One of the world’s largest plastics, chemical and refining companies, is constructing a plant for the production of polyethylene with particularly high density (HDPE = „High Density Polyethylene“) and an annual total capacity of 500 000 tons with the help of heat 11 GmbH & Co. KG on the Gulf coast of the USA.
The plant is scheduled to start production in 2019 and will supply about one twelfth of the total 6 million tons of polyethylene. The construction of the plant will create 1.000 jobs at the height of construction and 75 permanent jobs.
New production technology »Hyperzone PE«
The location at the Gulf coast will be the first of a total of 57 in18 countries which will use the new copyright protected technology »Hyperzone PE« for production. The innovation developed in the European Research & Development Center of the company in Frankfurt, Germany, and Ferrara, Italy, makes it possible to consume significantly less polyethylene pellets per unit and thus significantly increase the resource efficiency.
The technology allows the production of a wide range of HDPE which will be used among other in bottles, containers, games, movies, health articles, fuel tanks and industrial packaging. The manufacture of these products is preceded by the processing of the polyethylene in small pellets using an extruder system.
Pelletizing using an extruder system
Extruders are conveyors which – with a screw conveyor shaft – evenly presses solid to viscous masses from a shape-giving opening under high pressure and high temperature in a vacuum. In detail this is done as follows:
Through the discharge valve, the 300° hot plastic is conveyed with the help of the drive to the gear pump which additionally increases the pressure on the material so that the mass can flow out even faster at the die plate, the shape-giving opening at the end of process, and thus the effectiveness is increased. After passing through the screen changer which filters out impurities and smallest residual particles from the raw mass on two different positions with changing screenings, this gets to the die plate where the around 300° hot plastic is pressed through countless small holes. The plastic mass solidifies directly by the countercurrent 20° cold cooling water and is cut off by circular rotating knives to form small pellets.
Illustration: KOBELCO – www.kobelco.co.jp/english/products/resin/lcm/lcm/pelletizing.html
Constant heating and temperature control ensured by heat 11
Since the high temperature must be maintained during the entire process in the individual steps to maintain the polyethylene in its liquid state, it is essential for the production process that each influencing component is heated with the appropriate temperature.
In order to realize this, heat 11 GmbH & Co. KG will supply two plants to heat the extruder system with a total driving power of 10 MW (a driving power of the similar size to an ICE high speed train) on the corresponding individual components.
The first extruder heating application will be an electric thermal oil heater double plant consisting of a heating unit with a capacity of 900 kW for the plate and a second heating unit with a capacity of 560 kW for the screen changer.
Furthermore a second double plant will be supplied: a heating-cooling unit for the gear pump motor and the shaft temperature control of the gear pump each with a capacity of 40 kW (heating) and 235 kW or rather 420 kW of cooling capacity.
Underwater pelletizer, Image: Coperion GmbH – www.coperion.com/de/produkte-dienstleistungen/extruder-compoundiermaschinen/granulierungen/unterwassergranulierung-ug