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PLANE BEARING DESIGN AND MATERIALS Where and When to Use Plastics As A Bearing presented by David Biering Technical

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PLANE BEARING DESIGN AND MATERIALS Where and When to Use Plastics As A Bearing presented by David Biering Technical

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    1. PLANE BEARING DESIGN AND MATERIALS Where and When to Use Plastics As A Bearing presented by David Biering Technical Director

    3. PLANE BEARING PRODUCTS

    4. PLANE BEARING PRODUCTS

    5. What is a Plane Bearing? A plane bearing is any non-rolling element Sleeve or flange bushings Slide plates Friction Bearings Any situation where two surfaces rub together is a plane bearing

    6. Plane bearings offer several advantages when properly applied SIMPLE COMPONENTS SELF-LUBRICATING WIDE RANGE OF ENVIRONMENTS SERVED EASY INSTALLATION AND REMOVAL LOWER COST

    7. All plane bearing designs are material selection problems! All designs must include a review of the following: BEARING LOAD – P BEARING SPEED – V COMBINED P-V TEMPERATURE TEMPERATURE VARIATIONS ENVIRONMENT

    8. Bearing Loads are often the most difficult attribute to define PRESSURE (P) = Load/Projected Area P=LBS/ID X LENGTH P IS EXPRESSED IN PSI Each material is rated for a maximum static load (P)?

    9. The Relative Speed between the shaft and the bearing is usually easier to define. VELOCITY (V) =Circumference x RPM Circumference (C) = TTD/12 in feet V is expressed in Surface Feet per Minute (SFPM)? Every material is rated for a maximum velocity (V) at no load

    10. Pressure (P) and Velocity (V) do not occur independently and must always be dealt with in tandem! The combination of load and speed generates frictional heat AS A RESULT WE MUST ALWAYS REVIEW P X V or PV Every material has a maximum PV Rating

    11. Material Rating Overview Material Max. PV Max. P Max. V Graphite PI 300,000 6,000 1000 Carbon/PTFE PEEK 100,000 6,000 600 Tri Steel PE (lubed) 100,000 40,000 2,000 Tri Steel PI 50,000 36,000 1000 Oilite Bronze 50,000 2,000 1200 Carbon PEEK 50,000 6,000 600 FCJ 20,000 20,000 500 Ultracomp UC200 20,000 54,500 15 Ultracomp UC300 20,000 45,000 30 Rulon 10,000 1,000 400 CJ 10,000 35,000 150 Delrin AF 3,000 1,000 100 Nylon 6/6 1,000 300 360 UHMW 1,000 800 50

    12. Other Factors Can Affect The Ability of Plane Bearing Systems to Handle the P, V and PV AMBIENT TEMPERATURE - HIGHER AMBIENT TEMPERATURES REDUCE ALL CAPACITIES INTERMITTENT OPERATION – OSCILLATING AND RECIPROCATING MOTION ALLOW HIGHER P, V, AND PV VALUES SHAFT MATERIALS – MATERIALS THAT ARE GOOD THERMAL CONDUCTORS ALLOW INCREASED VALUES SURFACE FINISH – TOO SMOOTH A SURFACE FINISH WILL GENERATE HIGHER FRICTION, THUS MORE HEAT, AND WILL LOWER VALUES

    13. MANY PLANE MATERIALS ARE PLASTIC OR PLASTIC LIKE MATERIALS THESE MATERIALS ARE AFFECTED BY HEAT AND ALL HAVE A MAXIMUM CONTINUOUS OPERATING TEMPERATURE

    14. Maximum Operating Temperature of Plastics MATERIAL MAX. OPERATING TEMPERATURE °F Graphite Polyimide 650 Rulon 550 TriSteel PI 500 Carbon/PTFE PEEK 480 Carbon PEEK 480 FCJ/CJ 320 Ultracomp 266 Nylon 6/6 210 Delrin 180 UHMW 180

    15. Plane Bearing materials have coefficients of thermal expansion that differ from surrounding hardware! As a result, bearings that operate at elevated or extreme low temperatures or function in hot/cold cyclic environments must be given special design attention. Lack of attention to the thermal expansion rates of the bearing material will cause seizure or bearing drop out

    16. Plane Bearing Coefficients of Thermal Expansion MATERIALS EXPANSION IN/IN°F x 10E-6 Tri Steel PT 6.0 1040 Carbon Steel 6.0 FCJ 7.0 CJ 7.0 Carbon Fiber PEEK 7.0 660 Bronze 10.0 Aluminum 12.4 Carbon/PTFE PEEK 17.0 Graphite PI 27.0 Ultracomp 33.0 Rulon 35-49.0 Nylon 6/6 55.0 Delrin AF 63.0 UHMW 130.0

    17. A major strength of plane bearings is their ability to function in a wide range of environments Wet – fresh, salt, DI, slurry Dirty – coal, quartz, sand, road ballast Chemicals – full pH range Clean rooms – minimal debris production FDA/USDA/3A/NSF approvals AND ALL THIS WITHOUT LUBRICATION!

