Patent ID: 12202177

Like reference numbers indicate similar elements.

DETAILED DESCRIPTION

Referring toFIGS.1and2, a method and apparatus10for manufacturing fastening products features a rotating mold roll14with a cylindrical surface formed from an axial stack of plates or rings that define an array of mold cavities. Mold roll14forms a pressure nip11(e.g., a pressure zone) in cooperation with a stationary pressure shoe12, into which nip a molten, viscous resin28is introduced. As shown inFIG.1, molding apparatus10uses a continuous extrusion/roll-forming method for forming touch fastener elements32on an integral, resin sheet-form base24. Molding apparatus10includes a stationary pressure shoe12, a mold roll14, a resin source16, and a take-off roll18. Pressure shoe12is used in place of a conventional counter-rotating pressure roll to generate nip pressure to push resin into the mold cavities of the mold roll. The mold roll is preferably a chilled roll, such as the mold roll described in U.S. Pat. No. 4,775,310 to Fischer. As shown inFIG.2, a pressure in nip11is created by pressure shoe12being flexed against resin28at the nip, engaging mold roll14through the resin. Mold cavities40of mold roll14extend inward from its periphery15. In many cases, the cavities are each shaped to form a loop-engageable fastener element with an overhanging head. In some other cases, the cavities are shaped to form straight stems without overhanging heads, and the resulting stems are later plastically deformed to form heads.

As shown inFIG.2, pressure shoe12is flexed in nip11to force resin28to enter and fill exposed molding cavities40under high pressure (e.g., greater than 100 psi). Mold cavities40are shown enlarged for clarity, but each cavity40has a molding volume of between 0.0027 and 0.05 cubic millimeters. The miniature size of mold cavities40requires shoe12to apply high pressure at nip11to fill the cavities with the viscous resin28, particularly at a running speed of at least ten meters per minute. As pressure shoe12forces some of the resin28into cavities40, excess resin forms the resin base24on the peripheral surface15of mold roll14, interconnecting the filled cavities that form fastener elements32.

After the resin28has been carried on the mold roll a time/distance sufficient to solidify the resin in the mold cavities40and mold roll surface, the resin is peeled from the mold roll, and out of the fixed cavities40, by take-off roll18at a second nip17(FIG.1). Mold roll14can be continuously cooled, e.g., by controlled flow of coolant through its interior, heat is extracted from the fastening product as the product travels from the first nip11to the second nip17. The heat removal solidifies fastener elements32(e.g., hooks), subsequently allowing elements32to be peeled from their fixed cavities. In other words, after hardening, the molded fastener elements are of a shape essentially corresponding to the shape of molding cavities40.

As shown inFIG.2, as mold roll14rotates with respect to shoe12, mold roll14progressively introduces mold cavities40to nip11to be filled with resin28under pressure. Pressure shoe12has an outer surface13that, as shoe12is held in a flexed position, outer surface13is curved upstream of nip11. Outer surface13and mold roll14define between them an entrance gap upstream of nip11, of decreasing gap width as the nip is approached. The gap width progressively decreases to form a minimum gap of width ‘g’ between shoe12and mold roll14, at which outer surface13has a slope essentially and locally parallel to a tangent line (not shown) of mold roll14. The minimum gap width ‘g’ may be, for example, between 0.025 and 0.075 millimeters.

As shown inFIG.1, resin source16is a nozzle (e.g., round or slot nozzle) configured to introduce molten resin28into nip11. In this example, the minimum gap width ‘g’ occurs at the same elevation as the axis of the mold roll (i.e., the shoe engages the side of the mold roll), and the resin is dropped into the pressure nip11from above. Alternatively, the shoe and mold roll may be vertically stacked (i.e., the shoe engages an underside of the mold roll), in which case nozzle16is configured to drape a flow of resin laterally into the nip. Suitable resin28materials include linear low-density polyethylene (LLDPE), polypropylene, and nylon. To form fastener elements of suitable strength and resilience, the molten resin28may be introduced with a viscosity of between 700,000 and 1,275,000 centipoise, for example.

