Viral resistant seam for protective apparel, and method of manufacturing same

• US 5,879,493 A
• Filed: 07/02/1997
• Issued: 03/09/1999
• Est. Priority Date: 04/03/1995
• Status: Expired due to Term

• Current Assignee: 3M Company
• Original Assignee: 3M Company
• Inventors: Johnson, Mark V., Rauschenberg, Nancy C., Megchelsen, Sara L.
• Primary Examiner(s): SELLS, JAMES D
• Application Number:
  US08/887,490
• Time in Patent Office: 615 Days
• Field of Search: 156/73.1, 156/73.2, 156/73.3, 156/73.4, 156/157, 156/159, 156/304.1, 156/308.2, 156/308.4, 264/442, 264/443, 264/444, 264/445
• US Class Current: 156/73.3
• CPC Class Codes: A41D 27/245 made by welding or gluing joining of plastics by welding or gluing B29C65/00; sewing machines for concurrently making thread and welded seams D05B17/00; thermal or chemical fixing of seams and hems D06M
• CPC Class Codes: B29C 65/087 using both a rotary sonotrode and a rotary anvil
• CPC Class Codes: B29C 66/112 Single lapped joints
• 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 66/131 Single flanged joints, i.e. one of the parts to be joined being rigid and flanged in the joint area
• 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 66/71 characterised by the composition of the plastics material of the parts to be joined welding bar compositions B29C65/125
• CPC Class Codes: B29C 66/7234 comprising a barrier layer
• CPC Class Codes: B29C 66/727 being porous, e.g. foam
• CPC Class Codes: B29C 66/729 Textile or other fibrous material made from plastics
• CPC Class Codes: B29C 66/7294 Non woven mats, e.g. felt
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/81417 being V-shaped
• 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 66/81435 comprising several parallel ridges, e.g. for crimping comprising a single ridge B29C66/81427
• CPC Class Codes: B29C 66/83411 Roller, cylinder or drum types B29C66/83431 takes precedence; rollers, cylinders or drums moving relative to and tangentially to the parts to be joined B29C66/8362
• CPC Class Codes: B29C 66/83511 jaws mounted on rollers, cylinders or drums
• CPC Class Codes: B29C 66/91421 of the joining tools
• CPC Class Codes: B29C 66/919 characterised by specific temperature, heat or thermal flux values or ranges specific electrical resistance values B29C66/81262
• CPC Class Codes: B29C 66/93451 by controlling or regulating the rotational speed, i.e. the speed of revolution
• CPC Class Codes: B29C 66/939 : characterised by specific speed values or ranges
• CPC Class Codes: B29C 66/9517 : characterised by specific vibration amplitude values or ranges
• CPC Class Codes: B29K 2023/04 : Polymers of ethylene
• CPC Class Codes: B29K 2023/06 : PE, i.e. polyethylene
• CPC Class Codes: B29K 2023/10 : Polymers of propylene
• CPC Class Codes: B29K 2023/12 : PP, i.e. polypropylene
• CPC Class Codes: B29K 2025/04 : Polymers of styrene
• CPC Class Codes: B29K 2067/00 : Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2067/003 : PET, i.e. poylethylene terephthalate
• CPC Class Codes: B29K 2067/006 : PBT, i.e. polybutylene terephthalate
• CPC Class Codes: B29K 2077/00 : Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: Y10T 428/19 : Sheets or webs edge spliced or joined

Abstract

A reinforced viral resistant seam for an article of protective apparel constructed by arranging first and second thermoplastic webs and at least one reinforcing strip thermally bondable with the webs along a common seam edge. An ultrasonic welding wheel having a cutting edge immediately adjacent to the welding surface is used to form a viral resistant, comfortable, high tensile strength seam suitable for articles of protective apparel.

Claims

1. A method for forming a reinforced viral resistant seam for an article of protective apparel comprising the steps of:

arranging first and second attachment edge of first and second thermoplastic webs to form a common seam edge, the first and second webs defining a substantially common interface plane proximate one side of the common seam edge;

positioning at least one reinforcing strip to extend along the common seam edge defining a substantially common interface plane with the first or second web, the at least one reinforcing strip comprising a thermoplastic material thermally bondable with the first and second thermoplastic webs; and

forming an ultrasonic weld extending through the first and second webs and the reinforcing strip, the ultrasonic weld connecting the first and second attachment edges and the reinforcing strip proximate the common seam edge to form a viral resistant seam.

2. The method of claim 1 wherein the first and second webs comprise a thermoplastic microporous membrane thermally bonded on at least one side thereof to a thermoplastic web so that the first and second webs having viral barrier properties.

3. The method of claim 1 wherein the microporous membrane comprises thermoplastic polymer and a water- and oil-repellent fluorochemical compound that forms a microporous membrane with oleophobic and hydrophobic properties.

4. The method of claim 1 wherein the web comprises spunbond nonwoven polypropylene.

5. The method of claim 1 wherein the article of protective apparel comprises a surgical gown.

6. The method of claim 1 wherein the step of forming the ultrasonic weld comprises passing the common seam edge of the reinforcing strip and the first and second thermoplastic webs between an ultrasonic weld wheel having a cutting edge immediately adjacent to a welding surface and an ultrasonic generator.

7. The method of claim 6 wherein the welding surface comprise a cylindrical surface approximately 0.762 mm wide.

8. The method of claim 6 wherein the cutting edge is offset 1.0 cm from a sealed edge.

9. The method of claim 6 wherein the ultrasonic welding wheel has a line speed of greater than 5 meters/minute.

10. The method of claim 1 wherein the at least one reinforcing strip defines a substantially common interface plane with the first web.

11. The method of claim 1 wherein the at least one reinforcing strip defines a substantially common interface plane with the second web.

12. The method of claim 1 wherein the at least one reinforcing strip is interposed between the first and second thermoplastic webs along the common seam edge.