John R. Wagner

Rupture of the Triceps Muscle at the Musculotendinous Junction: A Case Report

Rupture of the triceps brachii at the musculotendinous junction is reported in a patient with diabetes mellitus and hypertension. Successful reconstruction was achieved by delayed primary repair. V-Y advancement of the triceps, and a plantaris tendon graft.

Film Properties for Good Performance on Vertical Form-Fill-Seal Packaging Machines

Technological improvements of flexible form, fill and seal packaging machines are yielding exceptional line speeds, productivity rates and bag features. This paper discusses the evolution of vertical packaging machine development and how it has impacted plastic film properties (e.g. COF, sealing temperature range, hot tack) required for optimal performance.

9 – Twin Screw Extrusion Process

This chapter discusses extrusion of polymeric materials to produce finished products for industrial or consumer applications, which is an integrated process, with the extruder comprising one component of the entire line. In some applications, the production lines are very long with numerous operators, requiring operators to communicate and work together to produce an acceptable finished product.

Design of Experiments

Design of experiments, referred to as DOE, is a systematic approach to understanding how process and product parameters affect response variables such as processability, physical properties, or product performance.

Data Analysis of an Extrusion Experiment

The objective of this work is to demonstrate the usefulness of high-speed data acquisition in characterizing the extrusion process. This article analyzes the barrel pressures and motor current data acquired using a high-speed data acquisition system. Graphical analysis shows the relationship between screw design and screw speed.

Plastic Behavior in the Extruder

Polymer response or behavior in the extruder, combined with the extruder processing conditions, i.e. barrel temperatures, screw speed, and screw design, allows the extruder to extrude a homogeneous polymer melt at a constant pressure and temperature.

Polymer Overview and Definitions

To troubleshoot and solve extrusion process problems, it is important to understand both the equipment operation and the polymer being processed. Understanding either the equipment or the polymers alone may not provide enough information to solve a particular extrusion problem. This chapter covers the definition of polymers, how they are formed, different types of polymers, and their structures.

11 – Twin Screw Extruder Equipment

There are many twin screw extruders commercially available, and the choice should depend on the end-use application.

Pipe and Tubing Extrusion

Pipe and tubing is profile extrusion with dies designed to produce round cross-sections. A pipe and tubing extrusion line is like a profile line except it uses a vacuum sizing cooling unit rather than a cooling or calibration tank.

22 – Processing Recommendations for Various Resin Systems

Extrusion processing condition guidelines for different resin systems are summarized in this chapter. These conditions are good starting points for the various resin systems and may require optimization for a specific extrusion process to obtain the maximum throughput rate while meeting or exceeding all the quality criteria.