Elastic laminate material, and method of making

• US 20060169387A1
• Filed: 12/30/2005
• Published: 08/03/2006
• Est. Priority Date: 01/03/2005
• Status: Abandoned Application

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Nielsen, Sharon K., Nayar, Satinder K., Pochardt, Donald L.
• Application Number:
  US11/322,385
• Publication Number:
  US 20060169387A1
• Time in Patent Office: Days
• US Class Current: 156/73.100
• CPC Class Codes: B29C 65/08 using ultrasonic vibrations non-plastics element to plastics elements B29C65/645
• CPC Class Codes: B29C 65/085 using a rotary sonotrode
• CPC Class Codes: B29C 65/086 using a rotary anvil
• CPC Class Codes: B29C 65/087 using both a rotary sonotrode and a rotary anvil
• CPC Class Codes: B29C 65/4815 Hot melt adhesives, e.g. thermoplastic adhesives
• CPC Class Codes: B29C 65/4825 Pressure sensitive adhesives
• CPC Class Codes: B29C 65/5057 positioned between the surfaces to be joined B29C65/5035 takes precedence
• CPC Class Codes: B29C 65/8207 by mechanical methods
• CPC Class Codes: B29C 65/8215 Tensile tests
• 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 66/21 said joint lines being formed by a single dot or dash or by several dots or dashes, i.e. spot joining or spot welding
• CPC Class Codes: B29C 66/232 said joint lines being multiple and parallel, i.e. the joint being formed by several parallel joint lines
• 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 66/435 Making large sheets by joining smaller ones or strips together
• CPC Class Codes: B29C 66/45 Joining of substantially the whole surface of the articles methods or apparatus for laminating B32B37/00
• 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 66/723 being multi-layered B29C66/7292, B29C66/72941 take precedence
• CPC Class Codes: B29C 66/7294 Non woven mats, e.g. felt
• CPC Class Codes: B29C 66/72941 coated
• CPC Class Codes: B29C 66/7352 Thickness, e.g. very thin
• CPC Class Codes: B29C 66/7392 : characterised by the material of at least one of the parts being a thermoplastic
• CPC Class Codes: B29C 66/73921 : characterised by the materials of both parts being thermoplastics
• 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 66/81811 : of the welding jaws
• CPC Class Codes: B29C 66/8222 : Pinion or rack mechanisms
• CPC Class Codes: B29C 66/8226 : Cam mechanisms; Wedges; Eccentric mechanisms
• CPC Class Codes: B29C 66/8242 : Pneumatic or hydraulic drives using fluid pressure directly acting on the parts to be joined B29C66/8266
• CPC Class Codes: B29C 66/82421 : using an inflatable element positioned between the joining tool and a backing-up part
• CPC Class Codes: B29C 66/8322 : Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/83413 : cooperating rollers, cylinders or drums
• CPC Class Codes: B29C 66/83415 : the contact angle between said rollers, cylinders or drums and said parts to be joined being a non-zero angle B29C66/83433 takes precedence
• CPC Class Codes: B29C 66/91216 : enabling contactless temperature measurements, e.g. using a pyrometer
• CPC Class Codes: B29C 66/91231 : of the joining tool
• CPC Class Codes: B29C 66/91421 : of the joining tools
• CPC Class Codes: B29C 66/9231 : by measuring the displacement of the joining tools
• CPC Class Codes: B29C 66/9241 : by controlling or regulating the pressure, the force or the mechanical power
• CPC Class Codes: B29C 66/92613 : the gap being kept constant over time
• CPC Class Codes: B29C 66/92651 : by using stops
• CPC Class Codes: B29C 66/929 : characterized by specific pressure, force, mechanical power or displacement values or ranges
• CPC Class Codes: B29C 66/934 : by controlling or regulating the speed
• CPC Class Codes: B29C 66/939 : characterised by specific speed values or ranges
• CPC Class Codes: B29C 66/9511 : by measuring their vibration frequency
• CPC Class Codes: B29C 66/9513 : characterised by specific vibration frequency values or ranges
• CPC Class Codes: B29C 66/9516 : by controlling their vibration amplitude
• CPC Class Codes: B29C 66/9517 : characterised by specific vibration amplitude values or ranges
• CPC Class Codes: B29C 66/961 : involving a feedback loop mechanism, e.g. comparison with a desired value
• CPC Class Codes: B29K 2007/00 : Use of natural rubber as moulding material
• CPC Class Codes: B29K 2021/00 : Use of unspecified rubbers as moulding material
• CPC Class Codes: B29K 2021/003 : Thermoplastic elastomers
• CPC Class Codes: B29K 2023/00 : Use of polyalkenes or derivatives thereof as moulding material
• 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 2075/00 : Use of PU, i.e. polyureas or polyurethanes or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2101/12 : Thermoplastic materials
• CPC Class Codes: B29K 2105/04 : cellular or porous
• CPC Class Codes: B29K 2105/0854 : in the form of a non-woven mat
• CPC Class Codes: B29K 2223/00 : Use of polyalkenes or derivatives thereof as reinforcement
• CPC Class Codes: B29K 2311/10 : Natural fibres, e.g. wool or cotton
• CPC Class Codes: B29K 2995/0046 : Elastic
• CPC Class Codes: B29L 2009/00 : Layered products
• CPC Class Codes: B29L 2031/4878 : Diapers, napkins
• CPC Class Codes: Y10T 442/659 : Including an additional nonwoven fabric
• CPC Class Codes: Y10T 442/674 : Nonwoven fabric with a preformed polymeric film or sheet

