Patent Publication Number: US-2007101557-A1

Title: Bendable fastener strips

Description:
TECHNICAL FIELD  
      This invention relates to bendable fastener strips.  
     BACKGROUND  
      Fastener strips are frequently used as a closure or other type of fastening mechanism. Fastener strips can be found on a variety of items ranging from power tools to diapers, for example.  
      A fastener strip can be created by molding a group of fastener elements to extend from a fastener base. The fastener elements and the fastener base can be formed using various materials. Thermoplastic resin is an example of a material that can be used to form the base. The fastener elements can be configured to detachably engage with another material, e.g. a loop material or other fastener elements, in order to produce a fastening effect.  
     SUMMARY  
      In one aspect the invention features, a method of forming a fastener strip, including introducing molten thermoplastic resin into a gap formed between a pressure device and a peripheral surface of a rotating mold roll. The peripheral surface of the mold roll defines an array of cavities therein, and the molten resin is introduced under pressure and temperature conditions selected to at least partially fill the cavities to form projections molded integrally with and extending from a resin base. The method further includes introducing a deformable member into the gap with the resin such that the deformable member becomes integrally joined to the resin base as the resin cools. The resulting fastener strip is configured to be plastically deformed to a desired shape and to retain the desired shape without a significant amount of recovery.  
      In another aspect, the invention features a fastener strip, including a thermoplastic base having an array of integral projections extending therefrom, and a deformable member at least partially encapsulated within the thermoplastic base. The fastener strip is configured to be plastically deformed to a desired shape and to retain the desired shape without a significant amount of recovery.  
      Embodiments may include one or more of the following features.  
      In some embodiments, the method further includes introducing the deformable member into a guideplate defining a guide sleeve to position the deformable member relative to the gap.  
      In some embodiments, the method further includes introducing a loop material into the gap.  
      In some embodiments, the method includes introducing multiple deformable members into the gap.  
      In some embodiments, the multiple deformable members are introduced in a parallel configuration.  
      In some embodiments, the deformable member comprises at least one metal.  
      In some embodiments, the deformable member comprises a wire.  
      In some embodiments, the pressure device comprises a pressure roll that rotates counter to the mold roll.  
      In some embodiments, the mold roll and the pressure roll are internally cooled.  
      In some embodiments, the cavities are J-hook shaped to form J-hook shaped projections.  
      In some embodiments, the cavities are stem-shaped to form stem-shaped projections.  
      In some embodiments, the method further includes deforming the stem-shaped projections to produce mushroom-shaped projections.  
      In some embodiments, the fastener strip is configured to experience deflection when a force of about 300 grams or less is applied to the fastener strip, and to recover about 20 percent or less of the deflection when the force is removed.  
      In some embodiments, the deformable member is substantially fully encapsulated within the base.  
      In some embodiments, the fastener strip comprises multiple deformable members.  
      In some embodiments, the multiple deformable members are aligned in a substantially parallel configuration.  
      In some embodiments, the multiple deformable members are aligned longitudinally along the fastener strip.  
      In some embodiments, a loop material is attached to the base.  
      In some embodiments, the projections include engageable heads that overhang the base.  
      In some embodiments, the heads overhang the base in multiple directions.  
    
    
      Other features and advantages will be apparent from the description and drawings, and from the claims.  
     DESCRIPTION OF DRAWINGS  
       FIG. 1  is a broken perspective view of a fastener strip including deformable members.  
       FIG. 2  is a cross-sectional view of the fastener strip shown in  FIG. 1 .  
       FIG. 3  is a cross-sectional view of a fastener strip including fastener elements extending from opposite sides of a base.  
       FIG. 4  is a cross-sectional view of a fastener strip including fastener elements extending from one side of a base and loops extending from an opposite side of the base.  
       FIG. 5  is a cross-sectional view of a fastener strip having partially encapsulated deformable members.  
       FIG. 6  is a cross-sectional view of fastener strip having a loop material bonded to its surface.  
       FIG. 7  is a plan view of a fastener strip having crisscrossing deformable members.  
