Touch fastener element loop retention

Abstract

A male touch fastener component having a sheet-form base and an array of molded fastener elements having stems and heads having lower surfaces forming an arched crook for retaining loops. The crooks have particularly high crook angles, such that a maximum side angle measured about the crook from a line normal to the forward edge of the stem at an elevation from the base corresponding to a lowermost extent of the tip, to a normal to the lower head surface, is greater than about 180 degrees.

1 - 22 . (canceled)  
   
   
       23 . A method of forming a touch fastener component having a sheet-form base and an array of fastener elements, the method comprising: 
 introducing molten resin to a peripheral surface of a rotating mold roll defining an array of inwardly-extending cavities each including 
 a stem region extending inwardly from the peripheral surface, and  
 a head region extending laterally from a distal end of the stem region to a blind tip, the head region bounded by an outer surface forming a crook inward of a forward edge of the stem region,  
 the crook defining an under crook angle, measured about the crook in side view from a line normal to the forward edge of the stem region at a mold roll radius to the tip, to a normal to the crook-forming outer surface, that is greater than about 180 degrees;  
   applying sufficient pressure to force the resin into the cavities to mold an array of fastener elements, while forming a sheet of the resin on the peripheral surface of the mold roll;    cooling the resin in the cavities; and then    stripping the sheet of resin from the surface of the mold roll, thereby pulling heads of the fastener elements formed in the head regions of the cavities through the stem regions of the cavities to remove the fastener elements from the cavities.    
   
   
       24 . The method of  claim 23 , wherein each fastener element has multiple heads extending in different directions.  
   
   
       25 . The method of  claim 24 , wherein each fastener element has two heads extending in essentially opposite directions.  
   
   
       26 . The method of  claim 25 , wherein each fastener element defines an upper well between the two oppositely-directed heads, the well extending down to a height, measured perpendicularly from a top surface of the sheet of resin, of at least about 70 percent of an overall height of one of the two oppositely-directed heads.  
   
   
       27 . The method of  claim 25 , wherein each fastener element has an overall length between opposite extents of the oppositely-directed heads, measured parallel to the sheet of resin, of at least 1.8 times an overall height of the fastener element.  
   
   
       28 . The method of  claim 23 , wherein a ratio of an overall height of each crook, measured perpendicular to the sheet of resin from a lowermost extent of the tip to an uppermost extent of the crook, to an entrance height measured perpendicular to the sheet-form base below a lowermost extent of the tip, is greater than 0.6.  
   
   
       29 . The method of  claim 23 , wherein each head has an overall thickness, measured parallel to the sheet of resin and perpendicular to a plane of the crook, that is greater than an entrance height measured perpendicular to the sheet of resin below a lowermost extent of the tip.  
   
   
       30 . The method of  claim 23 , wherein each stem and head region has side surfaces lying in parallel planes.  
   
   
       31 . The method of  claim 23 , further comprising introducing a backing material such that the backing material becomes laminated to a side of the sheet of resin opposite the fastener elements.  
   
   
       32 . The method of  claim 23 , wherein the under crook angle is at least about 190 degrees.  
   
   
       33 . The method of  claim 32 , wherein the under crook angle is about 200 degrees.