Patent Application
20050170157
The present invention relates to forming a composite product having projections that extend from a surface of a base.
There has been much development over the last thirty years in the field of hook-and-loop fasteners. Two such improvements are the development of continuous fastener tape molding using fixed mold cavities (see Fischer, U.S. Pat. No. 4,794,028) and the ability to provide loops on the back side of the male fastener tape as the fastener tape substrate and elements are being formed (see Kennedy et al., U.S. Pat. No. 5,260,015), thus creating a composite fastener tape capable of fastening to itself.
As another example of forming hook fasteners, described by U.S. Pat. No. 6,303,062, thermoplastic resin is extruded, at a relatively high temperature, onto protrusions of a sheet of protrusions. The extruded resin can then be stripped from the protrusions to deposit material thereon to form fastener elements with heads.
In general, the invention features a composite product and methods of making the product.
In one aspect, the invention features a method for forming a composite product. The method includes providing a projection component that includes discrete projections of resin that extend from a surface of a base. The distal ends of the projections are locally heated and the projections are foreshortened. A preformed substrate is applied to the distal ends to bond the preformed substrate and the projection component.
Implementations of this aspect can include one or more of the following features. For example, the projections can be foreshortened before, during and/or after applying the preformed substrate. In some cases, the preformed substrate is bonded to the distal ends of the projections within discrete bonding zones that are spaced-apart from the base. In certain cases, the substrate is removable (e.g., manually, mechanically) from the distal ends of the projections. In some cases, a material is carried by the substrate and bonded to the distal ends of the projections. The material can be selected from a group consisting of pigments, sand, silicone, fiberglass and paints. In some embodiments, the preformed substrate leaves an imprint within resin of the distal ends of the projections upon removal of the substrate.
In another aspect, the invention features a method of forming a composite product. The method includes providing a projection component that has projections that extend from a surface of a base. A preformed substrate is applied to the resin base such that at least one projection extends through the preformed substrate. The preformed substrate is affixed to the base by post-forming the at least one projection. In some cases, this aspect includes locally heating a distal end of the at least one projection. In some cases, post-forming the at least one projection may include contacting a distal end of the at least one projection with a contact surface.
Any of the above aspects can include one or more of the following features. The projections may be integrally molded with the base. In some cases, the distal ends of the projections are post-formed to form heads that overhang the base.
In a third aspect, the invention features a method for forming a fastener product having fastener elements comprising stem portions integrally molded with and extending from a sheet-form resin base and loop-engageable head portions. The method includes applying a preformed substrate to the stem portions forming an intermediate product having stems projecting through the preformed substrate and beyond an outer surface of the preformed substrate. The distal ends of the stems are heated and deformed to form head portions that overhang the sheet-form base.
Any of the above aspects can include one or more of the following features. For example, methods can include continuously introducing molten resin to a gap defined adjacent a periphery of a mold roll, such that resin forms at least a part of the base at the periphery of the mold roll and fills an array of fixed cavities defined in the rotating mold roll to form the projections. Methods can also include, solidifying the resin and stripping the resin from the periphery of the mold roll by pulling the solidified projections from their respective cavities.
In another aspect, the invention features a method for forming a fastener product having fastener elements comprising stem portions integrally molded with and extending from a sheet-form resin base and loop-engageable head portions. The method includes continuously introducing molten resin to a gap defined adjacent a periphery of a rotating mold roll, such that the resin forms at least a part of the base at the periphery of the mold roll and fills an array of fixed fastener element cavities defined in the rotating mold roll to form the fastener elements. The resin is solidified and stripped from the periphery of the mold roll by pulling the solidified fastener elements from their respective cavities. A preformed substrate is applied to the surface of the resin base forming an intermediate product having at least one of the fastener elements projecting through the sheet material and at least a portion of the at least one fastener element extending beyond an outer surface of the preformed substrate arranged to fasten the preformed substrate to the base. Implementations of this aspect can include heating and deforming the portion of at least one fastener element to affix the preformed substrate to the resin base.
In some cases, a plurality of stem portions of the fastener elements project through the preformed substrate and extend beyond an outer surface of the preformed substrate. Some or all of these stem portions may be heated and deformed.