       FIG. 8  is a plan view of a fastener strip having transverse deformable members.  
       FIG. 9  illustrates a method and apparatus for forming fastener strips including deformable members.  
       FIG. 9A  is a view of a nip between a mold roll and a pressure roll.  
       FIG. 10  illustrates another method and apparatus for forming fastener strips including deformable members.  
       FIG. 11  illustrates another method and apparatus for forming fastener strips including deformable members.  
       FIG. 12  illustrates another method and apparatus for forming fastener strips including deformable members.  
       FIG. 13  is a front cross-sectional view of a fastener strip produced by the method and apparatus of  FIG. 12 .  
       FIG. 13A  is a side cross-sectional view of a fastener strip produced by the method and apparatus of  FIG. 12 .  
       FIG. 14  is a cross-sectional view of a fastener strip having a substrate as produced by an alternative method and apparatus of  FIG. 12 .  
       FIG. 15  is a cross-sectional view of a fastener strip having stems as produced by another alternative method and apparatus of  FIG. 12 .  
       FIG. 15A  is a cross-sectional view of a fastener strip having flat-top fastener elements as produced by another alternative method and apparatus of  FIG. 12 .  
       FIG. 16  illustrates another method and apparatus for forming fastener strips including deformable members.  
       FIG. 17  is a cross-sectional view of an initial base having deformable members as produced by the method and apparatus of  FIG. 16 .  
       FIG. 18  is a cross-sectional view of a fastener strip having deformable members as produced by the method and apparatus of  FIG. 16 .  
       FIG. 19  illustrates another method and apparatus for forming fastener strips having deformable members.  
       FIG. 20  is a front cross-sectional view of the apparatus of  FIG. 19 .  
       FIG. 21  illustrates another method and apparatus for forming fastener strips having deformable members.  
       FIG. 22  is a cross-sectional view of a fastener strip produced by the method and apparatus of  FIG. 21 .  
       FIG. 23  illustrates another method and apparatus for forming a fastener strip having deformable members.  
       FIG. 24  is a cross-sectional view of a fastener strip produced by the method and apparatus of  FIG. 21 .  
       FIG. 25  illustrates a backing tape used in the method and apparatus of  FIG. 24 .  
       FIG. 26  is a cross-sectional view of a molding device in the process of forming a fastener strip.  
       FIG. 27A and 27B  illustrate a method and apparatus for testing plastic deformability and recovery of a fastener strip. 
    
    
      Like reference symbols in the various drawings indicate like elements.  
     DETAILED DESCRIPTION  
      Referring to  FIGS. 1 and 2 , a fastener strip  30  includes a base  40 , an array of projections or fastener elements  34 , and multiple deformable members  110 . As will be described below, the deformable members  110  and the base  40  allow the fastener strip  30  to be bent (e.g., manually deformed) to a desired shape and to substantially retain that shape bent shape.  
      The base  40  can be formed from a thermoplastic resin, such as high density polyethylene. A suitable high density polyethylene is Exxon Mobil #6908, for example. Alternatively or additionally, other materials exhibiting suitable plasticity (e.g., materials that can be substantially bent without rupture) can be used. For example the base  40  can be formed from low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), polypropylene, polyurethane, nylon, vinyl, thermoplastic elastomers (e.g., Santropene®) and various combinations of the aforementioned materials.  
      The fastener elements  34  can be any of various fastener elements, such as hook-shaped elements, mushroom-shaped fastener elements, and flat top stems. As shown in  FIG. 1 , the fastener elements  34  include a stem portion  35  that extends from the base  40  and an engageable head portion  37 . More specifically, the fastener elements  34  are J-shaped hooks adapted to engage with loops of a loop material (e.g., a non-woven material, a woven material, a knit material, etc.). The head portion  37  can be shaped to engage with any of various suitable materials in order to provide a desired degree of fastening strength. In some embodiments, for example, the head portion  37  is designed to engage with other like fastener elements (e.g., mushroom-shaped hooks) to form a self-engaging fastener strip.  
