Anti-Static Bulk Bags: What FIBCs are Safe for Flammable Powder Transport?
When handling sensitive bulk powders, or filling and discharging where flammable gases or vapors are present, static protection is essential to..
September 3, 2021
When handling dangerous bulk powders, or filling and discharging FIBCs where explosive gases or vapors are present, static protection is essential to prevent a fire or catastrophic blast. Electrostatic FIBCs offer static protection in the form of either a Type C or Type D bulk bag.
Texene is the leading provider of Type D bulk bag fabric through their patented CROHMIQ technology. Over 40 million CROHMIQ Type D FIBCs have been filled and discharged in dangerous environments without a single industrial accident. Southern Packaging proudly supplies CROHMIQ branded FIBCs to customers throughout the United States.
When bulk bags are filled and discharged, the movement of the material across the bag’s fabric can cause a buildup of static electricity. Static electricity is created by an imbalance of electric charge within or on the surface of a material. The charge remains until it is able to mov
e away by means of an electric current or electrical discharge. An electrical discharge is commonly represented in the form of a spark.
Electrical sparks can create severe hazards in those industries dealing with flammable substances, where a spark might ignite explosive mixtures. Airborne vapors and dust clouds of finely powdered substances can become combustible or explosive. Every year manufacturing facilities and warehouses across the globe explode or catch fire due to the ignition of their products or raw materials. Bulk bags made with Type D fabric allow the user to safely fill and discharge bags in explosive environments without needing to ground the bag.
CROHMIQ FIBC fabric is the patented technology of Texene LLC, a global leader in manufacturing slit olefin film fabrics. CROHMIQ anti-static bulk bag fabric provides protection from sparks and other hazardous discharges by dissipating electric charge. This technology allows a level of safety equal to a Conductive Type C bag without the need for proper grounding.
Bulk bags made with CROHMIQ Type D fabric are easily recognizable in the field by their blue color and branded bag tags. For manufacturers that prefer white fabric, Texene also offers white CROHMIQ Type D fabric. White and Blue color fabric offers the same level of electrostatic protection.
According to Texene, “CROHMIQ® static protective FIBC fabric provides protection from hazardous electrostatic discharges by safely dissipating charge into the atmosphere by a process called corona. Corona is one form of electrostatic discharge, but unlike sparks or brush discharges, corona is low energy and is not incendiary to flammable or explosive atmospheres. In CROHMIQ static protective FIBC fabric, corona is produced by patented quasi-conductive yarns that are interwoven with polypropylene tapes at intervals of about 20 mm (0.8 inch). The purpose of the quasi-conductive yarns is to concentrate the electric field from any charge that accumulates when filling or emptying an FIBC.”
In the high field strength region (>3MV/m), air is split into electrons and positive ions. This region of ionization quickly decays as the field strength falls off away from the quasi-conductive yarn. Ions produced in the air next to the quasi-conductive yarn are available to interact with any charge on the FIBC. Charge of the same polarity as that on the FIBC is repelled safely into the atmosphere, whilst charge of the opposite polarity combines with and neutralizes charge on the FIBC. The net effect is that charge is dissipated safely from the FIBC into the atmosphere.
The benefit of using corona to dissipate electrostatic charge is that it does not require a ground connection. Unlike conductive Type C bags that require attachment to a grounding wire, Type D bags can be safely filled and discharged without the risk of neglecting to connect the ground wire to the bag. This reduces or eliminates the risk of accidents caused by human error.
Type D bulk bags are required when transporting flammable powders. In addition, they are required when flammable conditions exist outside the bag. For example, Type D bags should be used when flammable vapors, gases, or combustible dusts are present around the bag.
Do not use Type D bulk bags when an FIBC’s surface is contaminated or coated with conductive material such as grease or other flammable and/or combustible materials.
The following chart summarizes the static protection levels of Type B, Type C, and Type D bulk bags.
Southern Packaging is a leading supplier of conductive Type C and anti-static Type D bulk bags. We currently offer a limited range of stock Type C and Type D bags for immediate delivery. For more information on stock bags or custom orders, please contact our sales team at info@southernpackaginglp.com.