Abstract

An ultrasonic welding apparatus, such as a rotary welding apparatus, and methods of using the same for making a laminate material are disclosed. The multi-layered laminate material has a nonwoven material ultrasonically welded to a base layer, which can include elastic.

Claims

1. A method of welding a nonwoven layer to a base layer, the method comprising:

(a) providing an ultrasonic system comprising an anvil and a horn stack comprising a horn, the anvil and horn having a gap therebetween;

(b) placing the nonwoven layer and the base layer together within the gap between the anvil and the horn;

(c) rotating at least one of the horn and the anvil while vibrating the horn with ultrasonic energy to obtain a frequency;

(d) contacting the nonwoven layer and the base layer with the horn and the anvil;

(e) monitoring at least one of the frequency and a temperature of at least one of the horn or the anvil; and

(f) while maintaining the gap between the anvil and the horn based on either the temperature or a change in the frequency, welding the nonwoven layer to the base layer.

2. The method of claim 1, wherein contacting the nonwoven layer and the base layer with the horn and the anvil comprises:

(a) contacting the nonwoven layer with the horn and the base layer with the anvil.

3. The method of claim 1, wherein placing the nonwoven layer and the base layer together within the gap comprises:

(a) including an adhesive layer positioned between the nonwoven layer and the base layer.

4. The method of claim 1, wherein placing the nonwoven layer and the base layer together within the gap comprises:

(a) placing the nonwoven layer and a base layer comprising elastic together within the gap.

5. The method of claim 4, wherein placing the nonwoven layer and the base layer together within the gap comprises:

(a) placing the nonwoven layer and a base layer comprising a first nonwoven surface on an elastic film, the first nonwoven surface positioned between the elastic film and the adhesive layer.

6. The method of claim 5, wherein placing the nonwoven layer and the base layer together within the gap comprises:

(a) placing the nonwoven layer and a base layer further comprising a second nonwoven surface on the elastic film opposite the first nonwoven surface.

7. The method of claim 1, wherein placing the nonwoven layer and the base layer together within the gap comprises:

(a) placing the nonwoven layer, a second nonwoven layer and the base layer within the gap.

8. The method of claim 1, wherein providing an ultrasonic system comprises:

(a) providing a mounting system for supporting a rotatable horn so that it can rotate about a first axis and such that the rotatable horn has only two additional degrees of freedom,

(i) the first additional degree of freedom being translational motion in a direction perpendicular to the first axis, and

(ii) the second additional degree of freedom being rotational motion about a second axis that is both perpendicular to the first axis and the direction of the first additional degree of freedom;

(b) mounting the horn within the mounting system; and

(c) contacting the web with the horn so as to treat the web.

9. The method of claim 8, wherein providing an ultrasonic system comprises providing a mounting system comprising:

(a) a frame having two side plates, each side plate having a bearing surface and having a slot therein;

(b) a pair of support elements each adapted to engage the horn in such a fashion that the horn is free to rotate, wherein each support element comprises;

(i) a slide portion slidably engaging one of the slots; and

(ii) a bearing portion having a curved surface engaging the bearing surface.

10. The method of claim 9, wherein maintaining the gap between the anvil and the horn comprises maintaining the gap between the anvil and the horn constant by providing a mechanism for limiting the maximum amount of motion within the second additional degree of freedom.