In pressure nip11, resin28is subjected to normal and shear stresses as it moves under pressure between stationary (i.e., shoe) and a moving (i.e., mold roll) surfaces. As shown inFIG.2, a resin bead29(e.g., a slight accumulation of resin) forms upstream of the pressure nip11, from which bead resin is steadily drawn into pressure nip11by operation of the moving mold roll surface. Referring also toFIG.2A, because resin moves between a stationary and a moving surface, a velocity gradient ‘V’ and corresponding shear gradient form in resin28as the resin passes through nip11. It is theorized that the velocity gradient ‘V’ causes a churning of resin within the bead29, rotating toward the mold roll surface in the upper portion of the bead. Such churning effect is referred to herein as the Kopanski effect. It has been observed that, due to the Kopanski effect, bead29has an asymmetric shape, compared to a generally symmetric bead as would be formed between two counter-rotating rolls, and that the stream31of resin dropping into the nip curves slightly toward the mold roll. Resin source16is preferably positioned slightly toward the shoe side of nip11(seeFIG.1). In addition, it is believed that the shear gradient increases the temperature of resin28in the nip11, slightly decreasing the effective viscosity and aiding in cavity filling.

Pressure shoe12is made of a flexible material such as90A silicone. Other materials that can be used include fluorinated elastomers such as Kalrez® (FFKM) or Aflas® (TFE/P), with a preferred durometer range of between 60 and 90 shore A. Such materials are sufficiently heat-resistant and wear-resistant to withstand high resin temperatures and high pressures at the molding nip. Such materials can also stand significant elastic deformation while maintaining a sufficiently firm outer surface to apply pressure against resin28at the pressure nip. In this example, pressure shoe12is a cantilevered compliant blade, with one end26fixed to a stationary base27, and a second end25flexed under pressure in nip11. Base27may be a clamp that secures shoe12in one position, or may be adjustable to move shoe12toward and away from the mold roll to control the pressure in nip11.

As shown in dashed lines inFIG.1, in another example, molding apparatus10includes a pressure roll20and a substrate feeder22feeding a flexible substrate23into a third nip21, in which the substrate is laminated to resin28. The substrate or sheet-form material23may be comprised of one or more of several suitable materials. For example, substrate23may be a loop material, a non-woven fabric, a reinforcing scrim, a porous material, paper, or stable foam.

Pressure roll20forms third nip21with mold roll14downstream of first nip11. Preferably, resin base24is still flowable or moldable (e.g., not yet solidified) when entering third nip21, allowing pressure roll20to laminate resin base24to a surface of substrate sheet23. Additionally, pressure roll20may be configured to further force resin into the molding cavities of mold roll14under pressure in pressure nip21. Pressure roll20can operate in an absence of substrate feeder22, configured to further force the resin into the molding cavities without laminating a substrate sheet23.

Now referring toFIG.3, the molding apparatus may include, instead of a mold roll, a movable molding surface42such as a flat plate that moves downward with respect to pressure shoe12. Molding surface42forms a pressure nip11with pressure shoe12. Like the mold roll inFIG.2, molding surface42defines an array of molding cavities40aextending from a periphery of molding surface42. Molding surface42progressively introduces molding cavities40to nip11to be filled with resin28. The flat plate may be a portion of a recirculating belt, for example.

