Consultants Corner

Welcome to Consultants Corner¶

• Vol. 3 #1, March 1974 - Screw flight wear
• Vol. 3 #2, August 1974 - Rapid extrusion line start up
• Vol. 3 #3, December 1974 - Twin screw extruders design and operating characteristics
• Vol. 4 #1, April 1975 - Calculating extruder performance
• Vol. 4 #2, July 1975 - More on screw flight wear
• Vol. 5 #2, November 1976 - Winding strains
• Vol. 6 #3, December 1977 - Extrusion technology - some new findings
  

• Vol. 7 #1, March 1978 - The programmable calculator, a tool for measurement of extruder performance
• Vol. 7 #2, July 1978 - Screw/barrel clearance
• Vol. 7 #2, July 1978 - Gels
• Vol. 7 #2, July 1978 - PVC gels
• Vol. 7 #3, December 1978 - More on the drag flow equation
• Vol. 7 #3, December 1978 - PVC testing
  

• Vol. 8 #1, August 1979 - Two stage extrusion
• Vol. 8 #2, August 1979 - Internal bubble cooling
• Vol. 8 #2, August 1979 - HDPE LDPE properties
• Vol. 8 #2, August 1979 - Screen pack pressure drop
• Vol. 8 #3, December 1979 - Blown film air cooling
  

• Vol. 9 #1, April 1980 - Nylon 6 screw design
• Vol. 9 #2, July 1980 - Strand cooling
• Vol. 9 #3, December 1980 - Technical developments
  

• Vol. 10 #1, April 1981 - Linear low density polyethylene
• Vol. 10 #2, August 1981 - Blown film - cooling air parameters
• Vol. 10 #2, August 1981 - Polycarbonate extrusion
  

• Vol. 11 #1, January 1982 - Extrusion of thermoplastic foams
• Vol. 11 #2, June 1982 - A new die lip can change your profits
• Vol. 11 #2, June 1982 - Solvents and thermoplastics separated in CRT extruders
• Vol. 11 #2, June 1982 - Excessive screw wear
• Vol. 11 #3, January 1983 - The importance of periodic audits of extrusion performance
• Vol. 11 #3, January 1983 - Nylon - the great misconception
• Vol. 11 #3, January 1983 - A case for shorter heating zones in the feed section of extruders
• Vol. 11 #4, June 1983 - Gear pumps - answers to questions
• Vol. 11 #5, February 1984 - Gear pumps - editorial comment
• Vol. 11 #5, February 1984 - More on gear pumps
• Vol. 11 #5, February 1984 - Precision profile extrusion
• Vol. 11 #6, June 1984 - Designing high performance screws
• Vol. 11 #6, June 1984 - Purging of extruders
• Vol. 11 #6, June 1984 - Polymer filtration
• Vol. 11 #7, September 1984 - Polymer filtration II
• Vol. 11 #7, September 1984 - More on polymer filtration
  

• Vol. 12 #1, February 1985 - Answers - preheating feedstocks for extrusion
• Vol. 12 #1, February 1985 - Polymer filtration III
• Vol. 12 #1, February 1985 - On-line quality analysis
• Vol. 12 #2, June 1985 - Excessive screw wear?
• Vol. 12 #2, June 1985 - Using shape factors for extrusion die design
• Vol. 12 #3, October 1985 - Is used equipment worth the effort?
• Vol. 12 #3, October 1985 - Process uniformity
• Vol. 12 #3, October 1985 - Extruder controls
  

• Vol. 13 #1, February 1986 - Feed screw temperature control (S.T.C.) in the single screw extruder
• Vol. 13 #1, February 1986 - The exciting future for cellular profiles
• Vol. 13 #2, July 1986 - Extrusion and safety
• Vol. 13 #2, July 1986 - Gage control for tubular film production
• Vol. 13 #2, July 1986 - Back to basics for profile extrusion
• Vol. 13 #3, November 1986 - Trade secrets
• Vol. 13 #3, November 1986 - Some considerations in drying
• Vol. 13 #3, November 1986 - "The wonderful world of extrusion expertise…"
  

