The temperature effects on high density polyethylene hdpe. What makes the difference in the physical properties of hdpe is the lack. This extruded material offers good corrosion resistance and low moisture permeability. Physical chemistry and mechanical properties of hdpe. With a high strengthtodensity ratio, hdpe is used in the production of plastic bottles, corrosionresistant piping, geomembranes and plastic lumber. Ldpe has more branching on about 2% of the carbon atoms than hdpe.
The mechanical characteristics and properties of hope gipes are highly affected by the environmental conditions. Hdpe, long chain macromolecule, thermoplastic, plastic welding. For this reason, low density polyethylene resins are sometimes blended with other resins to improve certain properties or, vice versa, they are added to other film resins to improve their film properties, like toughness and flexibility and to lower cost. Typical engineering properties of high density polyethylene. Mechanical properties of hdpe m624 with three filler inorganic and organic composites were assessed with respect to the effect of the filler content. In order to study the effects of the crystallinity of polyethylene with different densities on breakdown strength and conductance properties, this. The peel strength of highdensity polyethylene hdpe.
Properties and applications of ldpe or low density polyethylene. Effect of crystallinity of polyethylene with different densities on. Mechanical properties of filled high density polyethylene. Banks of phillips petroleum company discovered polypropylene, a highmelting crystalline aliphatic hydrocarbon. Hedenqvist a shun yu b stephan roth b karsten bruning c arnaud vieyres c konrad schneider c. Highdensity polyethylene hdpe or polyethylene highdensity pehd is a thermoplastic polymer produced from the monomer ethylene. Esd a 700 a low density polyethylene ldpe product data. The following serves to outline the benefits of high density polyethylene hdpe.
Leak test and tracer gas management with the tracermate ii this product profile describes how to measure and manage leak test and trace gas with the tracermate ii. Lowdensity polyethylene ldpe labware thermo fisher. Density figures for the ldpe polymers range from 0. Obvious improvement in the mechanical parameters was recorded depending on the filler type and mesh size. Aug 10, 2016 the mechanical properties of polymers, particularly as a function of temperature and strain rate, are key for implementation of these materials in design. History and physical chemistry of hdpe plastics pipe. Highdensity polyethylene hdpe or polyethylene highdensity pehd is a thermoplastic. Filled thermoplastics have been used widely as independent shell layer for coextruded nfpc with coreshell structure. Low density polyethylene ldpe high degree of short and long chain branching density 30. Sgm9450f is a highdensity polyethylene, developed for the high molecular weight film extrusion segment produced with bimodal technology. Mechanical properties of low density polyethylene request pdf. Polyethylene is used in numerous applications ranging from plastic grocery bags. All of our in ground flatsafe tornado shelters come with our patented. High density polyethylene structure, properties, and uses.
Mechanical and chemical properties of high density polyethylene. The mechanical response was found to be temperature and strain rate dependent. For more specific values, follow the links immediately below. A data cd containing relevant raw data files, such as modulus versus. The temperature effects on high density polyethylene hdpe pipes mahir h. This discovery led to the development of a new catalytic process. In 1951, while attempting to convert propylene into gasoline, j. Structure and properties of polyethylenebased and evoh. Low density polyethylene ldpe is an extruded engineered plastic that offers good corrosion resistance properties and low moisture permeability. Properties may be materially affected by molding techniques applied and by the size and shape of the item molded. The difference between these polyethylene processes and types is outlined below. Generally, in the polymerization process, these catalysts form free radicals at the end. Low density polyethylene ldpe is a highly flexible material with unique flow properties, making it great for plastic film applications such as shopping bags.
May 11, 2001 this page details the capabilities of the ultrapyc series from anton paar, an automatic gas pycnometers for solid density analysis. Ldpe low density polyethylene is defined by a density range of 0. Data sheets for these products are generally not available on our website. It is also harder and more opaque and can withstand somewhat higher temperatures 120 c248 f for short periods. No assurance can be implied that all molded articles will have the same properties as those listed. It is the most widely used plastic in the world, being made into products ranging from clear food wrap and shopping bags to detergent bottles and fuel tanks. Roughly 30% of the global packaging industry materials used is high density polyethylene hdpe, as it is a core plastic in rigid packaging. Each property range of values reported is minimum and maximum values of appropriate matweb entries. Mechanical properties of low density polyethylene jennifer l. The difference in strength exceeds the difference in density, giving hdpe a higher specific strength. Thermoplastic high density polyethylene hdpe substech.