Referring toFIG.4, a different configuration of a pressure shoe12ais illustrated. Pressure shoe12ais a flexible strip with two ends fixed by clamps44. Strip12amay be a thick, silicone strip or a similar material. Shoe12ahas a side surface13afacing mold roll14, with a portion of the side surface13aforming a pressure nip11ain cooperation with mold roll14. Clamps44hold strip12ain a curved state (e.g., a flexed, bent state) in an absence of pressure in nip11a. Similar to the pressure shoe inFIG.1, outer surface13a, when pressed against nip11a, forms an entrance gap with mold roll14. The entrance gap progressively decreases in width upstream of nip11ato form a minimum gap between shoe12aand mold roll14, at which outer surface13ahas a slope essentially and locally parallel to a tangent line (not shown) of mold roll14. Optionally, a shoe reaction surface38(e.g., a ram), shown in dashed lines, is positioned on a side of strip12aopposite mold roll14. Ram38is operable to move strip toward and away from resin28in nip11a, controlling the pressure in the pressure nip11a. Clamps44may also adjust the pressure in nip11aby further bending strip12aagainst resin28in pressure nip11a.

Referring toFIG.5, a similar example of a pressure shoe is shown. In this example, the molding apparatus uses a strip that can be advanced when the surface of strip exposed to nip11bbecomes worn. Pressure shoe12bis a long, flexible strip with two ends respectively wound to spool rollers34and36. Spool roller34functions as a strip material supply, and roller36functions as a worn strip material take-up spool. Flexible strip12bhas a side surface13bfacing mold roll14, with a portion of the side surface exposed to pressure nip11b. The portion of side surface13bexposed to nip11bwears out due to the heat and friction in nip11bcaused by the high temperature of the resin and high molding pressures. A pair of fixed clamps44′ hold strip12bat each end, with each clamp44′ positioned between pressure nip11band a respective spooled end of strip12b. At least one of clamps44′ is selectively operable to advance strip12bsuch that spool roller34supplies strip material to present an unworn portion of strip side surface13bto nip11b. while roller36takes up worn strip material. Similar to the molding apparatus inFIG.4and shown in dashed lines, a ram38can alternatively be positioned on a side of strip12bopposite mold roll14, to control the pressure at nip11b.

Referring toFIG.6A, a pressure shoe12′ is illustrated in form of a flexible strip. Pressure shoe12′ is mounted on a shoe holder38a(e.g., a ram) that has a curved corner39for the shoe12′ to curve at the pressure nip11. Shoe12′ is fixed on one side to ram38aby a mechanical fastener49and extends along a surface of the ram past the curved corner39of the ram. In some embodiments, the corner39has a corner radius that, as the shoe extends along the corner, the shoe surface exposed to the nip forms a corner radius ‘R’ of approximately 12.7 millimeters, with the shoe12′ having a thickness ‘t’ of approximately 3.2 millimeters.

FIG.6Billustrates the pressure shoe12shown inFIGS.1-3. Pressure shoe12has a cantilevered compliant ‘blade’ shape. Shoe12has a wide end26configured to be fixed (e.g., clamped or fastened to a ram) and an overhanging, narrow end25that flexes under pressure. Narrow end25is narrow enough to permit pressure shoe12to flex, as shown inFIG.1. Shoe12has two wide surfaces13and52, including a working surface13that contacts the resin at the pressure nip. Pressure shoe12has a length ‘l’ that may be selected according to a desired width of the product, as discussed below with respect toFIG.7. The dimensions of pressure shoe, ‘l’, ‘w’, and ‘h’ may be, for example, 10.2, 15.2, and 0.32 centimeters, respectively. When shoe12is flexed in the molding apparatus, working surface13is placed in tension, contacting the resin at the pressure nip, while lower surface52is placed in compression under bending stress. Shoe12is sufficiently conformable to accommodate slight variations in diameter of the mold roll along its length. This can, for example, help to form a fastener product having a particularly uniform resin base (e.g., substantially flat with a more uniform thickness).