Any of the above aspects can have one or more of the following features. Applying the preformed substrate may include pressing (e.g., from about 1 N/cm2 to about 100 N/cm2) the preformed substrate against the heated distal ends. In some cases, a pair of pressure rolls applies the pressure. The preformed substrate can be bonded without use of an adhesive (e.g., using only resin forming the projections). In some embodiments, the distal ends are heated to a temperature greater than that of the preformed substrate. The distal ends can be heated by a non-contact heat source. Suitable non-contact heat sources include flame, electrically heated nichrome wire and radiant heater blocks. The preformed substrate may include fibers. When distal ends of the projections are heated, material of the projections can encapsulate fibers of the preformed substrate.
In some cases, applying the preformed substrate includes foreshortening the distal ends of the projections, forming flat, foreshortened distal ends of the projections that are bonded to a surface of the preformed substrate. In some cases, resin of the projections encapsulates fibers of the preformed substrate. In some embodiments, the projections include heads that extend radially outward in one or more discrete directions. In some embodiments, the cavities form engageable heads. In some embodiments, the heads extend radially outward in multiple directions forming mushroom-shaped heads. The heads may be sized to engage mating elements, such as loops of a loop material. In some cases, the heads are sized to secure to the preformed substrate to the base.
The preformed substrate can be a film, a woven material, paper, a thermoplastic sheet, a non-woven web of fibers and/or a mesh material. The preformed substrate material can be any material suitable for attachment to the projections and does not necessarily soften upon contact with the heated distal ends of the projections. In some cases, the preformed substrate is a different material than the projections. In some embodiments, the preformed substrate can be formed of plastic, metal, or wood. In some cases, the preformed substrate comprises a fiberous material.
In another aspect, the invention features a composite product that includes a projection component having an array of molded projections of resin extending from a surface of the projection component. A preformed substrate has a surface that is bonded to resin of distal ends of the projections.
Implementations of this aspect may include one or more of the following features. The preformed substrate may be bonded to distal ends of the projections within discrete bonding zones that are spaced-apart from the surface of the projection component. In these cases, the composite can include an intermediate material between the preformed substrate and the surface of the projection component. In some embodiments, the intermediate material is a gas, such as air. In some cases, the intermediate material includes fibers, such as fastener-engageable fibers. In some cases, the intermediate material includes a foam. In some embodiments, the preformed substrate is removable from the distal ends of the projections. In some cases, the preformed substrate includes a bonding material carried by the preformed substrate that is deposited within resin of the projections. In some of these cases, the bonding material is selected from a group consisting of pigments, sand, silicone, fiberglass and paints.
In yet another aspect, the invention features a composite product that includes a projection component having an array of projections that include a head portion and a stem portion forming fastener elements extending from a surface of the projection component. The composite also includes a preformed substrate adjacent the projection component where the stems of the projection component extend into the preformed substrate.
Implementations of this aspect may include one or more of the following features. A head portion of at least one of the fastener elements may overhang a surface of the preformed substrate. In some cases, the head portion is sized to trap the preformed substrate adjacent to the projection component. In some cases, the head portion is arranged to engage loops of a loop material. In some cases, at least one fastener element is deformed to form an attachment to attach the preformed substrate to the surface of the projection component.
Implementations of the above aspects directed toward a composite product may include one or more of the following features. The preformed substrate can be bonded without the use of an adhesive (e.g., using only material forming the projections). The preformed substrate may be a different material than the projections. In some cases, the preformed substrate is a non-woven, a woven fabric, paper, a thermoplastic sheet material and/or a mesh. In some embodiments, the preformed substrate is formed of a material selected from plastic, metal and wood. In some embodiments, the preformed substrate has a thickness that is less than 40 percent, e.g., 20 percent or less, of a total thickness of the composite. In some embodiments, the preformed substrate has a higher softening point than the projections. In some cases, the projections include flat head portions that extend radially outward in multiple directions. In some embodiments, the head portion overhangs the preformed substrate. In some embodiments, the projections include thermoplastic resin. In some embodiments, thermoplastic resin of at least one projection encapsulates fibers of the preformed substrate. The preformed substrate may be porous or non-porous.
In another aspect, the invention features a method of preventing engagement of a fastener product includes providing a projection component comprising a first array of fastener elements having stems extending from a first broad surface of a base to heads; attaching a preformed substrate to the heads of the first array of fastener elements to bond the preformed substrate to the projection component within discrete bonding zones spaced-apart from the first broad surface of the base; attaching a second array of fastener elements to an opposite, second broad surface of the projection component, the second array of fastener elements capable of releasable engagement with the first array of fastener elements; and positioning the second array of fastener elements adjacent the preformed substrate, the preformed substrate providing a barrier between the first and second array of fastener elements.
