Metal Industry
Trapping of Cold-rolled Coil Protective Sheet
Cold-rolled coil is wrapped with a protective sheet before shipment. The protective sheet is charged with static electricity by separation during unwinding.
The charged protective sheet generates an induced charge on the surface of the cold-rolled coil, which causes a force to attract the protective sheet. As a result, the protective sheet gets trapped in the roll.
![Trapping of Cold-rolled Coil Protective Sheet](/Images/ss_static-casestudy_me_coil_001_1783609.png)
Conventional countermeasures
None
- Repeated packaging makes the work time longer.
- Workers may get an electric shock.
Countermeasures with static eliminators (ionizers)
An ionizer eliminates the necessity for repeated packaging and shortens the work time. The work environment is also improved.
![Countermeasures with static eliminators (ionizers)](/Images/ss_static-casestudy_me_coil_002_1783611.png)
Improvements and Effects
Words from the worksite
Shortened work time
Shortened time: 50 hours/month x time charge of $20/hour = $1,000/month
In addition, the work environment can also be improved.