Plastics Engineering - May 2014 - (Page 17)

commercial direct-extrusion applications include packaging films, PVc flooring, and wood-plastic composite profiles, notes coperion's von Hoffmann. Equipment reliability is especially important in direct extrusion, in which downtime directly affects the downstream process. Process Control & Simulation Although the overall compounding industry is generally basic in its approach to process control-typically monitoring only temperature and pressure-there is a trend towards more closely monitoring product attributes and controlling the associated process parameters, says Joseph golba, manager of process development at PolyOne. Achieving what golba calls "product control" has the advantages of increasing product quality and consistency and reducing waste and cost. At the sPE continuous compounding Topcon held in March 2014, presenters gave examples of how processcontrol tools are currently being used in compounding applications. On-line viscometry measurements can be used, for example, in blending resins with differing molecular weights, or in reactive extrusion, as a quality-control tool or as a process-control input, notes golba. As an input to a control system, the viscosity measurement could be used to adjust either feed composition or process parameters to keep the final product within specification. Another example is measuring color on-line during compounding, to monitor and control the color of the compounded product. "increased control gives you the opportunity to make every pellet within specification," says golba. One-dimensional process simulation, which can help engineers optimize screw designs and operating conditions using a virtual software program rather than physical plant trials, is another tool seeing increased acceptance. "The costs of raw materials, labor, energy, and lost production time have skyrocketed over the past 15 years, while the cost of the software remains basically the same. software cost can be justified by At the sPE continuous compounding Topcon held in March 2014, presenters gave examples of how process-control tools are currently being used in compounding applications. " the savings from running for as little as a few hours on a production line," says Adam Dreiblatt, director of process technology at cPM century Extrusion, who presented at the March 2014 sPE continuous compounding Topcon. The biggest limitation for one-dimensional simulation is the time and cost to characterize raw materials. As compounders know, small formulation changes, such as adding a lubricant, can have a large effect on processing. "in optimization and scale-up, however, it is not necessary to have the exact material characteristics," adds Dreiblatt. "in these two cases, as long as the same materials are used to compare both screw designs or to compare two different size extruders, then the modeling approach is valid." Thus, in the ongoing drive for increased productivity, compounders can benefit from new equipment technology and from process control and simulation tools. Custom-made TPE COPEC® - Combines incomparable silk-like haptics and resistance to skin oil and sun screens with additional adhesion properties to ABS, PC, ABS/PC. KRAIBURG TPE is a leading manufacturer of the highest quality and custom-engineered TPE in the industry...why not create the difference with KRAIBURG TPE? KRAIBURG TPE Corporation Phone 1 678 584-5020 · E-mail info-america@kraiburg-tpe.com · www.kraiburg-tpe.com www.plasticsengineering.org | www.4spe.org | MAY 2014 | PlAsTics EnginEEring | 17 http://www.kraiburg-tpe.com http://www.kraiburg-tpe.com http://www.plasticsengineering.org http://www.4spe.org

Plastics Engineering - May 2014

Table of Contents for the Digital Edition of Plastics Engineering - May 2014