11. The method of claim 1, wherein maintaining the gap between the anvil and the horn comprises:

(a) receiving a resonant frequency of the horn, wherein a portion of the horn is fixed a given distance from the anvil by a rigid mounting system; and

(b) determining a quantity standing in known relation to an approximate change in length of the gap, based upon the resonant frequency.

12. The method of claim 11, wherein determining the quantity standing in known relation to the approximate change in length of the gap comprises:

(a) accessing a table to obtain a gap corresponding to the resonant frequency.

13. The method of claim 11, wherein determining the quantity standing in known relation to the approximate change in length of the gap comprises:

(a) accessing a table to obtain first and second quantities corresponding to frequencies straddling the resonant frequency; and

(b) interpolating between the first and second quantities, to arrive at the approximate gap.

14. The method of claim 11, wherein determining the quantity standing in known relation to the approximate change in length of the gap comprises:

(a) calculating a dimension of the horn, as a function of the resonant frequency and material characteristics of the horn.

15. The method of claim 11, wherein maintaining the gap between the anvil and the horn comprises:

(a) adjusting the given distance between the fixed portion of the horn and the anvil, so as to substantially maintain a constant gap.

16. The method of claim 11, wherein maintaining the gap between the anvil and the horn comprises:

(a) adjusting the given distance between the fixed portion of the horn and the anvil, based upon the resonant frequency of the horn.

17. The method of claim 1, wherein maintaining the gap between the anvil and the horn comprises:

(a) applying a force to the horn, so as to urge the horn toward the anvil;

(b) positioning a deformable stop at a location, such that application of the urging force causes a member operatively connected to the horn to abut the deformable stop, and to deform the stop; and

(c) iteratively adjusting the urging force during operation of the horn, so as to adjust the extent of the deformation of the deformable stop, and to maintain the gap between the horn and the anvil substantially constant.

18. The method of claim 17, wherein maintaining the gap between the anvil and the horn comprises:

(a) monitoring the gap between the horn and the anvil, based upon the temperature of the horn.

19. The method of claim 17, wherein maintaining the gap between the anvil and the horn comprises:

(a) monitoring the gap between the horn and the anvil, based upon the resonant frequency of the horn.

20. The method of claim 1, wherein maintaining the gap between the anvil and the horn comprises:

(a) applying an AC signal to a converter coupled to the horn, the AC signal exhibiting an amplitude; and

(b) adjusting the amplitude of the AC signal during operation of the horn, so as to maintain the gap between the horn and the anvil substantially constant.

21. The method of claim 20, wherein maintaining the gap between the anvil and the horn comprises:

(a) monitoring the gap between the horn and the anvil, based upon the temperature of the horn.

22. The method of claim 20, wherein maintaining the gap between the anvil and the horn comprises:

(a) monitoring the gap between the horn and the anvil, based upon the resonant frequency of the horn.

23. The method of claim 20, wherein maintaining the gap between the anvil and the horn comprises:

(a) adjusting the position of the horn, so as to maintain the gap between the horn and the anvil substantially constant.

24. A multi-layered material comprising a first nonwoven layer and a second base layer bonded together by ultrasonic welding, the ultrasonic welding comprising:

(a) providing an anvil and a horn stack comprising a horn, the anvil and horn having a gap therebetween;

(b) rotating at least one of a horn and an anvil while vibrating the horn with ultrasonic energy to obtain a frequency;

(c) monitoring at least one of the frequency and a temperature of at least one of the horn or the anvil; and

(d) maintaining the gap between the anvil and the horn based on either the temperature or a change in the frequency.

25. The multi-layered material according to claim 24, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) providing a mounting system for supporting a rotatable horn so that it can rotate about a first axis and such that the rotatable horn has only two additional degrees of freedom,

(i) the first additional degree of freedom being translational motion in a direction perpendicular to the first axis, and

(ii) the second additional degree of freedom being rotational motion about a second axis that is both perpendicular to the first axis and the direction of the first additional degree of freedom;

(b) mounting the horn within the mounting system; and

(c) contacting the web with the horn so as to treat the web.

26. The multi-layered material according to claim 25, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by providing a mounting system comprising:

(a) a frame having two side plates, each side plate having a bearing surface and having a slot therein;

(b) a pair of support elements each adapted to engage the horn in such a fashion that the horn is free to rotate, wherein each support element comprises;

(i) a slide portion slidably engaging one of the slots; and

(ii) a bearing portion having a curved surface engaging the bearing surface.

27. The multi-layered material according to claim 26, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by providing a mechanism for limiting the maximum amount of motion within the second additional degree of freedom.

