasteners of the type comprising releasable, engaging hook and loop members, the sheet material providing effective loop fastener members for such fasteners while being very inexpensive to manufacture so as to be economical in use when the loop fastener members are intended for a limited amount of use. such as to removably attach a disposable diaper or other article of clothing or to attach an abrasive sheet to a reinforcing member by which it is driven.

According to a first aspect of the invention there is provided a method of manufacturing a sheet material adapted to be cut into pieces to form loop portions for fasteners of the type having releasable, engaging hook and loop portions, said method comprising:

providing a web formed by fibers and a reinforcement having front and occipital surfaces, the fibers having a basis weight in the range of 5-200 grams per square meter measured along said front surface of the reinforcement, for providing a sufficient open area between the fibers to provide ready engagement of the hook portion of said fastener with the fibers in the web material;

forming the web to have curved portions projecting in the same direction from the spaced-apart anchor portions of the web, said curved portions being formed with a height from the anchor portions of less than 0.64 cm;

connecting the spaced-apart anchor parts of the sheet to the front surface of the reinforcement, with the curved parts projecting from said front surface.

According to a second aspect of the present invention, there is provided a sheet material produced by the process described above.

According to a third aspect of the present invention, there is provided a disposable garment comprising a fastener comprising releasable, engaging hook and loop members, said loop member comprising:

a reinforcement with front and occipital surfaces; and

a plurality of fibers having portions bonded to said reinforcement along said front surface at spaced apart joints to form curved portions of said fibers projecting from the front surface of said reinforcement between said joints, said curved portions having a weight of said reinforcement of less than about 0.64 centimeters (0.250 inches) and said fibers having a basis weight in the range of 4 to 200 grams per square meter measured along the first surface to provide sufficient open area between said fibers along said curved portions to provide ready engagement of said fibers along said curved portions by the hook portion of said fastener.

According to a fourth aspect of the present invention, there is provided an abrasive sheet comprising a layer having first and second surfaces, an abrasive adhered along said first surface, and a loop member for hook and loop fasteners attached along said second surface, said loop member comprising:

a reinforcement having front and occipital surfaces, said posterior surface being attached along the second surface of said layer; and

a plurality of fibers having portions bonded to said reinforcement along said front surface at the spaced apart joints to form curved portions of said fibers protruding from the front surface of said reinforcement between said joints, said curved portions having a height from said reinforcement of less than about 0.64 centimeters (0.250 inches), and said fibers having a basis weight in the range of 5 to 200 grams per square meter measured along said front surface to provide a sufficient open area between the said fibers along said curved portions to form a finished engagement of said fibers along said curved portions of the hook portion of said fastener.

The strips may be elongated and generally parallel so that the joints are also elongated and generally parallel and are continuous across the front surface of the reinforcement in one direction so that the continuous rows of the bent portions extend across the reinforcement of the sheet material or may be alternately elongated in the strips, generally parallel and in a regular pattern of discontinuous lengths so that the parallel joints are also in a regular pattern of discontinuous lengths to form a regular pattern of discontinuous rows of the bent portions along the front surface of the reinforcement. It is also expected that the slats of the first corrugation unit may form interlocked closed patterns (e.g., round, diamond, octagonal) to form corresponding patterns for the curved portions of the fibers along the front surface of the reinforcement, in which case the second corrugation unit will be formed with post-like slats to press the fibers into the center of the closed patterns.

Extended bars on the corrugating units can be oriented at any angle in the range of 0 to 90 degrees with respect to their axes, so that the rows of bent parts, whether uninterrupted or continuous, can be aligned along or obliquely to the fiber webs passed between the corrugating unit or at an angle therebetween.

The reinforcement could be a woven, knitted, randomly woven, nonwoven layer or other layer of interwoven fibers, but is preferably a continuous polymer film in the range of about 0.0025 to 0.013 centimeters (0.001 to 0.005 inches) thick, which is generally less expensive than a reinforcement of interwoven fibres and allowing the reinforcement to be printed by conventional techniques along one of its surfaces with graphics (such as advertising, instructions or line marks) which are visible through the loop portions of the fibres due to their high percentage of open area. The film may be a single layer of a polymeric material such as polypropylene, polyester or polyamide; or may comprise a plurality of layers such as a main layer of a relatively high strength material such as polyester, a layer defining the first surface of a material more readily bonded to the fiber such as ethylene vinyl acetate or polyethylene and a layer defining its second surface adapted to adhere the reinforcement to a substrate such as polyethylene or a tie layer of room temperature non-adherent thermoplastic material adapted to adhere a fastener to a polyolefin layer (which may be present on a disposable diaper, for example) that can be bonded to the polyolefin layer under heat and pressure that leaves the polyolefin layer substantially undeformed and will hold the fastener to the polyolefin layer with a force greater than is required to release an engaging fastener, the tie layer of room temperature non-adherent thermoplastic material being described in U.S. Patent Application No. 126,746, filed November 30, 1987, and may comprise about 40% to about 100% thermoplastic material having a melting point generally below 120°C and preferably below 100°C and from about 60% to about 0% of an adhesive resin having a softening point below about 105°C and preferably below 95°C. Suitable thermoplastic materials include ethylene and propylene-based copolymers such as ethylene/vinyl acetate copolymers, ethylene/acrylic acid copolymers and ethylene/methacrylic acid copolymers. Preferred thermoplastic materials include include ethylene/vinyl acetate copolymers, particularly those having a melt index of about 40 to about 2500, and preferably those having a melt index between about 50 and about 1000. Such materials are commercially available as Elvax 40W, Elvax 150, Elvax 210W, Elvax 220W, Elvax310W, Elvax 410, and Elvax 4980W from EI DuPont de Nemours and Co. of Wilmington, Delaware; Escorene, UL7710 and Escorene UL7720 from Exxcon Chemical Co., Houston, Texas; and Ultrathene 639-35 and Ultrathene 649-04, available from USI Chemical Co. of Cincinnati, Ohio. Suitable adhesive resins are preferably solid or semi-solid, but liquid adhesive resins may also be used. The adhesive resin, if used, should be compatible with the thermoplastic material and may include rosin esters, rosin acid and derivatives thereof; hydrogenated rosin esters and rosin acid and derivatives thereof; aliphatic hydrocarbon resins; mixed aliphatic/aromatic hydrocarbon resins, polyterpene resins; resins prepared by the polymerization and hydrogenation of a dicyclopentadiene feed stream; polyterpene resins and aromatically modified polyterpene resins; resins prepared by the polymerization and hydrogenation of a C9 hydrocarbon stream; and resins prepared by the polymerization and hydrogenation of a mixture of alphamethylstyrene, styrene and vinyltoluene. Preferred adhesive resins include aliphatic hydrocarbon resins such as Escorez 1580 and Escorez 1310 available from Exxon Chemical of Houston, Texas; Hercotac 95 available from Hercules Chemical Co. of Wilmington, Delaware; and Wingtack Plus and Wingtack 95 available from Goodyear Tire and Rubber Company of Akron, Ohio. Additional preferred solid adhesive resins include the aromatic modified polyterpene resins such as Wingtack 86 available from Goodyear; Zontac 105 available from Arizona Chemical Co. of Panama City, Florida; and Res D-2083 available from Hercules; resins obtained by the Polymerization and hydrogenation of a dicyclopentadiene feed stream such as Escorez 5380 available from Exxon; resins prepared by the polymerization and hydrogenation of a C9 hydrocarbon stream such as Arkon P90 available from Arakawa Chemical Co. USA of Chicago, Illinois; and resins prepared by the polymerization and hydrogenation of mixtures of alphamethylstyrene, styrene and vinyltoluene such as Regalrez 1065, Regalrez 1078 and Regalrez 1094 available from Hercules. Conventional hot melt adhesive additives may also be added to the tie layer including, but not limited to, waxes, fillers, oils, pigments, antioxidants, ultraviolet light stabilizers and heat stabilizers.

