The versatility of polyethylene has made it a popular plastic for countless industrial applications that require durability, low friction, and chemical resistance. Friction force develops between contacting surfaces of two bodies and acts to resist relative motion between the bodies. Mathematically, μ = F/N, where F is the frictional force and N is the normal force. Friction coefficients between different wheel/tire materials and concrete . Coefficient of friction, ratio of the frictional force resisting the motion of two surfaces in contact to the normal force pressing the two surfaces together. endobj ... Coefficient of Friction - Static (Polished Steel) ASTM D-1894 --- .15 - .20 What kind of plastic? PET-P: (Polyester) Food Contact Grade Polyethylene terephthalate polyester has the best dimensional stability of any plastic, as well as excellent wear resistance and a low coefficient of friction. A value of zero would mean no friction at all, an elusive property. For steel and other materials, μ can decrease only when the material in a very high speed (100 m/s or above), but high speed has great effect on polymer materials. The correlation coefficient between these two variables is a very respectable +0.84. DESIGN COEFFICIENT TABLES Hazen-Williams Friction Factor (C) Pipe Material Values for C Range High/Low Average Value Typical Design Value Plastic, PVC, Polyethylene pipe or tubing 160/150 150-155 150 Cement or mastic lined iron or steel pipe 160/130 148 140 Copper, brass, lead, tin or glass pipe or tubing 150/120 140 130 The three most commonly used … You can find good background information on friction here.. Low coefficient of friction Near-zero moisture absorption. Coefficient of Friction, Plastics to Steel Static 0.30 0.30 Dynamic 0.28 0.28 Coefficient of Friction, Plastics to Plastic Static 0.76 0.76 Dynamic 0.44 0.44 Thermal Properties DSC Melting Point Homopolymer 320 - 329 °F 160 - 165 °C Copolymer 275 – 318 °F 135 – 159 °C Specific Heat (@ 23°C) 70 … Nevertheless, for the two data points furthest from the regression line (PP and PVC), if we were to use COF to predict surface energy, we’d be off by more than 10 and 8 dynes/cm, respectively. �; %���� x��][s�r~w��ü�j��9�gR.ֱ)_;r���y�i��/:�:���bи��.3@2S�X�����读�p���v���j�|������ջ�_�����q���ק//o6�������Y�����ן~r�5i�v��뷟~B�N��4B��Q��m^�釾y����O?�����O?�X5�4��������5_�pޜF�|���>�͡9 ���Rn �d�$U��"��?��k�0�s�p�d�v� k�@���.o����C���IZ���W-�_��տo���Z*���&����\��˛5_]Ǿ�uC�[���bEb�~$����ه��X�]��FT���=�h+�8���23r't��75����]i�9�_���L�Wf���ѿ�v�#�zt���k�w�In��1�\�GZã �-��׊�Q�����#��^�O��kBW6�����k�*(������ �Y�^���'lu��ѿ��� ���Pԗ� � UHMW (ultra high molecular weight polyethylene) is an extremely tough plastic with high abrasion and wear resistance. The interface friction coefficients for soil sliding on 12-inch (305-mm) square, 2-inch (51-mm) thick coupons of PE4710 high density polyethylene (HDPE) were measured in the laboratory by a direct shear (a) Oleic acid; (b) Atlantic spindle oil (light mineral); (c) castor oil; (d) lard oil; (e) Atlantic spindle oil plus 2 percent oleic acid; (f) medium mineral oil; (g) medium mineral oil plus ½ percent oleic acid; (h) stearic acid; (i) grease (zinc oxide base); (j) graphite; (k) turbine oil plus 1 percent graphite; (l) turbine oil plus 1 percent stearic acid; (m) turbine oil (medium mineral); (n) olive oil; (p) palmitic acid; (q) ricinoleic acid; (r) dry soap; (s) lard; (t) water; (u) rape oil; (v) 3-in-1 oil; (w) octyl alcohol; (x) triolein; (y) 1 percent lauric acid in paraffin oil. The coefficients of dynamic friction for a low-density polyethylene resin are presented in this paper as a function of the surface temperature, pressure, and velocity. Example applications include slide bearings, bushings and wear liners. <> <> {��ǵX=|X����n������� �`��� Below are provided a small number of values showing approximate values of friction coefficients to be used for steel screw fastened connections. Plastic film has very low friction due to which there are ample chances of slippage. The coefficient of friction of plastics is usually measured against polished steel. Ultra High Molecular Weight Polyethylene is another thermoplastic that exhibits a very low coefficient of friction, along with 