Cutting instruments and methods of making same

• US 3,911,579 A
• Filed: 04/18/1973
• Issued: 10/14/1975
• Est. Priority Date: 05/18/1971
• Status: Expired due to Term

• Current Assignee: Arthur E. Michael, George C. Lane, Phyllis M. Curtis
• Original Assignee: Arthur E. Michael, George C. Lane, Phyllis M. Curtis
• Inventors: Lane, George C., Curtis, Phyllis M., Michael, Arthur E.
• Primary Examiner(s): Vlachos, Leonidas
• Application Number:
  US05/352,374
• Time in Patent Office: 909 Days
• Field of Search: 76/14R,DIG.8 30/346.5,346.53,346.54,346.55 204/192 117/69R,7C,71M,93.4R,17.2R
• US Class Current: 30/346.54
• CPC Class Codes: B26B 21/54 Razor-blades B26B21/4006 takes precedence
• CPC Class Codes: C23C 14/022 by means of bombardment with energetic particles or radiation
• CPC Class Codes: C23C 14/34 Sputtering
• CPC Class Codes: C23C 14/345 using substrate bias
• CPC Class Codes: C23C 14/56 Apparatus specially adapted for continuous coating; Arrangements for maintaining the vacuum, e.g. vacuum locks
• CPC Class Codes: Y10S 76/08 Razor blade manufacturing

Abstract

The specific disclosure is directed to razor blades and methods of making the same wherein the cutting edge formed by two intersecting surfaces is sputter deposited with a refractory material which is subsequently overlaid with a sputter deposited coating of material displaying adhesion to a final lubricious coating.

Claims

1. A method of making a razor blade comprising the steps of:

forming a blade from a suitable material, the blade having an elongate edge comprising two intersecting surfaces;

sputter depositing on the edge a first coating of refractory material;

coating the edge with a second material displaying adhesion to a subsequent coating of lubricious material and to the refractory material; and

then coating the edge with the lubricious material.

2. The method of claim 1 wherein the first coating is RF sputter deposited and the second material is sputter deposited.

3. The method of claim 2 wherein the refractory material is corundum.

4. The method of claim 2 wherein the refractory material is selected from the group consisting of glass, corundum, quartz, alumina, beryllia, silicon carbide, boron nitride, and tungsten carbide.

5. The method of claim 4 wherein the refractory material comprises alloys and mixtures of materials selected from the group.

6. The method of claim 2 wherein the refractory material is synthetic sapphire.

7. The method of claim 1 wherein the total thickness of the deposited refractory material and the second material is limited to that necessary to maintain a desired degree of edge sharpness.

8. The method of claim 7 wherein the total thickness is approximately 500 Angstrom units.

9. The method of claim 7 wherein the thickness of the refractory material is approximately 300 Angstrom units and the thickness of the second material is approximately 25 Angstrom units.

10. The method of claim 2 wherein the RF sputter depositing comprises the steps of:

disposing the blade in an evacuated chamber having an electrode on which is mounted a target of refractory material;

introducing into the chamber an ionizable gas and establishing a plasma by imposing an RF potential between the electrode and the blade;

depositing on the edge particles dislodged from the target by impingement of gas ions formed in the plasma upon collision of RF excited electrons and the ionizable gas molecules.

11. The method of claim 10 wherein the chamber is evacuated to approximately 10 6 Torr and the ionizable gas is introduced to a pressure of approximately between 5 and 8 (10) 3 Torr.

12. The method of claim 11 wherein the refractory material is synthetic sapphire, the ionizable gas is Argon and the blade is positioned approximately 2 inches from the target, the edge apex being diSposed substantially in a plane parallel to the target and the refractory material is deposited at a rate of approximately 30 Angstroms per minute for a period between approximately 5 and 10 minutes.

13. The method of claim 12 wherein the frequency is 13.56 MC and wherein the blade is sputter etched prior to deposition of the refractory material and a shutter is interposed between the target and the blade during the step of sputter etching.

14. The method of claim 13 wherein capacitor means is serially connected between the blade and the RF potential and the shutter is connected to ground during sputter etching and wherein when the shutter is removed, the RF potential is connected to the electrode and the blade is connected to ground for sputter deposition.

15. The method of claim 14 wherein the target is pre-cleaned prior to sputter etching and wherein during pre-cleaning the shutter is interposed, the RF potential connected to the electrode and the shutter is connected to ground.

16. The method of claim 15 wherein the following parameters are maintained during pre-cleaning, sputter etching and sputter deposition, respectively:

17. The method of claim 10 wherein the second material is RF sputtered in accordance with the steps of claim 10.

18. The method of claim 17 wherein the second material is deposited to a thickness sufficient to provide adhesion of the subsequent lubricious material.

19. The method of claim 18 wherein the second material is deposited to a thickness of approximately 25 Angstrom units and the second material is a metal containing material.

20. The method of claim 19 wherein the second material is selected from the group consisting of chromium, platinum, aluminum, titanium and iron.

21. The method of claim 19 wherein the second material comprises mixtures and alloys of metals selected from the group consisting of chromium, platinum, aluminum, titanium and iron.

22. The method of claim 19 wherein the second material is chromium.

23. The method of claim 19 wherein the lubricious material is a polymer material.

24. The method of claim 23 wherein the polymer is selected from the group consisting of polytetrafluoroethylene, polypropylene, polyhexafluoropropylene, polychlorotrifluoroethylene and polyethylene.

