Page 30 - MetalForming May 2009

Tooling Technology ToolingUpdate
Pressure-Indicating Film Reduces
Press Setup Time and Maintenance Costs
other mechanical systems to be fine- tuned. This reduces their lifecycle main- tenance cost and improves part quality and consistency.”
Sensor Products Inc.: 973/884-1755; www.sensorprod.com
Mirco Graenert Consulting: 905/715-7508; www.canstampconsulting.com
Tool & Die Authority
Newsletter Delivers
Top-Notch Advice
Considering surface coatings for draw steels? Need to get a handle on job tracking and quoting systems? How do you effectively troubleshoot sheetmetal problems? Readers of the April issue of Tool & Die Authority, MetalForming mag- azine’s monthly premium e-newsletter designed for tool and die professionals, got the answers they were looking for to these and other questions.
With the tagline “Exclusive technical information and timely news, by industry experts for tool and die professionals,” Tool & Die Authority is a combination of blog- style news and exclusive information about tool and die companies, markets, customers and much more. Five expert columnists pro- vide solid technical tips not found anywhere else to help tool and die operations solve a range of challenges, enabling them to offer top-notch service to customers while improving the bottom line.
If you missed the April issue, you missed this:
• Troubleshooting Sheetmetal Prob- lems, by Danny Schaeffler
“It is entirely possible, and even expected, that the 10 to 20 coils pro- duced from the same heat will have dif- ferent mechanical-property test results, even if the mill used the same recipe for all processing.”
• Surface Coatings for Draw Steels— You May Not Need Them, by Peter Ulintz
This pressure image of the progressive die reveals that three of the four bumper blocks experienced pressure of 7000 to 20,000 psi, while one block failed to make contact, requiring a shut-height correction.
Pressurex, a thin, flexible, Mylar- based sensor film developed by Sensor Products Inc., Madison, NJ, instantly cap- tures and permanently records pressure distribution and magnitude between any two mating surfaces. In the pressroom, stampers can use the film—which reveals surface pressure from 2 to 43,200 psi and comes in eight pressure ranges—to pinpoint important pressure points that affect tool balancing, and key pressure areas that lead to die wear, to reduce long- term production-maintenance costs.
Proving this out is Shawn Eeles, gen- eral manager of Five Star Tooling, a progressive-die manufacturer in Ontario, Canada. Eeles, along with Mirco Graen- ert, of Mirco Graenert Consulting Inc., Newmarket, Ontario, put Pressurex through a 400-ton progressive-die trial to analyze its capabilities. They found that the film works as-specified in forming and piercing operations, identifying pres-
sure points affecting tool balancing and die maintenance.
Five Star Tooling applied Pressurex to a 5-ft.-long progressive die used to stamp a structural automotive part. It applied the film between mating cutting and forming components as well as to bumper blocks, revealing local pres- sures that can be modified to optimize die balancing.
“Accurately balancing the die by obtaining pressure readings from the various operations results in higher qual- ity dies and lower die-maintenance costs,” says Graenert. “The restrike sta- tion, for example, often exerts a con- centrated force near the exit side of the die. Unbalanced pressures can cause the die to ‘kick,’ causing premature fatigue, excess wear and subsequent cracking or breakage of die components. This can be minimized by using the pressure readings from the film and varying stripper pres- sures to balance the tool.”
Pressurex, similar in thickness to ordinary paper, changes color directly pro- portional to the amount of pressure applied. Metalformers can determine pressure distribution by comparing the exposed sensor film to a color-calibration reference chart. Or, Pressurex readings can be further analyzed using Sensor Product’s inhouse imaging service, or by leasing or purchasing its Topaq tactile- force-analysis system.
“The test proved,” says Graenert, “that bumper blocks, areas near cutting edges, gradual forms, trim-cutting edges and restrike stations all can be thoroughly analyzed, giving vital information that enables better die balancing. For some dies, these pressure values, particular- ly combined with die knowledge, reveal what is ‘unseen’ and allow dies and
28 METALFORMING / MAY 2009
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