• Vol. 14 #1, February 1987 - Coextrusion: opportunities and challenges
• Vol. 14 #1, February 1987 - Old vs. new extruders
• Vol. 14 #2, June 1987 - A bomb, a gun, or a useful tool
• Vol. 14 #2, June 1987 - Coextruded - why?
• Vol. 14 #3, November 1987 - Rheometers versus melt index for polymer analysis
• Vol. 14 #3, November 1987 - Linear optimization of film charting
  

• Vol. 15 #1, February 1988 - Performance of twin-screw extruders
• Vol. 15 #1, February 1988 - Basic film calculations
• Vol. 15 #2, July 1988 - Theoretical extrusion predictions
• Vol. 15 #2, July 1988 - Sheet/film coextrusion grows
• Vol. 15 #2, July 1988 - Extrusion dies
• Vol. 15 #2, July 1988 - Extrusion with plugged vented barrel extruders
• Vol. 15 #3, November 1988 - Shear rate and what it means
• Vol. 15 #3, November 1988 - Problems plus creative input equal opportunities
• Vol. 15 #3, November 1988 - Mixing myths
  

• Vol. 16 #1, November 1989 - SPC is here for extrusion
• Vol. 16 #1, February 1989 - Selection and maintenance of cooling rolls
• Vol. 16 #1, February 1989 - Film and sheet pinning techniques to promote heat transfer to cooling rolls
• Vol. 16 #2, December 1989 - Water cooling extruders
• Vol. 16 #2, December 1989 - Heating modes for extruder barrels:
• Vol. 16 #2, December 1989 - Barrel and screw wear
• Vol. 16 #2, December 1989 - Ten key principles of extrusion
  

• Vol. 17 #1, February 1990 - On/off barrel cooling control
• Vol. 17 #1, February 1990 - Extrusion screw wear
• Vol. 17 #1, February 1990 - Tubing draw down ratio
• Vol. 17 #2, July 1990 - Gauge control
• Vol. 17 #2, July 1990 - Calculating DC drive power
• Vol. 17 #2, July 1990 - Gearbox design ratings
• Vol. 17 #2, July 1990 - An expert witness
• Vol. 17 #1, July 1990 - Structural changes in PVC due to extrusion
• Vol. 17 #2, July 1990 - Vector forces in extrusion design
• Vol. 17 #3, December 1990 - The effect of pressure on output
• Vol. 17 #3, December 1990 - Scaling up the extrusion process
• Vol. 17 #3, December 1990 - Alternatives for extruder barrel construction
• Vol. 17 #3, December 1990 - Pressure gauge
• Vol. 17 #4, March 1991 - Borescoping an extruder
• Vol. 17 #4, March 1991 - Thermocouple depth
  

• Vol. 18 #2, July 1991 - Extruder surging
• Vol. 18 #2, July 1991 - Causes of extruder surging
  

• Vol. 19 #1, February 1992 - Notes on polyethylene extruder surging
• Vol. 19 #1, February 1992 - How to setup a correct heat profile
• Vol. 19 #1, February 1992 - Distributive mixing and energy distribution in twin screw extruders
• Vol. 19 #2, June 1992 - Melt blockage problems - styrene extruders running at high output rates
• Vol. 19 #2, June 1992 - Melt block problems
• Vol. 19 #2, June 1992 - Further comments on barrel profiles
• Vol. 19 #2, June 1992 - Extrusion of Nylon 66 simplified from melt rheology data
• Vol. 19 #3, November 1992 - How effective are purge compounds
• Vol. 19 #3, November 1992 - Machinery installation
• Vol. 19 #3, November 1992 - Barrel heater maintenance and installation
• Vol. 19 #3, November 1992 - Thickness uniformity in blown film extrusion
• Vol. 19 #3, November 1992 - Screw cooling in extrusion
• Vol. 19 #3, November 1992 - Surging
• Vol. 19 #3, November 1992 - Modular screw assembly
• Vol. 19 #3, November 1992 - Thrust bearings
  