28. The multi-layered material according to claim 24, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) receiving a resonant frequency of the horn, wherein a portion of the horn is fixed a given distance from the anvil by a rigid mounting system; and

(b) determining a quantity standing in known relation to an approximate change in length of the gap, based upon the resonant frequency.

29. The multi-layered material according to claim 28, wherein determining the quantity standing in known relation to the approximate change in length of the gap comprises:

(a) accessing a table to obtain a gap corresponding to the resonant frequency.

30. The multi-layered material according to claim 28, wherein determining the quantity standing in known relation to the approximate change in length of the gap comprises:

(a) accessing a table to obtain first and second quantities corresponding to frequencies straddling the resonant frequency; and

(b) interpolating between the first and second quantities, to arrive at the approximate gap.

31. The multi-layered material according to claim 28, wherein determining the quantity standing in known relation to the approximate change in length of the gap comprises:

(a) calculating a dimension of the horn, as a function of the resonant frequency and material characteristics of the horn.

32. The multi-layered material according to claim 28, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) adjusting the given distance between the fixed portion of the horn and the anvil, so as to substantially maintain a constant gap.

33. The multi-layered material according to claim 28, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) adjusting the given distance between the fixed portion of the horn and the anvil, based upon the resonant frequency of the horn.

34. The multi-layered material according to claim 24, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) applying a force to the horn, so as to urge the horn toward the anvil;

(b) positioning a deformable stop at a location, such that application of the urging force causes a member operatively connected to the horn to abut the deformable stop, and to deform the stop; and

(c) iteratively adjusting the urging force during operation of the horn, so as to adjust the extent of the deformation of the deformable stop, and to maintain the gap between the horn and the anvil substantially constant.

35. The multi-layered material according to claim 34, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) monitoring the gap between the horn and the anvil, based upon the temperature of the horn.

36. The multi-layered material according to claim 34, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) monitoring the gap between the horn and the anvil, based upon the resonant frequency of the horn.

37. The multi-layered material according to claim 34, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) determining a quantity standing in known relation to the adjusted urging force, based upon the gap between the horn and the anvil.

38. The multi-layered material according to claim 37, wherein determining the quantity standing in known relation to the adjusted urging force comprises accessing a table to obtain the adjusted force corresponding to the gap.

39. The multi-layered material according to claim 37, wherein determining the quantity standing in known relation to the adjusted urging force comprises accessing a table to obtain a control signal value corresponding to the gap.

40. The multi-layered material according to claim 24, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) applying an AC signal to a converter coupled to the horn, the AC signal exhibiting an amplitude; and

(b) adjusting the amplitude of the AC signal during operation of the horn, so as to maintain the gap between the horn and the anvil substantially constant.

41. The multi-layered material according to claim 40, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) monitoring the gap between the horn and the anvil, based upon the temperature of the horn.

42. The multi-layered material according to claim 40, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) monitoring the gap between the horn and the anvil, based upon the resonant frequency of the horn.

43. The multi-layered material according to claim 40, wherein the ultrasonic welding comprises maintaining the gap between the anvil and the horn constant by:

(a) adjusting the position of the horn, so as to maintain the gap between the horn and the anvil substantially constant.

44. The multi-layered material according to claim 43, wherein the position of the horn is adjusted within a range, and wherein the ultrasonic welding further comprises:

(a) determining whether the horn would have to occupy a position outside of the range, in order to maintain a constant gap between the horn and the anvil; and

(b) in the event of a positive determination, adjusting the amplitude of the AC signal.

45. The multi-layered material according to claim 43, wherein the amplitude of the AC signal may be adjusted within a range, and wherein the ultrasonic welding further comprises:

(a) determining whether the AC signal would have to exhibit an adjusted amplitude outside of the range, in order to maintain a constant gap between the horn and the anvil; and

(b) in the event of a positive determination, adjusting the position of the horn, so as to maintain the gap between the horn and the anvil substantially constant.

46. The multi-layered material of claim 24 further comprising an adhesive layer positioned between the nonwoven layer and the base layer.

47. The multi-layered material of claim 24, wherein the second base layer comprises elastic.

48. The multi-layered material of claim 47, wherein the second base layer comprises a first nonwoven surface on an elastic film, the first nonwoven surface positioned between the elastic film and the adhesive layer.

49. The multi-layered material of claim 48, wherein the second base layer further comprises a second nonwoven surface on the elastic film opposite the first nonwoven surface.

50. The multi-layered material of claim 24 further comprising a second nonwoven layer bonded to the second base layer.