    18. How do self lubricating plastics bearings lubricate? There are two types of lubrication methods in plastic plane bearings: Smearing systems – small amounts of lubricating additives such as PTFE, silicone, graphite or MOS2 are wiped into the microfinish Debris systems – small particles of the polymer are removed during normal operations and develop plastic “ball bearings”

    19. Smearing Systems Smearing systems are typical of PTFE and PTFE filled polymers As the shaft makes initial contact with the mating contact surface, softer lubricating material is wiped into the microfinish of that surface building a thin film of lubricant Lubricant remains in place and will not migrate out thus reducing the friction and wear on both the shaft and the bearing.

    20. Smearing System Materials Best know materials utilizing this type of self lubricating process: Rulon Fluorosint PTFE Blends Delrin AF Ertalyte TX BG PEEK Graphite PI TriSteel PT/PI Ultracomp

    21. Debris Systems Debris systems are found in harder thermoplastic or thermoset polymers that deposit particles of the actual resin between the shaft and bearing. These types of materials tend to be less efficient since the debris remains on the surface area between the dynamic faces rather than embedding. Over time the debris is “cast off” as residue and the wear process tends to be on a slow but continuous basis.

    22. Debris Systems Materials Nylon 6/6, 6/12 Acetal/Delrin 100/500 Cast Nylons UHMW It should be noted that debris materials have inherently low friction but not as low as smearing systems with migratory lubricants. It should also be noted that debris materials tend to be lower cost than the smear materials but they also have lower P,V,PV ratings and limited temperature ranges.

    23. Materials Review By far, the largest family of self lubricating plane bearings are the filled PTFE materials. The best known of these is Rulon, a family of blended PTFE materials designed for bearings, seals and structural components. Fluorosint family of mica filled PTFE for low thermal expansion applications

    24. Rulon Bearings

    25. Rulon Bearings Rulon™ is a product from Saint Gobain Performance Plastics – Formerly Dixon-Furon Family of products has over 300 blends Tri Star Plastics is the Master Distributor for Rulon products in North America

    26. Rulon Bearings All Rulon materials have similar properties: Temp. Range - -400 to +550/600F Inert to all chemistry Zero moisture absorption Self Lubricating Variable thermal expansion properties Outstanding wear life and strength

    27. Most Common Rulon Bearing Materials Rulon LR – maroon color, ceramic fiber filled, excellent creep and wear resistance, low friction – best used against 35RC hardness or better Rulon J – gold color, lowest friction of any plastic, non abrasive so will run against soft shaft materials Rulon 641 – white color, FDA grade for food processing and packaging applications Rulon 142 – blue/grey color – bronze filled for extremely low deformation, excellent sliding bearing for machine tools, motor mounts, slide pads

    28. Rulon Availability All Rulon materials are available in standard sleeve, flange and thrust sizes to match bronze standards Rulon is also available in rod, sheet, tape or tube for in house machining Rulon is very easy to machine and Tri Star can assist with techniques.

    29. Bearing Grade Composite Materials The newest generation of self lubricating plane bearings are composites Ultracomp – family of very high load, low speed bearing materials for high impact and vibration applications on oscillating pin bushings CJ – filament wound rigid epoxy bearing for extreme loads in oscillating or rotary applications. PTFE/Nomex liner on ID for low friction and long wear life FCJ – filament wound rigid epoxy bearing for extreme loads in full rotary or linear applications. Alloyed PTFE liner for increased speed ratings. Lower load rating than CJ and Ultracomp

    30. Ultracomp Ultracomp is a made using synthetic fibers and impact resistant thermoset resins for extreme loads. Ultracomp bearings have static load ratings of 54,500 psi to break and 18,500 psi to yield. Ultracomp is primarily a high load, low speed oscillating material. All Ultracomp materials have less than 0.1% swell in water All Ultracomp materials have migratory lubricants such as PTFE, graphite or MOS2

    31. Ultracomp

    32. Ultracomp Ultracomp materials are used in construction, agriculture, material handling, railway, and general industries for pin bushings, slide pads, spherical inserts, trunnion support bearings, etc. Ultracomp is easy to machine Ultracomp is an excellent replacement material for lubricated steel or bronze bushings

