Plastics processing, energy

The past 25 years have seen a tremendous improvement in the extrusion process (19). Productivity has increased 250-300% in this time. The process has evolved from an art to a science. The increased output is attributed to improvements in screw design and haul off equipment for increased cost effectiveness (70-80% lower than in the fifties). Processing costs have decreased due to energy efficiency. Plastic processing energy efficiency has increased 300-... 

Progress and Prospects for Energy Conservation in Plastics Processing... 

Heat. Thermal energy has proved to be easiest to conserve in plastics processing. Conservation has taken many forms produc-... 

As 1n any economic study certain assumptions must be made. It 1s not the Intent of this paper to analyze cost factors 1n fine detail, but rather to examine and compare the major direct cost contributors 1n molding large plastic parts by these major process techniques. These direct cost factors are productivity, raw materials, process energy, tooling, flxturlng, hourly labor and capital. Indirect costs that are based on these direct cost Items are not considered 1n this study. Such Indirect Items Include supervision, maintenance, general plant overhead, Insurance, taxes and building depreciation. 

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