Forming fastener elements
Arrays of male fastener elements are formed by molding preforms in cavities defined in one or more adjacent plates and shaped to mold preform arms that extend to a plate side, such as in a cross-machine direction of a continuous molding process. The preforms may be deformed to flatten their upper surfaces and lengthen the arms. Stems of preforms have molded side surfaces and each have width, measured in the longitudinal direction of the strip, that narrows with distance from the strip surface, and also narrows with distance from a parting line extending from the strip surface to the head between the arms.
1. A flexible fastener product comprising
an elongated resin strip having lateral edges and defining a longitudinal direction; and
an array of discrete, spaced-apart fastener elements carried on one side of the strip, each fastener element having
a stem of resin extending integrally from the strip and forming, together with resin of the strip, a single contiguous mass of resin; and
a head disposed at a distal end of the stem and having arms that extend in opposite directions from the stem to form overhangs for retaining fibers;
wherein the arms extend to distal tips each comprising a distal face bounded by a lip that extends outwardly about the arm at a perimeter of the distal face, such that the distal face is of greater area than a cross-section of the arm between the stem and the distal face.
2. The flexible fastener product of claim 1 , wherein the head of each fastener element forms a peak between the arms.
3. The flexible fastener product of claim 1 , wherein the stems have molded side surfaces facing in the longitudinal direction and each has a width that narrows with distance from the strip surface.
4. The flexible fastener product of claim 3 , wherein the width is measured in the longitudinal direction of the strip.
5. The flexible fastener product of claim 3 , wherein the width also narrows with distance from a parting line extending from the strip surface to the head between the arms.
6. The flexible fastener product of claim 1 , wherein each arm extends downward toward the side of the strip.
7. The flexible fastener product of claim 1 , wherein the distal face of each distal tip is flat.
8. The flexible fastener product of claim 7 , wherein the distal face of each distal tip is perpendicular to the side of the strip.
9. The flexible fastener product of claim 1 , wherein the arms have flat underside surfaces.
10. The flexible fastener product of claim 1 , wherein the lips comprise curved surfaces extending from side surfaces of the head to a peak at the distal face.