The individual fibers can consist of many polymer materials such as polypropylene, polyethylene, polyester or polyamide or compounds of such materials such as a polyester core and a sheath made of polypropylene, which provides a relatively high strength due to its core material and can be easily connected due to its sheath material. Fibers of one material or fibers of different materials or material compounds can be used in the same web-like material.

The fiber webs may be fed between the engaging slats of the corrugating units in the form of a nonwoven or randomly woven web or fabric in which the fibers may or may not be bonded together. In such a web, the fibers may be arranged in different directions with respect to the direction in which the fiber webs are fed between the corrugating units, so that the fibers in the resulting web-like material are arranged in different directions with respect to the spaced-apart joints. In such a web to be fed between the corrugating units with the spaced-apart slats, a majority of the Fibers (for example, over 90 percent) preferentially advance in one direction along the web, and the web is fed between the corrugating units with that direction approximately at right angles to the ridges on the corrugating units, so that the majority of the fibers in the resulting web-like material generally project at approximately right angles to the parallel joints.

As an alternative, the fibers may be provided in the form of yarns in the range of 50 to 300 denier, the yarns being distributed to provide a web of generally evenly distributed fiber by passing them through a comb, and the fiber webs fed between the corrugating units having elongated parallel ridges oriented in the range of 0 to 45 degrees with respect to their axes in a direction perpendicular to their axes, resulting in a sheet material in which all of the fibers extend in directions at approximately the same angles with respect to the parallel joints.

If the contact portions of the reinforcement and the fibers are made of the same thermoplastic material, then the bonding of the fibers to the reinforcement can be accomplished using sonic welding or other means for applying heat and pressure to melt the fibers to the reinforcement at the bonding locations. As an alternative, or if the contact portions of the reinforcement and the fibers are made of different materials, the fibers to the reinforcement can be adhesively bonded, such as by softening a thermoplastic bonding layer to the reinforcement using sonic energy or other means for applying heat and pressure to bond the fibers to the reinforcement at the bonding locations.

Short description of the drawing

The present invention will be further described with reference to the accompanying drawings, in which like reference numerals refer to like parts in different views:

Figure 1 is a perspective view of a sheet material in accordance with the present invention;

Figure 2 is a greatly enlarged plan view of the sheet material of Figure 1;

Figure 3 is a highly enlarged end view of the sheet material of Figure 1;

Figure 4 is a schematic view illustrating an apparatus and method in accordance with the present invention for producing the sheet material of Figure 1;

Figures 5 and 6 are top and side views, each illustrating a first alternative embodiment of the device of Figure 4;

Figures 7 and 8 are top and side views each illustrating a second alternative embodiment of the device of Figure 4;

Figures 9 and 10 are top and side views, respectively, of an alternative embodiment of a sheet material in accordance with the present invention produced by the apparatus of Figures 7 and 8.

Detailed description

Referring now to the drawings, there is shown in Figures 1, 2 and 3 a sheet material according to the present invention, generally designated by the reference numeral (10), wherein the sheet material (10) is adapted is to be cut into pieces for the manufacture of loop parts for fasteners of the type having releasable, engaging hook and loop parts.

Generally, the sheet material (10) comprises a transparent thermoplastic film reinforcement (12) (e.g., of polypropylene or polyester) in the range of about 0.0025 to 0.013 centimeters (0.001 to 0.005 inches) thick having front and occipital surfaces (13) and (14) and a plurality of fibers (16) having portions bonded (i.e., fused or adhesively attached) to the front surface (13) of the reinforcement (12) at spaced, elongated, generally parallel joints (18) that are continuous in one direction along the front surface (13) to form curved portions (20) of the fibers (16) extending from the front surface (13) of the reinforcement (12) between the joints (18) in continuous rows diagonally protrude beyond the web-shaped material (10). The bent portions (20) of the fibers (16) have a generally uniform height from the reinforcement (12) of less than about 0.64 centimeters (0.250 inches), and preferably less than about 0.318 centimeters (0.125 inches), the height of the fibers (16) is at least 1/3 and preferably 1/2 to 1 and 1/2 times the distance between the joints (18), the individual fibers (16) are less than 15 denier (preferably in the range of 1 to 10 denier), and the fibers (16) without the reinforcement (12) have a basis weight in the range of 5 to 200 grams per square (and preferably in the range of 10 to 75 grams per square meter) measured along the first surface (13) to provide a sufficient open area between the fibers (16) along the curved portions (20) (i.e., between about 10 and 70 percent open area) to provide a ready engagement of the fibers (16) along the curved portions (20) by the hook portion of the fastener.