    33. CJ Bearings CJ bearings are off the shelf replacement bearings to bronze standards CJ bearings use filament winding techniques at different helix configurations to improve strength through the wall. Nomex/TFE blended liner gives excellent wear life and lubricity CJ bearings have very low swell in water and are thermally stable for tight tolerance designs

    34. FCJ Bearings FCJ bearing is similar to the CJ but the Nomex/TFE liner is substituted with a alloyed PTFE tape liner Lower load limits than CJ but higher speed rating for full rotary applications without lubrication Excellent wear and friction properties

    35. TriSteel® Metal Backed Bearings TriSteel bearings are metal bearings with various self lubricating liner materials sintered into the substrate Liner materials vary depending on loads and speeds Liner materials include PTFE, Acetal, PEEK, PI/PTFE blends, PTFE/PVDF blends All TriSteel bearings have very high P, V and PV ratings and have extremely low deformation

    36. TriSteel Bearings

    37. Tri Steel Bearings Tri Steel bearings are available with tin or copper plated steel, 316 stainless or bronze. Liner materials will vary in thickness from .002” to .020” Wall thicknesses are .060 and .090 nominal

    38. TriSteel Bearings TriSteel bearings are capable of PV ratings up to 80,000 without lubrication and 2 million with lubrication Temperature ratings vary from -400F to +500F PEEK/SS grade excellent substitute for rolling element bearings in chemical pumps and other rotary equipment

    40. High Performance Materials An additional group of plane bearing materials are the HPM grades: PI – polyimide with graphite additives can operate at 700F without lubrication and with extremely low wear. PV ratings as high as 300,000 in some conditions without lube Trade names - Meldin®, Vespel®, Duratron®

    41. High Performance Materials

    42. High Performance Materials High Performance Materials are catagorized as imidized materials and advanced hybrid polymers. Imidized materials include: Celazole PBI Polyimide – Vespel, Meldin, Duratron Polyamide-imide – Torlon Kapton – polyimide film

    43. High Performance Materials PBI – Highest temperature polymer on the market HDT of over 800F with continuous service over 750F and short term excursions to 1100F Ionic impurities very low Very strong material without any fillers Lowest coefficient of thermal expansion of any unfilled plastic Highest compressive strength of any unfilled plastic Excellent thermal insulator Inherently good wear properties without PTFE

    44. High Performance Materials Polyimides True condensation polymer with excellent wear and thermal properties Vespel best known trade name. Meldin family is 8 different versions of polyimide Compression, isostatic or injection moldable. Also available in thin cast films known as Kapton Unfilled and filled versions available for different bearing or structural needs

    45. High Performance Materials Another family of HPM products is Torlon® which is a PAI. Excellent wear life at extreme speeds without lubrication PV values up to 3 million with lube Used as sleeve or thrust bearing in transmissions, gear boxes, final drives, etc. Thermally stable, coefficient of thermal expansion close to steel

    46. High Performance Materials PEEK – available with carbon fiber, graphite powder and PTFE fillers for outstanding high load, high speed rotary applications Inert to most chemistry, able to work in steam or high temperature liquids Very low thermal expansion, excellent wear life and low friction

    47. Other Bearing Grade Materials There are many more engineering grade plastics used in bearing applications PET – Ertalyte, Ertalyte TX PBT - Hydex PPS – Ryton, Techtron – Poor Mans PEEK Cast Nylons (Nylatron)?

    48. Final Comments Tri Star Plastics specializes in material development, design and fabrication of self lubricating plastic bearings. Our interest is in assisting customers with product selection, component development and successful production. Our website www.tstar.com is interactive and you can use our online design assistance to determine potential materials for your application.

    49. Final Comments Tri Star looks forward to working with you as you investigate improved performance, longer life and more cost effective bearing systems for your equipment. Remember – No lube/No maintenance!

    50. Supplier Recognition Ultracomp – Tri Star Plastics Hydex – Ensinger/Hyde TriSteel – Tri Star Plastics Ertalyte - Quadrant Delrin – E.I. DuPont Ryton - Phillips Celazole – Quadrant Torlon – Solvay Chemical PEEK – Victrex CJ/FCJ – Saint Gobain EPP Teflon – E.I. Dupont Duratron - Quadrant Rulon – Saint Gobain EPP Techtron - Quadrant Nylatron – Quadrant Fluorosint - Quadrant Nylon – E.I. DuPont Meldin – Saint Gobain EPP Vespel – E.I. DuPont Some names are registered tradenames of various companies. Values indicated are typical. Tri Star recommends testing in your particular application to insure performance expectations are met.

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