MANUFACTURERS AND SUPPLIERS OF QUALITY MARINE EQUIPMENT

 
 

The various grade of Tufnol are manufactured at their Birmingham, England factory and were one of the first non-metallic bearing materials to hit the market in the 1920's. Originally used for switchgear, Tufnol now manufacture a wide range of materials for use in the marine, aerospace, railway, construction and electrical industries.

 
 
Fabric Laminates and Bearing Materials  
Bear Brand Specifically designed for water lubricated marine propeller shaft and rudder bearings, can also be used in oil lubricated sterntubes. Data Sheet
Whale Brand General purpose medium weave material suitable for gears, wear resistant components and low voltage insulation. Data Sheet
Crow Brand Tough and rugged coarse weave material. Data Sheet
6F/45 Principle features are excellent electrical properties, good dimensional stability and  outstanding machinability. Data Sheet
RLF 1 ,2, 3 Rolled laminate fabric tube Data Sheet
2F/3/PTFE PTFE impregnated cotton weave material, excellent mechanical strength, rigidity, toughness and good machining characteristics with the self-lubricating and low friction properties of PTFE Data Sheet
Paper Laminates  
Kite Brand   Data Sheet
Glass Laminates  
10G/24   Data Sheet
10G/40, 41, 42, 44   Data Sheet
10G/50   Data Sheet
  Bear Brand Tufnol Stave sections in dovetail housing
ready for final machining to size.
 
Underground mine air extractor fan nose sections - Crow Bran 6F/45 Platesand Washers for use on a railway bogie Bear Brand Tufnol Staves in machining jig 10G-40 Isolating Bushes Machining 10G-40 Bushes
The uses for Tufnol grades is only limited by the imagination, we regularly supply the various grades Tufnol for the base plate of 3D printers, wear strips, croquet mallet heads, gears, pipe isolation plates, cryogenic tank supports, fan nose sections, isolation bushes, switch boards, instrument panels, sheave rollers as well as propeller shaft and rudder bearings.

 

Tufnol's high resin content components are used in the manufacture of ocean-going vessels for:

  • A Bracket bearings
  • Stern tubes bearings
  • Bow thruster bearings
  • Stave bearings

Their resin based materials are unaffected by sea water and have a low swell rate which is very predictable so that they can be very precisely designed and the stress accurately calculated. The bearings are water-lubricated so need no additional lubrication so no oil is used. Tufnol resin based components were used in the stave bearings of the QE2.

Tufnol resin materials are approved by:

  • Det Norske Veritas (DNV)
  • Lloyd’s Register of Shipping
  • The American Bureau of Shipping (ABS)

Cunard Liner

QE2

Sterntube Bearing
HMAS Tobruk

Bear Brand Staves

Application Guide for TUFNOL laminates - Typical Choices
Application Requirement Phenolic Paper Grades Phenolic Cotton Grades Epoxy Cotton and Paper Grades Polyester Glass Grades Glass Fabric Grades
General Mechanical  
Low Voltage Insulation
High Voltage Insulation  
High Temperature      
Wear Resistance      
Low Water Absorption (Bear Brand)
Dimensional Stability    
Good Machinability    
Resistance to the Environment  


Designing With Laminates
TUFNOL laminates are non-metallic engineering materials made from layers of fibrous reinforcement, such as cotton cloth, paper or woven glass cloth, which are bonded together with high quality thermosetting resins. In manufacture, the paper or fabric is first impregnated with the resin. Then, layers of this impregnated material are pressed together under high pressure and heated to about 160oC. This causes chemical changes in the resin, making it harden, and fusing the laminate into a tough, strong solid. By using alternative resins with different types of reinforcements and additives, a range of grades is created, with types to suit a wide variety of applications.

Also, by rolling or shaping the impregnated layers before pressing, stock shapes such as rods and tubes can be moulded. The resulting TUFNOL laminates combine mechanical strength with excellent chemical and weather resistance. They are rigid, with high strength and low weight and some grades can be used in temperatures ranging from around absolute zero to over 250ºC. They are also extremely useful for electrical and thermal insulation.
Designing Components Choice of Laminar Direction  
 
The designer who is considering using a laminate for a particular application should always bear in mind the fact that the material has a laminar structure and therefore has different strengths in different directions relative to the layers. It is therefore essential to ensure that the correct section of material is chosen, so that the laminations lie in the best direction to deal with the stresses involved. Even where components are not required to withstand any load in use, machining to produce the component itself causes stress. Lack of consideration for the structure of the laminate can lead to fracture during production, handling or transit. Figure 2 illustrates several examples where the laminar construction has influenced the choice of section away from the most immediately obvious. Many laminates are slightly sensitive to stress concentration and, as with other materials, wherever possible it is good design practice to avoid stress-raising features, such as sharp internal corners or sudden changes in section.
  Tolerances on standard sections  
High-pressure laminates cannot be moulded to precisely accurate dimensions and, when selecting sizes of standard materials for ordering purposes, an allowance should be made for the possible variations in, for example, the moulded thickness of a sheet or the concentricity of a rolled tube. These are usually greater with the coarser reinforcing materials and reference should be made to the British Standard relevant to the particular type of laminate.
  Machining Tolerances and Finishes
  Owing to the nature of the material, components cannot normally be machined to the finest tolerances achievable with metals; however, the surface of a laminated plastics component has a slight resilience, which usually renders very fine tolerances unnecessary for good fits to be achieved. Laminated bushes require a greater interference than metal bushes so that the same machining tolerance becomes much less significant. On the other hand, when inserted, the laminated bush may compress slightly on the bore, so an allowance may have to be made for this when determining the size to be machined. Similarly, the fibrous nature of the reinforcement causes considerable difficulty in achieving fine surface finish readings on machined faces. This obviously varies with different grades but, for example, a first-class milled face on a medium weave fabric laminate may record a surface finish of 3 to 4 micrometers (125 to 160 micro inches) and even prolonged polishing may only reduce these figures by half. Once again, the resilient surface of the laminate usually makes fine finishes unnecessary. The milled face mentioned above would be entirely suitable as a bearing surface, without polishing
The information above is extracted from Tufnol literature

Also available from C.E.& A. Co  
Also available from C.E.& A. Co.
Propeller Shaft and Rudder Bearings Propeller Shafts
Sterntubes and Rudder Trunks Rudder Carrier Bearings
Oil Lubricated Shaft Seals Deck Machinery
Water Lubricated Shaft Seals Chockfast Orange
ManeCraft - small boat seal PolyFlex Engine Mounts and Couplings
Spurs - Rope, Net and Weed Cutter Arctic Steel Water Strainers
Vickers Marine Oils Home Page
For further information, or to purchase Tufnol please contact us.
Wärtsilä Enviroguard
Water Lubricated Sea
l
Chockfast Orange
Epoxy Chocking Compound
 
  5 Schenker Drive, Royal Park.
South Australia. 5014

Ph: 08 8240 0777
Fax 08: 8240 0777

Int. Ph: +618 8240 0777
Int. Fax: +618 8240 0711
E-mail: ceaco@ceaco.com.au