PE Polyethylene Polyethylene is one of the most frequently produced synthetic  materials. During the course of the day you will meet a lot of things, consisting of PE. The field of application reachs from small plastic pags, pails over crates of beer, to pipes or dustbins. Polyethylene can be divided in multiple variations: • PE-HD or HDPE, soft-PE • PE-LD or LDPE, hard-PE "HD" denotes polyethylene with High Density. These high density is caused by low arborescent polymer chains. "LD" denotes PE with "low density". These polymers exhibit strong arborescent polymer chains, resulting in a lower density. The varied grad of arborescent is generated by different process parameter during the  fabrication. Manufacturing The production of polyethylene occurs by polymerisation of the gas ethene. PE-HD will be produced by the Ziegler-Natta or the Philips method. During the  Philips procedure temperatures between 80 and 180 °C and pressures between 30 and 40 bar will be applied. Furthermore catalysts like chromium oxide come into  operation. The Ziegler-Natta method uses titanester, aluminiumalkyl and  titanhalogenid as catalysts and works at pressures between 5 and 50 bar and  temperatures in the range of 20 to 150 °C. The manufacturing of PE-LD occurs at temperatures between 100 and 300 °C and pressures in the range of 1500 to 3000 bar. Additional, peroxids or oxigin come into operation as initiators. Properties Overview name polyethylene classification - polymer - thermoplastic Manufacturing monomers - ethene C₂H₄ Properties aggregate state solid general - transparent to dimmish - high flammability - permeable for carbon dioxided, oxigen and flavouring substances - high chemical resistance - waxy PE-HD PE-LD Mechanical density 0,97 g/cm³ 0,92 g/cm³ hardness tensile strength ~ 23 MPa breaking elongation friction coefficient 0,3 Electrical dielectric constant 2,5 (10³ - 10⁶ Hz) 2,3 (10³ - 10⁶ Hz) specific resistance   > 10¹⁰ Ω * mm dielectric strength 30 kV/mm Thermal melting temperature 129 °C 110 °C heat capacity 1,86 J/(g*K) heat conductivity combustion heat   5 MJ/kg operation temperature -60 to +70 °C -60 to +70 °C Optical refractive index Application • PE is tasteless and inodorus, products made of polyethylene contain no plasticiser in general • → Thus, this polymer is applicaple for sensible sections (medical secstion) • PE-HD is mainly used in form of hollowware • → Thus small bottles for soft drinks or even huge hoppers with a capacity over 1000 l are made of high density PE • Foils consisting of PE-HD exist too • but for foils, PE-LD is mainly used for the fabrication • → Thus, shrink films, bags or litterbags consist of PE-LD Copyright © 2010 polyneub.com  - Matthias Neuber - about  - general terms and conditions Manufacturer Service Provider