Longitudinal bead molding
View Patent ↗An edge-beaded fastener product such as a cushion cover tie-down has a molded profile bead secured to and extending along a flexible strip adjacent a longitudinal edge of the strip. The profile bead has a shoulder or an inboard sidewall extending away from the strip, such as for retaining a clip or hog ring. The flexible strip may have a reinforced region, inboard of the shoulder, in which resin contiguous with resin forming the profile bead encapsulates surface features of the strip. The product is made by molding resin directly onto the strip. Multiple lanes of resin may be molded on a single substrate, which is severed to form individual strips with severed, exposed strip edges.
1. A method of making a continuous sheet-form product carrying a profiled bead of resin along a length thereof, the method comprising:
continuously passing a flexible substrate through a nip defined between two counter-rotating rolls;
introducing a flow of moldable resin into the nip between the flexible substrate and a first of the two rolls, in an area in which an outer surface of the first of the two rolls defines a peripheral molding recess; and
molding the resin in the peripheral molding recess to form a profiled bead bonded to a side of the flexible substrate and extending along the substrate between exposed regions of substrate surface,
wherein the recess is shaped such that the profiled bead defines a longitudinal slitting channel extending along the flexible substrate, along which channel the profile bead has a lesser tear resistance than on either side of the channel.
2. The method of claim 1 , further comprising slitting the profiled bead and substrate longitudinally along the slitting channel, thereby forming two separate substrate strips each having a corresponding portion of the bead extending along an exposed, severed edge of the substrate.
3. The method of claim 1 , wherein the resin is introduced in separate flows to two spaced apart regions of the flexible substrate and molded in two corresponding molding recesses of the first of the two rolls, thereby forming two spaced-apart profiled beads each defining a slitting channel and each extending along the flexible substrate between longitudinal exposed regions of substrate surface.
4. The method of claim 3 , wherein a portion of the flowable resin engages the outer surface of the first of the two rolls adjacent the molding recess, and impregnates the substrate in a region immediately adjacent the profiled bead as the resin is molded, thereby forming a reinforced region of the substrate adjacent the profiled bead.
5. The method of claim 4 , wherein the outer surface of the first of the two rolls further defines a circumferential groove extending about the first of the two rolls and spaced from the peripheral recess, and wherein molding the resin forms a rib of resin in the groove, the rib forming a lateral edge of the reinforced region.
6. The method of claim 1 , wherein the substrate, as introduced to the nip, defines holes therethrough, and wherein the substrate is introduced to the nip with the holes aligned with the moldable resin, such that pressure in the nip forces some of the resin into the holes.
7. The method of claim 6 , wherein a second of the two rolls has a surface that defines a recess positioned to receive resin pressed through the holes of the substrate in the nip, thereby forming a molded protrusion of the resin on a side of the substrate opposite the profiled bead.
8. The method of claim 1 , further comprising passing the substrate and profiled bead through a second nip in which the formed bead is plastically deformed to alter a shape of the profiled bead.
9. The method of claim 1 , further comprising introducing a pre-formed, longitudinally continuous wire to the nip with the moldable resin, such that the wire becomes embedded in the profiled bead as the resin is molded.
10. A method of making a continuous flexible strip of substrate carrying a bead of resin along an edge thereof, the method comprising:
continuously passing a flexible substrate sheet through a nip defined between two counter-rotating rolls;
introducing a flow of moldable resin into the nip between the flexible substrate and a first of the two rolls, in an area in which an outer surface of the first of the two rolls defines a peripheral molding recess; and
molding the resin in the peripheral molding recess to form a profiled bead bonded to a side of the flexible substrate and extending along the substrate between exposed regions of substrate surface, the formed profiled bead having a cross-section that increases in thickness across a tapered region of the profiled bead to a longitudinal shoulder defining an abrupt transition in bead thickness; and then
longitudinally severing the substrate adjacent the tapered region of the profiled bead along a line spaced from the shoulder, thereby forming a strip of the substrate carrying a bead of molded resin adjacent a severed longitudinal edge of the strip.
11. The method of claim 10 , wherein the resin is introduced in separate flows to two spaced apart regions of the flexible substrate and molded in two corresponding molding recesses of the first of the two rolls, thereby forming two spaced-apart profiled beads each extending along the flexible substrate between longitudinal exposed regions of substrate surface.
12. The method of claim 11 , wherein a portion of the flowable resin engages the outer surface of the first of the two rolls adjacent the molding recess, and impregnates the substrate in a region immediately adjacent the profiled bead as the resin is molded, thereby forming a reinforced region of the substrate adjacent the profiled bead.
13. The method of claim 10 , wherein the substrate, as introduced to the nip, defines holes therethrough, and wherein the substrate is introduced to the nip with the holes aligned with the moldable resin, such that pressure in the nip forces some of the resin into the holes.
14. The method of claim 13 , wherein a second of the two rolls has a surface that defines a recess positioned to receive resin pressed through the holes of the substrate in the nip, thereby forming a molded protrusion of the resin on a side of the substrate opposite the profiled bead.
15. The method of claim 10 , wherein the substrate has a fabric surface on which the profiled bead is molded.
16. The method of claim 10 , wherein the bead is segmented, segments of the bead being longitudinally spaced and each defining a shoulder segment; wherein the peripheral recess is circumferentially discontinuous and includes separate recess cavities; and wherein molding the resin comprises filling the separate cavities from a continuous flow of the moldable resin.
17. The method of claim 16 , wherein molding the resin further comprises molding a series of resin protrusions extending from the substrate and spaced laterally from, and longitudinally between, adjacent segments of the bead.
18. The method of claim 16 , wherein molding the resin further comprises pressing resin through the substrate in spaces between the recess cavities, thereby forming a longitudinally spaced series of protrusions on a side of the substrate opposite the bead segments.