Static Charge Worthy of "Star Trek"

OVERVIEW

• Polypropylene film tape manufacturing plant
• S.E. US
• Study in month of August - long, long ago
• Reports of "strange things happening" around flim slitting machine
• Contamination of film web one of the problems reported

FILM EXTRUSION

• A polypropylene web produced with a width of 21 feet
• Static in this area not reported as a problem - used combination induction and nuclear static elimination devides throughout
• Wide web converted (slit) into "film jumbos" with width of 3 feet to 5 feet for coating with adhesive to make tape

CLIMATE CONDITIONS

• In the month of August, daytime temperature often over 100°F and R.H. above 95%
• At time of first measurement in this study, early in the morning, the temperature was 80°F and about 75-80% R.H.

FIELD (VOLTAGE) MEASUREMENTS

• Early in the morning, voltage was impossible to measure with a 200KV@12 inches measurement device from 20 feet away
• Operators of slitting equipment suggested I not get too close for awhile

SLITTER DESCRIPTION

OBSERVATIONS:

• Early in the morning, voltage measurements off scale from 20 feet away
• Upon entering "tent" created by web unwind stand, possible to feel static charge.
• When exactly half-way into area, static charge created a "wall" and t was impossible to walk through.
• Observed a fly get caught in the web

OBSERVATIONS AND REPORTING

• Meeting attended with plant management
• Plant Manager went to area, operators working normally around equipment
• Plant Manager walked through "tent" with no problem, and said "I must be crazy"
• Asked Plant Manager to join me early next morning

OBSERVATIONS CONTINUED

• Next morning, met Plant Manager at 6:30 and static measurements made - same as previous morning
• Plant Manager entered "tent" area and his curly gray heair straightened.
• He made it half-way and could not continue
• Could not decide if it "should be fixed or sell tickets"

CORRECTIVE ACTION

• Installed induction static eliminator across web at unwind
• Static immediately reduced throughout process to less than 50KV
• Possible to make measurements in rest of area
• Additional induction units installed at jumbo wind-up areas - <5KV at conclusion

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17th Annual Electrical Overstress / Electrostatic Discharge Symposium

September 11-14, 1995 * Hyatt Phoenix Hotel * Phoenix, Arizona

The seventeenth annual symposium dealing with electrical overstress (EOS) 
and electrostatic discharge (ESD) effects is being sponsored by the ESD 
Association in cooperation with the IEEE. The symposium will be devoted to 
the fundamental understanding of electrical transients and electrical 
overstress, and the application of this knowledge to the solution of 
problems in military, industrial, computing and communication, consumer 
and automotive electrical components as well as in systems, subsystems and 
equipment.

    General Chairman's Invitation
    General Information
        Registration Information
        Schedule of Fees
        Hotel Reservations
        Exhibits 
    Seminar and Tutorial Program
    Workshops
    Technical Program
        Symposium Opening And Keynote Address
        Session 1: On-Chip Protection
        Session 2: System-Level ESD
        Session 3: Factory Issues and ESD Training
        Session 4: Device Testing And Protection Circuits
        Session 5: ESD Control Materials and Measurements
        Session 6: Failure Analysis
        Session 7: Electrostatic Considerations In Industry 
    Registration Forms 

For further information, please contact the ESD Association:

               ESD Association
               P.O. Box 913,
               Rome, NY  13442-0913
               Phone: (315) 339-6726 
               FAX: (315) 339-6793

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   Sponsored by the ESD Association in cooperation with the IEEE