What kind of plastic? 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. <> The correlation coefficient between these two variables is a very respectable +0.84. 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. 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. Coefficients of friction between materials are best determined through testing. O;�,o�������ܼRh^\�C�?m�@Yf60^>��_��[P�;;P���6���"=J��A.Qў�HK�n���/��'���$� On the other hand, high polyurethane coefficient of friction is desirable for applications that want minimal slippage between surfaces. <> (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. Below are provided a small number of values showing approximate values of friction coefficients to be used for steel screw fastened connections. 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. 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. �; 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 Rubber in contact with other surfaces can yield friction coefficients from 1 to 2. 2 0 obj Values outside this range are rarer, but teflon, for example, can have a coefficient as low as 0.04. A value of zero would mean no friction at all, an elusive property. The versatility of polyethylene has made it a popular plastic for countless industrial applications that require durability, low friction, and chemical resistance. Fig.1: Showing the Concept of Coefficient of Friction . <>>> This self-lubricating polymer has excellent chemical resistance and a broad temperature range. It is famous for its abrasive resistance, toughness, and low cost. At what temperature? Here is an excellent discussion on friction coefficients, plus a comprehensive table of friction coefficients.. The value of μs is generally higher than the value of μk for a given combination of materials. Low polyurethane coefficient of friction is desirable for applications that want sliding to occur. F = μ k N. sliding (slip between surfaces) where μ s is the … The friction force is the force exerted by a surface when an object moves across it - or … However, it is possible to find tables in the literature for friction coefficients between various 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). Check out these structural calculators:  • Beam Analysis   • Bolted Joints   • Lug Analysis  • Column Buckling. Friction coefficients between different wheel/tire materials and concrete . It is usually symbolized by the Greek letter mu (μ). F = μ s N. static, impending slip. Image Source: Wiki Figure 1: Static vs dynamic friction Friction coefficients of thermoplastics against steel. The procedure permits the use of a stationary sled with a moving plane, or a moving sled with a stationary plane. Polystone® M UHMW is a tough, wear resistant plastic that combines an incredibly low coefficient of friction with outstanding impact strength. The friction coefficient of rubber will increase with sliding speed increasing, and then remain unchanged or decline. Fig.11.5 shows that the friction coefficient of rubber, plastics depend on the sliding speed. 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� � 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. Friction force develops between contacting surfaces of two bodies and acts to resist relative motion between the bodies. Redco™ UHMW has the highest impact strength of any thermoplastic presently made and is highly resistant to corrosive chemicals, with an … Low coefficient of friction Near-zero moisture absorption. What kind of rubber? 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. 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. Summary The Friction Table offers a convenient and effective way to measure friction. endobj 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, 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. Is this in atmosphere, water, vacuum, some other environment? 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. 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. coefficients. The three most commonly used … UHMW is an acronym for Ultra High Molecular Weight Polyethylene. You can find good background information on friction here.. 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