Type C vs Type D FIBC: Choosing the Right Anti-Static Bag

Each time powder is poured into or removed from a bulk bag, its particles rub against the fabric, causing a static charge to build up on both the bag and the product. In the case of ordinary goods, this is of little importance; near combustible dust or solvent vapour, however, a single spark can cause a fire. An anti-static bag provides a safe means for this charge to escape, and the two main types of FIBC bags designed for flammable powders are Type C and Type D. Although both kinds protect your plant, they deal with static in very different ways, and the correct choice will depend on the actual way your site operates.

How a Type C FIBC works

A Type C FIBC drains static through conductive threads, but only while it is connected to ground. That is why buyers often call these conductive bags or groundable bulk bags.

Conductive yarns run through the fabric in a grid, all linked to a grounding tab. Before filling or discharge starts, the operator clips that tab to a verified earth point. Charge then flows through the threads into the ground. If someone skips the clip, or the cable comes loose halfway through, the bag holds on to a dangerous charge. Our conductive FIBC bags are made for plants where grounding is already part of the daily routine.

How a Type D FIBC works

A Type D FIBC controls static without any ground connection. Its static dissipative fabric releases charge into the air through a low energy corona discharge. That discharge is far too weak to ignite dust or vapour.

Since nothing needs clipping, Type D removes the operator error that comes with grounding. There is one condition. The bag surface must stay clean and dry, because water or grease on the fabric stops it from working properly. Our dissipative FIBC bags suit sites where a reliable earth connection is hard to guarantee.

Type C vs Type D FIBC: anti static bag comparison

Which industries should use each type

In most cases either type can be used; what determines the choice is the way in which the plant operates, not the name of the product.

Chemical manufacturers who have fixed filling lines and earth points generally go for Type C; this is also the case with plants producing plastics and polymer resins, and similarly with paint and pigment works in which solvent vapour is present and the personnel already check the grounding before each batch.

Pharmaceutical plants usually lean towards Type D. Material moves between rooms and filling stations, so grounding every bag is difficult to enforce. Food ingredient processors handling sugar, flour or starch deal with combustible dust, and many of them prefer Type D for the same reason. Agrochemical formulators with frequent bag changes find it practical too. For a wider view, read our guide to the types of FIBC bulk bags.

A quick decision checklist

People frequently ask which anti-static bulk bag they should buy, and these simple rules provide you with a starting point.

• • If the earth connections at all filling and discharging points are tested and operators are trained, then select Type C.
  • If you run several filling stations, mobile loading or quick bag changes, choose Type D.
  • If the bag surface is likely to get wet or greasy, avoid Type D and use a properly grounded Type C.
  • If you are unsure about the hazard zone at your site, get an assessment before ordering either type.

Common mistakes buyers make

In our experience, most static problems trace back to a few avoidable errors.

• Using a Type C bag without connecting the grounding tab.
• Storing Type D bags where rain or oil can reach the fabric.
• Adding an unsuitable inner liner, which can cancel out the bag’s protection.
• Skipping the check for IEC 61340-4-4 marking and a valid test certificate. This standard sets how both types are tested, classified and labelled.
• Picking the cheapest option instead of the one that matches your process.

Get the right bag from a trusted FIBC Bags Manufacturer

Choosing between Type C and Type D is a safety decision, and it deserves expert input. Rishi FIBC manufactures conductive and dissipative bulk bags tested to international standards for plants and exporters around the world. Share your product details and filling setup with our team. We will help you select the anti static bag that fits your process and keeps your people safe.

FAQ