Plastic bottle and method of producing the same

• US 6,716,386 B2
• Filed: 01/09/2002
• Issued: 04/06/2004
• Est. Priority Date: 12/25/1998
• Status: Expired due to Term

• Current Assignee: TOYO Seikan Kaisha Limited
• Original Assignee: TOYO Seikan Kaisha Limited
• Inventors: Saito, Go, Kawaguchi, Kiyoshi, Etoh, Makoto, Maruhashi, Yoshitsugu
• Primary Examiner(s): McDowell, Suzanne E.
• Application Number:
  US10/040,476
• Publication Number:
  US 20020088767A1
• Time in Patent Office: 818 Days
• Field of Search: 264/532, 264/540, 264/319, 264/537, 264/539, 425/812, 425/410
• US Class Current: 264/532
• CPC Class Codes: B29C 2035/0811 using induction
• CPC Class Codes: B29C 2035/0822 using IR radiation
• CPC Class Codes: B29C 2043/3411 mounted onto arms, e.g. grippers, fingers, clamping frame, suction means
• CPC Class Codes: B29C 2043/3466 using rotating supports, e.g. turntables or drums
• CPC Class Codes: B29C 2043/3689 on a support table, e.g. flat disk-like tables having moulds on the periphery
• 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 2049/7879 Stretching, e.g. stretch rod
• CPC Class Codes: B29C 2949/0811 Wall thickness
• CPC Class Codes: B29C 2949/0821 of the lip, i.e. the very top of the preform neck
• CPC Class Codes: B29C 2949/0829 Height, length
• CPC Class Codes: B29C 2949/0845 of the body
• CPC Class Codes: B29C 2949/0872 Weight
• CPC Class Codes: B29C 31/048 the material being severed at the dispensing head exit, e.g. as ring, drop or gob, and transported immediately into the mould, e.g. by gravity
• CPC Class Codes: B29C 33/303 centering mould parts or halves, e.g. during mounting
• CPC Class Codes: B29C 43/00 Compression moulding, i.e. applying external pressure to flow the moulding material; Apparatus therefor by liberation of internal stresses B29C61/006
• CPC Class Codes: B29C 43/08 with circular movement , e.g. mounted on rolls, turntables
• CPC Class Codes: B29C 43/34 Feeding the material to the mould or the compression means B29C43/085 takes precedence
• CPC Class Codes: B29C 43/50 Removing moulded articles
• CPC Class Codes: B29C 49/02 Combined blow-moulding and manufacture of the preform or the parison
• CPC Class Codes: B29C 49/087 : Means for providing controlled or limited stretch ratio
• CPC Class Codes: B29C 49/12 : Stretching rods
• CPC Class Codes: B29C 49/6605 : Heating the article, e.g. for hot fill
• CPC Class Codes: B29K 2067/00 : Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2105/253 : Preform
• CPC Class Codes: B65D 1/0223 : characterised by shape

Abstract

A bottle having substantially no strain due to fluidized orientation in the bottom portion thereof which is homogeneously and uniformly drawn, and, as a result, exhibiting improved shock resistance and buckling strength in the bottom portion, featuring excellent resistance against environmental cracking at the center in the bottom portion, without developing crazing or whitening during the preservation, and offering excellent appearance. The bottle is formed by biaxially stretch-blow-molding a thermoplastic resin, and has a mouth portion, a shoulder portion, a barrel portion and a bottom portion, said bottom portion without being substantially affected by the residual strain due to orientation by fluidization.

Claims

1. A method of producing a bottle having a support ring in an outer periphery of a mouth portion thereof by biaxially stretch-blow-molding a pre-molded article for blow molding having the support ring and a barrel portion with bottom, wherein

said pre-molded article is obtainable through the steps of:

extruding a molten thermoplastic resin and cutting it into a mass of melt of nearly a predetermined amount;

arranging a male metal mold and a female metal mold so as to move relative to each other and feeding the mass of melt into the metal mold;

compression-molding the mass of melt into a pre-molded article while forming an and an annular groove in an inner peripheral edge in the lower surface of the support ring so that a change in the mass of the molten resin from the predetermined amount is absorbed as a change in height of the annular groove; and

cooling and solidifying the compression-molded article and discharging the molded article out of the metal mold.

2. A method of producing a bottle according to claim 1, wherein the mass of melt is compression-molded into the pre-molded article while discharging the air remaining in the metal mold.

3. A method of producing a bottle according to claim 1, wherein fine gaps or holes are formed in a portion of the metal mold forming the bottom portion of the pre-molded article.

4. A method of producing a bottle according to claim 1, wherein the male metal mold is constituted by a core metal mold and a follower metal mold surrounding the core metal mold and is allowed to be opened and closed coaxially therewith, the barrel portion with bottom is molded by the core metal mold and the female metal mold, and the mouth portion is molded by the core metal mold and the follower metal mold.

5. A method of producing a bottle by biaxially stretch-blow-molding a pre-molded article for blow molding that is obtainable through the steps of:

extruding a molten thermoplastic resin and cutting it into a mass of melt of nearly a predetermined amount;

arranging a male metal mold and a female metal mold so as to move relative to each other and feeding the mass of melt into the metal mold;

compression-molding the mass of melt into a pre-molded article having a barrel portion with bottom while discharging the air remaining in the metal mold; and

cooling and solidifying the compression-molded article and discharging the molded article out of the metal mold.

6. A method of producing a bottle by biaxially stretch-blow-molding a pre-molded article for blow molding that is obtainable through the steps of:

extruding a molten thermoplastic resin and cutting it into a mass of melt of nearly a predetermined amount;

arranging a male metal mold and a female metal mold so as to move relative to each other and feeding the mass of melt into the metal mold, said metal mold having fine gaps or holes in a portion of the metal mold forming the bottom portion of the pre-molded article;

compression-molding the mass of melt into a pre-molded article having a barrel portion with bottom in the metal mold; and

cooling and solidifying the compression-molded article and discharging the molded article out of the metal mold.

7. A method of producing a bottle by biaxially stretch-blow-molding a pre-molded article for blow molding that is obtainable through the steps of:

extruding a molten thermoplastic resin and cutting it into a mass of melt of nearly a predetermined amount;

arranging a male metal mold and a female metal mold so as to move relative to each other and feeding the mass of melt into the metal mold, said male metal mold being constituted by a core metal mold and a follower metal mold surrounding the core metal mold and being allowed to be opened and closed coaxially therewith;

compression-molding the mass of melt into a pre-molded article having a mouth portion and a barrel portion with bottom by using the metal mold, the barrel portion with bottom being molded by the core metal mold and the female metal mold, the mouth portion being molded by the core metal mold and the follower metal mold; and

cooling and solidifying the compression-molded article and discharging the molded article out of the metal mold.