Thus, one potential advantage of using a stationary, compliant shoe instead of a counter-rotating roll is that the fastening product can be produced with a very thin base layer. Such fastening products can be held to very close dimensional tolerances. The increased uniformity of the resin base thickness may allow shoe12to form an ‘ultra-thin’ resin base with a thickness of less than 0.025 millimeter. A fastening product with an ultra-thin base can be used to lower resin usage while maintaining the same functional attributes from the integrally molded features. This is advantageous for cost-sensitive markets such as personal care as well as applications in transportation markets where weight savings is desirable. It similarly can provide an improved hand, perceived as more cloth-like and less plastic-like. Additionally, a thinner resin base translates into improved flexibility, improving the peel-performance of the product, meaning that the lanes of fastener elements can be peeled off one-by-one, as opposed to stiffer products in which several lanes are peeled off all at once.

Referring now toFIG.7, a molding apparatus10′ is arranged with multiple pressure shoes12spaced apart in a lateral direction, forming multiple pressure nips11′. Each pressure nip11′ is formed between a respective pressure shoe12and a common surface of a mold roll14′ Each pressure shoe12may vary in length to mold resin strips60of different widths. They may also vary in hardness, stiffness and other properties. Alternatively, instead of multiple separate pressure shoes, molding apparatus10′ may include one pressure shoe with multiple shoe portions that contact mold roll14′, defining respective pressure nips11′ with the mold roll. Similar to the molding apparatus shown inFIG.1, a take-off roll18′ peels the solidified resin strips60from the fixed mold cavities of mold roll14′. In some examples, a substrate feeder (not shown) such as the one illustrated inFIG.1introduces a substrate to be laminated to some or all of the resin strips60.

Referring toFIGS.8A and8B, fixed mold cavities40are shown extending from a periphery15of mold roll14. As shown inFIG.8A, the profile of a J-shaped mold cavity40defines a pedestal portion or chamber ‘P’ and a crook portion ‘C’. Mold cavity40has a total height ‘h1’ of between 0.25 and 2.0 millimeters. Mold cavity has a base length ‘l1’ of only about 0.5 to 1.25 millimeters. The shape of the pedestal portion ‘P’ and the crook portion ‘C’ is specifically designed to facilitate easy removal of the solidified fastener elements by the take-off roll. The cavities are ‘fixed’ in that they do not open to release the molded hooks; rather, the molded resin is elastically distended to pull the resin back out through the opening of the cavity.

Referring also toFIG.8B, each mold cavity40is defined between two concentric engraved rings43and45held tightly together. Rings43and45have cylindrical outer surfaces15′ that together form the peripheral surface15of mold roll14. Mold roll14is formed of multiple rings stacked and disposed about a mandrel (not shown), which keeps the rings tightly pressed against one another to avoid mold flash. Each ring43has a small recess47in form of a hook and, in cooperation with a mating recess47, forms a mold cavity40. In some examples, mold cavities40are defined within a single ring43, either as a depression in one side of the ring or as an opening extending through the full width of the ring, with the cavities partially bounded by flat side surfaces of adjacent rings. Mold cavities40each have an entrance area, at the molding surface, of less than about 1.5 square millimeters, and the cavities each define a total molding volume of at least 0.0027 cubic millimeters.

While the molding cavities and fastener elements of the embodiments above have been described and illustrated as being J-hook-shaped, the molding cavities and fastener elements can be of various other shapes. The molding cavities can, for example, be shaped to mold palm tree-shaped fastener elements, mushroom-shaped fastener elements, and/or stems. Some cavity shapes may be defined in a continuous sleeve about a mold roll mandrel rather than in stacked plates.

Referring now toFIGS.9and10, two different fastening products are shown. Both fastening products include a flexible sheet substrate23, a resin base24, and fastener elements32interconnected by the resin base. The touch fastener elements32have discrete, spaced-apart resin stems extending from base24, and may be disposed at a density of, for example, 155 to 775 fastener elements per square cm. The fastener elements have heads that overhang the sides of their stems for releasable engagement of fibers. The fastening product inFIG.9may be manufactured, for example, by the molding apparatus inFIG.1. As illustrated inFIG.9, flexible sheet substrate23is laminated to thin resin base24from which touch fastener elements32extend. Resin base24is thin and flexible enough to not significantly impair the flexibility of the sheet. Substrate23may be a fabric, for example, a woven or knit material. In other examples, the substrate is a non-woven product, or a paper or film.