• Vol. 20 #1, March 1993 - Used extruders
• Vol. 20 #1, March 1993 - Gearcase maintenance
• Vol. 20 #1, March 1993 - Effect of temperature
• Vol. 20 #2, July 1993 - Don't always blame the extruder
• Vol. 20 #2, July 1993 - Upstack vs. downstack
• Vol. 20 #2, July 1993 - Borescoping
• Vol. 20 #2, July 1993 - Extruder alignment
• Vol. 20 #2, July 1993 - Where's the wear?
• Vol. 20 #2, July 1993 - Being an expert witness
• Vol. 20 #3, July 1993 - Where's the Wear? Part II
• Vol. 20 #3, July 1993 - Heater replacement
• Vol. 20 #3, July 1993 - Screw tip to screen changer
• Vol. 20 #3, July 1993 - Drive overload
• Vol. 20 #3, July 1993 - MD flow lines
• Vol. 20 #3, July 1993 - Purging of extruders (1993)
  

• Vol. 21 #1, June 1994 - AC drive update
• Vol. 21 #1, June 1994 - Single screw feeding
• Vol. 21 #1, June 1994 - Defining screw performance
• Vol. 21 #1, June 1994 - Screw and barrel wear
• Vol. 21 #1, June 1994 - Melt blockage due to false start up will cause dramatic rate drop
• Vol. 21 #1, June 1994 - Feed throat cooling (Consultant's Corner)
• Vol. 21 #1, June 1994 - Profile die for PVC and HIPS
• Vol. 21 #1, June 1994 - Coextruded sheets
• Vol. 21 #2, October 1994 - Single screw root wear
• Vol. 21 #2, October 1994 - Extruders that have been exposed to fire
• Vol. 21 #2, October 1994 - 30/30 melt temperature measuring method
• Vol. 21 #2, October 1994 - How to buy a screw - Part I
• Vol. 21 #3, December 1994 - Synthetic lubricants for extruders?
• Vol. 21 #3, December 1994 - How to buy a screw, Part II
• Vol. 21 #3, December 1994 - Carbon black dispersion
• Vol. 21 #3, December 1994 - Temperature contro
  

• Vol. 22 #1, May 1995 - Pyrometers
• Vol. 22 #1, May 1995 - How to buy a screw - part III
• Vol. 22 #1, May 1995 - Save money - monitor the little things
• Vol. 22 #1, May 1995 - Screw costs
• Vol. 22 #1, May 1995 - Naming screws for materials, compression ratios
• Vol. 22 #1, May 1995 - Misalignment
• Vol. 22 #1, May 1995 - Cross contamination
• Vol. 22 #1, May 1995 - Gear reducer
• Vol. 22 #1, May 1995 - Consultant travel tips
• Vol. 22 #2, September 1995 - Sources of gels
• Vol. 22 #2, September 1995 - Optimization of cast aluminum barrel coolers
• Vol. 22 #2, September 1995 - Purge compound and tool/die cleaning
• Vol. 22 #2, September 1995 - Buying used extrusion equipment
• Vol. 22 #2, September 1995 - Cleaning dies
• Vol. 22 #3, December 1995 - Planning the extrusion line
• Vol. 22 #3, December 1995 - Blown film versus the cast film process
• Vol. 22 #3, December 1995 - Correcting flow instability in coextrusion
• Vol. 22 #3, December 1995 - Additives - be careful!
  

• Vol. 23 #1, May 1996 - Heat transfer in extruders - an introduction
• Vol. 23 #1, May 1996 - Polymer devolatilization
• Vol. 23 #1, May 1996 - Shop foremen
• Vol. 23 #2, October 1996 - "Wave" pattern instability in multilayer coextrusion
• Vol. 23 #3, December 1996 - Retrofitting a screw into an existing extruder
• Vol. 23 #3, December 1996 - Extruder drives
• Vol. 23 #3, December 1996 - Worn barrel repair
• Vol. 23 #3, December 1996 - Compounding of blends
• Vol. 23 #3, December 1996 - Chrome plated steel casting drums
• Vol. 23 #3, December 1996 - Stability on single screw extruders
• Vol. 23 #3, December 1996 - Pressure transducer calibration
  