Implementations of this aspect can include one or more of the following features. The first array of fastener elements can be formed of thermoplastic resin. In some embodiments, the substrate is attached to the heads without the use of an adhesive (e.g., the substrate can be bonded to the heads using only material forming the heads). The step of positioning the second array of fastener elements adjacent the preformed substrate includes rolling the fastener product to form a roll. The second array of fastener elements includes a loop material, e.g., the pile of a carpet. The step of positioning the second array of fastener elements adjacent the preformed substrate includes stacking discrete lengths of the fastener product to form a stack.
Embodiments of the invention can have one or more of the following advantages. In some cases, a composite is provided that includes a hook-engageable preformed substrate (e.g., non-woven, woven, knit) bonded to the projection component. In these cases, the projections can serve as stops to reduce compression of the substrate over relatively large areas so that fibers of the hook-engageable preformed substrate tend to retain loft (i.e., the probability that the hook-engageable preformed substrate will become compressed, leading to a reduction in hook-engagability, is reduced). In some embodiments, the composite can be used as an insulator by spacing the preformed substrate from the base of the projection component. The space can be filled with, e.g., air or any other suitable substance including fibers and/or foams.
In some cases, the preformed substrate can be bonded to the projections without the use of adhesives. In certain ones of these cases, the preformed substrate can be bonded to the projections using only material forming the projections (e.g., using only thermoplastic resin forming the projections). This allows a wide variety of preformed materials to be bonded to the projections, including relatively thin sheets of various materials and materials having relatively high softening points, such as metals. In addition, in some cases, it is not necessary to soften the material forming the preformed substrate for bonding to occur between the projections and the preformed material. As a result, preformed substrates need not be pre-heated for bonding to occur.
In some embodiments, the substrate can be removed (e.g., manually, mechanically, etc.) to expose an array of fastener elements capable of releasably engaging a mating fastener component. By providing a removable substrate, the fastener elements can be relatively protected, e.g., during storage and/or transport, to minimize damage to the fastener elements.
The substrate can provide a temporary barrier between fastener elements and an adjacent, mating component. This can facilitate handling and storage of inter-engageable fastener products, such as stacks or rolls of composite fastener products, by providing a barrier between adjacent matable elements.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features and advantages of the invention will be apparent from the description and drawings, and from the claims.
Like reference symbols in the various drawings indicate like elements.
Various methods described below utilize the continuous extrusion/roll-forming methods for molding fastener elements on an integral, sheet-form base described by Fischer in U.S. Pat. No. 4,794,028, the disclosure of which is incorporated herein by reference. The relative sizes and positions of the rolls and other components illustrated in the figures are schematic and are not to scale.
Referring particularly to
As an alternative, as illustrated by the dashed lines in
The cavities 22 extend inwardly to form stem-shaped projections 32 that are integrally molded with the base 15. The cavities can also be hook-shaped to form hook-shaped projections having head portions that overhang the base 15 and stem portions that are integrally molded with the base.
As resin travels around the periphery of mold roll 18, it is at least partially cooled, solidifying the resin. The projections 32 are then stripped from their respective cavities by a stripper roll 28 to form a projection component 52. Along with the resin 14, a sheet material (not shown) can also be introduced to the gap 16, allowing the sheet material to be partially impregnated by resin and become permanently bonded to a face of the resin base. This is described in detail by Kennedy et al. in U.S. Pat. No. 5,260,015, the disclosure of which is incorporated herein by reference.
After stripping the solidified resin from the mold roll cavities 22, the resin preform is directed to a heater 30 where distal ends of the projections are heated. As indicated in
To ensure that only a portion of the projection 32 is heated to the softening temperature, it is preferred that heating device 30 include a non-contact heat source that is capable of quickly elevating the temperature of material that is very close to the heat source, without raising the temperature of material that is relatively further away from the heat source. Suitable non-contact heat sources are disclosed, e.g., in U.S. Pat. No. 6,248,276, the disclosure of which is hereby incorporated by reference. Such heat sources can include flame heaters, electrically heated nichrome wire, and radiant heater blocks. To heat to the softening temperature without contact, the heat source typically must be at a relatively high temperature. For example, if the softening temperature is from about 100 to 140° C., the temperature of the heat source will generally be from about 300 to 1000° C. and the heat source will be positioned from about 0.1 to 30 mm from the tips of the stems. In some embodiments the temperature of the heat source may be about equal to the softening temperature of the stem-forming material. For example, in some embodiments, it is preferable to form stems of a polyamide (e.g., nylon) having a softening temperature of about 260° C. In these embodiments, the heat source can be about 260° C.