In the embodiment illustrated inFIG.10, a flexible sheet substrate23carries spaced-apart, parallel, longitudinal lanes or strips60of touch fastener elements. Fastening product30may be manufactured, for example, in the molding apparatus shown inFIG.7, by introducing a substrate sheet to be laminated to the back of the resin strips60. The resin strips or lanes60each have a thin resin base24laminated to a side surface62of substrate23. Each lane60has a width ‘wL’ controllable by the amount of resin disposed in the pressure nip and dependent, among other conditions, on the pressure applied at the pressure nip and the length of the pressure shoe. The width ‘wL’ may be, for example, from 3 to 27 millimeters and may be separated from adjacent lanes by exposed widths of the substrate surface, which widths depend on the distance separating the pressure shoes (seeFIG.7). Resin bases24may have a thickness of 0.075 millimeters or less, as measured from the substrate surface, and in some cases are of negligible thickness. The touch fastener elements32may be disposed in arrays with rows and columns of fastener elements. While illustrated for simplicity with fastener elements in only some regions of the lanes, it will be understood that each lane60is essentially covered with its array of fastener elements32. In some cases, each lane consists of a longitudinal series of discrete islands of fastener elements (e.g., created by interrupted introduction of resin at the pressure nip), each surrounded by exposed substrate. Such striated fastening product30can be cut into discrete fastener products, such as fastening tabs for diapers and other disposable personal care products, or to produce bandages or fastening straps, for example.

Referring toFIG.11, a molding apparatus10csimilar to the molding apparatus inFIG.1is illustrated. Molding apparatus10cuses a similar ‘extrusion/roll-forming’ method as the molding apparatus inFIG.1. Molding apparatus10chas a substrate feeder22that introduces a flexible sheet substrate23into a pressure nip11c. Substrate23moves along outer surface13cof pressure shoe12cto enter pressure nip11cfrom upstream of pressure nip11c. Like in the molding apparatus inFIG.1, the pressure nip is formed between stationary pressure shoe12cand mold roll14. The pressure in nip11cis created by pressure shoe12cbeing flexed at the nip, engaging mold roll14through the substrate23and resin28. Pressure shoe12cis flexed in nip11cto force resin28to enter and fill exposed molding cavities under significant pressure. As shoe12cforces resin28into the cavities of mold roll14, excess resin forms a base24c, interconnecting the filled cavities that form fastener elements32.

As discussed herein, another advantage of using a stationary compliant shoe instead of a counter-rotating roll is that the substrate can be melted to strengthen the product and form a transparent ‘window’ with fastener elements. For example, substrate feeder22may supply a material that can be melted (e.g., a non-woven substrate) such as a spunbond sheet23. With a spunbond sheet, molding apparatus10ccan form a fastening product that has a longitudinal window of resin, by continuously melting a portion of the sheet when laminating the resin to the sheet. Referring also toFIGS.12A and12B, a front view and a side view are illustrated showing the lamination and melting process of substrate23. It is theorized that the difference in temperature between the surface of the chilled mold roll14(e.g., around 4 to 21 degrees Celsius) and the surface of pressure shoe12c(e.g., about the temperature of the molten resin) causes a section of the substrate to melt at the nip11c. More specifically, unlike in a setup with two counter-rotating chilled rolls, the resin28is not chilled uniformly (i.e., the resin facing the mold roll chills first and stops recirculating), leaving hot resin exposed to substrate23for a sufficient time to melt a portion23aof the substrate and contact the pressure shoe12c. The melted portion23aof the substrate mixes with the resin forming resin base24cthat links the two unmelted sides of the substrate. The flowable resin28facing shoe12ccontinues to recirculate creating a sharing effect in the resin (as discussed above with respect toFIG.2A) which decreases the viscosity of the resin, allowing the resin to migrate laterally between the shoe12cand the substrate23. The resin28is able to further migrate laterally under pressure due to the compliant surface of shoe12c, forming wings28aof tapering thickness extending from the resin base24c. The resin wings28athat extend from each side of base24care each laminated to the back of a respective unmelted section of the substrate. This process forms a longitudinally continuous window with fastener elements on one side and a generally uniform resin surface on the opposite side. After the resin28has been carried on the mold roll a time/distance sufficient to solidify the resin in the mold cavities and mold roll surface, the resin is peeled from the mold roll, and out of the fixed cavities, by take-off roll18at a second nip17c. Alternatively, a compliant counter-rotating pressure roller can be used instead of pressure shoe12cto produce a similar product with a transparent window.

