Extrusion

The extrusion process is used to plastic sheet, film, fiber, or profiles. It begins with the polymer being melted and pumped by an extruder. Then, the material is formed into the correct shape by a die. Finally, it is stretched, cooled, and cut to length by process-specific equipment.  Examples of extruded products include window profiles, catheters, tubing, and pipe. Coextrusion is the process of extruding two or more polymer melts at the same time.   

The Department of Plastics Engineering has equipment to extrude 

  • Flat film and sheet
  • Blown film
  • Tubing and pipe
  • Fiber
  • Filament of FDM additive manufacturing

Future capabilities include fluoropolymer sheet, high temperature blown film, and coextrusion of film.

In addition, the Department of Plastics Engineering can extrude thermoset rubber film and fibers.  For more information, see Elastomers Lab.

Extrusion also is used for mixing or compounding polymer systems. For more information on these capabilities, see Compounding. 

Putnam Plastics S. J. Chen Extrusion Lab

Equipment in Putnam Plastics S.J. Chen Extrusion Lab
The roll stack was donated by Gillette.
This laboratory, located in Ball Hall, Room 110, is named for the late Professor S. J. Chen. Professor Chen was a respected faculty member and researcher in the area of extrusion processing. The lab is sponsored by Putnam Plastics Corporation, which specializes in micro-extrusion. 

Cast Film and Sheet Line

  • Welex 1.5-inch single screw extruder with L/D of 30:1
  • Sheet die with coat hanger manifold and 6-inch-wide flex lip
  • David Standard vertical roll stack and wind-up unit
    • Separate temperature control for the three rolls 
  • Winding system

Pipe Line

  • Killion (Davis Standard) 1-inch single screw extruder with an L/D of ~25:1
  • Crosshead die with multiple manifold and bushing inserts
  • Vacuum sizing unit
  • Conair belt puller

Websites

Gloucester Engineering Blown Film Line

Blow film extrusion equipment
The blown film line located in the ETIC high bay was sponsored by Gloucester Engineering Co, Inc. (now part of Davis Standard). In blown film extrusion, a tube of polymer melt exits the die and is inflated to create a bubble. After the bubble of melt is cooled, it is collapsed and the film is wound onto rolls.  

Blown Film Line

  • Gravimetric feeder
  • 2.5-inch single screw extruder with L/D of 24:1
  • Blown film die with spiral flow manifold and 4-inch-diameter
  • Dual lip air ring
  • Take-off tower with nip roll and collapsing rolls 
  • Winding system

Other Extrusion Lines

Equipment

FET Q2216 Extrusion Line for Mono and Bicomponent Fibers

  • Two single screw extruders with gear (metering) pumps
    • 1: 25-mm diameter, 30:1 L/D extruder with gear pump of 1.2 cc/rev
    • 2: 20-mm-diameter, 30:1L/D extruder with gear pump of 0.6 cc/rev
  • Spinpacks
  • Monofilament spinnerets with 6, 12, or 24 holes, bicomponent spinnerets for core-sheath fibers (24 holes), and side-by-side fibers (12 holes), and custom-designed spinnerets for other fibers
  • Air quench cabinet (400 mm x 250 mm with height of 1200 mm)
  • Drawing station with four 120-mm-diameter temperature-controlled Godet rolls
  • Take up winder

This line is located in the Saab ETIC high bay.

Filament Extrusion Line

  • Dr. Collin 1-inch single screw extruder with an L/D of 30:1
  • Custom-designed monofilament die
  • Puller
  • Winder

This line is located in the Saab ETIC high bay.

Tube and Strand Line

  • Davis Standard (DS-10 HM) 1-inch single screw extruder with an L/D of 24:1
  • Dies for extrusion of tube, standard, and some profiles
  • On Line Controls Inc., MicroAir I, air pressure regulator
  • Bay Plastics Machinery water bath
  • Conair Precision Series Belt Puller

This line is located in Ball Hall, Room 201B.

Strand Line

  • Davis Standard 1.5-inch single screw extruder with an L/D of 30:1
  • Strand die
  • Custom-designed water bath
  • Puller
  • Reduction Engineering pelletizer

This line is located in Ball Hall, Room 116.