US 6,982,055 B2
Multiheaded hook
Jayshree Seth, Woodbury, Minn. (US); Ronald W. Ausen, St. Paul, Minn. (US); and Janet A. Venne, Roseville, Minn. (US)
Assigned to 3M Innovative Properties Company, St. Paul, Minn. (US)
Filed on Mar. 25, 2003, as Appl. No. 10/396,652.
Prior Publication US 2004/0187276 A1, Sep. 30, 2004
Int. Cl. B29C 47/88 (2006.01)
U.S. Cl. 264—145 7 Claims
OG exemplary drawing
 
1. A method of forming a unitary fastener comprising the steps of extruding a thermoplastic resin in a machine direction through a die plate having a continuous base portion cavity and one or more ridge cavities extending from the base portion cavity, the extrusion being sufficient to induce melt flow molecular orientation in the polymer flowing through at least the ridge cavities forming a base portion with ridges, forming discrete projections from the ridges, which projections are separated each from the other and project from the base portion, and cutting either the ridges or the projection such that at least a portion of the discrete projections are bisected by one or more cut lines along a portion of its height.