As shown inFIG.12B, a width of the melted portion23a(and by extension the width of the window37) can be approximately the same as a diameter of the resin stream or column28before entering the pressure nip. It is theorized that the resin28melts the substrate soon after initial contact (e.g., before the resin spreads considerably on the substrate), which causes the resin to melt the substrate only along a width generally equivalent to the diameter of the resin column28. Thus, by controlling various parameters of the molding apparatus10c(e.g., running speed of the mold roll and the resin flow rate), the rest of the resin is laminated to a back of the substrate, creating window37with a width ‘Ww’ generally equivalent to the diameter ‘D’ of the resin stream31. The window width ‘Ww’ and resin diameter ‘D’ may be, for example, 6.5 millimeters each, with the mold roll14running at a speed of at least ten meters per minute. The base24cand wings28atogether may be formed with a width ‘WB’ of around 25.5 millimeters.

FIGS.13A and13Bshow the fastening product30formed in molding apparatus10c. The product30has a longitudinally continuous window37of resin with a resin base24cthat extends beyond a bottom surface of the substrate23and from which wings28aextend. The resin base and wings are a contiguous formation free of melt lines. Resin base24cis generally coplanar with the top surface of the substrate23. As shown inFIG.13B, window37is bounded by exposed regions23′ of the substrate. Fastening product30can be used, for example, in applications where resin28is transparent (e.g., having a high transmittance of visible light), allowing a user to see an image beneath the fastening product30through window37when the product is engaged. Such applications may range from functional medical devices that require a transparent fastener material, to personal care products in which aesthetics can be enhanced by allowing the view of a printed pattern. Another advantage of melting the substrate to form a window of resin is that the transition from resin base24cto substrate23is smoother compared to a laminated product with a resin base extending from the substrate. For example, as shown inFIG.13A, the top surface of resin base24cand the top surface of substrate23are generally coplanar, such that the hooks32appear to be extending directly from the substrate23. This feature may allow the product to feel smoother to the touch and may improve the aesthetic appearance of the product. In some examples, fastening product30can be formed with longitudinal islands of fastener elements (e.g., created by interrupted introduction of resin at the pressure nip), with each island having a window37surrounded by exposed substrate.

In addition, instead of a window bounded by exposed regions of substrate, molding apparatus10cmay produce a fastening product melting the entire substrate as it passes through the nip. Melting and mixing the entire substrate23with resin28at the nip may produce a stronger product and improve the molding process by requiring less resin. For example, instead of laminating a substrate to the resin (e.g., producing two distinct layers), melting and mixing a substrate with resin reinforces the product by increasing a tensile strength of the solidified product. This allows the molding apparatus to mold fastening products with less resin while producing a stronger product. The higher strength may translate to a thinner and lighter fastening product.

