Methods of molding a syringe

• US 7,740,792 B2
• Filed: 08/03/2007
• Issued: 06/22/2010
• Est. Priority Date: 08/03/2006
• Status: Active Grant

• Current Assignee: Bayer Healthcare LLC (Bayer AG)
• Original Assignee: Medrad Incorporated (Bayer AG)
• Inventors: Rhinehart, Edward J., Haury, John A., Belcher, Samuel L.
• Primary Examiner(s): Daniels; Matthew J.
• Application Number:
  US11/833,427
• Publication Number:
  US 20080033367A1
• Time in Patent Office: 1,054 Days
• Field of Search: 264/531, 264/532, 264/535, 264/537, 264/523, 425/529, 425/533
• US Class Current: 264/532
• CPC Class Codes: A61M 2207/10 Device therefor
• CPC Class Codes: A61M 5/007 for contrast media
• CPC Class Codes: A61M 5/14546 Front-loading type injectors
• CPC Class Codes: A61M 5/14566 with a replaceable reservoir for receiving a piston rod of the pump
• CPC Class Codes: A61M 5/3129 Syringe barrels A61M5/3205 and A61M5/50 take precedence
• CPC Class Codes: B29B 11/08 Injection moulding
• CPC Class Codes: B29B 11/10 Extrusion moulding
• CPC Class Codes: B29B 11/14 characterised by structure or composition
• CPC Class Codes: B29C 2949/0715 the preform having one end closed
• CPC Class Codes: B29C 2949/072 having variable wall thickness
• CPC Class Codes: B29C 2949/073 having variable diameter
• CPC Class Codes: B29C 2949/0762 Conical
• CPC Class Codes: B29C 2949/0767 the shape allowing stacking or nesting
• CPC Class Codes: B29C 2949/077 characterised by the neck
• CPC Class Codes: B29C 2949/0776 not containing threads
• CPC Class Codes: B29C 2949/078 characterised by the bottom
• 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 2949/3026 : having two or more components
• CPC Class Codes: B29C 2949/3028 : having three or more components
• CPC Class Codes: B29C 2949/3032 : having components being injected
• CPC Class Codes: B29C 2949/3034 : having two or more components being injected
• CPC Class Codes: B29C 2949/3036 : having three or more components being injected
• CPC Class Codes: B29C 2949/3042 : having two or more components being extruded
• CPC Class Codes: B29C 2949/3044 : having three or more components being extruded
• CPC Class Codes: B29C 49/04 : Extrusion blow-moulding
• CPC Class Codes: B29C 49/06 : Injection blow-moulding
• CPC Class Codes: B29C 49/071 : Preforms or parisons characterised by their configuration, e.g. geometry, dimensions or physical properties
• CPC Class Codes: B29C 49/12 : Stretching rods
• CPC Class Codes: B29C 49/22 : using multilayered preforms or parisons
• CPC Class Codes: B29K 2023/086 : EVOH, i.e. ethylene vinyl alcohol copolymer
• CPC Class Codes: B29K 2023/12 : PP, i.e. polypropylene
• CPC Class Codes: B29K 2025/00 : Use of polymers of vinyl-aromatic compounds or derivatives thereof as moulding material
• CPC Class Codes: B29K 2027/08 : PVDC, i.e. polyvinylidene chloride
• CPC Class Codes: B29K 2067/00 : Use of polyesters or derivatives thereof, as moulding material
• CPC Class Codes: B29K 2077/00 : Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• CPC Class Codes: B29L 2031/7544 : Injection needles, syringes
• CPC Class Codes: Y10T 428/1352 : Polymer or resin containing [i.e., natural or synthetic]
• CPC Class Codes: Y10T 428/1379 : Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit

Abstract

A syringe for use in a pressurized injection of a fluid includes a syringe barrel including a polymeric material having undergone expansion via blow molding. An inner diameter of the syringe barrel can, for example, be sufficiently constant (over at least a portion of the axial length of the syringe) that a plunger slidably positioned within the syringe barrel and in generally sealing contact with an inner wall of the syringe barrel can be used within the syringe barrel to generate a pressure of at least 1 psi within the syringe barrel. In several embodiment, the inner diameter of the syringe barrel is sufficiently constant to generate a pressure of at least 100 psi, at least 300 psi, or even at least 500 psi within the syringe barrel. A method of forming a syringe includes the steps of: injection molding at least one polymeric material to form a preform; placing the preform into an blow mold die; and expanding at least a portion of the preform while heating the preform within the die to form a barrel of the syringe. The syringes can be formed to withstand relatively high pressures as described above. The at least one polymeric material can, for example, be polyethyleneterephthalate, cyclic olefin polymer, polypropylene, polystyrene, polyvinylidene chloride, polyethylene napthalate and/or nylon.

