The plastics engineer working on the shop floor in a plastics manufacturing plant often needs quick answers to questions such as why the extruder output is low or whether he can expect better quality product by changing the resin or if the die pressure can be lowered. Applying state-of-the art numerical software to address these issues is time-consuming and costly.
Starting from practical design formulas which are easily applicable, and yet take the resin rheology into account, this guide provides answers to these questions quickly and effectively by guiding the user step by step through the computational procedures on the basis of illustrative technical examples.
Problems related to melt fracture, homogeneity of the melt, effect of screw geometry on the quality of the melt and the effect of die pressure on the pellet surface and their troubleshooting are only few of the topics among many that are dealt with in detail.
All the calculations involved can be handled by pocket calculators and hence can be performed right on the site where the machines are running. This guide is a valuable tool not only to troubleshoot but also to estimate the effect of design and process parameters on the product quality in plastics processing.
Autorentext
Natti S. Rao did his B.Tech (Hons) in Mechanical and M.Tech in Chemical Engineering at the Indian Institute of Technology in India. He received his Ph.D. in Chemical Engineering from the University of Karlsruhe in Germany, and then joined BASF AG. He has developed software for designing polymer machinery which is being used by well-known companies in various countries. As proprietor of
Plastics Solutions International, a consultant company, Dr.Rao is presently involved in consultant work in plastics and chemical engineering , and also holds seminars teaching the application of his software of designing polymer machinery. Dr.Rao authored four books on designing plastics machinery. He has approximately 60 publications in the fields of extrusion and injection molding and has worked as a visiting professor of Plastics Engineering at the Indian Institute of Technology, Chennai (Madras). Dr.Rao is a fellow of the Society of Plastics Engineering (SPE).
Klappentext
Resin Characterization by power law exponent
Effect of shear rate
Effect of temperature
How to calculate power law exponent - Worked-out example
Practical screw design
Output
Feed and metering depths
Motor power
Practical die design
Step by step calculation of pressure drop in a tube die - Example
Pressure drop in a flat die - Example
Case studies of optimizing dies
Pelletizer dies - Example
Blow molding dies - Example
Blown film dies - Example
Extrusion coating dies - Example
Optimizing melt quality
Poor melt quality in a coating process - Example
Improving melt quality in blown film - Example
Air bubbles in a flat film - Example