Method and installation for the production of containers

• US 8,354,051 B2
• Filed: 09/16/2009
• Issued: 01/15/2013
• Est. Priority Date: 11/22/2004
• Status: Active Grant

• Current Assignee: Sidel Participations (Tetra Laval Holdings BV)
• Original Assignee: Sidel Participations (Tetra Laval Holdings BV)
• Inventors: Feuilloley, Guy, Desoutter, Luc
• Primary Examiner(s): Davis, Robert B
• Application Number:
  US12/561,198
• Publication Number:
  US 20100072673A1
• Time in Patent Office: 1,217 Days
• Field of Search: 264/454, 264/458, 264/535, 425/174.4, 425/526
• US Class Current: 264/458
• CPC Class Codes: B29B 13/024 Hollow bodies, e.g. tubes or profiles
• CPC Class Codes: B29C 2035/0822 using IR radiation
• CPC Class Codes: B29C 2035/0838 using laser
• CPC Class Codes: B29C 2949/0715 the preform having one end closed
• CPC Class Codes: B29C 35/0805 using electromagnetic radiation
• CPC Class Codes: B29C 49/06 Injection blow-moulding
• CPC Class Codes: B29C 49/645 by cooling the neck
• CPC Class Codes: B29C 49/68 Ovens specially adapted for heating preforms or parisons
• CPC Class Codes: B29C 49/6835 using reflectors

Abstract

The invention relates to a method of producing a container from a thermoplastic blank (2), comprising: a step in which the blank (2) is heated using at least one beam (22) of coherent electromagnetic radiation, and a step in which the container is formed from the blank (2) thus heated. The invention also relates to an installation (1) which is used to produce containers (2) and which comprises a unit (16) for heating the blanks (2) in order to form containers from the blanks (2) thus heated. The inventive installation (1) defines a path (23) along which the blanks (2) travel inside the heating unit (16). In addition, the heating unit (16) comprises at least one coherent electromagnetic radiation source (26) which is directed towards a zone (25) that is located on the aforementioned path (23).

Claims

1. A method of thermally treating thermoplastic parisons for use in blow molding operations, the method comprising the steps of:

transporting a series of parisons through a path of a heating unit of a blow molding machine, wherein each of the parisons has a neck and the heating unit is configured to heat the parisons while the parisons are oriented neck up in the heating unit;

irradiating the parisons using one or more sources of coherent electromagnetic radiation at one or more wavelengths in a wavelength band between 700 nm and 1600 nm; and

heating the parisons to at least one desired temperature,

wherein the path is defined by opposing a first wall and a second wall which comprises;

slits disposed on a side of the second wall proximate the path, and

the sources of coherent electromagnetic radiation which are disposed on other side of the second wall, distally from the path, and emit the coherent electromagnetic radiation through the slits across the path toward the first wall and across substantially an entire length of a body of each parison which follows the path.

2. The method as claimed in claim 1, wherein said source of coherent electromagnetic radiation is an infrared-emitting device.

3. The method as claimed in claim 1, wherein said source of coherent electromagnetic radiation is an infrared-emitting laser.

4. The method as claimed in claim 1, wherein said source of coherent electromagnetic radiation is a near infrared-emitting device.

5. The method as claimed in claim 1, wherein said source of coherent electromagnetic radiation is a near infrared-emitting laser.

6. The method as claimed in claim 1, wherein said source of coherent electromagnetic radiation is a near infrared-emitting laser diode.

7. The method as claimed in claim 1, wherein the one or more wavelengths are selected to increase the energy absorbed by the parisons.

8. The method as claimed in claim 1, wherein the one or more wavelengths are selected for efficiently heating the parisons.

9. The method as claimed in claim 1, wherein the one or more wavelengths are selected to reduce the exposure time required to heat the parisons to a desired temperature.

10. The method as claimed in claim 1, wherein the one or more wavelengths are selected to achieve a desired amount of energy absorbed by the parisons for a given power density.

11. The method as claimed in claim 1, wherein the one or more wavelengths are selected to achieve a desired heating quality of the parisons.

12. The method as claimed in claim 1, wherein the one or more wavelengths are selected to achieve good diffusion of the radiant energy through the at least one predetermined thickness of the parisons.

13. The method as claimed in claim 1, wherein the method comprises heating at least one section of the parisons to a temperature of about 80°

C.

14. The method as claimed in claim 1, wherein the method comprises heating at least one section of the parisons to a temperature of about 115°

C.

15. The method as claimed in claim 1, wherein the method comprises heating at least one section of the parisons to a temperature of about 120°

C.

16. The method as claimed in claim 1, wherein the method comprises heating at least one section of the parisons to a temperature of about 130°

C.

17. The method as claimed in claim 1, wherein the method comprises a first step of heating at least one section of the parisons to a temperature of about 80°

C. and a second step of heating at least one section of the parisons to a temperature of about 130°

C.

18. The method as claimed in claim 1, wherein the method comprises a first step of heating at least one section of the parisons to a temperature of about 120°

C. and a second step of heating at least one section of the parisons to a temperature of about 130°

C.

19. The method as claimed in claim 18, wherein the first step and the second step are performed in different heating units of the blow molding machine.

20. The method as claimed in claim 1, wherein the parisons have at least one wall section having a thickness between 1 mm and 3 mm.

