Extrusion of articles

• US 7,738,993 B2
• Filed: 10/10/2003
• Issued: 06/15/2010
• Est. Priority Date: 10/10/2003
• Status: Expired due to Fees

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Silberg, Kevin, Lindquist, Jeffrey S.
• Primary Examiner(s): Kasenge; Charles R
• Application Number:
  US10/683,081
• Publication Number:
  US 20050080507A1
• Time in Patent Office: 2,440 Days
• Field of Search: 700/196, 264/40.1, 264/40.6, 264/165, 264/167, 264/209.4, 264/250, 264/407, 425/113, 425/135, 604/523, 604/526, 604/527, 604/96.01, 604/264, 604/525, 604/915
• US Class Current: 700/196
• CPC Class Codes: B29C 2049/7871 of the extruded preform thickness
• CPC Class Codes: B29C 2049/7873 Extrusion speed; Extruded preform position or length; Extrusion fall speed
• CPC Class Codes: B29C 2049/7874 Preform or article shape, weight, defect or presence
• CPC Class Codes: B29C 2948/92009 Measured parameter
• CPC Class Codes: B29C 2948/92076 Position, e.g. linear or angular
• CPC Class Codes: B29C 2948/92085 Velocity
• CPC Class Codes: B29C 2948/92123 Diameter or circumference
• CPC Class Codes: B29C 2948/92209 Temperature
• CPC Class Codes: B29C 2948/92314 Particular value claimed
• CPC Class Codes: B29C 2948/92428 Calibration, after-treatment, or cooling zone
• CPC Class Codes: B29C 2948/92438 Conveying, transporting or storage of articles
• CPC Class Codes: B29C 2948/92514 Pressure
• CPC Class Codes: B29C 2948/92523 Force; Tension
• CPC Class Codes: B29C 2948/9258 Velocity
• CPC Class Codes: B29C 2948/9259 Angular velocity
• CPC Class Codes: B29C 2948/92609 Dimensions
• CPC Class Codes: B29C 2948/92619 Diameter or circumference
• CPC Class Codes: B29C 2948/92704 Temperature
• CPC Class Codes: B29C 2948/92714 Degree of crosslinking, solidification, crystallinity or homogeneity
• CPC Class Codes: B29C 2948/92809 Particular value claimed
• CPC Class Codes: B29C 2948/92857 : Extrusion unit
• CPC Class Codes: B29C 2948/92876 : Feeding, melting, plasticising or pumping zones, e.g. the melt itself
• CPC Class Codes: B29C 2948/92885 : Screw or gear
• CPC Class Codes: B29C 2948/92923 : Calibration, after-treatment or cooling zone
• CPC Class Codes: B29C 2948/92933 : Conveying, transporting or storage of articles
• CPC Class Codes: B29C 2948/92952 : Drive section, e.g. gearbox, motor or drive fluids
• CPC Class Codes: B29C 48/06 : Rod-shaped
• CPC Class Codes: B29C 48/07 : Flat, e.g. panels
• CPC Class Codes: B29C 48/08 : flexible, e.g. films
• CPC Class Codes: B29C 48/09 : Articles with cross-sections having partially or fully enclosed cavities, e.g. pipes or channels
• CPC Class Codes: B29C 48/10 : flexible, e.g. blown foils
• CPC Class Codes: B29C 48/12 : Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• CPC Class Codes: B29C 48/2694 : Intermittent extrusion
• CPC Class Codes: B29C 48/92 : Measuring, controlling or regulating
• CPC Class Codes: B29C 49/04 : Extrusion blow-moulding
• CPC Class Codes: B29C 49/42426 : by pressure difference deforming parts of the preform
• CPC Class Codes: B29C 49/78 : Measuring, controlling or regulating

Abstract

An extrusion control system for use with one or more extruders has a data acquisition module in communication with one or more data acquisition nodes that are associated with an extrusion process. A control module is also in communication with one or more control nodes associated with the extrusion process. A synchronization signal to one or more control nodes causes the nodes to adjust to a predetermined setting.

