Biaxially oriented polyethylene terephthalate resin bottle-shaped container

• US 5,248,533 A
• Filed: 04/06/1992
• Issued: 09/28/1993
• Est. Priority Date: 02/15/1984
• Status: Expired due to Term

• Current Assignee: Yoshino Kogyosho Company Limited
• Original Assignee: Yoshino Kogyosho Company Limited
• Inventors: Tanaka, Fuminori, Uesugi, Daisuke, Sugiura, Horoaki
• Primary Examiner(s): AFTERGUT, KAREN K
• Application Number:
  US07/866,099
• Time in Patent Office: 540 Days
• Field of Search: 264/521, 264/523, 264/529, 264/530, 264/25, 264/235, 264/346, 264/519, 264/520, 264/532, 264/535, 215/1 C, 215/224, 215/294, 428/35.1, 428/35.7, 428/36.8, 428/36.92, 428/910
• US Class Current: 428/35.7
• CPC Class Codes: B29C 2049/7862 characterised by temperature values or ranges
• CPC Class Codes: B29C 2049/78645 characterised by temperature values or ranges
• CPC Class Codes: B29C 2049/7868 of the articles
• CPC Class Codes: B29C 2949/0715 the preform having one end closed
• CPC Class Codes: B29C 49/00 Blow-moulding, i.e. blowing a preform or parison to a desired shape within a mould; Apparatus therefor
• CPC Class Codes: B29C 49/06 Injection blow-moulding
• CPC Class Codes: B29C 49/16 using pressure difference for pre-stretching, e.g. pre-blowing
• CPC Class Codes: B29C 49/18 using several blowing steps B29C49/16 takes precedence
• CPC Class Codes: B29C 49/642 and shrinking of the preform
• CPC Class Codes: B29C 49/6472 in several stages
• CPC Class Codes: B29C 61/02 Thermal shrinking
• CPC Class Codes: B29K 2067/00 Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2995/0017 Heat stable
• CPC Class Codes: B29K 2995/0053 bi-axially
• CPC Class Codes: Y10S 264/906 And heat-shrinking outside of mold including subsequent re-expanding of shrunken article using differential fluid pressure
• CPC Class Codes: Y10S 428/91 Product with molecular orientation
• CPC Class Codes: Y10T 428/1331 Single layer [continuous layer]
• CPC Class Codes: Y10T 428/1352 Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1397 Single layer [continuous layer]

Abstract

A biaxially oriented polyethylene terephthalate resin bottle-shaped container made by thermally crystallizing a neck portion of a preform, heating the preform, blow-molding the preform to form a primary intermediate molded bottle-shaped piece, raising the temperature of the primary intermediate molded bottle-shaped piece to a temperature greater than the temperature during blow-molding the preform to thermally contract the primary intermediate molded bottle-shaped piece to form a secondary intermediate molded bottle-shaped piece, and blow-molding the secondary intermediate molded bottle-shaped piece to form a bottle-shaped container.

Claims

1. A biaxially-oriented polyethylene terephthalate resin bottle-shaped container, said container exhibiting no substantial deformation when exposed to a temperature of 120°

C. for 30 minutes and being made according to a method comprising the sequential steps of;

(a) thermally crystallizing a neck portion of a preform;

(b) heating said preform;

(c) biaxial-orientation blow-molding said preform at a predetermined temperature to form a primary intermediate molded bottle-shaped piece;

then

(d) applying heat to said primary intermediate molded bottle-shaped piece for heat treating said primary intermediate molded bottle-shaped piece by heating said primary intermediate molded bottle-shaped piece to a temperature greater than said predetermined temperature during biaxial-orientation blow molding of said preform to thermally contract said primary intermediate molded bottle-shaped piece to form a secondary intermediate molded bottle-shaped piece; and

(e) biaxial-orientation blow-molding said secondary intermediate molded bottle-shaped piece to form said bottle-shaped container exhibiting no substantial deformation when exposed to said temperature of 120°

C. due to said application of heat to said primary intermediate molded bottle-shaped piece at said greater temperature.

2. The container of claim 1 wherein said preform is heated to a temperature which approaches but does not reach a thermal crystallization temperature of polyethylene terephthalate.

3. The container of claim 1 wherein said primary intermediate molded bottle-shaped piece is heat treated in a range that does not exceed a temperature immediately before a melting temperature point of 255°

C. of polyethylene terephthalate.

4. The container of claim 1, wherein said step of thermally crystallizing is conducted without orienting deformation.

5. The container according to claim 4, wherein said neck portion remains in substantially the same shape during said step of thermally crystallizing.

