Do I Need a Coated or Lined Bulk Bag?
Coated fabric helps reduce powder leakage and moisture effects; an inner liner provides a separate barrier for powder and water. An unlined bulk bag can still be coated, so ask about both when comparing products.
Coated vs lined: what is the difference?
-
Uncoated and unlined: woven polypropylene fabric with no coating or separate inner film. Check particle retention, moisture exposure and airflow requirements.
-
Coated or laminated: a coating on the fabric helps prevent powder escaping through the weave and reduces moisture effects to some extent. It is not a separate liner.
-
Lined: an inner film retains powder and provides a waterproof barrier when intact, correctly fitted and properly closed. The outer fabric can be coated or uncoated.
Which option suits powders?
Consider coated fabric to reduce leakage through the weave. Consider an inner liner when the contents need a separate film barrier against powder leakage and water.
Check seams, filling and discharge openings, and closures too. A fabric coating alone does not establish that the complete bag is waterproof.
Storage conditions help determine the bag and liner specification.
What liner thickness do I need?
60–80 microns (μm) is usually sufficient for general applications. We offer thicknesses up to 200 microns, with the final thickness confirmed for your requirements. Thickness alone does not establish suitability.
Check the complete bag-and-liner combination
-
Fit: match liner dimensions to the bag body and its filling and discharge openings.
-
Closure: confirm how the liner is fitted, secured and closed. An open or damaged liner cannot provide the intended protection.
-
Use: explain the material, storage conditions and any temperature, airflow or documentation requirements.
A liner does not increase the bag’s safe working load or automatically make it suitable for food, hazardous materials or electrostatic protection.
Need coated bags or inner liners?
Our made-to-order special material bags offer laminated fabric and optional inner liners. Liners are not included with every standard product; we confirm construction, availability and minimum quantities.
Email us for a quote with the quantity required. If known, add your material, weight or volume per bag, delivery postcode and protection needed. Bags are sold in packs, not individually.