      The fastener elements  34  are integrally molded with the base  40 . The base  40  and the fastener elements  34  are preferably formed of a single thermoplastic resin. However, the base  40  and the fastener elements  34  can be formed of different materials.  
      The deformable members  110  are permanently attached to the base  40 . More specifically, as shown in  FIG. 2 , the deformable members  110  are completely encapsulated by resin forming the base  40 . Encapsulation of the deformable members  110  stabilizes the deformable members  110  inhibiting their movement relative to the base  40 . This ensures that the deformable members  110  will be maintained in a predetermined alignment relative to each other, which can ensure that the fastener strip  30  will maintain a desired range of flexibility across its length and width.  
      Each of the deformable members  110  has mechanical properties selected to enable the deformable members  110  to be formed into different bent shapes and to substantially retain the respective bent shapes while remaining attached to the base  40 . This allows the fastener strip  30  to be bent into a desired shape when a user applies a bending force (e.g., bends the ends of the fastener strip toward one another) and to retain that desired shape after the bending force is released. The fastener strip  30  can be bent, for example, in a position that allows it to be easily grasped by the user. Similarly, the fastener strip  30  can be bent in a desired position so that it does not impede the user&#39;s ability to grasp surrounding objects.  
      The preferred mechanical properties of the deformable members  110  are dependent upon many variables. For example, the mechanical properties can depend on the thickness of the base  40 , the material from which the base  40  is formed, and the number and geometry of deformable members  110  attached to the base  40 . The preferred mechanical properties allow the deformable members  110  to be bent by the user such that the deformable members  110  are plastically deformed and the strain produced by the user is less than the relevant failure strain. Suitable materials for forming the deformable members  110  include those that exhibit plasticity (i.e., the material can be deformed plastically into a desired shape or shapes without rupture). The deformable members  110 , once bent, are capable of substantially retaining that bent shape while remaining attached to the base  40 . Due to the mechanical properties of the deformable members  110  and the base  40 , the fastener strip  30  can be bent into a desired shape and retain that shape.  
      As shown in  FIGS. 1-6 , multiple deformable members  110  are preferably arranged parallel to one another along the longitudinal direction of the base  40 . However, other suitable arrangements may be used. Referring to  FIG. 7 , for example, the deformable members  110  may be arranged in a crisscrossing pattern along the base  40 . Similarly, as shown in  FIG. 8 , the deformable members  110  may be arranged transversely across the base  40 . In addition, many other arrangements are contemplated. For example, the deformable members may be arranged diagonally. Furthermore, the deformable members may be restricted to discrete regions along the fastener strip, such that the fastener strip is retainably bendable only in those discrete regions.  
      The flexibility of the fastener strip  30  depends, in part, on the arrangement of the deformable members  110  with respect to the base  40 . For example, a longitudinally parallel arrangement of deformable members  110  will produce a fastener strip that can be retainably bent about the transverse direction of the fastener strip, but not about the longitudinal direction. Similarly, when the deformable members  110  are arranged in a transversely parallel direction along the fastener strip  30 , they can provide for retainable bending about the longitudinal direction, but not about the transverse direction. Arranging the deformable members  110  in a crisscrossing pattern provides for retainable bending in both the longitudinal and transverse directions.  
      The deformable members  110  are preferably deformable metal wires. However, any other suitably shaped device having mechanical properties that allow the deformable members  110  to be manually formed (e.g., bent) into a desired shape and to substantially retain that shape while remaining attached to the base  40  may be used. For example, the deformable members  110  may be in the shape of bars, plates, sheets, and/or strips. The deformable members  110  may be constructed of any suitable material or materials, such as metals (e.g., annealed steel, copper, aluminum).  
