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Multigrain diamond abrasive
_News Cutting abrasive wear Plant users handling abrasive materials are beginning to recognise the economic advantages of protecting surfaces with abrasion and impact resistant linings. A steel reinforced polyurethane has been developed for use by handlers of bulk materials to protect the surfaces of such plant as chutes, hoppers, silos, mills, pelletising drums, and dredgers. Tufsheet comprises a specially formulated abrasion and tear resistant polyurethane, having a Shore hardness of 80, and an integral imbedded open lattice reinforcement of 1.2 mm thick steel. The manufacturers describe the product as "proof against highly abrasive materials such as iron ore, coke, coal ash, grain and gravel, even when subject to shock, high shear force and impact loading". They state that its impact shear force and abrasion resistance is better than ordinary
rubber sheeting, several times as thick and suggest that, although it is expensive compared with the same volume of rubber, it is highly competitive with rubber per unit of performance. Tufsheet has a smooth surface giving a lower coefficient of friction than comparable rubber sheeting. The manufacturers claim that it is unaffected by weather, low temperature, water, weak acids, tar, or oil. A test piece of Tufsheet was recently fitted in the most wear-prone part of a large sea-going dredger. After 42 000 tonnes of gravel had passed over it, the wear was reported as "negligible". 12 mm thick Tufsheet is now being used in this application, and the manufacturers suggest that the life will be " . . . considerably longer than the 1 in thick rubber previously used". Hytek Mouldings Ltd, Hallcroft Industrial Estate, Retford, Nottinghamshire DN22 7SS, UK
Air bonded lubricant passes US military test Recently introduced is an aerosol can form, Molykote 3402 is produced for a wide range of applications in the aircraft and related industries. The product has passed the new US Military Specification L-46147A for lubrication and corrosion resistance. Molykote 3402 is a solvent dispersion of solid lubricants, corrosion inhibitors and an organic binder. It is said to be ideal for applications involving metals whose properties might change at the high curing temperatures required by some bonded lubricants. Typical uses include aluminium-t o-aluminium,
aluminium-to-steel, and steel-to-steel mating surfaces. Molykote 3402 cures at room temperature and is recommended for such applications as: an anti-fretting/ anti-corrosion treatment for threaded fasteners; a dry lubricant for hinges, ball-joints, and linkages; and a corrosion treatment for parts in storage, which also provides dry lubrication on start-up. It is also compatible with rubbers, plastics and oils.
Multigrain diamond abrasive Significant improvements in grinding ratio can be achieved with a recently announced synthetic resin bond diamond abrasive. In dry grinding of ISO K10 carbide, for example, De Beers CDA-M gave a G-ratio of 100 compared with a G-ratio of 60 given by standard nickel clad diamond grits working under identical conditions. Individual grains of CDA-M (Carbon Diamond Abrasive-Multigrain) are composed of many fine diamond particles bonded together with a metal matrix. The matrix gives a strong chemical bond between metal and diamond, the structure being consolidated by fusion of the metal surfaces. According to De Beers, the composite grain structure gives an abrasive with stock removal characteristics similar to coarser grits, while producing surface finishes normally associated with finer mesh sizes. This combination of properties is said to eliminate the need for a range of grit sizes. De Beers Industrial Diamond Division (Pty) Ltd, Charters, Sunninghill, Ascot, Berkshire SL5 9PX, UK
Dow Coming Ltd, Reading Bridge House, Reading RG1 8PW, UK
Diesel engine oil Easy cold starting and good lubrication at operating temperatures are two of the advantages claimed for a recently announced SAE 20W/30 engine oil. The oil has been developed primarily for agricultural use. Crown Unilube Super was formulated to meet the requirements of tractor engines, gear boxes and transmissions,
including those fitted with wet brakes. It satisfies MIL-L-21043B, MIL-L2104C, Series III, and MIL-L-46152 and is recommended for gasoline engines as well as naturally aspirated and turbo-charged diesel engines. W.F. Smallman and Son Ltd, Great Bridge St, West Bromwich, West Midlands B70 ODE, UK
Muln'grain synthetic resin bond diamond abrasives give better grinding ratios than standard metal clad diamond grits.
TRIBOLOGY international June 1978
197
rubber sheeting, several times as thick and suggest that, although it is expensive compared with the same volume of rubber, it is highly competitive with rubber per unit of performance. Tufsheet has a smooth surface giving a lower coefficient of friction than comparable rubber sheeting. The manufacturers claim that it is unaffected by weather, low temperature, water, weak acids, tar, or oil. A test piece of Tufsheet was recently fitted in the most wear-prone part of a large sea-going dredger. After 42 000 tonnes of gravel had passed over it, the wear was reported as "negligible". 12 mm thick Tufsheet is now being used in this application, and the manufacturers suggest that the life will be " . . . considerably longer than the 1 in thick rubber previously used". Hytek Mouldings Ltd, Hallcroft Industrial Estate, Retford, Nottinghamshire DN22 7SS, UK
Air bonded lubricant passes US military test Recently introduced is an aerosol can form, Molykote 3402 is produced for a wide range of applications in the aircraft and related industries. The product has passed the new US Military Specification L-46147A for lubrication and corrosion resistance. Molykote 3402 is a solvent dispersion of solid lubricants, corrosion inhibitors and an organic binder. It is said to be ideal for applications involving metals whose properties might change at the high curing temperatures required by some bonded lubricants. Typical uses include aluminium-t o-aluminium,
aluminium-to-steel, and steel-to-steel mating surfaces. Molykote 3402 cures at room temperature and is recommended for such applications as: an anti-fretting/ anti-corrosion treatment for threaded fasteners; a dry lubricant for hinges, ball-joints, and linkages; and a corrosion treatment for parts in storage, which also provides dry lubrication on start-up. It is also compatible with rubbers, plastics and oils.
Multigrain diamond abrasive Significant improvements in grinding ratio can be achieved with a recently announced synthetic resin bond diamond abrasive. In dry grinding of ISO K10 carbide, for example, De Beers CDA-M gave a G-ratio of 100 compared with a G-ratio of 60 given by standard nickel clad diamond grits working under identical conditions. Individual grains of CDA-M (Carbon Diamond Abrasive-Multigrain) are composed of many fine diamond particles bonded together with a metal matrix. The matrix gives a strong chemical bond between metal and diamond, the structure being consolidated by fusion of the metal surfaces. According to De Beers, the composite grain structure gives an abrasive with stock removal characteristics similar to coarser grits, while producing surface finishes normally associated with finer mesh sizes. This combination of properties is said to eliminate the need for a range of grit sizes. De Beers Industrial Diamond Division (Pty) Ltd, Charters, Sunninghill, Ascot, Berkshire SL5 9PX, UK
Dow Coming Ltd, Reading Bridge House, Reading RG1 8PW, UK
Diesel engine oil Easy cold starting and good lubrication at operating temperatures are two of the advantages claimed for a recently announced SAE 20W/30 engine oil. The oil has been developed primarily for agricultural use. Crown Unilube Super was formulated to meet the requirements of tractor engines, gear boxes and transmissions,
including those fitted with wet brakes. It satisfies MIL-L-21043B, MIL-L2104C, Series III, and MIL-L-46152 and is recommended for gasoline engines as well as naturally aspirated and turbo-charged diesel engines. W.F. Smallman and Son Ltd, Great Bridge St, West Bromwich, West Midlands B70 ODE, UK
Muln'grain synthetic resin bond diamond abrasives give better grinding ratios than standard metal clad diamond grits.
TRIBOLOGY international June 1978
197