Method and apparatus for ultrasonically stomping slider end stops on zipper

• US 7,033,451 B2
• Filed: 04/06/2004
• Issued: 04/25/2006
• Est. Priority Date: 04/01/2002
• Status: Expired due to Fees

• Current Assignee: Illinois Tool Works Inc.
• Original Assignee: Illinois Tool Works Inc.
• Inventors: Crevier, Donald L., McMahon, Michael J., Share, Lawrence, Piotrowski, Stanley, Pollack, Michael A., Knight, Nigel D.
• Primary Examiner(s): SELLS, JAMES D
• Application Number:
  US10/820,234
• Publication Number:
  US 20040188000A1
• Time in Patent Office: 749 Days
• Field of Search: 156/73.1, 156/290, 156/308.2, 156/308.4, 156/553, 156/580.1, 156/580.2, 264/442, 264/443, 264/445, 425/174.2
• US Class Current: 156/73.1
• CPC Class Codes: B29C 2793/009 after shaping
• CPC Class Codes: B29C 65/08 using ultrasonic vibrations non-plastics element to plastics elements B29C65/645
• CPC Class Codes: B29C 65/18 using heated tools
• CPC Class Codes: B29C 65/305 involving the use of cartridge heaters
• CPC Class Codes: B29C 65/72 by combined operations or combined techniques, e.g. welding and stitching
• CPC Class Codes: B29C 66/0242 Heating, or preheating, e.g. drying B29C66/3464 takes precedence
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/1222 comprising at least a lapped joint-segment
• CPC Class Codes: B29C 66/1224 comprising at least a butt joint-segment
• CPC Class Codes: B29C 66/326 Shaping the burr, e.g. by the joining tool
• CPC Class Codes: B29C 66/346 Making joints having variable thicknesses in the joint area, e.g. by using jaws having an adapted configuration
• CPC Class Codes: B29C 66/349 Cooling the welding zone on the welding spot
• CPC Class Codes: B29C 66/43 Joining a relatively small portion of the surface of said articles B29C66/45 takes precedence
• CPC Class Codes: B29C 66/43121 Closing the ends of tubular or hollow single articles, e.g. closing the ends of bags closing tube ends B29C57/10
• CPC Class Codes: B29C 66/474 said single elements being substantially non-flat
• CPC Class Codes: B29C 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/81419 and flat
• CPC Class Codes: B29C 66/81425 being stepped, e.g. comprising a shoulder
• CPC Class Codes: B29C 66/81429 comprising a single tooth
• CPC Class Codes: B29C 66/81431 : comprising a single cavity, e.g. a groove
• CPC Class Codes: B29C 66/81433 : being toothed, i.e. comprising several teeth or pins comprising a single tooth B29C66/81429, or being patterned
• CPC Class Codes: B29C 66/8322 : Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29K 2023/0625 : LLDPE, i.e. linear low density polyethylene
• CPC Class Codes: B29K 2023/0633 : LDPE, i.e. low density polyethylene
• CPC Class Codes: B29K 2023/065 : HDPE, i.e. high density polyethylene
• CPC Class Codes: B29K 2023/12 : PP, i.e. polypropylene
• CPC Class Codes: B29K 2025/06 : PS, i.e. polystyrene
• CPC Class Codes: B29K 2027/06 : PVC, i.e. polyvinylchloride
• CPC Class Codes: B29K 2027/08 : PVDC, i.e. polyvinylidene chloride
• CPC Class Codes: B29K 2055/02 : ABS polymers, i.e. acrylonitrile-butadiene-styrene polymers
• CPC Class Codes: B29K 2059/00 : Use of polyacetals , e.g. POM, i.e. polyoxymethylene or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2061/00 : Use of condensation polymers of aldehydes or ketones or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2067/006 : PBT, i.e. polybutylene terephthalate
• CPC Class Codes: B29K 2069/00 : Use of PC, i.e. polycarbonates or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2077/00 : Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2995/0025 : Opaque
• CPC Class Codes: B29K 2995/0026 : Transparent
• CPC Class Codes: B29L 2005/00 : Elements of slide fasteners
• CPC Class Codes: B29L 2031/7129 : open
• CPC Class Codes: B31B 70/8131 : Making bags having interengaging closure elements
• CPC Class Codes: B65D 33/259 : End stops
• CPC Class Codes: Y10T 156/1737 : Discontinuous, spaced area, and/or patterned pressing

Abstract

An ultrasonic welding assembly comprising a horn, an anvil and an anvil cover. The horn comprises a generally T-shaped flattening surface and a rail projecting forward of the flattening surface. The rail is shaped to serve as a dam for flowing thermoplastic zipper material during stomping of slider end stops. The horn further comprises a plurality of vertical energy directors designed to direct ultrasonic energy into the mass of zipper material and deflect flowing zipper material toward the dam. The horn further comprises first and second recesses located on opposite sides of a stem of the T-shaped flattening surface. The anvil cover overlies opposing portions of the anvil and comprises a T-shaped cutout. The T-shaped flattening surface of the horn fits in the T-shaped cutout of the anvil cover. The resulting zipper has slider end stops located at opposing ends. Each end stop comprises flattened zipper material having a plurality of spaced indentations, the indentations being formed by the energy directors during stomping. The zipper can be pre-heated prior to ultrasonic stomping. A flange of the zipper can be cooled by fluid during ultrasonic stomping of the zipper parts.

