High Density Polyethylene (HDPE)
“HDPE is defined by a density of greater or equal to 0.941 g/cm3. HDPE has a low degree of branching and thus stronger intermolecular forces and tensile strength. HDPE can be produced by chromium/silica catalysts, Ziegler-Natta catalysts or metallocene catalysts. The lack of branching is ensured by an appropriate choice of catalyst (for example, chromium catalysts or Ziegler-Natta catalysts) and reaction conditions. HDPE is used in products and packaging such as milk jugs, detergent bottles, margarine tubs, garbage containers and water pipes.” (Wikipedia 9/19/2009)
Butt Fusion Welding HDPE Pipe
HDPE Creep
HDPE Crystallization
HDPE Injection Molding
HDPE /Mica Composites
HDPE Recycling
HDPE /Wood Composites
Polyethylene
Polymers /Resins
Recent US Patents
12/21/2010
7,855,253
High density polyethylene and articles made therefrom
Shannon and Ehrman of Univation Technologies, Texas, have developed multimodal polyethylenes with densities from 0.940 to 0.965 g/cm3.and containing a low molecular weight ethylene copolymer having a weight average molecular weight from 5,000 amu to 50,000 amu; and a high molecular weight ethylene copolymer having a weight average molecular weight from 60,000 amu to 800,000 amu, both components having a desirable balance of short chain branching making the multimodal polyethylene suitable for films, pipes, rotomolding applications and blow molding applications. (RDC 6/20/2011)
Recent Journal Articles
Estimation of Elongation Viscosity of Polyethylene Melts
(367-376) Journal of Thermoplastic Composite Materials 24 #3 (2011)
Abstract
Liang and Zhong of South China University of Technology, China, introduced temperature T into H function which represents the destruction rate of network junctions and a new viscosity equation was derived based on Phan-Thien—Tanner model for extensional flow. The elongation viscosities of a high-density polyethylene (HDPE) and a low-density polyethylene (LDPE) melts were estimated using this equation at 150°C, and the calculations were compared with the measured data from the extension experiments of the HDPE and LDPE melts reported in reference. Good agreement was showed between the predictions and the measured data. Furthermore, the parameters in this equation were easy to be determined. (RDC 5/25/2011) (See Extensional Flow )