After the distal ends of the stems have been heated, the base 15 moves to a conformation head 40 that carries a preformed substrate 42 that is formed such that it is penetrable by projections 32. Preformed substrate 42 is delivered to a surface of the base 15 forcing projections 32 at least partially through the preformed substrate, while the projection component 52 passes between conformation roll 40 and drive roll 44. Conformation roll 40 forms the distal end of the projections into a desired head shape, while the preformed substrate is delivered to the projection component 52. Resin of the formed heads 46 encapsulates fibers of the preformed substrate, the heads serving to affix the preformed substrate 42 adjacent to the base 15 (see
Generally, preformed substrate 42 may or may not be fastener element engageable, but is porous enough to allow the projections 32 to extend into preformed substrate. Suitable preformed substrates for use in this embodiment include, for example, wovens, non-wovens, mesh products such as a screen, and foams. Depending, at least in part, on the height of the projections and thickness of the substrate, in some cases, projections 32 extend only partially through preformed substrate 42. It may be desirable for preformed substrate to be formed of an absorbent material to control fluid flow.
It is preferred that the temperature of conformation roll 40 (the forming temperature) be lower than the softening temperature of the resin material forming the projections. Maintaining the conformation roll 40 at this relatively low temperature has been found to prevent adhesion of the thermoformable polymer to the conformation roll. Generally, to obtain the desired forming temperature it is necessary to chill the conformation roll, e.g., by running cold water through a channel in the center of the roll, to counteract heating of the conformation roll by the heat from distal ends of the stems. If further cooling is needed to obtain the desired forming temperature, the drive roll may be chilled in a similar manner.
In some cases, it may be preferable to deliver preformed substrate 42 to the projection component prior to heating projections 32 and forming heads 46. This reduces encapsulation of, e.g., fibers, of preformed substrate 42 as projections 32 penetrate. After delivering preformed substrate 42 to the projection component, distal ends of projections 32 can be heated and post-formed, as described above. Using this variation, heads 46 can be formed that overhang preformed substrate 42 and serve to trap the substrate under the overhanging heads.
Referring now to
In some embodiments, the distal ends of the projections may be foreshortened and/or flattened with conformation roll 40 prior to delivering the preformed substrate to the heated distal ends of the projections 32. Where the distal ends are foreshortened and/or flattened prior to delivering the preformed substrate 56, it is preferable that a pressure roll be used to exert pressure on the preformed substrate 56 and projections 32 to bond the preformed substrate 56 to the distal ends of the projections 32. In some cases, heat from a heat source may be applied to soften the foreshortened and/or flattened distal ends prior to delivery of the preformed substrate to facilitate bonding between the substrate and the distal ends.
Importantly, the pressure exerted on the projections 32 within the gap is high enough to secure the preformed substrate 56 to the projection component 52 in the discrete bonding zones at the distal ends of the projections 32. The pressure is low enough, however, for the preformed substrate, within the bonding zones, to remain spaced-apart from the base 15 of the projection component 52.
In the embodiment shown in
Referring to
In the embodiments shown by
Referring particularly to
In some cases, it may be desirable to remove preformed substrate 56 after bonding the preformed substrate to distal ends of the projections 32 to expose, e.g., the overhanging heads. In these cases, preformed substrate 56 is bonded to distal ends of the projections such that the preformed substrate can be removed upon application of a sufficient peel force (e.g., by machine such as a take-up roll, by hand). Referring now to
In some embodiments, it is preferable that the peel force needed to remove preformed substrate 56 be low enough so that the preformed substrate can be removed from the ends by hand (see
Use of a removable preformed substrate may be particularly useful in, e.g., protecting the fastener elements from deformation during shipping and reducing unintended or unwanted fastener engagement between adjacent fastener products. For example, referring to
In cases where substrate 56 is removable, either the substrate or the projection component can be disposable. For instance, it may be desirable to bond the substrate to the heads of fastener elements to protect the fastener elements, e.g., from deformation during transport and storage. The substrate can be formed of a relatively inexpensive material, such as a polyester nonwoven, that can be e.g., discarded or recycled after removal. In other cases, it may be desirable to bond the substrate to a projection component to protect the substrate (e.g., to maintain loft). As described with regard to
The material and form of removable substrate can be selected as desired. Suitable materials for forming a removable preformed substrate include, e.g., polyester and polypropylene. The preformed substrate can be in in the form of woven materials, nonwoven materials, knit materials, mesh materials, and films including transparent or semi-transparent films to allow for viewing of the fastener elements through the transparent or semi-transparent film.
