Continuous production of molded plastic containers

• US 7,455,807 B2
• Filed: 05/21/2007
• Issued: 11/25/2008
• Est. Priority Date: 11/17/2003
• Status: Expired due to Fees

• Current Assignee: Graham Packaging Pet Technologies Inc (Graeme Richard Hart, MBA)
• Original Assignee: Graham Packaging Pet Technologies Inc (Graeme Richard Hart, MBA)
• Inventors: Larsen, W. Bruce
• Primary Examiner(s): Davis; Robert B
• Application Number:
  US11/751,164
• Publication Number:
  US 20070228620A1
• Time in Patent Office: 554 Days
• Field of Search: 264/531, 264/532, 264/543, 425/528, 425/534
• US Class Current: 264/531
• CPC Class Codes: B29B 11/12 Compression moulding
• CPC Class Codes: B29C 2043/3277 for rotatable suports, e.g. carousels, drums
• CPC Class Codes: B29C 2043/5833 movement of moulds or mould parts, e.g. opening or closing, actuating
• CPC Class Codes: B29C 2049/78805 Computer or PLC control
• CPC Class Codes: B29C 2793/0081 before shaping
• CPC Class Codes: B29C 2949/22 at neck portion
• CPC Class Codes: B29C 2949/24 at flange portion
• CPC Class Codes: B29C 2949/26 at body portion
• CPC Class Codes: B29C 2949/28 at bottom portion
• CPC Class Codes: B29C 2949/3008 at neck portion
• CPC Class Codes: B29C 2949/3012 at flange portion
• CPC Class Codes: B29C 2949/3016 at body portion
• CPC Class Codes: B29C 2949/302 at bottom portion
• CPC Class Codes: B29C 2949/3024 characterised by the number of components or by the manufacturing technique
• CPC Class Codes: B29C 2949/3026 having two or more components
• CPC Class Codes: B29C 2949/3028 having three or more components
• CPC Class Codes: B29C 2949/303 having more than three components
• CPC Class Codes: B29C 2949/3056 having components being compression moulded
• CPC Class Codes: B29C 2949/3058 having two or more components being compression moulded
• CPC Class Codes: B29C 2949/306 having three or more components being compression moulded
• CPC Class Codes: B29C 2949/3062 : having more than three components being compression moulded
• 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 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 43/58 : Measuring, controlling or regulating for bank adjustment in calendering B29C43/245
• CPC Class Codes: B29C 48/07 : Flat, e.g. panels
• CPC Class Codes: B29C 48/21 : the layers being joined at their surfaces
• CPC Class Codes: B29C 48/49 : using two or more extruders to feed one die or nozzle
• CPC Class Codes: B29C 49/02 : Combined blow-moulding and manufacture of the preform or the parison
• CPC Class Codes: B29C 49/0685 : Compression blow-moulding
• CPC Class Codes: B29C 49/22 : using multilayered preforms or parisons
• CPC Class Codes: B29C 49/24 : Lining or labelling
• CPC Class Codes: B29C 49/36 : rotatable about one axis
• CPC Class Codes: B29C 49/42101 : Conveyors, e.g. flat conveyor or clamping between two bands
• CPC Class Codes: B29C 49/6409 : Thermal conditioning of preforms B29C49/68 takes precedence
• CPC Class Codes: B29C 49/6436 : characterised by temperature differential
• CPC Class Codes: B29C 49/78 : Measuring, controlling or regulating
• CPC Class Codes: B29K 2023/00 : Use of polyalkenes or derivatives thereof as moulding material
• CPC Class Codes: B29K 2023/086 : EVOH, i.e. ethylene vinyl alcohol copolymer
• CPC Class Codes: B29K 2067/00 : Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2995/0041 : Crystalline
• CPC Class Codes: B29K 2995/0067 : non-permeable
• CPC Class Codes: B29L 2031/712 : Containers; Packaging elements or accessories, Packages closures therefor B29L2031/56; ink or toner cartridges B29L2031/7678; squeeze tubes B29L2023/20; suitcases B29L2031/7418

Abstract

A system for making plastic containers includes a source for providing a continuous stream of molten plastic, and a cutter for severing a continuing series of individual mold charges from the continuous molten plastic stream. A compression molder includes a plurality of compression molds arranged in a continuing series for receiving the mold charges in sequence and compression molding the mold charges into a continuing series of individual plastic container preforms. A blow molder includes a plurality of blow molds arranged in a continuing series for receiving the individual plastic container preforms in sequence and blow molding the preforms into a continuing series of plastic containers. A common drive coordinates continuous and synchronous operation of the molten plastic source, the cutter, the compression molder and the blow molder to provide the continuing series of plastic containers from the continuous stream of molten plastic.

