Method for control of extrusion process

• US 6,627,127 B1
• Filed: 03/28/2001
• Issued: 09/30/2003
• Est. Priority Date: 10/02/1998
• Status: Expired due to Fees

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Piovoso, Michael Joseph, Wetzel, Mark David, Shea, Paul Thomas, Shih, Chi-Kai
• Primary Examiner(s): Eashoo, Mark
• Application Number:
  US09/806,280
• Time in Patent Office: 916 Days
• Field of Search: 264/40.4, 264/40.7, 264/349, 425/145
• US Class Current: 264/40.4
• CPC Class Codes: B29B 7/483 the other mixing parts being discs perpendicular to the screw axis
• CPC Class Codes: B29B 7/489 Screws B29B7/482 takes precedence
• CPC Class Codes: B29B 7/726 Measuring properties of mixture, e.g. temperature or density B29B7/724 takes precedence
• CPC Class Codes: B29B 7/728 Measuring data of the driving system, e.g. torque, speed, power, vibration B29B7/724 takes precedence
• CPC Class Codes: B29B 7/7495 for mixing rubber
• CPC Class Codes: B29C 2948/92019 Pressure
• CPC Class Codes: B29C 2948/92038 Torque
• CPC Class Codes: B29C 2948/92047 Energy, power, electric current or voltage
• CPC Class Codes: B29C 2948/92209 Temperature
• CPC Class Codes: B29C 2948/92228 Content, e.g. percentage of humidity, volatiles, contaminants or degassing
• CPC Class Codes: B29C 2948/92285 Surface properties
• CPC Class Codes: B29C 2948/92314 Particular value claimed
• CPC Class Codes: B29C 2948/92514 Pressure
• CPC Class Codes: B29C 2948/9259 Angular velocity
• CPC Class Codes: B29C 2948/926 Flow or feed rate
• CPC Class Codes: B29C 2948/92704 Temperature
• CPC Class Codes: B29C 2948/92828 Raw material handling or dosing, e.g. active hopper or feeding device
• 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 2948/92904 : Die; Nozzle zone
• CPC Class Codes: B29C 2948/92952 : Drive section, e.g. gearbox, motor or drive fluids
• CPC Class Codes: B29C 48/05 : Filamentary, e.g. strands
• CPC Class Codes: B29C 48/08 : flexible, e.g. films
• CPC Class Codes: B29C 48/12 : Articles with an irregular circumference when viewed in cross-section, e.g. window profiles
• CPC Class Codes: B29C 48/2564 : Screw parts
• CPC Class Codes: B29C 48/288 : in solid form, e.g. powder or granules
• CPC Class Codes: B29C 48/2886 : of fibrous, filamentary or filling materials, e.g. thin fibrous reinforcements or fillers
• CPC Class Codes: B29C 48/29 : in liquid form
• CPC Class Codes: B29C 48/395 : using screws surrounded by a cooperating barrel, e.g. single screw extruders
• CPC Class Codes: B29C 48/404 : the screws having non-intermeshing parts
• CPC Class Codes: B29C 48/405 : Intermeshing co-rotating screws
• CPC Class Codes: B29C 48/76 : Venting , drying means; Degassing means
• CPC Class Codes: B29C 48/83 : Heating or cooling the cylinders
• CPC Class Codes: B29C 48/832 : Heating
• CPC Class Codes: B29C 48/92 : Measuring, controlling or regulating
• CPC Class Codes: B29K 2105/0005 : containing compounding ingredients releasing, lubricating or separating agents B29C33/56, fibers B29K2105/08, B29K2105/12; fillers B29K2105/16, recycled material B29K2105/26
• CPC Class Codes: B29K 2105/16 : Fillers
• CPC Class Codes: G05B 13/048 : using a predictor
• CPC Class Codes: G05B 17/02 : electric
• CPC Class Codes: G05B 19/00 : Programme-control systems

Abstract

Disclosed is a process for controlling extrusion processes by applying dynamic periodic pulses to the process throughout and during the process, analyzing the pulse response data and feeding back the results of the analysis to the process parameters and product properties.

Claims

1. An improved process for controlling the properties of a mail extruded in a continuous extrusion process, the improvement comprising the application of multiple periodic pulses, throughout the entire period of the said continuous extension process, so as to provide continuous control over the properties of the continuously extended material, wherein the periodic pulse comprises:

(1) a pulse of known amount of material that is added to a steady extrusion process,

(2) dynamic signals generated by a extruder drive and control system that are transmitted to data acquisition system signal conditioning front end hardware, which isolates, amplifies and filters the dynamic signals and outputs analog signals, and

(3) analog signals output by the data acquisition system sign conditioning front end hardware are converted to digital signals, the digital signals are transmitted to a pulse analysis and control computer, which calculates setpoints, which are transmitted back to the extruder drive and control system or a feed control system used by the extrusion process.