Rubber extrusion course held.

"Rubber extrusion technology" is a course offered by the University of Wisconsin-Milwaukee, to be held February 25-27 at the UWM School of Continuing Education in Milwaukee, WI.

Applicable basic information on all aspects of the rubber extrusion process will be provided. The course will encompass products ranging from intricate profile extrusions to tires, and having compositions ranging from a single thermoplastic elastomer to multiple dense and cellular compounds coextruded with carriers and reinforcements.

To achieve the course objective, the immense variety of products, equipment and processing conditions within the rubber extrusion industry will be unified by considering such common operations as compound selection, evaluation and processing; equipment needed for pumping, shaping (including die design), curing and monitoring; operating procedures to insure high production rates and quality; and analysis and control of process variation.

New technologies will be featured in one section that will explain how to make extrudates with variable cross-section and composition along their length, to form curved sections and to control screw speed for individual extruders forming laminate structures.

This course will conclude with a troubleshooting guide giving problems, causes and corrective actions.

This course is said to benefit materials and process engineers, die designers, quality control personnel, supervisors, and managers responsible for these functions. It is said to benefit those responsible for specifying equipment purchases, and particularly individuals new to the rubber extrusion industry.

Instructors will include James F. Stevenson of Honeywell and John S. Dick of Alpha Technologies.

Elastomer properties presented during the course will include chemical structure, molecular weight/distribution, morphology and crystallinity, viscosity (flow), elasticity (swell) and scorch.

Laboratory tests for extrudability will be examined, including Mooney viscosity tests, processability tests, state of cure tests and standard die (Garvey) tests.

Compound ingredients discussed will include elastomers, fillers, plasticizers and process aids and cure systems/nitrosamines.

Processing and compounding of EPDM, polychloroprene, SBR/BR, nitrile rubber, chlorosulfonated polyethylene, silicone rubber, fluoroelastomers and thermoplastic elastomers will be examined.

Screw extruder types (hot/cold teed) will be discussed, in addition to barrels, screws, screw types (gear extruder), two-stage screws, continuous mixers/twin screw extruders and feed devices.

Ram (preform) extruder auxiliary devices will be highlighted, including shear head, cavity transfer mixers and gear pumps.

Drives and transmission temperature controllers will be featured, as well as heater/cooler geometry.

Shaping equipment will be examined during the course, including heads Online, crosshead, coextrusion, breaker plates and screen changers) and dies (types and design criteria, flow, drawdown, sheet dies, profile dies, design computations, die relief strategies and finite element simulation).

Continuous vulcanization (low pressure) downstream equipment will be examined and compared, including liquid curing media, hot air, microwave, infrared and fluidized bed. Reinforcement (braiding) equipment will also be featured.

Instrumentation discussed will include extrusion line systems, temperature sensors (thermocouples, resistance devices and infrared probes), pressure sensors (strain gauge and Pie zoelectric), dimension sensors (lasers, electromechanical, diode array, length and coating thickness), and weight and area sensors (scales and radiation).

Extruder dynamics will be presented during the course, including flow in screw pumps, output rate, operating curves, heat transfer, extrudate temperature, conveyor operation, extrudate contraction and extrudate curvature.

Productivity and quality will be examined, including optimum conditions, feed strip geometry, feed mill operation, adjustments on pin barrels, stability testing, screw and barrel wear, and starved operation.

Process variation and control will be discussed, including sources of variation, process capability, statistical process control, diagnosis by crosscorrelation, feedback control, size control, shape control, guides for online measurement and commercial systems.

Advanced technologies discussed during the course will include changing extrudate shape, switching feed streams, directed flow technology, multicomponent process control and low resistance dies.

The registration tee for this course is $1,290. Further information is available from Murali Vedula [phone].