Lesson 1 – The Sheet Extrusion Line: Parts and Operation

An overview of the machinery that makes up the sheet line, and how it operates. Discussion includes roll stand designs and operation, design and operation of the chill rolls, types of gauging systems, static discharge systems, design, and operation of trimmers, pull rolls, winders, and cutters. 

Lesson 2 – Sheet Extrusion Dies

The first part of this lesson discusses sheet die construction, and the parts of the sheet die including the manifold, heaters, restrictor bar, deckle bars, and types of die lips including fixed lip, adjustable lip, and flexible lip. The second part of the lesson discusses plastic flow behavior through the sheet die.

Lesson 3 – Controlling Plastic Flow in the Die

This lesson discusses the design and operation of the T-type, the Coathanger, and the Curved Manifold sheet die designs, as well as how the restrictor bar and the die gap adjustment are used to control plastic flow through the sheet die. Feed block and co-extrusion dies are also discussed.

Lesson 4 – Plastic Behavior in the Sheet Extrusion Line

Discusses what happens to the plastic once it leaves the sheet die and travels through the downstream sheet line. Orientation, die swell, the effects of roll speed and roll cooling, how cooling affects semi-crystalline plastics, uniaxial and biaxial orientation, and annealing are all discussed.  The lesson also discusses the fundamentals of process control of the sheet line.

Lesson 5 – Pre-Start, Start-up, and Steady-State Operating Procedures

This lesson discusses how to plan and startup the sheet extrusion line safely and efficiently. Proper steady state operations, such as monitoring the equipment and sheet product are also discussed.

Lesson 6 – Safety and Shutdown Procedures

This lesson discusses how to safely shut down the sheet line.  Emergency shutdown procedures are also discussed. The lesson finishes with a discussion on safety in the sheet extrusion plant.

Lesson 7 – Troubleshooting the Sheet Extrusion Line

This lesson discusses common sheet defects, such as surface lines and warp and their possible causes and solutions.