- October 01, 2008, By Charlie Acquista, Adchem Corp.
Here are some of the concerns faced by converters and suppliers that handle substrates converted on high-speed webs:
- Personal Safety
An electrostatic discharge (ESD) can be painful and cause burns, cardiac problems, and even death. In addition to the direct health effects of exposure to electrical current, there is also the secondary hazard of operators suddenly recoiling from the shock and injuring themselves by falling against dangerous machinery.
- Explosion and Equipment Damage
Static discharge is a spark. Areas with flammable liquids or gases, such as solvents, must remain spark-free at all times. Electrostatic discharge can have sufficient energy to ignite hazardous vapors in coating heads and gravure printing operations. An ESD event also can disrupt logic in PLCs and sensing equipment, causing processing errors and costly downtime.
- Damage to the Adhesive System
Static buildup and ESD events can damage the pressure-sensitive adhesive (PSA) release liner of the product being unwound. When the silicone coating is disrupted by static, it will no longer function as a release system in the area affected by the discharge. The adhesive will “split” between two sides of release liner. Alternatively, the liner can fail to release where it is damaged, making it very difficult to remove the liner as designed.
- Equipment Jams
The accumulation of electrostatic charges can cause problems, even if ESD events do not occur. If static charges are not neutralized, sheets of material will stick together, creating jams in downstream processes.
- Product Damage
Electrostatic fields also attract dust particles, fibers, bugs, and hair, which result in surface contamination. This causes obvious quality problems in printing, coating, and laminating, as well as cleanliness problems with medical PSA applications. Moreover, static charges can cause uneven coatings and “wicking” of inks, and p-s tape carrying a static charge can damage sensitive electronic components.
Want To Learn More?
Find information on static elimination at www.pffc-online.com. Click on the Surface Prep button for one-stop browsing of our archives. Also see What's New Products starting on p54.