Additional Information - Posters
Plastic Pipes Conference Association # 1995 Edinburgh
Isaac, Eccott, Pittman, Farah
This study has sought to characterise the variations in mechanical properties and residual stresses that develop as a result of the differential cooling rates that occur through the thickness of commercially produced polyethylene pipes. The mechanical behaviour has been studied through measurement of tensile properties and creep performance. Significant differences in these properties have been recorded for samples taken from different regions of the pipe wall. As well as having the best tensile properties, samples from the inner regions of the pipe wall (with the slowest cooling rate) exhibited the lowest creep rates. In addition, residual strains have been measured using strain gauges, attached with a recently developed adhesive. The procedure involved machining pits to a series of different depths in commercial pipes, attaching strain gauges and then removing the bulk material from around the pit. This technique has allowed measurement of the variation in strains that develop through the thickness of pipe walls during processing.
Related papers
Author(s) : Pittman, Farah
Once a grade of polymer has been specified for pipe production, the properties of the finished pipe depend on the processing conditions. By properties we mean here those attributes that will influence the in-service performance, and these can be grouped under three headings: Pipe geometry. To meet specifications and...
Author(s) : Isaac, Eccott, Perridge, Pittman
A detailed investigation has been carried out on the microstructure of various polyethylenes recently developed for applications in the pipe industry. Of particular interest have been the PElOO formulations, and samples of these have been studied both from commercial piping and from laboratory produced plaques....
Author(s) : Pittman, Farah
Heat transfer coefficients for splay cooling in the manufacture of blue, yellow and black PE-80 and PE100 MDPE pipes are determined by measuring pipe surface tempemhtres in the annealing zones between splay tanks, and then fitting a computer simulation of the cooling process by adjustment of heat wander coefficients....
Author(s) : Pittman, Whitman, Gwynn, Beech
Comprehensive operating data from a large-scale pipe cooling lime are reported, including in-situ measurements of temperatures within the pipe wall. A finite element simulation of cooling, coupled with gravity induced flow, or slump, in the pipe wall is described. Computed temperatures within the wall are compared...
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