Forming fastener components of multiple streams of resin

• US 6,540,863 B2
• Filed: 06/29/2001
• Issued: 04/01/2003
• Est. Priority Date: 02/17/1995
• Status: Expired due to Fees

• Current Assignee: Velcro Industries BV (Chartwell Industries Ltd)
• Original Assignee: Velcro Industries BV (Chartwell Industries Ltd)
• Inventors: Jacobs, Martin I., Routhier, Brian J., Kenney, Randall B.
• Primary Examiner(s): Eashoo, Mark
• Application Number:
  US09/896,482
• Publication Number:
  US 20010038161A1
• Time in Patent Office: 641 Days
• Field of Search: 156/244.11, 156/244.25, 156/244.27, 264/167, 264/171.1, 264/171.13, 264/171.14, 264/171.17, 264/173.12, 264/173.16, 264/177.1, 264/171.11
• US Class Current: 156/244.25
• CPC Class Codes: A44B 18/0076 Adaptations for being fixed to a moulded article during moulding
• CPC Class Codes: A44D 2203/00 Fastening by use of magnets
• CPC Class Codes: B29C 2043/465 having one or more cavities, e.g. for forming distinct products
• CPC Class Codes: B29C 33/16 using magnetic means
• CPC Class Codes: B29C 48/0014 producing flat articles having components brought in contact outside the extrusion die
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 48/07 Flat, e.g. panels
• CPC Class Codes: B29C 48/08 flexible, e.g. films
• CPC Class Codes: B29C 48/21 the layers being joined at their surfaces
• CPC Class Codes: B29C 48/355 Conveyors for extruded articles
• CPC Class Codes: B29C 48/873 in the direction of the stream of the material
• CPC Class Codes: B29C 48/875 for achieving a non-uniform temperature distribution, e.g. using barrels having both cooling and heating zones
• CPC Class Codes: B29C 48/90 with calibration or sizing, i.e. combined with fixing or setting of the final dimensions of the extruded article
• CPC Class Codes: B29C 48/906 using roller calibration
• CPC Class Codes: B29C 48/914 cooling drums
• CPC Class Codes: B29L 2031/729 Hook and loop-type fasteners
• CPC Class Codes: Y10T 24/2783 having filaments constructed from coated, laminated, or composite material
• CPC Class Codes: Y10T 24/2792 having mounting surface and filaments constructed from common piece of material
• CPC Class Codes: Y10T 428/24008 including fastener for attaching to external surface
• CPC Class Codes: Y10T 428/24017 Hook or barb
• CPC Class Codes: Y10T 428/24182 : Inward from edge of web or sheet

Abstract

A fastening component of a separable fastener is molded out of two separate flows of resin joined under pressure in a nip as the fastening elements are molded in cavities of a cavity roller. The joined flows of resin travel about the cavity roller while being cooled, and are then passed about a stripping roller to pull the formed fastener strip from the cavity roller.

Claims

1. A method of continuously forming a separable touch fastener strip having a flexible base unitarily molded with a plurality of fastening elements extending from a fastening surface thereof, the method comprising:

providing an apparatus having

a cavity roller that contains cavities for forming the fastening elements, and

a base roller which defines, together with the cavity roller, a nip;

supplying a first stream of molten plastic to the nip under conditions which cause the plastic of the first stream to fill the cavities of the cavity roller and form the fastening surface of the base;

while

supplying a second stream of molten plastic to the nip along with the first stream of molten plastic, such that plastic of the first stream and plastic of the second stream are joined in the nip to form the fastener strip;

allowing the formed fastener strip to travel around the cavity roller; and

then

passing the formed fastener strip around a stripping roller to pull the formed fastener strip from engagement with the cavity roller.

2. The method of claim 1 wherein the fastener elements are hook-shaped.

3. The method of claim 1 wherein the first and second streams are of identical materials.

4. The method of claim 1 wherein the first and second streams are of different materials.

5. The method of claim 1 wherein the base further comprises a non-fastening surface.

6. The method of claim 1 wherein the first and second streams of plastic are forced through corresponding die orifices of a cross-head coextrusion die head.

7. The method of claim 1 wherein a pool of material of the first stream forms upstream ahead of the nip.

8. The method of claim 7 wherein a pool of material of the second stream also forms upstream ahead of the nip.

9. The method of claim 1 wherein material of the second stream is flattened and spread out into a web shape, along with a quantity of material of the first stream to form the base.

10. The method of claim 1 further comprising, after passing the formed fastener strip around a stripping roller, passing the formed fastener strip to a wind-up roll.

11. The method of claim 1 further comprising continuously laminating a preformed substrate to the base of the fastener strip as the fastener strip is being formed.

12. The method of claim 11 wherein the preformed substrate is inserted into the nip to bond intimately with the base and become an integral part of the fastener strip.

13. The method of claim 11 wherein the preformed substrate comprises a loop component of a hook and loop fastener pair.

14. The method of claim 1 wherein the formed fastener strip is cooled while traveling around the cavity roller.