Extrusion of articles

• US 20050080507A1
• Filed: 10/10/2003
• Published: 04/14/2005
• Est. Priority Date: 10/10/2003
• Status: Active Grant

• Current Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Original Assignee: Boston Scientific Scimed (Boston Scientific Corporation)
• Inventors: Lindquist, Jeffrey S., Silberg, Kevin
• Granted Patent: US 7,738,993 B2
• Time in Patent Office: Days
• 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 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 that are associated with an extrusion process;

a control module in communication with one or more control nodes associated the extrusion process; and

a synchronization signal generator that generates a synchronization signal for the one or more control nodes to cause the one or more control nodes to adjust to a predetermined setting.

2. The extrusion control system of claim 1, further comprising a part profile that corresponds to an extruded part to be produced by the one or more extruders.

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

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

5. The extrusion control system of claim 2, wherein the synchronization signal generator generates a synchronization signal at a substantially repeating period.

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

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

8. The extrusion control system of claim 2, further comprising a first event marker associated with the part profile, whereby the synchronization signal generator generates a synchronization signal when the system encounters the event marker.

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

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

11. The extrusion control system of claim 2, 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.

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

13. 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.

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

15. 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.

16. The extrusion control system of claim 1, further comprising a velocity sensor that allows the velocity of an extruded article to be measured.

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

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

19. The extrusion control system of claim 1, wherein the control module is in communication with a PID controller associated with a variable speed drive for the extruder, and the synchronization signal causes the PID controller to return to a preset speed.

20. The extrusion control system of claim 1, wherein the control module carries out a PID control sequence after the synchronization signal generator generates the synchronization signal.

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

22. The extrusion control system of claim 21, wherein the control module causes a switchover form a first material in a first extruder to a second material in a second extruder.

23. The extrusion control system of claim 1, 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.

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

25. A method of producing an extruded article comprised of a plurality of extruded parts, comprising:

defining a part profile;

associating a plurality of control parameters with the part profile, wherein each control parameter has an initial value;

producing a first extruded part using the plurality of control parameters in a closed-loop control system;

resetting each of the plurality of control parameters to its initial value;

producing a second extruded part using the plurality of control parameters in a closed-loop control system.

26. The method of claim 25, wherein the step of resetting comprises sending a synchronization signal to a plurality of control nodes.

27. The method of claim 25, wherein the synchronization signal is a pulse.

28. The method of claim 25, wherein the synchronization signal is transmitted on a dedicated communication path.

29. The method of claim 25, wherein the synchronization signal is sent after the first extruded part is produced and before the second extruded part is produced.

30. An extruded article, comprising:

a plurality of extruded parts;

a plurality of material transitions, wherein each part contains at least one material transition; and

wherein the material transitions are each shorter than 0.25 inches in extruded length.

31. The extruded article of claim 30, wherein the plurality of extruded parts comprises more than 30 parts.

32. The extruded article of claim 30, wherein the plurality of extruded parts comprises more than 50 parts.

33. A plurality of extruded parts produced as part of a substantially continuous extrusion process, comprising:

a first section on each of the plurality of extruded parts having a constant outside diameter;

a second section on each of the plurality of extruded parts having an increasing outside diameter;

wherein the outside diameter of the first section of each of the plurality of extruded parts is substantially identical to the outside diameter of the first section of each of the other extruded parts; and

wherein the outside diameter along the second section of each of the plurality of extruded parts is substantially identical to the outside diameter along the second section of each of the other extruded parts.

34. The plurality of extruded parts of claim 33, wherein the outside diameter of the first section of the first extruded part differs from the outside diameter of the first section of any other of the plurality of parts by no more than 0.0010.

35. The plurality of extruded parts of claim 33, wherein the outside diameter of the first section of the first extruded part differs from the outside diameter of the first section of any other of the plurality of parts by no more than 0.0005″

.

36. A extruded catheter, comprising:

a catheter tip made of a first plastic material;

a balloon having an expanding portion, a middle portion, and a contracting portion; and

a catheter shaft defining a lumen connected to the contracting portion,

wherein the catheter shaft has a transition zone smaller than 0.25 inches in which the catheter shaft transitions from the first plastic material to a second plastic material.