      The fastener strip  30  is configured to be plastically deformed to a desired shape and to substantially retain that shape without a significant amount of spring back or recovery. The plastic deformability and recovery can be tested using a testing apparatus like the one shown in  FIGS. 27A and 27B , for example. To test the deformability and recovery, fastener strip  30  is laid flat on a support  50  (e.g., a bench or a table) having a substantially flat top surface  51  and a relatively sharp edge  52 . The fastener strip  30  is arranged with an end  31  of the fastener strip overhanging the edge  52  of the support  50  by a distance d of about 15 millimeters. A force F of about 300 grams is then applied to the end  31  of the fastener strip  30 , causing the fastener strip  30  to plastically deform, as shown in  FIG. 27B . The deformed fastener strip  30  experiences deflection ρ of between about one degree and about 90 degrees. Upon releasing the force F from the end  31  of the fastener strip  30 , the deformed end of the fastener strip  30  springs back or recovers about 20 percent or less (e.g., 15 percent or less, ten percent or less, five percent or less, three percent or less, one percent or less) of the deflection ρ.  
      In certain embodiments, the fastener strip  30  is configured such that a force of less than 300 grams (e.g., 250 grams or less, 200 grams or less, 150 grams or less, 100 grams or less, 50 grams or less) can have a similar effect on the fastener strip. In such embodiments, the fastener strip  30  can become plastically deformed in response to the force F applied to its end  31  such that the fastener strip  30  experiences a deflection ρ of between about one degree and about 90 degrees and recovers about 20 percent or less (e.g., 15 percent or less, ten percent or less, five percent or less, three percent or less, one percent or less) of the deflection ρ.  
      Referring to  FIGS. 3-5 , other fastener strip embodiments are shown. As shown in  FIG. 3 , the fastener strip  30  may include fastener elements  34  extending from opposite sides of the base  40 . In another variation, as shown in  FIG. 4 , the fastener strip  30  may include fastener elements  34  extending from one side of the base  40  and a loop material  44  (e.g., hook-engageable loop material) extending from an opposite side of the base  40 . As shown in  FIG. 6 , the fastener strip  30  may include only loop material extending from one side of the base  40 . The loop material can, for example, be bonded to the base  40 , as discussed in more detail below. The loop material  144  is preferably a non-woven knit material. However, any suitable material capable of engaging a fastener element may be used.  
      Referring to  FIG. 5 , the fastener strip  30  includes deformable members  110  that are only partially encapsulated by the material forming the base  40  with fastener elements  34  extending from only one side of the base  40 . Of course the fastener strip  30  can include fastener elements  34  extending from both sides of the base  40 , fastener elements  34  extending from one side and loops of a loop material extending from another side, only loop material extending from one or both sides, or any other suitable arrangement of fastener elements and/or loop material.  
       FIG. 9  illustrates multiple methods and apparatus for producing the above described bendable fastener strip. The methods build upon the continuous extrusion/roll-forming method for molding fastener elements on an integral, sheet-form base described by Fischer in U.S. Pat. No. 4,794,028, and the nip lamination process described by Kennedy et al. in U.S. Pat. No. 5,260,015, each of which is incorporated by reference herein. An extrusion head  100  supplies a continuous sheet of molten resin  140  to a nip  102  between a rotating mold roll  104  and a counter-rotating pressure roll  106  (nip arrangement illustrated in  FIG. 9A ). The mold roll  104  contains an array of miniature, fastener element-shaped mold cavities  134  extending inward from its periphery for molding the fastener protrusions or elements  34  (shown in  FIGS. 1-5 ). Pressure in the nip  102  forces resin into the fastener element cavities and forms the substrate or base  40  (shown in  FIGS. 1-6 ). The formed product is cooled on the mold roll until the solidified fastener elements (e.g., hooks) are stripped from their fixed cavities by a stripping roll  108 . Along with the molten resin, the deformable members  110  are fed into the nip  102 , where they are bonded with the resin  140  and become permanently encapsulated within the substrate or base  40 . Thus, the product  162  that is stripped from the mold roll  104  includes both fastener elements  34  and deformable members  110  as illustrated, for example, in  FIG. 1  described above.  