21. The method as claimed in claim 1, wherein the parison has a non-uniform wall thickness, in which the weight of the thermoplastic material is distributed according to a desired temperature profile for producing a particular profile of a container to be produced from the parison.

22. The method as claimed in claim 1, wherein at least two sections of the parisons are heated to different temperatures.

23. The method as claimed in claim 1, wherein at least three sections of the parisons are heated to different temperatures.

24. The method as claimed in claim 22 or 23, wherein the step of heating the parisons produces a non-uniform temperature profile over the length of the parisons.

25. The method as claimed in claim 22 or 23, wherein the step of heating the parisons produces a non-uniform vertical heating profile of the parisons.

26. The method as claimed in claim 23, wherein a middle section of the parison is heated to a temperature that is lower than the temperature to which two end sections of the parison are heated.

27. The method as claimed in claim 23, wherein the middle section of the parison is heated to a temperature of about 115°

C. and the two end sections are heated to a temperature of about 130°

C.

28. The method as claimed in claim 7 or 8, wherein the energy efficiency of the method is greater than 15%.

29. The method as claimed in claim 7 or 8, wherein the energy efficiency of the method is from greater than 15% to 50%.

30. The method as claimed in claim 10, further comprising heating said parisons for less than about 6 minutes at a power density of about 25 W/mm2.

31. The method as claimed in claim 10, further comprising heating said parisons for less than about 3 minutes at a power density of about 40 W/mm2.

32. The method as claimed in claim 10, further comprising heating said parisons for less than about 2.5 minutes at a power density of about 50 W/mm2.

33. The method as claimed in claim 10, further comprising heating said parisons for less than about 2 minutes at a power density of about 55 W/mm2.

34. The method as claimed in claim 10, further comprising heating said parisons for less than about 3 minutes at a power density of about 10 W/mm2.

35. The method as claimed in claim 10, further comprising heating said parisons for less than about 1.5 minutes at a power density of about 20 W/mm2.

36. The method as claimed in claim 10, further comprising heating said parisons for less than about 1 minute at a power density of about 30 W/mm2.

37. The method as claimed in claim 11, comprising selecting one or more of selecting beam shape, energy profile and power density to increase heating quality.

38. The method as claimed in claim 1, wherein the heating step is performed at a power adapted to prevent uncontrolled crystallization of the thermoplastic material.

39. The method as claimed in claim 1, wherein the thermoplastic parisons comprise polyethylene terephthalate (PET).

40. The method as claimed in claim 1, wherein the thermoplastic parisons comprise polyethylene naphthalate (PEN).

41. The method as claimed in claim 38, wherein the source of coherent electromagnetic radiation comprises at least one laser diode.

42. The method as claimed in claim 38, wherein the source of coherent electromagnetic radiation comprises at least one near infrared laser diode emitting radiation at a wavelength of 808 nm.

43. The method as claimed in claim 38, wherein the source of coherent electromagnetic radiation comprises at least two near infrared laser diodes emitting radiation at wavelengths of 808 nm and 940 nm.

44. The method as claimed in claim 1, wherein the heating step is conducted in the absence of broader wavelength heating radiation.

45. The method as claimed in claim 1, wherein the one or more wavelengths are selected to provide good diffusion through the thickness of the thermoplastic material.

46. The method as claimed in claim 1, wherein the one or more wavelengths are selected to provide uniform diffusion through the thickness of the thermoplastic material.

47. The method as claimed in claim 1, further comprising regulating the power of selected diodes to attain a desired temperature profile of the parisons.

48. The method as claimed in claim 1, further comprising regulating the power of at least one array of diodes to attain a desired temperature profile of the parisons.

49. The method as claimed in claim 1, further comprising regulating the power of separate arrays of diodes to attain a desired non-uniform temperature profile of the parisons.

50. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 700 and 1064 nm.

51. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 700 and 940 nm.

52. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 700 and 808 nm.

53. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 808 and 1600 nm.

54. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 808 and before 1000 nm.

55. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 808 and 1064 nm.

56. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 808 and 940 nm.

57. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 940 and 1600 nm.

58. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 940 and before 1000 nm.

59. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 940 and 1064 nm.

60. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 1000 and 1600 nm.

61. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 1000 and 1064 nm.

62. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 1064 and 1600 nm.

63. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within at least one wavelength of 808 nm, 940 nm, and 1064 nm.

64. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within at least two wavelengths of 808 nm, 940 nm, and 1064 nm.

65. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy at two wavelengths of 808 nm and 940 nm.

66. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy at a wavelength of 808 nm.

67. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy at a wavelength of 940 nm.

68. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy at a wavelength of 1064 nm.

69. The method as claimed in claim 1, wherein the near infrared laser diodes are operative to emit radiant energy at a wavelength of 1064 nm.

70. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 700 and 1600 nm.

71. The method as claimed in claim 1, wherein the near infrared laser diode heating elements are operative to emit radiant energy within a wavelength range between 700 and before 1000 nm.

72. The method as claimed in claim 1, wherein the transporting comprises:

transporting the series of parisons through the path by retaining the bodies of the parisons between and within the first and second walls and projecting the necks of the parisons above the first and second walls, during the irradiating of the parisons.