Releasable fastenings with barriers

Abstract

A releasable fastening features a first fastening strip including an elongated, flexible base carrying an array of discrete fastener elements arranged in rows and columns, and a second fastening strip configured to releasably engage with the first fastening strip. The first fastening strip also includes a longitudinally continuous rib supported by the upper surface of the base of the first fastening strip, the rib extending sufficiently far from the base of the first fastening strip to engage a sealing portion of the second fastening strip, and of a bending strength sufficiently low that the rib is placed in an elastically bent state, when the first and second fastening strips are in the engaged state, thereby forming with the sealing portion of the second fastening strip a non-interlocking barrier to resist flow across the fastening with the first and second fastening strips in the engaged state.

What is claimed is: 
     
         1 . A releasable fastening comprising:
 a first fastening strip comprising an elongated, flexible base carrying an array of discrete fastener elements arranged in rows and columns, the array extending across a portion of a width of the base, each of the fastener elements having a resin stem extending from an upper surface of the base, and a lip disposed at a distal end of the stem and overhanging the base; the upper surface of the base and the stems of the fastener elements together forming a contiguous mass of resin; and   a second fastening strip configured to releasably engage with the first fastening strip, the second fastening strip comprising a flexible base with a field of fastener elements carried on a fastening side thereof, the field of fastener elements arranged to overlap with the array of discrete fastener elements of the first fastening strip, such that when the first and second fastening strips are brought into engagement the overhanging lips of the discrete fastener elements of the first fastening strip cooperate with the fastener elements of the second fastening strip to releasably hold the first and second fastening strips in an engaged state;   wherein the first fastening strip also comprises a longitudinally continuous rib supported by the upper surface of the base of the first fastening strip, the rib extending sufficiently far from the base of the first fastening strip to engage a sealing portion of the second fastening strip, and of a bending strength sufficiently low that the rib is placed in an elastically bent state, when the first and second fastening strips are in the engaged state, thereby forming with the sealing portion of the second fastening strip a non-interlocking barrier to resist flow across the fastening with the first and second fastening strips in the engaged state.   
     
     
         2 . The fastening of  claim 1 , wherein the lip of each of the fastener elements of the first fastening strip overhangs the base in a longitudinal direction of the base. 
     
     
         3 . The fastening of  claim 1 , wherein at least a portion of the rib forms a part of the contiguous mass of resin. 
     
     
         4 . The fastening of  claim 1 , wherein the field of fastener elements of the second fastening strip comprises an array of discrete fastener elements configured to interlock with the fastener elements of the first fastening strip. 
     
     
         5 . The fastening of  claim 1 , wherein the rib is disposed between two portions of the array of discrete fastener elements of the first fastening strip. 
     
     
         6 . The fastening of  claim 1 , wherein the rib is positioned outboard of the array of discrete fastener elements of the first fastening strip. 
     
     
         7 . The fastening of  claim 1 , wherein the second fastening strip has a rib stop extending from the fastening side of the base of the second fastening strip and positioned to engage a portion of the rib with the rib in its elastically bent state. 
     
     
         8 . The fastening of  claim 7 , wherein the rib stop comprises a column of discrete fastener elements. 
     
     
         9 . The fastening of  claim 7 , wherein the rib stop comprises a substantially straight, upstanding spine. 
     
     
         10 . The fastening of  claim 1 , wherein the rib has a height, as measured from the upper surface of the base of the first fastening strip, that is between about 0.8 and 3 times an overall width of the rib, excluding any fillets. 
     
     
         11 . The fastening of  claim 1 , wherein the rib has a height, as measured from the upper surface of the base of the first fastening strip, that is at least 5 times an overall width of the rib, excluding any fillets. 
     
     
         12 . The fastening of  claim 1 , wherein the rib comprises a substantially straight, upstanding spine terminating in a slender distal tip. 
     
     
         13 . The fastening of  claim 12 , wherein the spine has a height, as measured from the upper surface of the base of the first fastening strip, that is greater than that of the fastener elements. 
     
     
         14 . The fastening of  claim 12 , wherein the bending strength of the rib is sufficiently low to allow the rib to at least partially buckle when the first and second fastening strips are in the engaged state. 
     
     
         15 . The fastening of  claim 1 , wherein the rib extends directly from the upper surface of the base of the first fastening strip to a distal rib edge that overhangs the upper surface of the base of the first fastening strip in a relaxed state. 
     
     
         16 . The fastening of  claim 15 , wherein the distal rib edge overhangs the upper surface of the base of the first fastening strip in a lateral direction of the base. 
     