Claims

1. A system for making plastic containers, which includes:

a source for providing a continuous stream of molten plastic,

a compression preform molder including a turret carrying a plurality of compression molds for receiving a continuous series of mold charges in sequence cut from said stream and compression molding the charges into a continuing series of individual plastic container preforms,

a preform conditioner connected between said compression molder and a blow molder for conditioning performs from said compression molder preparatory to blow molding in a blow molder,

a blow molder including a turret carrying a plurality of blow molds arranged in a continuing series for receiving said individual plastic container preforms in sequence and blow molding said preforms into a continuing series of plastic containers, and

a common drive connected to and coordinating continuous and synchronous operation of said source, said compression molder, said perform conditioner and said blow molder.

2. The system set forth in claim 1 wherein said common drive includes a drive/control mechanism connected to a drive of said source, a drive of said compression molder, a drive of said preform conditioner, and a drive of said blow molder.

3. The system set forth in claim 2 wherein said drive/control mechanism includes servo control electronics for synchronizing operation of servo motors connected to said source, said compression molder, said preform conditioner, and said blow molder.

4. The system set forth in claim 2 wherein said drive/control mechanism comprises a single motor connected by drive mechanisms to operating mechanisms of said source, said compression molder, said preform conditioner, and said blow molder.

5. The system set forth in claim 1 wherein said source comprises an extruder which provides said continuous stream.

6. The system set forth in claim 1 wherein said preform conditioner comprises a conveyor loop or rotating turret around which said preforms travel and wherein said common drive is connected to and coordinates continuous and synchronous operation of said preform conditioner conveyor loop or rotating turret.

7. The system set forth in claim 1 further including a transfer device connected to said preform conditioner for conveying said conditioned preforms to said blow molder, and wherein said common drive is also connected to and coordinates continuous and synchronous operation of said transfer device.

8. The system set forth in claim 1 further including a conveyer connected to said blow molder for receiving said continuing series of plastic containers from said blow molder, and wherein said common drive is also connected to and coordinates continuous and synchronous operation of said conveyer.

9. The system set forth in claim 1 wherein said compression molder molds multiple performs at each mold stage.

10. The system set forth in claim 1 wherein said blow molder molds multiple containers at each mold stage.

11. The system set forth in claim 1 including a cutter for severing a continuing series of individual mold charges from said continuous stream, and wherein said common drive is connected to and coordinates continuous and synchronous operation of said cutter.

12. A method of making plastic containers, which includes the steps of:

(a) providing a continuous stream of molten plastic,

(b) compression molding said plastic into a continuing series of plastic container preforms, said compression molding being performed on a turret carrying a plurality of compression molds for receiving a continuous series of mold charges in sequence cut from said stream and compression molding the charges into said continuous series of preforms,

(c) transferring said continuing series of plastic container preforms in sequence to a continuing series of blow molds, wherein said transferring step includes conditioning said plastic container performs preparatory to blow molding in said step (d),

(d) blow molding a continuing series of plastic containers in said blow molds, wherein said blow molder includes a turret carrying said plurality of blow molds,

(e) removing said containers in sequence from said blow molds, and

(f) operating said steps (a) through (e) in synchronism to provide a continuing series of blow molded containers from said molten plastic stream.

13. The method set forth in claim 12 wherein said conditioning comprises transporting said preforms on a conveyor loop or rotating turret to obtain a temperature profile suitable for blow molding.

14. The method set forth in claim 12 that includes at least one step, prior to said step (c) or subsequent to said step (e), selected from the group consisting of:

crystallizing all or a portion of a finish of the preform or container, and attaching all or a portion of a finish to the preform or container.

15. The method set forth in claim 12 that includes the step of attaching a label to the container during or subsequent to said step (d).

16. The method set forth in claim 12 wherein after said step (d) the preforms are transferred to a conditioning stage where they are allowed to cool to a temperature suitable for blow molding.

17. The method set forth in claim 16 wherein said step (f) includes operating said steps (a) through (e) in synchronism with said conditioning step.

18. The method set forth in claim 12 wherein during step (c) the preforms are heated to a temperature suitable for blow molding.

19. The method set forth in claim 12 wherein during said step (b) multiple preforms are compression molded in a single mold cycle.

20. The method set forth in claim 12 wherein during said step (d) multiple containers are blow molded in a single mold cycle.

21. The method set forth in claim 12 wherein said step (f) of operating in synchronism comprises connecting a common or integrated drive/control mechanism to a drive of an extruder for providing said continuous stream of molten plastic, a drive of the compression molding turret for said step of compression molding of said preforms, a drive of a transfer device for said step of transferring of said preforms to said blow molds, a drive of the blow molder turret carrying said blow molds, and a drive of a conveyer for said step of removing said containers from said blow molds.

22. The method of claim 12 including the step of cutting such continuous stream into individual mold charges and transferring said mold charges in sequence to a continuing series of compression molds for said step of compression molding, and wherein said operating step (f) includes operating said cutting step in synchronism with steps (a) through (e).

23. The method set forth in claim 12 wherein the continuous stream of molten plastic is fed to a cutter and transfer mechanism for severing a continuing series of individual mold charges from said stream and transferring the mold charges into individual compression molds carried by the turret which is operated in synchronism with the cutter and the transfer mechanism.