       FIG. 9  indicates several variations of the above-described method. For instance, rather than introducing the deformable members  110  through the nip  102  and thereby joining them to the substrate as the substrate is molded, the deformable members may be joined to the substrate after the substrate has been formed, such as is indicated by the run  110 ′ of deformable members shown in dashed outline. In this case, a front face idler  122  is heated and has a contoured surface to bond the deformable members and the substrate in desired areas while not damaging the molded hooks.  
       FIG. 9  also illustrates a method and apparatus for producing a bendable fastener strip having engageable loops on one surface. In this method, the deformable members  110  are fed into the nip  102  along with the extruded resin  140 . The nip  102  is formed between the mold roll  104  and the pressure roll  106 , but in this embodiment, the mold roll  102  lacks element-forming mold cavities. A continuous strip of loop material  144 , as described above in reference to  FIG. 6 , is simultaneously fed into the nip  102 . The deformable members  110  and the loop material  144  are bonded to the resin of the substrate by pressure in the nip  102 .  
       FIG. 10  illustrates an alternative method and apparatus for forming the above-described bendable fastener strips. The contoured surface of an extrusion head  200  (sometimes called an injection head) is placed adjacent a mold roll  104  (mold roll  104  once again lacking fastener protrusion shaped cavities to produce the loop bearing strip of  FIG. 6 ), and a continuous flow of molten resin is injected under pressure into the gap  202  defined between the head  200  and the mold roll  104 , filling the gap  202  and forming the front and back faces of the substrate or base. The configuration and construction of the mold roll  104  is similar to that of  FIG. 8 . In this embodiment, the extrusion head  200 , rather than the pressure roll  106 , creates the pressure necessary to fill the molding cavities with resin and/or bond the loop material to the base. To create the loop bearing strip, such as that illustrated in  FIG. 6  above, using this method and apparatus the strip  144  of loop material is fed through a predetermined region of the gap  202 , and held up against the surface of the mold roll  104  by resin pressure in the gap  202 . The deformable members  110  are laminated to the back face of the substrate, while the molded product is retained on the mold roll  104 , by pressure supplied by the pressure roll  206 .  
       FIG. 10  also illustrates an alternative method and apparatus for producing the bendable fastener protrusion bearing strip illustrated in  FIG. 5 , for example. In this embodiment loop material  144  is not present and mold roll  104  has fixed fastener element molding cavities as described above with respect to  FIG. 9 . Resin alone is fed through the extrusion head  200  into the gap  202  between the extrusion head  200  and the mold roll  104  where gap pressure forces the resin to fill the mold cavities as previously described. The deformable members  110  are laminated to the back face of the substrate, while the molded product is retained on the mold roll  104 , by pressure supplied by the pressure roll  206  to produce a bendable fastener strip having protruding fastener elements.  
      In an alternative method and apparatus illustrated in  FIG. 10 , deformable members  110 ″ (as indicated by dashed lines) are fed directly into the gap  202 . The deformable members  110 ″ are preferably in the form of wire, rod, or bar, as discussed above. In this embodiment, the deformable members  110 ″ can become more fully encapsulated within the resin.  
       FIG. 11  illustrates an additional method and apparatus for producing the above described bendable fastener strip. In this embodiment an extruder head  300  supplies resin flows or films  140 ,  141  into the nip  102  formed by the mold roll  104  (the mold roll having fixed fastener element molding cavities  134  as described above with respect to  FIG. 9  to produce a product such as that illustrated in  FIG. 1 ) and the pressure roll  106 , respectively. The arrangement of the nip  102  is as described above in reference to  FIGS. 9 and 9 A. Simultaneous with the resin feed, multiple deformable members  310  are fed through an extrusion die of the extruder head  300  and into the nip  102  between the separate resin flows or films  140 ,  141 . Pressure and temperature conditions in the nip  102  force the resin flow or film  140  to flow into the molding cavities as described above, encapsulates the deformable members  310  within the resins  140 ,  141 , and bonds the separate resin flows or films  140 ,  141  to create an integral fastener strip having deformable members insulated within a substrate and fastener protrusions extending from a surface of the substrate.  