The fibers (16) may be arranged in different directions with respect to the parallel connection points (18) and may or may not be arranged at transition points in the bent portions (20) connected together; may be arranged with respect to the parallel joints (18) with the majority of the fibers (16) (i.e., over 90 percent): extending in directions approximately at right angles to the joints (18); or all of the fibers (16) may extend in directions generally at right angles to the spaced apart generally parallel joints (18).

The reinforcement (12) may have a print (22) either along one or both of its faces (13) or (14) applied by conventional printing techniques, the print (22) being readily visible through the curved parts (20) of the fibres (16).

Figure 4 schematically illustrates a method in accordance with the present invention for making the sheet material (10) which generally comprises making the fibers (16) into a fibrous web having curved portions protruding in the same direction from the spaced generally parallel anchor portions (24) of the web and bonding the spaced generally parallel anchor portions (24) of the fibrous web (16) to the front surface (13) of the reinforcement (12) with the curved portions of the fibers (16) protruding from the front surface (13) of the reinforcement. This method is preferably carried out by providing first and second heated (e.g., 280 degrees Fahrenheit) corrugating units or rollers (26) and (27), each having an axis and enclosing a plurality of circumferentially spaced, generally axially extending slats (28) around and defining its periphery, the slats (28) having outer surfaces and defining spaces between the slats (28) adapted to receive portions of the slats (28) of the other corrugating unit in engaging relationship with the fiber web between the engaging slats (28) and to provide rolling engagement between the slats (28) and spaces of the corrugating units in the manner of interlocking. The corrugating units (26) and (28) are mounted in an axially parallel relationship, the portions of the slats (28) of the corrugating units (26) and (27) generally engaging in a spline manner; at least one of the corrugating units (26) or (27) is rotated; and the fiber web is guided between the engaging portions of the slats (28) of the corrugating units (26) and (27) to generally conform the fiber web to the periphery of the first corrugating unit (26) and to form the bent portions of the fibers in the spaces between the slats (28) of the first corrugating unit (26) and the generally parallel anchor portions (24) of the fiber web along the outer surfaces of the slats (28) on the first corrugating unit (26). The formed fiber web is held along the periphery of the first corrugating unit after it has moved past the engaging portions of the slats (28); the reinforcement is bonded at the parallel anchor portions (24) of the fiber web to the end faces of the strips (28) on the first corrugating unit (26) by means of the action of a sonic welder (30) or by means of other heat and pressure sources such as heat from the interior of the first corrugating unit (26); and the bonded reinforcement (12) and the fibers (16) or the sheet material (10) are separated from the first corrugating unit (26).

The fibrous web which is guided between the engaging portions of the slats (28) of the corrugating units (26) and (27) may be in the form of a non-woven fabric or web or, as shown in Figure 4, in the form of yarns (33) distributed to provide a web of evenly distributed fibers by passing the yarns (33) through a comb (34) and between the engaging portion of the slats (28) of the corrugating units (26) and (27), all of the fibers (16) extending generally vertically to the axes of the corrugating units (26) and (27). The corrugating units (26) and (27) adapted to receive such a fibrous web (32) may have their slats (28) generally oriented in the range of 0 to 45 degrees with respect to their axes, but have their slats (28) preferably aligned at about 5 degrees with respect to their axes so that the sonic welder (30) is always adjacent and heats the parallel portions (24) of the fiber web along a portion of at least one of the strips (28) to match the amount of energy of the welder (30) and so that the fibers (16) in the web-like material (10) all extend in directions at approximately right angles (e.g. 85 degrees) to the parallel joints (68).

In addition, the method may further comprise printing the reinforcement along one of its surfaces prior to the bonding step, such as along its rear surface (14) with a printer (36), preferably carried out at a location remote from the corrugating units (26) and (27).

Figures 5 and 6 schematically illustrate a first alternative way of carrying out the method in accordance with the present invention for making a sheet material (40) in accordance with the present invention, the method generally comprising forming the fibers (38) into a web having bent portions (41) protruding in the same direction from the spaced generally parallel anchor portions of the fiber web and connecting the spaced anchor portions of the fiber web to the fibers along a front surface of a reinforcement (43), the bent portions (41) protruding from the front surface of the reinforcement (43). As illustrated, the method may be carried out by providing first and second cylindrically heated corrugating units or rollers (44) and (45), each having an axis and enclosing a plurality of generally annular, circumferentially extending, axially spaced slats (46) around and defining its periphery, the slats (46) having outer surfaces and defining spaces between the slats (46) adapted to engage portions of the slats (46) of the other corrugating unit (44) or (45) in mating relationship. with the fiber web received between the engaging portions of the slats (46). The corrugating units (44) and (45) are mounted in axially parallel relationship to engage the slats (46) portions of the corrugating units (44) and (45); at least one of the corrugating units (44) or (45) is rotated; and the fiber web is guided between the engaging portions of the slats (46) of the corrugating units (44) and (45) to generally conform the fiber web to the periphery of the first corrugating unit (44) and to form the bent portions (41) of the fibers in the spaces between the slats (46) of the first corrugating unit (44) and the generally parallel anchor portions of the fibers along the outer surfaces of the slats (46). The formed fiber web is held along the periphery of the first corrugating unit (44) after separation of the slats (46); the reinforcement (43) is bonded to the parallel anchor portions (42) of the fibrous web at the end faces of the slats (46) of the first corrugating unit at spaced, generally parallel joints corresponding to the end faces of the slats (46) on the first corrugating unit (44) by the action of a sonic welder (50) or by other sources of heat and pressure, such as heat from the interior of the first corrugating unit (44); and the finished web material (40) is separated from the first corrugating unit (44).