Referring toFIG.14, a different configuration of a molding apparatus10dis illustrated. Molding apparatus10dis similar to the molding apparatus inFIG.1, with the main differences being (a) the presence of a wiper or scraper70downstream of the pressure nip11dand (b) the structure of the mold roll14d. Like the apparatus inFIG.1, pressure nip11dis formed between stationary pressure shoe12dand mold roll14d. The pressure in nip11dis created by pressure shoe12dbeing flexed at the nip, engaging mold roll14dthrough the resin28. Alternatively, a counter-rotating pressure roller can be used instead of pressure shoe12c. Referring also toFIG.15A, the mold roll surface includes raised surface portions13dbounded by channels or grooves41. The raised portions13dtogether make the molding surface15dof mold roll14d. The surface channels41are interconnected, and extend from one mold cavity to another. Surface channels41have a width ‘wC’ similar to the size of the opening of the mold cavities and ranges, for example, from 0.1 to 0.8 millimeters. Pressure shoe12dis flexed in nip11dto force resin28to enter and fill exposed molding cavities40dand surface channels41under pressure. As shoe12dforces resin28into the cavities and channels of mold roll14d, excess resin forms a base24dinterconnecting the filled cavities and surface channels that form the fastener product. Wiper70then removes (i.e., wipes or scrapes off) resin base24dfrom the raised portions13d, preferably before it has solidified, exposing the raised portions to leave resin only in the mold cavities40dand channels41. After the excess resin is wiped from mold roll14d, take-off roll18dpeels the solidified resin product from the mold cavities and surface channels in the form of a continuous web. Alternatively, instead of using wiper70to remove the resin base24d, pressure shoe12dcan apply sufficient pressure at the nip11dto remove the resin from the raised surface portions13d(e.g., acting as both, a reaction surface and a wiper). In some examples, molding apparatus10dcan be configured without wiper70and instead, mold a product with a resin base (e.g., with the shoe leaving resin on the surface of the mold roll) to be later burned to form the continuous web, as discussed in detail with respect toFIG.16A.

FIG.16shows the continuous web30dof interconnected threads25dproduced by molding apparatus10d. The product30dincludes resin threads25dformed in surface channels41of the mold roll, and fastener elements32dformed in mold cavities40dof the mold roll. Threads25dform a network that interconnects fastener elements32d, forming an integral, flexible meshing product. Threads25dbound apertures71which are formed on the mold roll or after striping the web from the mold roll, as discussed above with respect toFIG.14. The threads25dthat make up the framework of the product are in substantially an as-molded, unstretched state without significant residual stresses. Because the fastener elements extend from threads rather than a solid resin base, the netting product30dhas less material which may reduce the weight of the product. Fastening product30dcan be used in filtering systems and other applications where allowing fluid or solids to pass through openings71can be advantageous. Some examples include geotextiles, breathable garments, and blood pressure cuffs.

Because fastener product30dis molded under pressure in nip11dand doesn't require additional processing (e.g., cutting or stretching) for forming the net-like openings71, the openings can be configured in a wide variety of shapes and sizes, providing the fastener product30dwith a desirable porosity and flexibility.

Referring now toFIG.15B, an exploded view of two mold roll rings76and78is shown, with the rings spaced apart to view one of the molding cavities. Mold roll14dis formed of multiple rings stacked and disposed about a mandrel (not shown), which keeps the rings tightly coupled to one another. Rings76and78cooperate to define multiple fastener-shaped (e.g., hook-shaped) molding cavities40d. In this example, first ring78cooperates with second ring76(e.g., when the rings are pressed together) to define mold cavities40dand surface channels41. Rings76and78are stacked together such as to leave a gap between both rings sufficiently small to prevent resin from entering such gap. When assembled, peripheral surface84of rings76and78help define the outer surface15dof mold roll14d. The surface channels include peripheral channels41aand transverse channels41bthat intersect at multiple points. The channels may be formed by aligned recesses in the rings. The depth ‘d’ of surface channels41is generally between 0.02 and 0.5 millimeters, with hook cavities extending another 0.19 to 2.5 millimeters deeper than the surface channels. The dimensions (e.g., depth and width) of the channels may vary, for example, to match cavities of different shapes or to increase the thickness of the product. Additionally, the configuration of the channels41may be other than a square configuration (i.e., which forms a square netting product), such as a diamond configuration, or any polygonal configuration, in order to form products with a different netting configuration.