      The method and apparatus illustrated in  FIG. 11  are also capable of producing fastener strips such as that illustrated in  FIG. 6  and described above. In such an arrangement the mold roll  102  lacks fastener protrusion shaped cavities and the loop material  144  (shown as dashed lines in  FIG. 11 ), as described above with reference to  FIG. 6 , is fed directly onto the surface of the mold roll  102  prior to the entrance of the resin flow  140  into the nip  102 . The methods and apparatus of  FIGS. 9, 10 , and  11  are also capable of forming bendable fastener strips having both fastener protrusions (e.g., hooks or mushrooms) and loop fastener material capable of engaging the protrusions to form a fastening, as shown in  FIG. 4 . Using the above described techniques wherein the mold roll  104  has fastener protrusion forming cavities and the loop material  144  is fed into the nip or gap while resin and deformable members are introduced can yield a self-engageable fastener strip having both types of fastener elements.  
      Referring now to  FIG. 12 , a continuous fastener strip  600  is manufactured by feeding multiple deformable members  602  into a nip  604  formed by a rotating mold roll  606  and a counter-rotating pressure roll  608 . The deformable members  602  are laterally spaced apart from one another as they enter nip  604 . In order to control the lateral position of the deformable members as they enter the nip, guide rollers  616  are provided with individual grooves, one for each deformable member introduced, to prevent the deformable members  602  from wandering laterally as they approach the nip  604 . Furthermore, the pressure roll  608  has corresponding grooves that aid in aligning the deformable members  602  during the encapsulation process now to be described.  
      Simultaneously with the deformable members  602 , a band  610  of molten thermoplastic resin is introduced to the nip  604  from the extruder head  612 . Pressure and temperature conditions in the nip cause the molten resin to envelop the deformable members  602  and also cause a portion of the resin to fill hook shaped cavities  614  provided in the mold roll  606 . As the cooled mold roll continues to rotate, the resin and encapsulated deformable members remain adjacent the periphery of the mold roll until take-off rollers  618  and  620  act to strip the product  600  from the mold roll  606 , thus extracting the now solidified hooks  622  from their respective cavities  614 .  
      Referring now to  FIGS. 13 and 13 A, the product  600  has a thermoplastic resin base  632  with an upper surface  624  and a lower surface  626 . Loop-engageable hooks  622  extend from the upper surface  624 , each hook being an integral extension of the thermoplastic resin of the insulating body. Hooks  622  have a stem portion  623  and a loop-engageable head portion  625  that extends outward from the stem to overhang the upper surface  624 . The bottom surface  626  has peaks  628  corresponding to the deformable member guiding grooves in the pressure roll  608  with a valley  630  of reduced thickness separating adjacent peaks  628 . Each deformable member  602  is encapsulated within a peak  628  and separated from an adjacent deformable member by thermoplastic resin body  632 . In one example, the resin body  632  is of a deformable PVC material.  
      The position of deformable members  602  relative to the upper surface  624  and the lower surface  626  is dictated by the relative positions of the deformable member and the molten thermoplastic resin as they enter the nip and the flow dynamics of the molten thermoplastic resin within the nip. As illustrated in  FIG. 12 , by introducing the deformable members  602  above the extruder head  612  the tendency is for the deformable members to be relatively nearer the upper surface  624  of the final product  600  (as indicated by deformable members  602 ′ shown as dashed lines in  FIG. 13 ). Conversely, if the deformable members are fed from below the extruder head (as indicated by deformable member feed  602 A illustrated in dashed lines in  FIG. 12 ) the tendency is for the deformable members to be relatively nearer the lower surface  626  in the final product  600  (as indicated by deformable members  602 ″ shown as dashed lines in  FIG. 13 ). The deformable members can be introduced into the resin so that only a lower portion or an upper portion of the deformable member is encapsulated by the resin to produce a product as shown in  FIG. 5 , for example.  