Low density polyethylene ldpe is a high molecular weight polyolefin material. The density of polyethylene can be measured by means of the density gradient method astm d1505 or by the titration technique. Effects of microstructure on creep characteristics by joy j. This thermoplastic is available in a range of flexibilities depending on the production process. Jm eagles blackyellowstriped polyethylene gas distribution pipe, fittings, and oil and gas gathering pipe are manufactured from pe 34083608 or pe 34084710 highdensity polyethylene material that is classified according to astm d3350 and has a cell classification of 345464c or 445574c for the pe 4710 product. Structure and properties of polyethylenebased and evohbased. Poylpropylene and highdensity polyethylene national. Linear lowdensity polyethylene lldpe is very comparable to ldpe, with the added advantage of being altered by adjusting the formula constituents and using less energy during production. It can be used in applications where corrosion resistance is a factor, but stiffness, high temperatures, and structural strength are not. With such an understanding, the piping designer can use the properties of the material to design for optimum performance. Linear low density polyethylene lldpe is very comparable to ldpe, with the added advantage of being altered by adjusting the formula constituents and using less energy during production. Medium density polyethylene mdpe refers to polymer with a density between 0. Benefits of high density polyethylene hdpe clean it up. High density polyethylene hdpe storm and tornado shelters.
Lowdensity polyethylene ldpe is a highly flexible material with unique flow properties, making it great for plastic film applications such as shopping bags. Polyethylene is one of the most commonly used engineering plastics. High density polyethylene is a hydrocarbon polymer that can be prepared from ethylene via a catalytic process. The mechanical response was found to be temperature and strain rate dependent, showing an increase. For these applications refer to its counterpart high. Lowdensity polyethylene ldpe is a thermoplastic made from the monomer ethylene. Ldpe low density polyethylene united plastic components. High pressure polyethylene was first produced by the high pressure process by ici, britain, in the 1930s. Mechanical and chemical properties of high density. This property data is a summary of similar materials in the matweb database for the category high density polyethylene hdpe, ultra high molecular weight.
Select a product number from the table below to view a product data sheet for these materials using polyethylene as the base resin. It is also accepted by usda, nsf and canadian department of agriculture. Polyethylene is used in numerous applications ranging from plastic grocery bags to heavy duty plastic. Structure and properties of polyethylenebased and evohbased multilayered films with layer thicknesses of 150 nm and greater author links open overlay panel nazanin alipour a ulf w. Hdpe is produced from the polymerization of ethylene. Ecofriendly, low density and high mechanical properties of the composite have made them good reinforcing materials for the synthesis of composite materials. Some of the common catalysts used here include zieglernatta catalysts, chromiumsilica catalysts phillips catalyst, and metallocene catalysts. The process and the properties of the materials make all the difference, however, the. High density polyethylene hdpe refers to polymer with a. The properties of hdpe include three common variations. Its chemical resistance properties and ease of fabrication make it popular in the chemical industries.
Polyethylene is a member of the important family of polyolefin resins. Much of the global plastic sheeting website is dedicated to a wide variety of polyethylene such as high density polyethylene, low density polyethylene and the like. This page details the capabilities of the ultrapyc series from anton paar, an automatic gas pycnometers for solid density analysis. Hdpe is more rigid and harder than low density materials and is three times better in compressive strength. Feb 05, 2015 this feature is not available right now. It is lighter than water, easily withstands exposure a wide variety of common lab chemicals, and has a. Ignition temperature cloud 790 f 420 c minimum radiant flux for ignition 20 kwm2. Highdensity polyethylene, unlike polypropylene, cannot withstand normally required autoclaving conditions. Sgm9450f is a high density polyethylene, developed for the high molecular weight film extrusion segment produced with bimodal technology. Much of the global plastic sheeting website is dedicated to a wide variety of polyethylene such as high density polyethylene, low. In this paper, the compressive response of low density polyethylene ldpe was investigated across a range of strain rates and temperatures. Like all polyolefins, ldpe is nontoxic, noncontaminating and exhibits a high degree of break resistance. High density polyethylene hdpe compounds rtp company.