10 times the resistance to abrasion than carbon steel. Is this in atmosphere, water, vacuum, some other environment? We have collected some of those tables here. coefficients. The friction coefficient of rubber will increase with sliding speed increasing, and then remain unchanged or decline. Summary The Friction Table offers a convenient and effective way to measure friction. Most commonly referred to as UHMW. Most dry materials in combination have friction coefficient values between 0.3 and 0.6. Static and Kinetic coefficient of friction . The table below is from Barrett, "Fastener Design Manual," NASA Reference Publication 1228, 1990: The table below is from MIL-HDBK-60, "Threaded Fasteners - Tightening to Proper Tension," 1990: Affordable PDH credits for your PE license, Barrett, "Fastener Design Manual," NASA Reference Publication 1228, 1990, MIL-HDBK-60, "Threaded Fasteners - Tightening to Proper Tension," 1990. Friction coefficient table of solid lubricants, metals, plastics and anti-friction materials. It is also self-lubricating with extremely low moisture absorption, and it has the highest impact strength of any thermoplastic polymer presently on the market. 1.1 This test method covers determination of the coefficients of starting and sliding friction of plastic film and sheeting when sliding over itself or other substances at specified test conditions. 2 0 obj The coefficient of friction testing helps to determine two values, i.e. In addition to PTFE, the classic bearing and wear materials made of polyimide, PEEK, PPS, Nylon, Acetal and Polyester are also known for their good sliding friction properties. Plastic Pipes - Friction Head Loss - Friction head loss (ft/100 ft) in plastic pipes - PVC, PP, PE, PEH Tag Search en: hazen-williams coefficients factors pipe tube O;�,o�������ܼRh^\�C�?m�@Yf60^>��_��[P�;;P���6���"=J��A.Qў�HK�n���/��'���$� Is the rubber subject to other forces? For example, static friction can prevent an object from sliding down a sloped surface. Much has been Plastic, Molding and Extrusion Material, Polyethylene and Copolymers (Low to High Density) ISO Duravar UHMW utilizing Premium UHMW Polymer Resins is in compliance with ISO#11542-1/2 for molding and extrusion materials. It is also important to consider the coefficient of thermal expansion of the plastic, particularly if it is to be used in contact with a mating metal part. Please use one of the following formats to cite this article in your essay, paper or report: APA. This self-lubricating polymer has excellent chemical resistance and a broad temperature range. "�? <>/ExtGState<>/XObject<>/ProcSet[/PDF/Text/ImageB/ImageC/ImageI] >>/MediaBox[ 0 0 612 792] /Contents 4 0 R/Group<>/Tabs/S/StructParents 0>> The value of μs is generally higher than the value of μk for a given combination of materials. The coefficient of friction is required in calculating tightening torques and resulting bolt tensile forces and stress and in calculating the resulting friction between the connected surfaces. UHMW (Polyethylene) Redco™ Ultra High Molecular Weight Polyethylene (UHMWPE) has extremely low moisture absorption, a very low coefficient of friction, is self lubricating and is highly resistant to abrasion (10 times more resistant to abrasion than carbon steel). endobj 4 0 obj Here is an excellent discussion on friction coefficients, plus a comprehensive table of friction coefficients.. The coefficient of friction testing is done to determine the easiness with which two facades when placed in contact with each other are able to slide on one another. It is famous for its abrasive resistance, toughness, and low cost. @. It is usually symbolized by the Greek letter mu (μ). Low polyurethane coefficient of friction is desirable for applications that want sliding to occur. Friction coefficient table for various material pairs in atmosphere and vacuum (see the definition of friction coefficient) is shown below.The data was collected from various sources [1,2,3]. Static friction is friction between two or more solid objects that are not moving relative to each other. 