      One alternative for controlling the vertical position of the deformable members  602  within the base  632  is to provide a supporting substrate  633  beneath the deformable members as the molding process takes place. As illustrated in  FIG. 12 , a substrate  633  (shown as dashed lines) is fed onto the grooved pressure roll  608  so that it sits on the peaks of the grooves of the roll. The substrate  633  can be any material that suitably allows the molten thermoplastic resin to flow through and encapsulate the substrate during the molding process. In one example, the substrate  633  is a mat of nonwoven fibers. The deformable members  602 A are then fed onto the substrate at positions corresponding to the guiding grooves of the pressure roll  608 . The somewhat resilient substrate  633  allows deformable members  602 A to enter only partially into their respective guiding grooves in the pressure roll  608 , thus allowing the lateral position of the deformable members to be controlled while preventing the deformable members from reaching the bottom of the grooves. Upon entering the nip, molten resin  610  flows upward to fill cavities  614  and downward through the substrate  633  to fill the grooves of the pressure roll, meanwhile the substrate  633  prevents the deformable members  602 A from sinking into contact with the pressure roll  608 .  
      The resulting product  600 ′, as shown in  FIG. 14 , has the supporting substrate  633  embedded beneath the deformable members  602  within the base  632 .  
      In an alternative embodiment, also illustrated in  FIG. 12  and further referring to  FIGS. 15 and 15 A, mold cavities  614  are of a shape protruding straight inwardly from the periphery of the mold roll  606  toward its center, i.e., the cavities  614  are shaped to form stems only and do not have an undercut portion for forming an engaging head of a fastener element. The rest of the fastener strip forming method proceeds as described above except the product  600 ″ ( FIG. 15 ) stripped from the mold roll has only integrally molded stems  622 ′ protruding from its upper surface  624 ′. Subsequent to the stripping operation, the strip  600 ″ is passed between a heated roller  634  and an anvil roller  636  (shown in dashed lines) to produce a final fastener strip  600 ′″ ( FIG. 15A ). Rollers  634 ,  636  are arranged so that the heated roller  634  contacts and deforms a tip portion  623 ′ of each stem  622 ′ to form a loop-engageable head portion  625 ′ that overhangs upper surface  624 ′.  
      Referring now to  FIGS. 16-18 , another technique for avoiding any potential problems of centering and/or fully encapsulating the deformable members within the base is to form the base in a two step process. Initially, an intermediate product  640  ( FIG. 16 ) is formed by feeding deformable members  602  and a band  610  of thermoplastic resin into a nip formed by two pressure rolls  644  and  646 . Similar to the pressure roll  608  described above with reference to  FIG. 12 , the lower pressure roll  646  has peak and valley forming grooves on its surface to aid in guiding the wires laterally, however, in this two step process, upper pressure roll  644  has a flat peripheral surface which forms the flat upper surface  648  ( FIG. 17 ) of the intermediate product  640 . The intermediate product  640  is then fed into a second nip  651  formed by a grooved lower pressure roll  650  and a mold roll  652  having hook cavities as described above. Simultaneously with the intermediate product  640 , a band of thermoplastic resin  654  is introduced from an extruder head  653  to the nip directly adjacent the periphery of the mold roll  652 , and hooks  656  (shown in  FIG. 18 ) are formed in a manner similar to that described above with reference to  FIG. 12 . The resulting final product  658  has a multi-layered structure including an upper, hook bearing layer  660  permanently bonded during the hook molding operation to a lower layer  662  that was initially formed as intermediate product  640 . The deformable members  602  are either fully encapsulated by lower layer  662  or are fully encapsulated by being sandwiched between the upper and lower layers  660 ,  662 , respectively.  
      Referring now to  FIGS. 19 and 20 , in yet another method for forming a continuous strip with integrally molded fastener element stems extending from a base, a die  670  is positioned just upstream of a nip  672 . The die  670  includes a deformable member guide plate  674  defining individual guide sleeves  676  each of which receives and guides a deformable member  678 . The guide sleeves  676  can be cylindrically shaped for receiving wires of round cross-section or can be of rectangular cross-section for receiving flattened members to produce relatively flat strips. Arranged perpendicular to the feed direction of the deformable members is an extruder  680  which introduces molten thermoplastic resin through a nozzle  681  to an internal resin flow path  683  defined by the die  670 . The flow path  683  directs the molten resin to flow above, below and between the plurality of deformable members  678  before the combination  682  of deformable members and molten resin is forced through a slot  684  and into the immediately adjacent nip  672 . Once the material is in the nip  672 , the molding process proceeds as described above with reference to  FIG. 12  with no further need for lateral or vertical wire guiding and/or alignment.  