Referring back toFIG.14, a heating device87may be alternatively used to form the fastener product30dshown inFIG.16. Heating device87may be used in absence of wiper70, with the molding process carried out such that a film of resin is left on the raised surfaces15dof the mold roll to solidify and become integral with resin threads25d, as shown inFIG.16A. Thus,FIG.16Adepicts a product30′ formed when resin base24dis not removed by wiper70or pressure shoe12d. In fastening product30′, the resin threads25dextend from a thin resin base24d. Referring also toFIG.17A, resin base24dhas a thickness ‘tB’ of approximately 0.025 millimeters. As shown inFIG.14, heating device87is positioned to apply heat from a side of the fastener product30′ opposite the fastener elements32d. Heating device87is disposed downstream of the take-off roll18d, arranged to melt (e.g., by flame treatment) the resin base between the threads, leaving only the threads25dand hooks32d, as shown inFIGS.17B and16.

Referring back toFIG.14, a pressure roll20dmay be used to laminate a substrate23dto the resin disposed in the surface channels of the mold roll. Pressure roll20dforms a nip with mold roll14ddownstream of molding nip11d, and is configured to laminate the substrate to the resin in the channels after the resin base24dhas been removed from the mold roll14d. In a preferred embodiment, pressure roll20dfeatures a compliant surface made, for example, of a resilient external layer such as urethane elastomer. The compliance of the relatively soft surface of pressure roll20dresults in a relatively wide contact area between the pressure roll and the mold roll14d, and helps to slightly push the substrate into the surface channels41, allowing the substrate to be firmly laminated to the resin in the surface channels41. After substrate23dis laminated to the resin and the resin is allowed to solidify, the substrate and resin are stripped together from the molding surface by take-off roll18din the form of a web laminated to a substrate, as shown inFIG.18.FIG.18depicts the continuous web of resin threads25dlaminated to the substrate23d, with the apertures71between the threads being covered by substrate23d.

Referring now toFIG.19, fastener elements may also be formed by deforming stems of resin after stripping the stems from the molding cavities. For examples, the cavities of the mold roll may have only a stem forming portion, configured to form stems that extend from the resin base24d. The stems can then be post-treated to form engaging heads. For example, after molding and stripping the product from the mold roll, the tops of the molded stems can be deformed by pressing against a heated pressure roller114, or first heated by a heater116and then pressed against a chilled pressure roller114, to create discs or other shapes that overhang the base of the product and are capable of engaging, e.g., loop material or like fastener elements.

Referring toFIGS.20and21, a different configuration of the mold roll14dand product shown inFIG.14is formed of hook rings176and spacer rings178. Similar to the rings shown inFIG.15B, hook rings176define the mold cavities140of the mold roll illustrated inFIG.20. Each hook ring176has a first side surface that defines recesses147in form of fastener hooks. Each hook ring is sandwiched between two spacer rings178that defines raised edge regions142that form part of the outer surface of the mold roll. Valleys formed between aligned raised edge regions of the spacer rings, and the edges of the mold rings176, define the channels141that form the resin threads125of the fastening product130shown inFIG.21. Fastening product130is a continuous web similar to the product inFIG.16. Fastening product130defines fastener elements132in the shape of mold cavities140, extending from resin threads125. The apertures171of product130are formed by the raised edge portions of the spacer rings.

While a number of examples have been described for illustration purposes, the foregoing description is not intended to limit the scope of the invention, which is defined by the scope of the appended claims. There are and will be other examples and modifications within the scope of the following claims.