6. The container according to claim 1, wherein said biaxial-orientation blow-molding of said preform is performed in a first blow-mold at a first blow-mold temperature, and wherein during said heat treating, said primary intermediate molded bottle-shaped piece is heated to a temperature at least 20°

C. higher than said first blow-mold temperature.

7. The container according to claim 1, wherein said preform is blow-molded in a first blow-mold, and said secondary intermediate molded bottle-shaped piece is blow-molded in a second blow-mold, separate from said first blow-mold.

8. The container according to claim 1 wherein said primary intermediate method bottle-shaped piece is heat treated at 170°

C. to 255°

C.

9. The container of claim 1 wherein a size of said primary intermediate molded bottle-shaped piece is at least as great as a size of said bottle-shaped container.

10. The container of claim 1 wherein a maximum diameter of said primary intermediate molded bottle-shaped piece is at least as great as a maximum diameter of said bottle-shaped container.

11. The container of claim 1 wherein an orientation-molded portion of said secondary intermediate molded bottle-shaped piece is substantially the same size as or slightly smaller than an orientation-molded portion of said bottle-shaped container.

12. The container of claim 1 wherein orientation magnification from said secondary intermediate molded bottle-shaped piece to said bottle-shaped container is quite small, so that almost no residual stress is created in said bottle-shaped container.

13. The container of claim 1 wherein said preform is heated at 100°

C. to 120°

C.

14. The container according to claim 1, wherein said preform is orientation area magnified 5 to 13 times to form said primary intermediate molded bottle-shaped piece.

15. The container according to claim 1, wherein said preform is orientation area magnified 5 to 13 times to form said primary intermediate molded bottle-shaped piece so that a body portion of said container is not thermally crystallized even when subjected to said first blow-mold heated at 110°

to 230°

C.

16. The container according to claim 1, wherein a body portion of said container is clear and transparent.

17. The container according to claim 1, wherein a temperature of a secondary blow-mold is several degrees greater than a preselected maximum temperature to which said molded bottle-shaped container is subjected during use.

18. The container according to claim 1, wherein a temperature of a secondary blow-mold is several degrees greater than a preselected maximum temperature to which said molded bottle-shaped container is subjected during use such that said bottle-shaped container is heat set by said secondary blow-mold, and therefore said bottle-shaped container has no residual stress as well as high heat resistance.

20. The biaxially-oriented polyethylene terephthalate resin bottle-shaped container of claim 17, said container exhibiting no substantial deformation when contents of said container are heat treated in said container.

19. A biaxially-oriented polyethylene terephthalate resin bottle-shaped container, said container exhibiting no substantial deformation when exposed to a temperature of 120°

C. for 30 minutes, and being made according to a method comprising the sequential steps of;

(a) thermally crystallizing a neck portion of a preform;

(b) heating said preform;

(c) biaxial-orientation blow-molding said preform in a first blow-mold heated at 110°

C. to 230°

C. to form a primary intermediate molded bottle-shaped piece;

then

(d) applying heat to said primary intermediate molded bottle-shaped piece for heat treating said primary intermediate molded bottle-shaped piece by heating said primary intermediate molded bottle-shaped piece to a temperature at least 20°

C. higher than said temperature of said first heated blow-mold to thermally contract said primary intermediate molded bottle-shaped piece to form a secondary intermediate molded bottle-shaped piece; and

(e) biaxial-orientation blow-molding said secondary intermediate molded bottle-shaped piece in a secondary blow-mold, distinct from said first blow-mold, heated at 100°

C. to 150°

C. to form said bottle-shaped container exhibiting no substantial deformation when exposed to said temperature of 120°

C. due to said application of heat to said primary intermediate molded bottle-shaped piece at said higher temperature.

21. The container according to claim 19 wherein said primary intermediate molded bottle-shaped piece is heat treated at 130°

to 255°

C.

22. The container according to claim 19 wherein said primary intermediate molded bottle-shaped piece is heat treated at 200°

to 235°

C.

23. The container according to claim 19 wherein said primary intermediate molded bottle-shaped piece is heat treated at 170°

to 255°

C.

24. The container according to claim 19 wherein said second blow-mold is heated at 120°

C. to 150°

C.