The fibers (38) which are guided between the engaging slats (46) of the corrugating units (44) and (45) may be in the form of a non-woven fabric by adhering the fibers together, or another web formed by the fibers having sufficient internal strength so that the fiber web will groove lengthwise to conform to the slats (46) when pulled into the nip between the engaging slats (46) of the corrugating units (44) and (45). A plurality of the fibers (38) in such a non-woven fiber web are oriented transversely to the direction of the fiber web which is guided between the corrugating units (44) and (45) so that a plurality of fibers are in the resulting web-like material (60) in directions approximately at right angles to the parallel joints (68). In addition, the method may further comprise printing the reinforcement along one of its surfaces prior to the joining step (not shown).

Like the sheet material (10), the sheet material (40) made by the process illustrated in Figures 5 and 6 includes the reinforcement (43) (which may be a thermoplastic film) and the fibers (38) bonded (i.e., by being melted or adhesively attached) to the reinforcement (43) at spaced-apart elongated generally parallel joints along the front surface, the joints extending continuously in one direction across the sheet material (40) to form curved portions (54) of the fibers (38) projecting from the front surface of the reinforcement (43) between the joints in continuous rows, except that the continuous rows of curved portions (54) in the sheet material (40) extend longitudinally along the sheet material (40) rather than extending obliquely. over the web-like material as in the case of the web-like material (10).

Figures 7 and 8 illustrate schematically a second alternative way of carrying out the method in accordance with the present invention for producing a sheet material (60) as illustrated in Figures 9 and 10, the method illustrated in Figures 7 and 8 comprising forming fibers (59) into a web having curved portions (61) projecting in the same direction from spaced, generally parallel anchor portions (62) of the fiber web, and bonding the spaced, generally parallel anchor portions (62) of the fiber web to a front surface (58) of a reinforcement (63) to form joints (68), the curved portions (61) projecting from the front surface (58) protrude. As illustrated, the method may be carried out by providing first and second cylindrically heated corrugating units or rollers (64) and (65), each having an axis and comprising a plurality of circumferentially spaced generally axially extending discontinuous slats (66) around and defining its periphery, the slats (66) on each corrugating unit (64) or (65) having outer surfaces and defining spaces between the slats (66) adapted to receive a portion of the slats (66) of the other corrugating unit (64) or (65) in engaging relationship in the manner of a spline with the fibrous web (59) between the engaging portions of the slats (66). The corrugating units (64) and (65) are mounted in axially parallel relationship to engage portions of the slats (66) of the corrugating units (64) and (65) in the manner of a spline; at least one of the corrugating units (64) or (65) is rotated; and the fiber web (59) is guided between the engaging portions of the slats (66) of the corrugating units (64) and (65) to conform the fiber webs generally to the periphery of the first corrugating unit (64) and to form the bent portions (61) of the fibers in the spaces between the slats (66) of the first corrugating unit (64) and the generally parallel anchor portions (62) of the fiber webs along the outer surfaces of the slats (66). The formed fiber web is retained along the periphery of the first corrugating unit (64) after it has moved past the engaging portions of the slats (66); the reinforcement (63) is connected to the parallel anchor parts (62) of the fiber web at the end faces of the strips (66) of the first corrugating unit (64) by means of the action of a sonic welder (67) or by means of other heat and pressure sources such as heat from the interior of the first corrugating unit (64); and the finished web-shaped material (60) is separated from the first corrugating unit (64).

The fibers (59) can be fed between the engaging parts of the strips (66) of the corrugating units (64) and (65) in the form of yarn (70) which is distributed to to distribute a web of evenly distributed fibers (59) by passing the yarn (70) through a comb (72) and can be passed between the engaging slats (66) of the corrugating units (64) and (65), all of the fibers extending generally vertically to the axes of the corrugating units (64) and (65), in which case the corrugating units (64) and (65) have their slats (66) oriented in the range of 0 to 45 degrees with respect to their axes, but preferably have their slats (66) oriented at about 5 degrees with respect to their axes, so that the sonic welder (67) is always adjacent and heats the parallel anchor portions (62) of the fibers along a portion of one of the slats (66) to help out the amount of energy of the welder (67) and so that the fibers in the web material (60) all extend in directions at approximately right angles (for example 85 degrees) to the parallel joints (68) between the fibers (59) and the reinforcement (63). As an alternative, the fibers (59) which are guided between the engaging slats (66) of the corrugating units (64f) and (65) may be in the form of non-woven fabric or randomly woven fabric formed by adhering fibers together or by piling up unbonded fibers. In this case, the slats (66) may be oriented at any angle with respect to the axes of the corrugating units (64) and (65) and a plurality of fibers in such a fiber web are preferably oriented at right angles to the slats (66) so that a plurality of fibers in the resulting sheet material (60) extend in directions at approximately right angles to the parallel joints (68). In addition, the method may further comprise printing the reinforcement along one of its surfaces prior to the bonding step (not shown).

Like the sheet materials (10) and (40), the sheet material (60) produced by the process illustrated in Figures 7 and 8 and illustrated in Figures 9 and 10 comprises the reinforcement (63) (which may be a thermoplastic film) and the fibers (59) bonded (i.e. by being fused or adhesively attached) to the front surface (58) of the reinforcement (63) at the spaced apart elongated substantially parallel joints (68) to form rows of bent portions (61) of the fibers (59) projecting from the front surface (58) of the reinforcement (63) between the joints (68), except that the rows of bent portions (69) are discontinuous and form a uniform pattern along the sheet material (60) rather than being continuous in one direction across the sheet material as in the case of the sheet materials (10) and (40).