• Vol. 24 #1, March 1997 - Downstream mixing in twin screw extruders
• Vol. 24 #1, March 1997 - Immersed thermocouples
• Vol. 24 #2, September 1997 - Interfacial instabilities during coextrusion of LDPEs
• Vol. 24 #2, September 1997 - Cord connected equipment
• Vol. 24 #2, September 1997 - Lost output
• Vol. 24 #2, September 1997 - Pelletizing die cleaning
• Vol. 24 #2, September 1997 - Material flowability
• Vol. 24 #2, September 1997 - Ten myths about gear lubrication
• Vol. 24 #3, December 1997 - Extrusion evaluation through pressure and melt temperature analysis
• Vol. 24 #3, December 1997 - Screw installation and removal
• Vol. 24 #3, December 1997 - Casting of extruded semi-crystalline film and sheet
• Vol. 24 #3, December 1997 - Troubleshooting polymer processing operations
• Vol. 24 #3, December 1997 - Single screw mixing
• Vol. 24 #3, December 1997 - Sticking of extruded sheet
  

• Vol. 25 #1, May 1998 - Screen pack selection
• Vol. 25 #1, May 1998 - Minimizing flow oscillations for continuous extrusion
• Vol. 25 #1, May 1998 - Plastics technology and the web
• Vol. 25 #1, May 1998 - Extensional viscosity and melt strength and their role in film blowing
• Vol. 25 #2, September 1998 - The effects of molecular structure, rheology, morphology and orientation on polyethylene bl
• Vol. 25 #2, September 1998 - Leaking pressure transducers
• Vol. 25 #2, September 1998 - Proper extruder installation insures optimum performance and safety
• Vol. 25 #3, December 1998 - The extruder drive
• Vol. 25 #3, December 1998 - Vent flow
• Vol. 25 #3, December 1998 - Feed stability
• Vol. 25 #3, December 1998 - How to determine if a gear pump is right for you
• Vol. 25 #3, December 1998 - Melt temperature measurement
• Vol. 25 #3, December 1998 - Orientation in sheet extrusion and its effect upon quality
• Vol. 25 #3, December 1998 - Check out the obvious
• Vol. 25 #3, December 1998 - Cast film - air knives
• Vol. 25 #3, December 1998 - Estimating flow rate of a continuous sheet line
• Vol. 25 #3, December 1998 - Make a business of your consulting
  

• Vol. 26 #1, March 1999 - Polymer drying
• Vol. 26 #1, March 1999 - Extruder maintenance
• Vol. 26 #1, March 1999 - Are you a candidate for a continuous screen changer?
• Vol. 26 #1, March 1999 - Coextruded multilayer distribution
• Vol. 26 #1, March 1999 - Maximum rate of an extruder
• Vol. 26 #1, March 1999 - Casting of extruded semi-crystalline film and sheet edge curl in sheet casting
• Vol. 26 #1, March 1999 - Project management
• Vol. 26 #2, September 1999 - The use of statistics in extrusion
• Vol. 26 #2, September 1999 - An introduction to statistics
• Vol. 26 #2 September 1999 - You can get more from your resin conveying system
• Vol. 26 #2, September 1999 - Starve feeding
• Vol. 26 #2, September 1999 - Volume reduction
• Vol. 26 #2, September 1999 - Screw maintenance
• Vol. 26 #2, September 1999 - Screw cleaning
• Vol. 26 #2, September 1999 - Extruder order specifications
• Vol. 26 #2, September 1999 - Extrusion feeding
• Vol. 26 #2, September 1999 - Two stage extrusion screws
• Vol. 26 #2, September 1999 - DC motor maintenance
• Vol. 26 #3, December 1999 - Blown film
• Vol. 26 #3, December 1999 - Melt pump design tips
• Vol. 26 #3, December 1999 - How to get power law viscosity from two melt index values
• Vol. 26 #3, December 1999 - Horizontal cast film and sheet units
• Vol. 26 #3, December 1999 - Die cleaning (Dec 1999)
• Vol. 26 #3, December 1999 - Barrels with integral feed throats
• Vol. 26 #3, December 1999 - Increase your profits by saving resin
• Vol. 26 #3, December 1999 - Cut to length accuracy for extruded plastic tubing and profiles
• Vol. 26 #3, December 1999 - Extrusion process troubleshooting
• Vol. 26 #3, December 1999 - Imparting shear into the process by modifying feed rate
  