3 0 obj The coefficient of static friction, typically denoted as μ s, is usually higher than the coefficient of kinetic friction. On the other hand, high polyurethane coefficient of friction is desirable for applications that want minimal slippage between surfaces. Rubber in contact with other surfaces can yield friction coefficients from 1 to 2. stream However, it is possible to find tables in the literature for friction coefficients between various materials. Image Source: Wiki %PDF-1.5 Values outside this range are rarer, but teflon, for example, can have a coefficient as low as 0.04. F = μ s N. static, impending slip. At what temperature? The coefficient of friction between two materials in relative sliding may depend on contact pressure, surface roughness of the relative harder contact surface, temperature, sliding velocity and the type of lubricant whether the level of contamination. 1 0 obj Fig.11.5 shows that the friction coefficient of rubber, plastics depend on the sliding speed. Due to its low coefficient of friction, PTFE (polytetrafluoroethylene) is often used for sliding applications. Coefficients of friction between materials are best determined through testing. Plastic Co-efficient of Friction - Co-efficient of Friction of Engineering Thermoplastics. The static and kinetic friction coefficient values reference table shown in this article will be helpful for finding the COF values of commonly used materials. <>>> UHMW is an acronym for Ultra High Molecular Weight Polyethylene. Polystone® M UHMW is a tough, wear resistant plastic that combines an incredibly low coefficient of friction with outstanding impact strength. The procedure permits the use of a stationary sled with a moving plane, or a moving sled with a stationary plane. Example - Friction Force The friction force of a 100 lb wooden crate pushed across a concrete floor with friction coefficient of 0.62 can be calculated as: Ff = 0.62 (100 lb) = 62 (lb) 1 lb = 0.4536 kg Example - Car Stopping Distance A car with mass 2000 kg drives with speed 100 km/h on a wet road with friction coefficient 0.2. It is important to evaluate the coefficient of friction, wear rate, and pressure velocity limitations of the material. COF depends on the nature of the materials and surface roughness. Coefficient of Friction Steel PVC HDPE Non-Lubed Polywater® J 0 0.2 0.4 0.6 Coefficient of Friction Non-Lubed Lube 1 Lube 2 Lube 3 Lube 4 Lube 5. The friction force is the force exerted by a surface when an object moves across it - or … Corrosion resistant steel or nickel base alloys/silver plated materials. PTFE's coefficient of friction is 0.05 to 0.10, which is the third-lowest of any known solid material (BAM being the first, with a coefficient of friction of 0.02; diamond-like carbon being second-lowest at 0.05). Fig.1: Showing the Concept of Coefficient of Friction . Coefficient of Friction 0.29 0.29 Thermal Properties DSC Melting Point Homopolymer 275 °F 135 °C Copolymer 230 – 273 °F 110 – 134 °C Specific Heat (@ 23°C) 2.25 kJ/kg °K Heat of Fusion Homopolymer 245 kJ/kg Copolymer 140 – 232 kJ/kg Thermal conductivity Homopolymer 0.49 W / m °K Figure 1: Static vs dynamic friction Friction coefficients of thermoplastics against steel. F = μ k N. sliding (slip between surfaces) where μ s is the … Check out these structural calculators:  • Beam Analysis   • Bolted Joints   • Lug Analysis  • Column Buckling. The friction force, F, is proportional to the normal force, N, and the coefficient of friction, μ: where μs is the coefficient of static friction and μk is the coefficient of kinetic friction. endobj Dotmar EPP Pty Ltd. (2019, April 29). Coefficient of friction (COF) is a dimensionless number that is defined as the ratio between friction force and normal force (Eqn (2.1)).Materials with COF smaller than 0.1 are considered lubricous materials. What kind of rubber? At what ambient pressure? Redco™ UHMW has the highest impact strength of any thermoplastic presently made and is highly resistant to corrosive chemicals, with an … And low cost relative motion between the bodies of a stationary sled with a moving sled with a stationary with! To each other ample chances of slippage μ = F/N, where f is the normal force develops contacting. And N is the frictional force and N is the frictional force and N is normal... 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