      In one particular embodiment, illustrated in  FIGS. 21 and 22 , the deformable members and thermoplastic resin are fed through a nip  700  formed by two mold rolls  702 ,  704 , rotating in opposite directions. Each mold roll  702 ,  704  defines an array of hook (or stem) forming cavities  706 , similar to those described above. In the embodiment shown, two streams  708 ,  710  of molten thermoplastic resin are fed into the nip  700  while a plurality of laterally spaced apart deformable members  709 , in the form of flat strips, are introduced to the nip  700  between the streams  708 ,  710  of resin. Alternatively, the streams  708 ,  710  of resin can be initially two solidified thermoplastic resin films. The temperature and pressure conditions in the nip force the thermoplastic resin (whether initially molten or solid) to at least partially fill the cavities so that a solidified product  712  stripped from the exit side of the nip has loop-engageable fastener elements  714  (or stems that can be later post-formed as described above) protruding from opposite broad surfaces  716 ,  718  of the body  720  of thermoplastic resin.  
      Yet another method for producing fastener strips is illustrated in  FIGS. 23-26 . The method is a lamination process in which a pre-formed hook tape  730 , spaced apart deformable members  732  and a backing tape  734  are simultaneously fed between two bonding rollers  736 ,  738 . The pre-formed hook tape  730  is of a thermoplastic resin, having a base  740  defining first and second surfaces  742 ,  744 , respectively. Hooks  746  extend from the base  740 . The hooks  746  are protrusions of the thermoplastic resin of first surface  742  and are suitable for engaging a loop material. The hook tape  730  is fed between the pressure rolls  736  and  738  with its hook-bearing first surface  742  immediately adjacent the peripheral surface of the first pressure roll  736 . The backing tape  734  defines a first surface  748  and a second surface  750  and is fed between the rolls  736  and  738  with its first surface  748  immediately adjacent the peripheral surface of pressure roll  738 .  
      Simultaneously with the hook tape  730  and the backing tape  734 , a plurality of deformable members  732  is introduced between the pressure rolls  736 ,  738  in laterally spaced apart fashion. The deformable members  732  are positioned between the second surface  744  of the hook tape  730  and the second surface  750  of the backing tape  734 . The pressure roll  736  has a series of protruding rings  752  arranged to contact the first surface  742  of the hook tape  732  only along regions  753  of a forming laminate  754  that lie between the spaced-apart deformable members  732 . The rolls  736  and  738  are heated and positioned to create pressure in the regions  753  corresponding to each ring  752  such that thermal bonding occurs along the contacted regions of the laminate  754 . The thermal bonding lines act to permanently weld the hook tape  730  to the backing tape  734  in a manner that isolates the deformable members  732  from one another and at least partially encapsulates the deformable members between the hook tape and the backing tape. The pre-formed hook tape  734  can be provided with regions  753  distinguished by flat areas (as illustrated in  FIG. 24 ) on first surface  742 , i.e., areas lacking rows of hooks  746 . Alternatively, the first surface  742  of pre-formed hook tape can have a uniform array of hooks  746  across its surface, the hooks in regions  753  subsequently coming into contact with the rings  753  whereby the hooks are melted and or crushed by the applied pressure and heat. Either way, the hooks remaining on the surface  742 , i.e., those positioned between rings  752  during the lamination process, are sufficient to provide the necessary fastening capability with mating loop materials.  
      In another alternative, the pressure roll  736  acts as an anvil (rotary or stationary) while the pressure roll  734  is ultrasonically vibrated at a frequency which causes the hook tape  730  to be welded to the backing tape  734  along the regions  753  where the rings  752  contact the hook tape  730 .  
      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.