Claims

1. A method of forming a syringe, comprising:

injection molding at least one polymeric material to form a preform that is open at both ends, wherein injection molding the preform comprises;

forming an open-ended syringe tip defining a syringe outlet at a distal end of the preform, forming a barrel section in fluid connection with the syringe outlet via a passage between the barrel section and the syringe outlet, and forming an opening at a proximal end of the preform in connection with the barrel section;

placing the preform into a blow mold die; and

expanding at least a portion of the preform within the die, wherein expanding a portion of the preform comprises;

extending a stretch rod through the opening in the proximal end of the preform and into a rearward portion of the syringe tip to seal the syringe outlet;

forcing a gas within the preform;

preventing the gas from entering the syringe tip; and

further extending the stretch rod within the preform to form a barrel of the syringe.

2. The method of claim 1 further comprising heating the at least a portion of the preform to be expanded before placing the preform into the blow mold die.

3. The method of claim 1 further comprising heating the at least a portion of the preform during expansion within the die.

4. The method of claim 1 further comprising a heat setting process.

5. The method of claim 1 wherein injection molding the preform further comprises forming a retention mechanism on a proximal end of the syringe adapted to connect the syringe to a powered injector, the retention mechanism comprising at least one flange.

6. The method of claim 5 wherein the retention mechanism is not substantially altered during the expansion of the preform.

7. The method of claim 1 wherein injection molding the preform further comprises forming a connector adjacent the distal end of the preform.

8. The method of claim 7 wherein the connector is not substantially altered during expansion of the preform.

9. The method of claim 1 wherein the at least one polymeric material comprises polyethyleneterephthalate, cyclic olefin polymer, polypropylene, polystyrene, polyvinylidene chloride, polyethylene napthalate or nylon.

10. The method of claim 1 wherein injection molding the preform further comprises forming a removable closure on a distal end of the syringe outlet.

11. The method of claim 10 wherein the closure is removably connected to the syringe outlet via a wall section of reduced thickness.

12. The method of claim 1 wherein an inner diameter of a wall of the syringe barrel does not vary by greater than 0.007 in. over the axial length of the syringe.

13. The method of claim 1 wherein an inner diameter of a wall of the syringe barrel does not vary by greater than 0.01 in. over the axial length of the syringe.

14. The method of claim 1 wherein an inner diameter of a wall of the syringe barrel does not vary by greater than 0.004 in. over the axial length of the syringe.

15. A method of forming a syringe, comprising:

injection molding at least one polymeric material to form a preform that is open at both ends, wherein injection molding the preform comprises;

forming an open-ended syringe tip defining a syringe outlet having a precision molded connector at a distal end of the preform;

forming a barrel section in fluid connection with the syringe outlet; and

forming a second opening at a proximal end of the preform that is in fluid connection with the barrel section;

placing the preform into a blow mold die; and

stretch blow molding the preform within the die, wherein stretch blow molding the preform comprises;

extending a stretch rod through the second opening in the proximal end of the preform and into engagement with a rearward portion of the syringe tip to seal the syringe outlet;

forcing a gas within the preform;

preventing the gas from entering the syringe tip, thereby maintaining the syringe outlet and the precision molded connector in an unaltered state; and

further extending the stretch rod within the preform to extend the preform axially and form the barrel of the syringe.

16. The method of claim 15, further comprising:

heating the preform before placing the preform into the blow mold die.

17. The method of claim 15, further comprising:

heating the preform during stretch blow molding of the preform.

18. The method of claim 15 wherein injection molding the preform further comprises forming a retention flange on a proximal end of the syringe.

19. The method of claim 18 wherein the retention flange is not substantially altered during stretch blow molding of the preform.

20. The method of claim 15 wherein the at least one polymeric material comprises polyethyleneterephthalate, cyclic olefin polymer, polypropylene, polystyrene, polyvinylidene chloride, polyethylene napthalate or nylon.

21. The method of claim 15 wherein an inner diameter of a wall of the barrel section does not vary by greater than 0.01 in. over the axial length of the syringe.

22. The method of claim 15 wherein the precision molded connector is formed with a male luer taper and luer threading.

23. The method of claim 15, further comprising:

heat setting the stretch blow molded syringe.