The following are illustrative examples of sheet materials in accordance with the present invention which are formed by the process previously described.

example 1

A sheet material in accordance with the present invention was prepared using 2.4 denier individual polypropylene fibers commercially available as type 80/2 yarn, 70/34 denier solution dyed upset textured olefin fibers from Roselon Industries of New York, NY, and a reinforcement of conventional polypropylene film (some of which was printed onto a sheet) having a thickness of about 50 micrometers. The yarn of polypropylene filaments was passed through a comb having 6.3 teeth per centimeter (16 teeth per inch) to form a web of uniformly distributed filaments which was then passed between two corrugating rollers having engaging slats of the type described above with respect to Figure 4, carried along the periphery of a first of the corrugating rollers, and the parallel anchor portions of the fiber web carried along the outer surfaces of the slats which were ultrasonically fused to the reinforcement in the manner described above. The slats and spaces between the slats were shaped to effect a feed rate of the fiber web approximately twice the film reinforcement and to result in sheet material having parallel, elongated joints generally vertical to all of the fibers, having a transverse width of about 0.076 centimeters and spaced every 0.381 centimeters along the sheet material; and having projecting curved portions of the fibers, approximately semicircular in shape, with heights of about 0.381 centimeters (0.125 inches) between the parallel joints. The pressure on the reinforcement could be easily seen through the curved portions of the fibers. The sheet material was tested for dynamic shear and T-peel in accordance with the test procedures described at the end of this specification when it was clamped to a 2-inch by 1-inch piece of both the mushroom head hook material sold under the trade designation SJ-3492; "SCOTCHMATE" fasteners from Minnesota Mining and Manufacturing Co,. St. Paul, Minn. available from U.S. Patent No. 4,894,060, as well as a hook material (referred to herein as "molded hook material") which is made in accordance with the teachings in U.S. Patent No. 4,894,060 by extruding a thermoplastic resin through a die shaped to form a base layer and spaced slats protruding above an upper surface of the base layer having the cross-sectional shape of the hook portions to be formed, the slats being transversely cut at spaced locations along their lengths to form separate portions of the slats and the reinforcement layer being stretched to divide those portions of the slats which are then the spaced hook units, the hook units each comprising a bar portion attached to the reinforcement at one end and a head portion at the end of the bar portion opposite the reinforcement, the hook units each having a height dimension from the upper surface of the reinforcement of 0.102 Centimeters (0.04 inches); the bar and head portions each have generally equal thickness dimensions of about 0.025 centimeters (0.01 inches) in a first direction parallel to the surfaces of the reinforcement; the bar portions each have a thickness dimension of about 0.027 centimeters (0.01 inches) in a second direction generally at a right angle to the first direction and parallel to the surfaces of the reinforcement, and the head portions each have a thickness dimension in the second direction that is about 0.066 centimeters (0.026 inches) greater than the thickness dimension of the bar portion and an overall width of about 0.066 centimeters (0.026 inches); the closure portion comprises about 70 hook units per square centimeter (450 hook units per square inch); while the total cross-sectional area occupied by the head portions in a plane parallel to the upper surface is about 11.7 percent of the area of the upper surface.

The average results are tabulated in Table 1 below.

Example 2

A sheet material in accordance with the present invention was prepared as described in Example 1, except that the individual fibers used were 6.2 denier polypropylene fibers which are commercially available in the form of 420/68 yarn from Philips Fibers Incorporated, Greenville, SC. The pressure on the reinforcement of the sheet material could be easily seen through the bent portions of the fibers. The sheet material was tested as in Example 1 and the average results were tabulated in Table 1 below.

Example 3

A sheet material in accordance with the present invention was prepared as described in Example 1, except that the individual fibers used were 6.2 denier polypropylene fibers which were in the form of 420/68 yarn commercially available from Philips Fibers Incorporated, Greenville, SC, and the ridges and spaces between the ridges of the corrugated rolls were shaped to provide projecting curved portions of the fibers approximately semi-circular in shape with heights of about 0.381 centimeters (0.125 inches) between parallel joints. It was found that the pressure on the reinforcement of the sheet material could be readily seen through the curved portions of the fibers. The sheet material was tested as in Example 1 and the average results were tabulated in Table 1 below.

Example 4

A sheet material in accordance with the present invention was prepared as described in Example 1 except that no comb was used and that the individual fibers used were 11 denier polypropylene sheath and polyester core fibers commercially available from BASF Corporation, Williamsburg VA, a nonwoven web having a basis weight of about 35 grams per square meter was formed from the fibers after orienting the majority or 90% of the fibers in one direction by standard carding techniques, and a nonwoven web was fed into the rolls, said one direction being vertical to the axes of the rolls, and the ridges and spaces between the ridges of the corrugated rolls were shaped to cause protruding curved portions of the fibers, approximately in semicircular shape, with heights of about 0.381 centimeters (0.125 inches) between the parallel joints. The sheet material was tested as in Example 1 and the average results were tabulated in Table 1 below. Table 1 Injection Molded Hook Material Scotchmate Hook Dynamic Shear T-Peel Dynamic Shear T-Peel (lbs) Example * Reinforcements extended and hooks not released from the loop

Comparative examples 5-19

A series of sheet materials in accordance with the present invention, Examples 5-13, were prepared as described in Example 4, except that the individual fibers used were a blend of 65 percent of the 11 denier polypropylene sheath and polyester core fibers commercially available from BASF Corporation, Williamsburg VA, and 35 percent 6 denier polypropylene fibers commercially available from Hercules Inc., Wilmington, Del. The nonwoven fabrics made from these fibers were varied in density to produce a series of basis weights for the fibers (the reinforcement is not included) measured along the first surface of the reinforcement of the sheet material. The sheet materials in accordance with the present invention, Examples 14-19, were also prepared as described in Example 1, except that the individual fibers used were 2.9 denier polypropylene fibers commercially available in the form of 100/34 yarn from Amoco Fabrics and Fibers Company, Atlanta, Ga, wherein the reinforcement of the web material was not printed and the fiber content of the web materials was varied in their densities or basis weights by varying the number of yarns per width to produce a range of basis weights for the fibers (the reinforcement is not included) measured along the first surface of the reinforcement of the web material.

All of the sheet materials so prepared were tested for T-peel in accordance with the test methods attached at the end of this specification when attacked with a 2-inch by 1-inch piece of the mushroom head hook material available under the trade designation SJ-3492; "SCOTCHMATE" fasteners from the Minnesota Mining and Manufacturing Co, St. Paul, Minn. and the average results were obtained as tabulated in Table 2 below.

