Apparatus and method for purging injection molding system

• US 6,514,440 B1
• Filed: 09/07/2000
• Issued: 02/04/2003
• Est. Priority Date: 04/21/1998
• Status: Expired due to Fees

• Current Assignee: Synventive Molding Solutions Incorporated
• Original Assignee: Synventive Molding Solutions Incorporated
• Inventors: Kazmer, David O., Doyle, Mark J., Bassett, Brian, Moss, Mark D.
• Primary Examiner(s): HEITBRINK, JILL LYNNE
• Application Number:
  US09/656,846
• Time in Patent Office: 880 Days
• Field of Search: 264/39, 264/40.1, 264/40.5, 264/37.33, 264/37.27, 264/328.8, 425/145, 425/146, 425/149, 425/161, 425/225, 425/542
• US Class Current: 264/39
• CPC Class Codes: B29C 2045/2687 controlling the filling thereof B29C2045/2691 takes precedence
• CPC Class Codes: B29C 2045/2722 Nozzles or runner channels provided with a pressure sensor
• CPC Class Codes: B29C 2045/279 Controlling the flow of material of two or more nozzles or gates to a single mould cavity
• CPC Class Codes: B29C 2045/2817 Several valve pin drive cylinders connected to the fluid distributor
• CPC Class Codes: B29C 2045/2872 with at least three positions, e.g. two different open positions to control the melt flow
• CPC Class Codes: B29C 2045/2882 closing by a movement in the counterflow direction
• CPC Class Codes: B29C 2045/2886 closing at a distance from the gate
• CPC Class Codes: B29C 2045/304 Adjustable torpedoes
• CPC Class Codes: B29C 2045/306 Movable torpedoes
• CPC Class Codes: B29C 2945/76006 Pressure
• CPC Class Codes: B29C 2945/7628 manifolds
• CPC Class Codes: B29C 2945/76428 Purging
• CPC Class Codes: B29C 2945/76498 Pressure
• CPC Class Codes: B29C 2945/76568 Position
• CPC Class Codes: B29C 2945/76759 manifolds
• CPC Class Codes: B29C 2945/76906 Purging
• CPC Class Codes: B29C 45/1753 Cleaning or purging, e.g. of the injection unit B29C45/24 takes precedence
• CPC Class Codes: B29C 45/2701 Details not specific to hot or cold runner channels B29C45/2725 takes precedence
• CPC Class Codes: B29C 45/2806 consisting of needle valve systems B29C45/2896 takes precedence
• CPC Class Codes: B29C 45/281 Drive means therefor
• CPC Class Codes: B29C 45/30 : Flow control means disposed within the sprue channel, e.g. "torpedo" construction
• CPC Class Codes: B29C 45/76 : Measuring, controlling or regulating measuring in general G01; controlling or regulating in general G05
• CPC Class Codes: B29C 45/77 : of velocity or pressure of moulding material

Abstract

An injection molding apparatus, system and method are provided in which the rate of material flow during the injection cycle is controlled. According to one preferred embodiment, a method of open-mold purging is provided in an injection molding system including a manifold to receive material injected from an injection molding machine. The method includes the steps of selecting a target purge pressure; injecting material from the injection molding machine into the manifold; and controlling the purge pressure to substantially track the target purge pressure, wherein the purge pressure is controllable independently from the injection molding machine pressure.

Claims

1. A method of open-mold purging in an injection molding system including a manifold to receive material injected from an injection molding machine, comprising the steps of:

(A) selecting a target purge pressure;

(B) injecting material from the injection molding machine into the manifold; and

(C) controlling the purge pressure to substantially track the target purge pressure;

wherein the purge pressure is controllable between the injection molding machine and the gate independently from the injection molding machine pressure.

2. The method of claim 1, wherein step (A) includes selecting a target purge pressure that is greater than the pressure supplied by the injection molding machine.

3. The method of claim 1, wherein step (A) includes selecting a target purge pressure that is less than the pressure supplied by the injection molding machine.

4. The method of claim 1, wherein step (C) is performed inside the manifold.

5. The method of claim 1, wherein step (C) is performed inside an injection nozzle.

6. An injection molding system comprising:

a mold;

an injection molding machine;

a manifold; and

a controller used to control open mold purging of the manifold, wherein the controller controls a pressure of material used to purge the manifold, independently from the injection molding machine injection pressure and between the injection molding machine and the gate.

7. The injection molding system of claim 6, wherein the controller controls the pressure of material based on a selected target purge pressure.

8. An injection molding system comprising:

a manifold to deliver material into a mold that is injected into the manifold from an injection molding machine; and

a controller used to control open mold purging of the manifold, the controller to control a pressure of material used to purge the manifold, independently from the injection molding machine injection pressure and between the injection molding machine and the gate.

9. The injection molding system of claim 8, wherein the controller controls the purge pressure using a valve pin.

10. The injection molding system of claim 8, wherein the controller controls the purge pressure inside the manifold.