Lubricant, drawing

Algard. [Wiico] Stamping lubricants, die films, die lubricants, drawing compds. 

Uses Corrosion inhibitor, EP agent, lubricant, antiwear agent for slushing, turbine, hydraulic, press, and rolling oils, temper mill lubricants, drawing compds., and metalworking fluids... 

As a rule, in practice, the surface defects are revealed by the magnetic-powder and capillary methods. However, in the case of nonmagnetic materials the magnetic-powder methods are not applicable and the capillary ones do not detect the subsurface defects or defects filled with the lubricant after the grinding, wire-drawing and so on. 

Cold Forming. Some ABS grades have ductihty and toughness such that sheet can be cold formed from blanks 0.13—6.4 mm thick using standard metal-working techniques. Up to 45% diameter reduction is possible on the first draw subsequent redraws can yield 35%. Either aqueous or nonaqueous lubrication is required. More details are available in Reference 147. 

Various other soft materials without the layer—lattice stmcture are used as soHd lubricants (58), eg, basic white lead or lead carbonate [598-63-0] used in thread compounds, lime [1305-78-8] as a carrier in wire drawing, talc [14807-96-6] and bentonite [1302-78-9] as fillers for grease for cable pulling, and zinc oxide [1314-13-2] in high load capacity greases. Graphite fluoride is effective as a thin-film lubricant up to 400°C and is especially useful with a suitable binder such as polyimide varnish (59). Boric acid has been shown to have promise as a self-replenishing soHd composite (60). 

In some metal-forming operations such as rod and wire drawing, various surface treatments are appHed to the workpiece. These include descaling, cleaning the apphcation of lubricant carriers, and the use of lubricants (see Lubrication and lubricants). Descaling can be mechanical or chemical (pickling). 

The patented wire is again cleaned with acid, rinsed, and brass plated just before the second drawing. The brass acts as a drawing lubricant and as well as an adhesive to mbber. The brass composition is typically 60—70% copper with 2inc as the remainder. The patented, brass-plated wire is drawn into filaments of 0.15—0.38 mm diameter. 

Figure 12-61 also illustrates three basic types of trunnion rollbearing assemblies. Antifriction pihow blocks are the most common on modern diyers however, when the dryer load requires larger than a 12.7- to 15.2-cm-diameter bearing on the trunnion shaft, the dead-shaft antifriction bearing is substituted. This represents a considerable cost saving compared with the larger pillow blocks. They are completely sealed and continuously bathed in lubricant. Pillow-block bushings are less often used. The thrust washers are difficult to seal against dust, and they draw more power. Thrust roll mountings are depicted also in Fig. 12-61. These are usually dead-shaft.

Neutral cleaners (non-caustic based) These are ethylene oxide condensates, and easily emulsify the mineral oils and greases. They are more useful for sheet-metal components, which contain no lead compound lubricants (as used for deep-drawing operations), and are also suitable for non-ferrous... 

Clays have plate-like molecules with charges on their surfaces (Chapter 16). The charges draw water into the clay as a thin lubricating layer between the plates. With the right moisture content, clays are plastie they can be moulded, extruded, turned or carved. But when they are dried, they have sufficient strength to be handled and stacked in kilns for firing. 

As a part of the lubrication program, oil should be periodically tested. The testing requires drawing oil from the system for a laboratory analysis. The usual tests conducted to determine the condition of oils include viscosity, pH and neutralization number, precipitation, color and odor, and a check for foreign particles in the oil. The results should be reviewed and compared with new oil characteristics to determine the life characteristics of the oil. 

The crystallization of wax from lubricating oil fractions makes better oil. This is done by adding a solvent (often a mixture of benzene and methyl ethyl ketone) to the oil at a temperature of about -5 F. The benzene keeps the oil in solution and maintains fluidity at low temperature the methyl ethyl ketone acts to precipitate the wax. Rotary filters deposit the wax crystals on a sp woven cloth stretched over a perforated cylindrical drum. A vacuum in the drum draws the oil through the perforations. The wax crystals are removed from the cloth by metal scrapers and ol vent-washed to remove oil followed by solvent distillation to remove oil for reuse. 

---