Hook fasteners and methods of making the same
View Patent ↗A method of making a touch fastener includes coextruding, side-by-side, a plurality of lanes of polymeric material to form a sheet-form base. The sheet-sheet form base includes a lane of a first polymeric material disposed between two lanes of a second polymeric material, the second polymeric material is different from the first polymeric material. The method further includes molding a plurality of discrete fastener element stems extending outwardly from and integral with the sheet-form base in each of the two lanes of the second polymeric mateial and forming engageable heads on the stems.
1. A method of making a touch fastener, the method comprising:
forming a plurality of lanes having edges, including a lane comprising a first polymeric material and a lane comprising a second polymeric material which is foamed;
joining the lanes side-by-side along their edges to provide a composite polymeric sheet; and
forming a plurality of discrete fastener element stems extending outwardly from at least one exposed surface of the composite sheet.
2. The method of claim 1 further comprising forming engageable heads on the discrete fastener element stems.
3. The method of claim 1 wherein the lanes are joined with an adhesive.
4. The method of claim 1 wherein the lanes are coextruded.
5. The method of claim 1 wherein the second polymeric material is foamed by utilizing a chemical foaming agent.
6. The method of claim 1 wherein the second polymeric material is foamed by injecting gas.
7. The method of claim 1 wherein the second polymeric material is a thermoset.
8. The method of claim 1 wherein the composite polymeric sheet includes a plurality of lanes comprising first and second materials.
9. The method of claim 8 wherein the lanes comprising the first and second polymeric material alternate.
10. The method of claim 1 wherein the first polymeric material is polypropylene.
11. The method of claim 1 wherein the second polymeric material is an elastomer.
12. The method of claim 11 wherein the elastomer is a polypropylene-based thermoplastic vulcanizate.
13. The method of claim 1 wherein the lane comprising the second polymeric material has a height that is greater than a height of the lane comprising the first polymeric material, each height being measured from a back surface of the respective lane to the top surface of the respective lane.
14. The method of claim 1 wherein the at least one exposed surface of the composite sheet defines a portion of a top surface of the lane comprising the first polymeric material.
15. The method of claim 1 wherein the forming of the lanes and the joining of the lanes is performed concurrently.