Page 20 - MetalForming March 2011

Lube Success
on a regular basis, to improve oxidation stability, corrosion stability and staining characteristics, among other benefits,” he says. “We’ve even found success in certain deep-drawing applications on cold-rolled steel using a new nonchlo- rinated water-soluble lubricant.”
Drawing Cosmetic Brass Parts
Both Harry Miller and Angler supply custom-blended lubricants, as well as
cleaning compounds, to metalformer Carby Corp., Watertown, CT, a deep- draw stamper operating some 70 Waterbury Farrel and U.S. Baird trans- fer presses, rated to 75-ton capacity. Up until 2005, Carby blended its own lubricants, but as suppliers of com- pounds started to discontinue some of their ingredients, the stamper looked to outsource lubricant formulation.
Among the products Carby now
receives from Harry Miller is Hamilube 9900-C, a combination of oils, EP addi- tives (chlorinated paraffins) and emul- sifiers that allows Carby to severely deep-draw brass parts (90-10 and 70- 30) to a strict cosmetic-finish specifi- cation. Draw ratios can exceed 30:1 on parts the company stamps for med- ical devices, writing instruments, elec- tronic products and other applications.
Carby technical support manager Gary Coviello describes one particu- larly challenging job—deep-drawing brass parts for ink pens. “We used to run these parts using a water-based lubricant that contained lard oil,” he says. “It satisfied our cosmetic require- ments, but as an organic compound it created problems with sump life, par- ticularly in warm weather. In some cases sump life would be as short as one week. Now, with the new water-sol- uble lubricant from Harry Miller, sump life typically is several weeks.”
Among the products Angler formu- lates for Carby is a lubricant developed for deep drawing of stainless-steel parts. “Here, chlorinated paraffin in our previous lubricant caused corro- sion and staining of the parts,” says Coviello. “Angler’s lubricant (Accu- Draw 4640) solved those problems.”
For his part, Coviello is acutely aware of the EPA’s close scrutiny of use of chlorinated paraffins in the metal- working industry, and so he’s taking a hard look at “green” compounds. “We’ve just begun to test vegetable- based products for stamping some of our nickel-silver parts,” he says, noting that not only will he evaluate stamping and drawing performance but also must consider sump life, cleanability and other factors.
“The parts we’re looking at have a relatively high draw ratio (30:1) and also require a good surface finish,” he says. “We’re having problems with the chlorinated paraffin lubricant we’re currently using on this application, as it’s attacking our tooling—specifically, the binder in the carbide dies. Staining also is an issue, and we’re hoping that the vegetable-based lubricant comes to the rescue.” MF
18 MetalForming/March 2011
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