In addition, the bent portions of the fibers on certain of the sheet materials were measured on an IBAS Image Analyzer using Routine #455, measuring 6 fields of 2.2 square centimeters for each sheet material and the average results for the percent open area were obtained tabulated in Table 2 below. TABLE 2 Fiber Source (see above) Fiber Basis Weight (grams/sq. yard) T-Skim (lbs. Open Area % Nonwoven Blend Yarn

Example 20

A sheet material in accordance with the present invention was prepared to demonstrate the adhesive bonding of fibers to a reinforcement. The sheet material was prepared as described in Example 1 except that no comb was used; the fibers used were 9 denier polypropylene staple fibers commercially available from Hercules Incorporated, Norcrosse, GA; the reinforcement used was a 0.0056 centimeter (0.0022 inch) polypropylene film extrusion coated with about 0.005 centimeter (0.002 inch) of low melt temperature ethylene vinyl acetate hot melt adhesive; a nonwoven fabric having a basis weight of about 17 grams per square meter was formed from the fibers by joining them together after the majority or about 90 percent of the fibers are oriented in one direction, and the nonwoven fabric was fed into the corrugating rolls, said one direction being vertical to the axes of the corrugating units; the reinforcement was adhesively bonded to the parallel portions of the fibers carried along the outer surfaces of the strips by heating the first roll to plasticize the ethylene vinyl acetate layer rather than by sonic welding; and the ridges and spaces between the ridges on the corrugated rolls were shaped to cause projecting curved portions of the fibers to be approximately semi-circular in shape, with radii of about 0.381 centimeters (0.125 inches) between the parallel joints. The sheet material was not tested, although it appeared to work as well as the better examples described above.

Example 21

A sheet material in accordance with the present invention was prepared as generally described in Example 1, except that the fibers used were those commercially available from Hercules as 10d T-181 fibers. A very open web having a basis weight in the range of about 20 to 25 grams per square meter was formed from the fibers by randomly orienting the fibers and by spot bonding about 4 to 6% of the fibers together at their bonding points, and this web was then passed between two corrugating rollers having engaging slats of the type described above with respect to Figure 4, along the periphery of a first of the Corrugated rolls and had the parallel curved portions of fabric or fiber web carried along the outer surfaces of the strips, which were fused to the reinforcement by ultrasonic means in the manner described above.

Example 22

A sheet material in accordance with the present invention was prepared as described in Example 1, except that the backing of the sheet material is a bilayered film comprising a low melt adhesive ethyl vinyl acetate layer having a softening point of 150 degrees Fahrenheit and a propylene layer similar to the film of Example One; and that a rubber roller is used at the location of the ultrasonic horn to achieve adhesive bonding of the fibers to the ethyl vinyl acetate layer through the use of heat and pressure.

Example 23

A sheet material in accordance with the present invention was prepared as described in Example 1, except that no comb was used and that the majority of the fiber used to form the fibrous web was that which is commercially available from Hercules as 9d T-101 fibers. The fibers were used in an amount to provide a basis weight of 45 grams per square meter for the fibrous web, and the orientation of the fibers in the web was estimated to be in a ratio of about seven in the length direction to one in the cross direction.

Peeling test Facilities:

1. Tensile tester model Instron TM equipped with "C" load cell or tensile tester (Thwing Albert) model "Intelect".

2. 11 ± 1/4 pound (5.0 ± 0.1 kg) roll with a 4 1/8" (104.8 mm) diameter and a 3" (76 mm) length, which can be rolled manually or mechanically.

3. Hook and loop parts are supplied in a width not exceeding 2" (51 mm); materials larger than 2" (51 mm) in width should be cut to a 2" (51 mm) width.

4. Scissors

Sample:

A strip of suitable hook or mushroom material at least 7" (178 mm) long in width and an equal length of the loop to which it will be fitted. When removing the specimens from a roll of material, remove the outside cover of the material before selecting the number of strips required. Each strip must have the end closest to the center of the roll marked. These marks are used to indicate the bundling of the specimens.

Equipment preparations:

1. See TM Appendix #3 for load cell calibration procedure using a "CT" load cell.

2. See Instron for the following conditions:

a. Cross bar speed: 12 in./min (305 mm/min)

b. Feed rate: 5-12 in./min. (127-305 mm/min.

c. Measuring length: 3 ± 1/8" (76.2 ± 3.2 mm)

d. Load range: 10 lbs (44.5 N) Full scale load

e. Peeling distance: 3" (876.2 mm)

Conditions:

All hook and loop specimens should be conveniently placed face up and conditioned for at least 24 hours at 70 ± 20 F (21.1 ± 1.1ºC) and 65 ± 2% relative humidity prior to testing the specimens.

Proceedings

1. Carefully align and overlap the hook strip over the loop strip so that the hook strip covers the loop strip and the marked ends match.

2. Attack the entire length of the mated strips using the roller by rolling over the surface at a speed of approximately 12" (305 mm)/min., making one pass in each direction 3 times. Then manually separate at least 2-1/2" (63.5 mm) but not more than 3" (76.2 mm) of the mated samples.

3. Place the free end of the specimen to be tested into the Instron with the hook strip end in the upper clamp and the free end of the loop strip in the lower clamp. The peel line should be centered.

4. Turn on the pen and the writing devices and start the peel test.

5. Ignore the first peak and select the five highest peaks from the remaining peaks and calculate an average for the peel force value.

6. A total of 6 separate sample combinations will be tested, 3 with marked ends together and 3 with opposite marked ends.

3 each: Hook Loop

7. The average value of the 6 peel tests should be recorded in pounds per inch width to the nearest ten of a pound. This value characterizes a sample.

Shear strength test Facilities:

1. Tensile tester model Instron TM equipped with "C" load cell or tensile tester (Thwing Albert) model "Intelect".

2. 11 ± 1/4 pound (5.0 ± 0.1 kg) roll with a 4 1/8" (104.8 mm) diameter and a 3" (76 mm) length, which can be rolled manually or mechanically.

3. Hook and loop parts are supplied in a width not exceeding 2" (51 mm); materials larger than 2" (51 mm) in width should be cut to a 2" (51 mm) width.