The mechanical properties of polymers, particularly as a function of temperature and strain rate, are key for implementation of these materials in design. Hdpe has greater tensile strength, heat distortion temperature, viscosity, and chemical resistance than ldpe, but has lower impact strength. Hdpe is a boon to developing countries like india where it is used to prevent groundwater. Highdensity polyethylene hdpe is an odorless, tasteless, and nontoxic polymer that makes it suitable for food contact applications. Hdpe complies with fda requirements for direct food contact applications. Of the three types of polyethylene specimens, high density polyethylene recorded an excellent performance in terms of yield behaviour, absorbed energy, stiffness, and strength properties than that. The length, width and depth of each item was measured at the longest edge. It has a high degree of short and long chain branching, which means that the chains do not pack into the crystal structure as well. They are reemerging as a valuable product family, combining excellent clarity with the stiffness and density favored by converters for downgauging. So often people want to understand how the thickness of polyethylene is measured. Feb 20, 2012 so often people want to understand how the thickness of polyethylene is measured. Among the factors controlling the physical properties of hdpe are mfr, density, molecular weight, molecular weight distribution, crystallinity, double bonds, branched species, etc.
This discovery led to the development of a new catalytic process for the making of high density polyethylene. For example, it was demonstrated that a pure high density polyethylene hdpe. Media related to lowdensity polyethylene at wikimedia commons. No information supplied by rtp company constitutes a. Polyethylene, light, versatile synthetic resin made from the polymerization of ethylene. Overview of materials for high density polyethylene hdpe. It is sometimes called alkathene or polythene when used for hdpe pipes. It is a kind of thermoplastic which is famous for its tensile strength. Engineering properties of polyethylene introduction a fundamental understanding of material characteristics is an inherent part of the design process for any piping system.
It has therefore less strong intermolecular forces as the instantaneousdipole induceddipole attraction is less. Plastic packaging takes up a large volume of the high density polyethylene produced. Highdensity polyethylene, usually shortened to hdpe or pehd, is a plastic. The film produced from this resin has high tenacity and excellent resistance to impact characteristics. Its molecular structure provides the key to its versatility. High density polyethylene is also commonly used for. But the three basic physical properties factors that regulate physical properties are molecular weight, molecular weight distribution and density. Thermoplastic means that when it is heated it turns to liquid rather than burning, and when cooled takes on the properties of a solid. Advantages of using polyethylene for large plastic products. The process and the properties of the materials make all the difference, however, the proof is most evident in the quality of the end product.
Improving the design stresses of high density polyethylene pipes and vessels used in reverse osmosis desalination plants. Two different products a and b were manufactured under the same reference in an interval of six years and supplied in sheets extrusion process. High density polyethylene composites reinforced with. The physical properties of hdpe can vary depending on the molding process that is used to. High density polyethylene composites reinforced with hybrid. The material is free from branching and the use of stereospecific catalysts makes it possible. Banks of phillips petroleum company discovered polypropylene, a high melting crystalline aliphatic hydrocarbon. Volumes were calculated by multiplying the weight by an average density value for the material type. Select a product number from the table below to view a product data sheet for these materials using polyethylene as the base resin 799x numbered products are our proprietary formulations. For example, it was demonstrated that a pure highdensity polyethylene hdpe.
Hdpe materials inventor autodesk knowledge network. Ldpe low density polyethylene after its experimental preparation in the 1930s, the application in high frequency radar cables during world war ii, gave impetus to its commercial production. Mechanical properties value unit dineniso tensile strength at yield 25 mpa 527d638 elongation at yield 9 % 527 modulus of elasticity in tension mpa 527d638 modulus of elasticity in flexure 1400 mpa 178d 790. Experimental investigation of possible use of hdpe as thermal storage material in thermal storage type solar cookers pdf. Essaheb mechanical engineering department, college ofengineering, king saud university, riyadh, saudi arabia abstracf. Metallocene linear low density polyethylene mlldpe refers to tougher lldpe type polymer with a density between about 0. The graph bars on the material properties cards further below compare hdpe to. Another noteworthy pe resin is ultra low density polyethylene or uldpe. Ldpe plastics ldpe materials low density polyethylene. The material tested in this work is hdpe high density polyethylene, grade 500 natural produced by rochling engineering plastics kg.