Referring back to
Referring now to
In a method similar to that shown by
Preformed substrate 56 can carry any other suitable material (e.g., silicon, fiberglass, powdered metals, magnetic materials, glass, adhesives, liquids including paints), to be deposited within the material forming the heads of the fastener elements. In some cases, a bonding agent is used to adhere the material to be deposited to the preformed substrate 56 prior to bonding the preformed substrate to the fastener element heads. The bonding material retains the material to be deposited on the preformed substrate and allows the material to be removed from the surface of the preformed substrate upon stripping the preformed substrate from the heads of the fastener elements. In some embodiments, a roller, such as a printing roller, applies the material to be deposited, and the bonding material, if one is used, to the preformed substrate prior to bonding the preformed substrate to the heads of the fastener elements. A transparent or semi-transparent preformed substrate can be used to view material carried by the preformed substrate and bonded to the heads of the fastener elements.
Referring back to
Referring now to
Referring now to
As discussed briefly above, in some embodiments the projections can serve as stops or spacers, e.g., to preserve loft of a substrate by reducing compression of the substrate while the composite is enagaged with a mating fastener component. For example, referring to
The following examples are intended to be illustrative and not limiting
An apparatus similar to that described with reference to
The nonwoven fabric was encapsulated by the plastic of the fastener element heads. The composite thus formed could be separated into its constituents by hand, one from the other, without destroying either the fiber layer or the fastener elements. The surface of the heads, with the fabric removed, manifested a somewhat rough imprinted pattern of random grooves. The fastener elements retained their ability to engage mating fastener elements.
Exactly the same set up as described above in Example A, however, a roll of nonwoven fabric identified as Lutradur 3025, formed of polyester fibers, available from Freudenberg was directed to the heads by a pressure roll where the fabric was bonded to the heads. As above, the nonwoven fabric was integrated into the plastic of the fastener element heads. The composite thus formed could be separated into its constituents by hand, one from the other, without destroying either the fiber layer or the fastener elements. The surface of the heads, with the fabric removed, manifested a somewhat rough imprinted pattern of random grooves. The fastener elements retained their ability to engage mating fastener elements.
Exactly the same set up as described above in Examples A and B, however, a roll of knit fabric identified as loop 3200, formed of polyester yarns, available from Velcro USA was directed to the heads by a pressure roll where the fabric was bonded to the heads. As above, the knit fabric was integrated into the plastic of the fastener element heads. The composite thus formed could be separated into its constituents by hand, one from the other, without destroying either the fiber layer or the fastener elements. The surface of the heads, with the fabric removed, manifested a somewhat rough imprinted pattern of relatively structured grooves. The fastener elements retained their ability to engage mating fastener elements.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. For example, in some cases, embodiments described above can be used in combination. It may be desirable to deliver a preformed substrate to the base of the fastener component, as described above, and then bond a second preformed substrate to the distal ends of the projections, in discrete bonding zones spaced from the base.
In another variation, projections are formed extending from opposite broad surfaces of a base. Referring to
Projection component 162 is then directed to a pair of heaters 174, 176 that heat distal ends of the stem-shaped projections 164 and a pair of conformation rollers 173, 175 that foreshorten the stem-shaped projections to form mushroom-shaped fastener elements having overhanging heads 172 that can engage mating fastener elements (e.g., loops).
The foreshortened distal ends are then directed to heaters 178, 180, that reheat the distal ends to soften the resin and then preformed substrates 56 are directed to the heated heads 172 of the fastener elements extending from each of the opposite broad surfaces of the base and bonded thereto by pressure rolls 182, 184 within discrete bonding zones that are spaced-apart from base 170.
Referring to
Other suitable methods can be employed to form the projection component. For example, a longitudinally extending projection extending from a base can be extruded. The longitudinally extending projection can then be cut at predetermined locations along the length of the longitudinally extending projection to form an array of discrete projections extending from the base. The base can be stretched to increase the distance between individual ones of the array of projections. The preformed substrate can then be bonded to the projection component as described above. In another embodiment, the projection component can be formed of woven fibers where at least some of the fibers extend upwardly from a base formed by the woven fibers. Accordingly, other embodiments are within the scope of the following claims.