25. The container of claim 19 wherein at least one of a height and a maximum diameter of said primary intermediate molded bottle-shaped piece is at least as great as a corresponding one of a height and a maximum diameter of said bottle-shaped container.

26. The container of claim 19 wherein a size of said primary intermediate molded bottle-shaped piece is at least as great as a size of said bottle-shaped container.

27. The container of claim 19 wherein a maximum diameter of said primary intermediate molded bottle-shaped piece is at least as great as a maximum diameter of said bottle-shaped container.

28. The container of claim 19 wherein an orientation-molded portion of said secondary intermediate molded bottle-shaped piece is substantially the same size as or slightly smaller than an orientation-molded portion of said bottle-shaped container.

29. The container of claim 19 wherein an orientation magnification from said secondary intermediate molded bottle-shaped piece to said bottle-shaped container is quite small, so that almost no residual stress is created in said bottle-shaped container.

30. The container of claim 19 wherein said preform has a predetermined shape prior to said step of heating said preform.

31. The container of claim 30 wherein said preform has said predetermined shape formed by injection molding.

32. The container of claim 19 wherein said preform is heated to 100°

C. to 120°

C.

33. The container of claim 19 wherein said second blow-mold is heated to a temperature higher than a sterilizing temperature of contents for said bottle-shaped container.

34. The container of claim 19, wherein said step of thermally crystallizing is conducted without orienting deformation.

35. The container according to claim 34, wherein said neck portion remains in substantially the same shape during said step of thermally crystallizing.

36. The container of claim 19 wherein said heat treating of said primary intermediate molded bottle-shaped piece to form said secondary intermediate molded bottle-shaped piece eliminates residual stress developed in said primary intermediate molded bottle-shaped piece from biaxial orientation blow-molding.

37. The container of claim 19 wherein said heat treating of said primary intermediate molded bottle-shaped piece deforms said primary intermediate molded bottle-shaped piece by climinating internal residual stress to form said secondary intermediate molded bottle-shaped piece.

38. The container according to claim 19, wherein said preform is orientation area magnified 5 to 13 times to form said primary intermediate molded bottle-shaped piece.

39. The container according to claim 19, wherein said preform is orientation area magnified 5 to 13 times to form said primary intermediate molded bottle-shaped piece so that a body portion of said container is not thermally crystallized even when subjected to said first blow-mold heated at 110°

to 230°

C.

40. The container according to claim 19, wherein said preform is orientation area magnified so that a density of said resin becomes 1.36 or greater.

41. The container according to claim 19, wherein a body portion of said container is clear and transparent.

42. The container according to claim 19, wherein said temperature of secondary blow-mold is several degrees greater than a preselected maximum temperature to which said molded bottle-shaped container is subjected during use.

43. The container according to claim 19, wherein said temperature of secondary blow-mold is several degrees greater than a preselected maximum temperature to which said molded bottle-shaped container is subjected during use such that said bottle-shaped container is heat set by said secondary blow-mold, and therefor said bottle-shaped container has no residual stress as well as high heat resistance.

44. The container of claim 19, wherein said preform is heated to 90°

C. to 130°

C.

45. A biaxially-oriented polyethylene terephthalate resin bottle-shaped container, said container exhibiting no substantial deformation when exposed to a temperature of at least 120°

C. for 30 minutes, and being made according to a method comprising the sequential steps of;

(a) thermally crystallizing a neck portion of a preform;

(b) heating said preform;

(c) biaxial-orientation blow-molding said preform in a first blow-mold heated at 110°

to 230°

C. to form a primary intermediate molded bottle-shaped piece, said preform being orientation area magnified 5 to 13 times to form said primary intermediate molded bottle-shaped piece;

then

(d) applying heat to said primary intermediate molded bottle-shaped piece for heat treating said primary intermediate molded bottle-shaped piece by heating said primary intermediate molded bottle-shaped piece to a temperature at least 20°

C. higher than said temperature of said first heated blow-mold to thermally contract said primary intermediate molded bottle-shaped piece to form a secondary intermediate molded bottle-shaped piece; and

(e) biaxial-orientation blow-molding said secondary intermediate molded bottle-shaped piece in a secondary blow-mold, distinct from said first blow-mold, heated at 100°

C. to 150°

C. to form said bottle-shaped container, said secondary intermediate molded bottle-shaped piece having a substantially small orientation magnification so that almost no residual stress is created in said bottle-shaped container.