• Vol. 27 #1, March 2000 - Sheet extrusion equipment for in-line thermoforming
• Vol. 27 #1, March 2000 - Twin screw extrusion system compounds high levels of metal fillers into polymers
• Vol. 27 #1, March 2000 - Feed throat design
• Vol. 27 #1, March 2000 - Screw cooling length
• Vol. 27 #1, March 2000 - Flow surging
• Vol. 27 #1, March 2000 - Materials with feed stability problems
• Vol. 27 #1, March 2000 - Material conveying systems
• Vol. 27 #1, March 2000 - Troubleshooting tools
• Vol. 27 #1, March 2000 - IR temperature probes
• Vol. 27 #1, March 2000 - Centrifugal fans
• Vol. 27 #1, March 2000 - Mean residence time characterization in corotating twin screw extruder
• Vol. 27 #2, November 2000 - Measuring RPM
• Vol. 27 #2, November 2000 - An introduction to statistics - Part II
• Vol. 27 #2, November 2000 - Electrical checks
• Vol. 27 #2, November 2000 - Autogenetic screw operation
• Vol. 27 #2, November 2000 - AC variable frequency drives
• Vol. 27 #2, November 2000 - Safety considerations
• Vol. 27 #2, November 2000 - Angel hair
• Vol. 27 #2, November 2000 - Continuous soy protein films by twin and single screw extrusion
• Vol. 27 #2, November 2000 - Finding what you need on the internet
• Vol. 27 #3, December 2000 - Twin screw extruder screw design: one, two, three
• Vol. 27 #3, December 2000 - Profile extruder specifications
• Vol. 27 #3, December 2000 - Vent flow in twin screw extruders
• Vol. 27 #3, December 2000 - Twin screw extruder operating range
• Vol. 27 #3, December 2000 - Removing screw elements from splined shafts
  

• Vol. 31 #2, Fall 2004 - Single Screw Performance Characterization
• Vol. 31 #2, Fall 2004 - Melting Limitations in Single Screw Extruders
• Vol. 31 #2, Fall 2004 - Surging
• Vol. 31 #2, Fall 2004 - Controlling Bow in Profile Extrusion
• Vol. 31 #2, Fall 2004 - Assessing LDPE for Extrusion Coating
• Vol. 31 #2, Fall 2004 - What is the Objective in Die Design?
• Vol. 31 #2, Fall 2004 - Why is Proper Drying so Critical?
• Vol. 31 #2, Fall 2004 - Practical Application of the Kinematics Solids Conveying Model
• Vol. 31 #2, Fall 2004 - Tips for Optimizing Twin-Screw Extruder Performance
• Vol. 31 #2, Fall 2004 - Troubleshooting
  

• Vol. 33 #1, Summer 2006 - Extra Brooms Are Cheap
• Vol. 33 #1, Summer 2006 - Ask the Extruder
• Vol. 33 #1, Summer 2006 - Financially Speaking
• Vol. 33 #1, Summer 2006 - Purging Extruder Systems
• Vol. 33 #1, Summer 2006 - The Impact of Barrel and Feedscrew Wear
• Vol. 33 #1, Summer 2006 - Extruder Screw Performance Characterization
• Vol. 33 #1, Summer 2006 - Comparing Processes for Producing Coextrusion Barrier Film
• Vol. 33 #1, Summer 2006 - What's Wrong with Melt Index for Design Input?
  

• Vol. 36 #1, Spring 2011 - Solving Gravimetric Blender Problems