Claims

1. A method of manufacture comprising the following steps:

(a) forming first and second interlockable zipper parts having respective base portions connecting a respective zipper flange to a respective zipper profile, the respective base portions having outermost portions disposed on opposite sides of the zipper when the first and second zipper parts are interlocked;

(b) interlocking said first and second zipper parts;

(c) inserting a slider on an undeformed portion of said interlocked zipper parts; and

(d) transmitting sufficient ultrasonic wave energy into a T-shaped area of said interlocked zipper parts to cause said interlocked zipper parts to flatten and fuse in said T-shaped area, the outermost portions of the base portions of said interlocked zipper parts being undeformed on both sides of a stem of said T-shape.

2. The method as recited in claim 1, further comprising the step of directing said ultrasonic wave energy to form a series of spaced indentations in said flattened T-shaped area.

3. The method as recited in claim 1, further comprising the step of pre-heating at least one of said zipper parts prior to said step of transmitting ultrasonic wave energy.

4. The method as recited in claim 1, further comprising the step of directing cooling fluid toward a flange of at least one of said zipper parts during said step of transmitting ultrasonic wave energy.

5. The method as recited in claim 1, wherein said stem of said T shape is oriented generally transverse to a machine direction, further comprising the steps of:

(e) joining respective flanges of said first and second zipper parts to first and second portions of film material along respective first and second band-shaped zones disposed generally parallel to said machine direction;

(f) placing said first and second portions of film material in opposing relationship; and

(g) cross sealing the first and second portions in opposing relationship along a strip-shaped area generally oriented in the transverse direction,

wherein the strip-shaped area of cross sealing overlaps the flattened T-shaped area.

6. The method as recited in claim 5, wherein step (f) is performed prior to step (e).

7. The method as recited in claim 5, further comprising the step of cutting the cross-sealed strip of the opposing portions of web material along a line generally oriented in the transverse direction, the cut generally bisecting the flattened T-shaped area.

8. A method of manufacture, comprising the following steps:

joining interlocked zipper parts to respective band-shaped portions of first and second webs of film material;

ultrasonically deforming the zipper parts to form a flattened T-shaped area having a stem oriented generally transverse to a machine direction;

cross sealing opposing portions of said first and second webs of film material along a strip-shaped area generally oriented in the transverse direction, the strip-shaped area of cross sealing overlapping the flattened T-shaped area; and

cutting the cross-sealed strip of the opposing portions of said first and second webs along a line generally oriented in the transverse direction, the cut generally bisecting the flattened T-shaped area.

9. The method as recited in claim 8, wherein said deforming step comprises the steps of flattening the zipper material at the ends of the zipper parts and forming a series of spaced indentations in the flattened T-shaped area.

10. The method as recited in claim 8, further comprising the step of pre-heating at least one of the zipper parts prior to ultrasonically deforming the zipper parts.

11. The method as recited in claim 8, further comprising the step of directing cooling fluid toward a flange of at least one of the zipper parts during the ultrasonic deformation.

12. The method as recited in claim 8, wherein said first and second webs are connected by a fold line.

13. A method of manufacture, comprising the following steps:

(a) forming first and second interlockable zipper parts, said first zipper part comprising a first base, a first profiled closure element projecting from one side of said first base, and a first flange having a proximal end connected to said first base, and said second zipper part comprising a second base, a second profiled closure element projecting from one side of said second base, and a second flange having a proximal end connected to said second base, wherein respective first portions of said first and second bases adjacent the connection with said first and second flanges respectively have an outer dimension greater than an outer dimension of respective second portions of said first and second bases remote from the connection with said first and second flanges respectively when said first and second zipper parts are interlocked;

(b) interlocking said first and second zipper parts;

(c) inserting a slider on an undeformed portion of said interlocked first and second zipper parts, said slider comprising respective hooks that latch under said first portions of said first and second bases of said zipper to retain said slider on said zipper; and

(d) ultrasonically deforming said first and second zipper parts to form a flattened area, said flattened area comprising a central region wherein said first and second zipper parts are flattened over the full height of said first and second bases, and first and second regions on opposite sides of and contiguous with said central region wherein said first and second zipper parts are flattened over partial heights of said first and second bases, said first portions of said first and second bases being not flattened in said first and second regions.

14. The method as recited in claim 13, further comprising the following steps:

(e) joining said first and second flanges to respective band-shaped zones on first and second portions of film material;

(f) cross sealing opposing regions of said first and second portions of said film material along a strip-shaped area generally oriented in the transverse direction, the strip-shaped area of cross sealing overlapping the flattened T-shaped area; and

(g) cutting the cross-sealed strip of said first and second portions of said film material along a line generally oriented in the transverse direction, the cut generally bisecting the flattened T-shaped area.

15. The method as recited in claim 14, wherein said first and second portions of said film material are connected by a fold line.

16. The method as recited in claim 13, wherein said first and second zipper parts are formed by extrusion.

17. The method as recited in claim 13, wherein said deforming step comprises the step of forming a series of spaced indentations in the flattened T-shaped area.