25. The method of claim 23 wherein the lubricious material comprises copolymers and telomers of polymers selected from the group consisting of polytetrafluoroethylene, polypropylene, polyhexafluoropropylene, polychlorotrifluoroethylene and polyethylene.

26. The method of claim 23 wherein the polymer is polytetrafluoroethylene.

27. The method of claim 6 wherein the lubricious material is sputter deposited onto the edge.

28. The method of claim 27 wherein the lubricious material is deposited to a thickness of at least 1,000 Angstrom units.

29. The method of claim 17 wherein the edge is sputter etched in a first vacuum chamber, the blade is moved through a vacuum interlock to a second vacuum chamber in which the edge is sputter deposited with the refractory material, the blade is then moved through a second vacuum interlock to a third vacuum chamber in which the edge is sputter deposited with the second material, and finally the blade is moved through a third vacuum interlock to a fourth vacuum chamber which is then vented to the atmosphere to permit blade removal for subsequent coating with the lubricious material.

30. The method of claim 29 wherein blades are continuously sequentially passes through the chambers.

31. The method of claim 1 wherein the refractory material comprises an aluminum oxide compound formed on the elongate edge when material sputtered from an aluminum target combines with oxygen present in The environment.

32. The method of claim 10 wherein the sputtering rate is increased by the presence of a reactive gas.

33. A cutting instrument comprising:

an elongate edge of narrow included angle formed by two intersecting surfaces of a refractory material, an overlay coating of material over the edge for providing adhesion to the refractory material and a lubricious material, and a final coating of the lubricious material.

34. The cutting instrument of claim 33 wherein the refractory material and the coating are sputter deposited on the edge.

35. The cutting instrument of claim 33 wherein the refractory material is synthetic sapphire.

36. The cutting instrument of claim 34 wherein the refractory material is selected from the group consisting of corundum, alumina, glass, quartz, beryllia, silicon carbide, tungsten carbide and boron nitride.

37. The cutting instrument of claim 35 wherein the refractory material is RF sputter deposited on the edge.

38. The cutting instrument of claim 37 wherein the overlay coating is RF sputter deposited.

39. The cutting instrument of claim 38 wherein the lubricious material is RF sputter deposited.

40. The cutting instrument of claim 37 wherein the total thickness of the refractory material and the overlay coating does not exceed approximately 500 Angstrom units.

41. The cutting instrument of claim 40 wherein the thickness of the refractory material is approximately 300 Angstrom units and the thickness of the overlay coating is approximately 25 Angstrom units.

42. The cutting instrument of claim 41 wherein the intersecting surfaces are honed surfaces and the narrow included angle is less than approximately 30*.

43. The cutting instrument of claim 42 wherein the narrow included angle is approximately 20*.

44. The cutting instrument of claim 43 wherein the cutting instrument material is stainless steel.

45. The cutting instrument of claim 43 wherein the cutting instrument material is selected from the group consisting of stainless steel, carbon steel, chromium steel, tungsten steel, molybdenum steel, and chrome-nickel steel.

46. The cutting instrument of claim 43 wherein the cutting instrument material is an alloy containing material selected from the group consisting of stainless steel, carbon steel, chromium steel, tungsten steel, molybdenum steel, and chrome-nickel steel.

47. A method for applying a lubricious material to a cutting instrument having an edge formed by two intersecting surfaces of a refractory material having limited adhesion to the lubricious material comprising the steps of:

sputter depositing on the edge an overlay coating displaying adhesion to the lubricious material; and

then coating the edge with the lubricious material.

48. The method of claim 47 wherein both the refractory material and the overlay coating material are sputtered on the edge and the refractory material is synthetic sapphire.

49. The method of claim 48 wherein both the refractory material and the overlay material are RF sputtered on the edge.

50. The method of claim 49 wherein the refractory material is selected from the group consisting of glass, quartz, corundum, alumina, beryllia, silicon carbide, tungsten carbide and boron nitride.

51. The method of claim 49 wherein the refractory material is an aluminum oxide compound formed by sputter depositing aluminum in an oxygen atmosphere.

52. The method of claim 49 wherein the lubricious material is selected from the group consisting of polytetrafluoroethylene, polypropylene, polyhexafluoropropylene, polychlorotrifluoroethylene and polyethylene.

53. The method of claim 52 wherein the lubricious material is sputter deposited on the overlay coating.

54. The method of claim 49 wherein the overlay coating is a metal containing material.

55. The method of claim 54 wherein the metal is selected from the group consisting of chromium, platinum, titanium, aluminum anD iron.

56. The method of claim 54 wherein the overlay coating is an alloy containing metal selected from the group consisting of chromium, platinum, titanium, aluminum and iron.

57. The method of claim 54 wherein the overlay coating material is chromium.

58. The method of claim 54 wherein the overlay coating thickness is approximately 25 Angstrom units and the total thickness of both the refractory material and the overlay coating is limited to that necessary to maintain a desired degree of edge sharpness.

59. The method of claim 58 wherein the refractory material coating is approximately 300 Angstrom units in thickness.

60. The method of claim 32 wherein said reactive gas is oxygen.

61. The cutting instrument of claim 33 wherein the cutting instrument is a razor blade.

62. The cutting instrument of claim 35 wherein the cutting instrument is a razor blade.

63. The cutting instrument of claim 36 wherein the cutting instrument is a razor blade.

64. The cutting instrument of claim 37 wherein the cutting instrument is a razor blade.

65. The cutting instrument of claim 38 wherein the cutting instrument is a razor blade.

66. The cutting instrument of claim 40 wherein the cutting instrument is a razor blade.