     
         17 . The fastening of  claim 1 , wherein the sealing portion of the second fastening strip comprises a pedestal structure positioned on the fastening side of the base of the second fastening strip. 
     
     
         18 . The fastening of  claim 1 , wherein the sealing portion of the second fastening strip comprises the base of the second fastening strip. 
     
     
         19 . The fastening of  claim 1 , wherein the first fastening strip further comprises a pedestal structure extending directly from the upper surface of the base of the first fastening strip, and wherein the rib extends directly from the pedestal structure. 
     
     
         20 . The fastening of  claim 1 , wherein the rib is a first rib, and wherein the sealing portion of the second fastening strip comprises a second longitudinal rib positioned on the fastening side of the base of the second fastening strip. 
     
     
         21 . The fastening of  claim 20 , wherein the height of the first rib is less than a height of the fastening elements. 
     
     
         22 . The fastening of  claim 1 , wherein the rib comprises a wedge-shaped structure defining a relatively thick base section continuously tapering to a relatively narrow convex peak. 
     
     
         23 . The fastening of  claim 22 , wherein the rib is a first rib, and wherein the sealing portion of the second fastening strip comprises at least two second ribs defining a trough therebetween, the second ribs positioned on the fastening side of the base of the second fastening strip such that the first rib is received by the trough when the fastening strips are in the engaged state. 
     
     
         24 . The fastening of  claim 23 , wherein the second ribs are wider than the first rib. 
     
     
         25 . A releasable fastening comprising
 a first fastening strip comprising an elongated, flexible base carrying an array of discrete fastener elements arranged in rows and columns, the array extending across a portion of a width of the base, each of the fastener elements having a resin stem extending from an upper surface of the base, and a lip disposed at a distal end of the stem and overhanging the base; the upper surface of the base and the stems of the fastener elements together forming a contiguous mass of resin; and   a second fastening strip configured to releasably engage with the first fastening strip, the second fastening strip comprising a flexible base with an array of discrete fastener elements carried on a fastening side thereof, the field of fastener elements configured to interlock with the fastener elements of the first fastening strip to releasably hold the first and second fastening strips in an engaged state;   wherein the first fastening strip also comprises a longitudinally continuous rib that extends from the upper surface of the base of the first fastening strip to a longitudinally continuous peak; and   wherein the second fastening strip has a longitudinally continuous, convex surface region arranged to engage the peak of the rib of the first fastening strip in the engaged state, such that tension between the fastener elements of the first and second fastening strips balances a compressive force between the peak and convex surface region in the engaged state, thereby forming a non-interlocking barrier to resist flow across the fastening with the first and second fastening strips in the engaged state.   
     
     
         26 . The fastening of  claim 25 , wherein the first fastening strip comprises two parallel ribs with respective peaks separated by a distance less than a width of the convex surface region. 
     
     
         27 . The fastening of  claim 25 , wherein the convex surface region is of a compressible material carried on the upper surface of the fastening side of the base of the second fastening strip. 
     
     
         28 . A releasable fastening comprising
 a first fastening strip comprising an elongated, flexible base carrying an array of discrete fastener elements arranged in rows and columns, the array extending across a portion of a width of the base, each of the fastener elements having a resin stem extending from an upper surface of the base, and a lip disposed at a distal end of the stem and overhanging the base; the upper surface of the base and the stems of the fastener elements together forming a contiguous mass of resin; and   a second fastening strip configured to releasably engage with the first fastening strip, the second fastening strip comprising a flexible base with a field of fastener elements carried on a fastening side thereof, the field of fastener elements arranged to overlap with the array of discrete fastener elements of the first fastening strip, such that when the first and second fastening strips are brought into engagement the overhanging lips of the discrete fastener elements of the first fastening strip cooperate with the fastener elements of the second fastening strip to releasably hold the first and second fastening strips in an engaged state;   wherein the first fastening strip also comprises a longitudinally continuous rib that extends from the upper surface of the base of the first fastening strip to a distal peak, the rib extending sufficiently far from the base of the first fastening strip to engage the base of the second fastening strip when the first and second fastening strips are in the engaged state, thereby forming with the base of the second fastening strip a barrier to resist flow across the fastening with the first and second fastening strips in the engaged state;   wherein the rib undulates in widthwise position on the upper surface of the first fastening strip base, along the first fastening strip, with some sections of the peak disposed closer to one lateral edge of the first fastening strip than other sections of the peak.   
     
     
         29 . The fastening of  claim 28 , wherein the field of fastener elements of the second fastening strip comprises an array of discrete fastener elements configured to interlock with the fastener elements of the first fastening strip.