4. Scissors

5. Bell jar with a supersaturated magnesium acetate solution and water in the bottom to maintain the relative humidity at 65% at 70ºF (21ºC).

Sample:

A strip of suitable hook or (missing) material at least 4" (102 mm) long in width and an equal length of the loop to which it will be fitted. If the samples are taken from a roll of material, remove the outside cover of the material before selecting the number of strips required.

Equipment preparations:

1. Calibrating the load cell

2. See Instron for the following conditions:

a. Cross bar speed: 12" (305 mm/min)

b. Feed rate: 5-12" (127-305 mm/min.

c. Measuring length: 3 ± 1/8" (76 ± 3 mm)

d. Load range: 100 pounds (445 N)

Full scale load Conditions:

All hook and loop specimens should be conveniently placed face up and conditioned for at least 24 hours at 70 ± 2º F (21 ± 1º C) and 65 ± 2% relative humidity prior to testing.

Procedure:

1. Place the 4" (102 mm) long loop material strip, loop side up, on a flat rigid surface.

2. Carefully align and overlap 2 ± 1/16" (50 ± 2 mm) of the hook strip over the loop strip. Lightly join the strips together using finger pressure.

3. Attack the entire length of the mated strips using the roller by rolling over the surface at a speed of approximately 12" (305 mm)/min., making one pass in each direction 3 times.

4. Place the free end of the specimen to be tested into the Instron with the hook strip end in the upper clamp and the free end of the loop strip in the lower clamp. The peel line should be centered.

5. Turn on the pen and the writing devices and start the peel test.

6. Observe and record the maximum value obtained during the complete division of each of the sample combinations.

7. A total of 4 separate samples will be tested and the average will be calculated to characterize a sample.

Claims (25)

