Introduction
A 1990 Taguchi Study conducted by Phoenix, along with a major stamping manufacturer, found three primary sources of variation within the stamping process. These sources were blank size/shape, blank location and lubrication. Observation suggests these findings to be relevant today.
Description
Sheet Metal lubrication is an input to the forming process critical to material flow. Analysis of this input strives to understand the impact of specific lubricant variables on the current forming output
Background
A 1990 Taguchi Study conducted by Phoenix, along with a major stamping manufacturer, found three primary sources of variation within the stamping process. These sources were blank size/shape, blank location and lubrication. Observation suggests these findings to be relevant today.
Purpose
- Measure and track lubricant on blank.
- Type, volume, distribution, viscosity, temperature
- Application- at blanking source, wash, press applied, and mist
- Define desired lubrication amount and measurement methodology.
- Correlate lubrication to the forming output- splits, buckles, strains, etc.
Steps
1. Determine measurement method based on available tools: Worldscan/Microderm/Cardboard/Visual/Phund Gauge)
2. Measure incoming blanks
a) Top of 2nd blank, 1 blank per lift
b) Follow standard measurement location template
c) Record on standard worksheet
3) If blanks washed, oil reapplied, or mist application
a) Pull one blank directly after all application complete
b) Follow standard template
c) Record on standard worksheet
4) Record set up of blank wash, reapply, or misting units (if settings are different for top and bottom of blank repeat step 3 for bottom of blank)
5) Analyze the formed panel against lube measurements
a) Determine best method for measuring output (ex. Thinning Analysis)
b) Record output result relative to lube using standard worksheet.
Examples from the field
A tier one automotive supplier forming Body Side Outers thought they had a problem with the coating on their steel. The results of lubrication analysis were combined with those of other tools to eliminate the steel as root cause. In this case, lubrication variation was also eliminated as a root cause. Location Template
A European tier one automotive supplier converting from steel coated with a hot dip process to an electro galvanized process, experienced significant changes in material performance. Lubrication Variation Analysis was used to Identify lube as the most critical input to this forming process and created tools for monitoring lube in the future.
Contributing authors George Coates, Wil Fras, Bill Shinskey, Timothy Smith, and Kirk Wiley