Claims

1. An extrusion control system for use with one or more extruders, comprising:

a data acquisition module in communication with one or more data acquisition nodes arranged to gather data from an extrusion process;

a control module in communication with one or more control nodes to control the extrusion process in association with information obtained from the data acquisition module;

a synchronization signal generator to generate a synchronization signal for the one or more control nodes to cause the one or more control nodes to periodically reset to an earlier setting determined before a current operation cycle; and

an electronically-stored part profile that corresponds to an extruded part to be produced by the one or more extruders, wherein the control module is operable to use the part profile to produce a plurality of continuously extruded parts matching the part profile.

2. The extrusion control system of claim 1, wherein the part profile comprises a representation of the outer diameter of the extruded part.

3. The extrusion control system of claim 2, wherein the part profile comprises a minimum specified part profile and a maximum specified part profile.

4. The extrusion control system of claim 1, wherein the synchronization signal generator generates the synchronization signal at a substantially repeating period.

5. The extrusion control system of claim 4, wherein the substantially repeating period is a function of the length of the extruded part.

6. The extrusion control system of claim 5, wherein the synchronization signal is generated for each part.

7. The extrusion control system of claim 1, further comprising a first event marker associated with the part profile, whereby the synchronization signal generator generates the synchronization signal when the system encounters the event marker.

8. The extrusion control system of claim 7, wherein the first event marker corresponds to the beginning of the part profile.

9. The extrusion control system of claim 7, wherein the first event marker corresponds to the end of the part profile.

10. The extrusion control system of claim 1, wherein the data acquisition module and the control module are each in communication with a computer that monitors and controls the operation of the one or more extruders.

11. The extrusion control system of claim 10, further comprising a display associated with the computer that presents an image of the part profile.

12. The extrusion control system of claim 1, wherein the synchronization signal generator communicates with each of the one or more control nodes over a dedicated communication channel.

13. The extrusion control system of claim 12, wherein the synchronization signal comprises a synchronization pulse.

14. The extrusion control system of claim 1, wherein the synchronization signal generator communicates with each of the one or more control nodes over a shared communication medium.

15. The extrusion control system of claim 1, further comprising a velocity sensor that allows the velocity of an extruded article to be measured, wherein data from the velocity sensor is used by the control module to control an extrusion speed for the one or more extruders.

16. The extrusion control system of claim 1, wherein a data acquisition node comprises a laser gauge.

17. The extrusion control system of claim 16, wherein the laser gauge acquires data relating to the outside diameter of an extruded article produced by the extrusion process.

18. The extrusion control system of claim 1, wherein the control module communicates with control nodes on more than one extruder.

19. The extrusion control system of claim 18, wherein the control module causes a switchover from a first material in a first extruder to a second material in a second extruder.

20. The extrusion control system of claim 1, further comprising a reporting module that provides data acquired by the data acquisition module.

21. An extrusion control system for use with one or more extruders, comprising:

a data acquisition module in communication with one or more data acquisition nodes arranged to gather data from an extrusion process;

a control module in communication with one or more control nodes to control the extrusion process in association with information obtained from the data acquisition module; and

a synchronization signal generator to generate a synchronization signal for the one or more control nodes to cause the one or more control nodes to periodically reset to an earlier setting determined before a current operation cycle,

wherein the control module is in communication with a PID controller associated with a variable speed drive for the one or more extruders, and the synchronization signal causes the PID controller to return to a preset speed.

22. An extrusion control system for use with one or more extruders, comprising:

a data acquisition module in communication with one or more data acquisition nodes arranged to gather data from an extrusion process;

a control module in communication with one or more control nodes to control the extrusion process in association with information obtained from the data acquisition module; and

a synchronization signal generator to generate a synchronization signal for the one or more control nodes to cause the one or more control nodes to periodically reset to an earlier setting determined before a current operation cycle at a predetermined interval,

wherein the control module carries out a PID control sequence after the synchronization signal generator generates the synchronization signal.

23. An extrusion control system for use with one or more extruders, comprising:

a data acquisition module in communication with one or more data acquisition nodes arranged to gather data from an extrusion process;

a control module in communication with one or more control nodes to control the extrusion process in association with information obtained from the data acquisition module; and

a synchronization signal generator to generate a synchronization signal for the one or more control nodes to cause the one or more control nodes to periodically reset to an earlier setting determined before a current operation cycle,

wherein the control module is in communication with a sizing air device controller associated with an extruder, and the synchronization signal causes the sizing air device controller to set to a predetermined value.