1. A method of making a sheet material adapted to be cut into pieces to form loop portions for fasteners of the type having releasable, engaging hook and loop portions, said method comprising: providing a web formed by fibers (16, 38, 59) and a reinforcement (12, 43, 63) having front and occipital surfaces, the fibers having a basis weight in the range of 5-200 grams per square meter measured along said front surface (13, 58) of the reinforcement, to provide sufficient open area between the fibers (16, 38, 59) to provide ready engagement of the hook portion of said fastener with the fibers (16, 38, 59) in the web material (10, 40, 60); forming the web to have curved portions (20, 54, 69) projecting in the same direction from the spaced-apart anchor portions of the web, said curved portions (20, 54, 69) being formed with a height from the anchor portions of less than 0.64 cm; connecting the spaced-apart anchor parts of the sheet to the front surface of the reinforcement, with the curved parts protruding from said front surface. 2. A method for producing a web-shaped material (10, 40, 60) according to claim 1, characterized in that said manufacturing step comprises the following steps: Providing first and second generally cylindrical shaft units (27, 28; 44, 45; 64, 65), each having an axis and a plurality of spaced apart slats (28, 46, 66) defining the periphery of the corrugating unit, the slats (28, 46, 66) having outer surfaces and defining spaces between said slats (28, 44, 66) adapted to receive portions of the slats (28, 44, 66) from the other corrugating unit in engaging relationship with the path of fibers (16, 38, 59) therebetween; Mounting the shaft units (27, 28; 44, 45; 64, 65) in axially parallel relationship with the parts of the strips (28, 46, 66) in an engaging relationship; Rotating at least one of the shaft units (27, 28; 44, 45; 64, 65); feeding the fiber web (16, 38, 59) between the engaging portions of the strips (28, 46, 66) to conform the fiber webs (16, 38, 59) generally to the periphery of the first corrugating unit (27, 44, 69) and to form the bent portions (20, 54, 59) of the fibers (16, 38, 59) in the spaces between the strips (28, 46, 66) of the first corrugating unit (27, 44, 64) and the anchor portions of the fiber webs (16, 38, 59) along the outer surfaces of the strips (28, 46, 66) of the first corrugating unit; Retaining the formed fiber webs (16, 38, 59) along the periphery of the first corrugated unit (27, 44, 64) after movements past the engaging parts of the strips (28, 46, 66); characterized in that said joining step takes place with the formed fiber webs (18, 38, 59) located along the periphery of the first corrugation unit (27, 44, 64) after movements past the engaging portions of the strips (28, 46, 66); and said method further includes splitting the web-shaped material (10, 40, 60) from the first corrugating unit (27, 44, 64). 3. A method according to claim 2, characterized in that in said feeding step the Fiber webs (16, 38, 59) fed between the engaging parts of the strips (28, 46, 66) of the corrugating units (27, 28; 44, 45; 64, 65) are in the form of a non-woven fabric. 4. A method according to claim 2, characterized in that said slats (28, 46, 66) are elongated and parallel, and in said feeding step the fiber webs (16, 38, 59) fed between the engaging portions of the slats (28, 46, 66) of the corrugating units (27, 28; 44, 45; 64, 65) are in the form of a nonwoven fabric having a plurality of the fibers (16, 38, 59) projecting generally at right angles to the slats (28, 44, 66). 5. A method according to claim 2, characterized in that said strips (28, 66) are elongated and parallel and are oriented at an angle in the range of 0 to 45 degrees with respect to the axes of the corrugating units (27, 28; 44, 45; 64, 65), and said feeding step includes the following steps: Providing the fibers (16, 59) in the form of yarn in the range of 50 to 300 denier. Distributing the yarns to provide a web of generally evenly distributed fibers (16, 59); and Feeding the fiber webs (16, 59) between the engaging slats (28, 66) of the device, wherein all of the fibers (16, 59) extend generally at a right angle to the axes of the corrugating units (27, 28; 64, 65). 6. A method according to claim 2, characterized in that said strips (28, 66) are oriented at an angle of about 5 degrees with respect to the axes of the corrugating units (27, 28; 64, 65) and said feeding step includes the following steps; Providing the fibers (16, 59) in the form of yarn in a range of 50 to 300 denier; Distributing the yarns to provide a web of generally evenly distributed fibers (16, 59); and Feeding the fiber webs (16, 59) between the engaging portions of the strips (28, 66), all of the fibers (16, 59) extending generally at right angles to the axes of the corrugating units (27, 28; 64, 65). 7. A method according to claim 1 further comprising the step of printing the reinforcement (12, 43, 63) along one of its surfaces prior to said bonding step. 8. A method according to claim 1, characterized in that the reinforcement (12, 43, 63) and the fibers (16, 38, 59) comprise the same thermoplastics, and said joining step comprises melting the fibers (16, 38, 59) onto the reinforcement (12, 43, 63) at the joining locations (18, 68). 9. A method according to claim 1, characterized in that said joining step comprises gluing the fibers (16, 38, 59) to the reinforcement (12, 43, 63) at the joints (18, 68). 10. A sheet material made by the process of claim 1. 11. A sheet material (10, 40, 60) according to claim 10, characterized in that the fibers (16, 38, 59) in said curved parts (20, 54, 69) protrude to approximately the same height above said front surface (13, 58), and said height is at least 1/3 of the distance between said joints (18, 68). 12. A sheet material (10, 40) according to claim 10, characterized in that said joints are elongated, generally parallel and continuous in a direction along said front surface (13) of said reinforcement (12, 43) to form continuous rows of said bent portions (20, 54) along said front surface (13) of said reinforcement (12, 43). 13. A sheet material (60) according to claim 10, characterized in that said joints (68) are elongated, generally parallel and in a uniform pattern of discontinuous lengths to form a pattern of discontinuous rows of said curved portions (69) along said front surface (58) of said reinforcement (63). 14. A sheet material (10, 40, 60) according to claim 10, characterized in that said joints (18, 68) are elongated and generally parallel, and said fibers (16, 38, 59) are arranged in different directions with respect to said parallel joints (18, 68). 15. A sheet material (10, 40, 60) according to claim 10, characterized in that said joints (18, 68) are elongated and generally parallel, and said fibers (16, 38, 59) are arranged in different directions with respect to said parallel joints (18, 68), the majority of said fibers (16, 38, 59) extending in directions generally at right angles to said joints (18, 68). 16. A web-shaped material (10, 40, 60) according to claim 10, characterized in that said junctions (18, 68) are elongated and generally parallel, and all of said fibers (16, 38, 59) necessarily extend in directions generally at right angles to said spaced, generally parallel junctions (18, 68). 17. A sheet material (10, 40, 60) according to claim 10, characterized in that said fibers (16, 38, 59) have a basis weight in the range of 10 to 75 grams per square meter, measured along said front surface (13, 58) of said reinforcement (12, 43, 63), wherein the fibers (16, 38, 59) in said curved portions (20, 54, 69) protrude to approximately the same height above said front surface (13, 58), and said height is in the range of 1/2 to 1 and 1/2 the distance between said joints (18, 68). 18. A sheet material (10, 40, 60) according to claim 10, characterized in that said reinforcement (12, 43, 63) is a polymeric film material which is at least 0.013 centimeters thick. 19. A sheet material (10, 40, 60) according to claim 10, characterized in that said reinforcement (12, 43, 63) is a polymeric film material and has a print along one of said surfaces, the print being visible through said curved portions (20, 54, 69) of said fibers (16, 38, 59). 20. A sheet material (10, 40, 60) according to claim 10, characterized in that said reinforcement (12, 43, 63) and said fibers (16, 38, 59) comprise the same thermoplastics, and said fibers (16, 38, 59) are fused to said reinforcement (12, 43, 63) at said joints (18, 68). 21. A web-like material (10, 40, 60) according to claim 10, characterized in that the reinforcement (12, 43, 63) and said fibers (16, 38, 59) are glued to said reinforcement (12, 43, 63) at said connection points (18, 68). 22. A disposable garment comprising a fastener comprising releasable, engaging hook and loop portions, said loop portion comprising: a reinforcement (12, 43, 63) with front and occipital surfaces (13 and 14, 58); and a plurality of fibers (16, 38, 59) having portions joined to said reinforcement (12, 43, 63) along said front surface (13, 58) at spaced apart joints (18, 68) to form bent portions (20, 54, 69) of said fibers (16, 38, 59) protruding from the front surface (13, 58) of said reinforcement (12, 43, 63) between said joints (18, 68), said bent portions (20, 54, 69) having a height from said reinforcement (12, 43, 63) of less than about 0.64 centimeters (0.250 inches), and said fibers (16, 38, 59) have a basis weight in the range of 5 to 200 grams per square meter measured along said first surface (13, 58) to provide sufficient open area between said fibers (16, 38, 59) along said curved portions (20, 54, 69) to provide ready engagement of said fibers (16, 38, 59) along said curved portions (20, 54, 69) from the hook portion of said fastener. 23. A disposable garment according to claim 22, characterized in that said garment further comprises an outer polymer layer and said back surface (14) said reinforcement (12, 43, 63) is adhered to said outer polymer layer. 24. A disposable garment according to claim 22, characterized in that said disposable garment further comprises an outer polymer layer, a portion of said outer polymer layer providing said reinforcement (12, 43, 63) for said loop portion. 25. An abrasive sheet comprising a layer having first and second surfaces, an abrasive adhered along said first surface, and a loop member for surface zippers attached along said second surface, said loop member comprising: a reinforcement (12, 43, 63) having front and occipital surfaces (13 and 14, 58), said rear surface being attached along the second surface of said layer; and a plurality of fibers (16, 38, 59) having portions joined to said reinforcement (12, 43, 63) along said front surface (13, 58) at said spaced apart joints (18, 68) to form bent portions (20, 54, 69) of said fibers (16, 38, 59) protruding from the front surface (13, 58) of said reinforcement (12, 43, 63) between said joints (18, 68), said bent portions (20, 54, 69) having a height from said reinforcement (12, 43, 63) of less than about 0.64 centimeters (0.250 inches), and said fibers (16, 38, 59) having a basis weight in the range of 5 to 200 grams per square meter measured along the said front surface (13, 58) for providing a sufficiently open area between said fibers (16, 38, 59) along said curved portions (20, 54, 69) to permit a complete engagement of said fibers (16, 38, 59) along the said curved parts (20, 54, 69) from the hook part of said closure.