Why Use a Liner in Your FIBC?
A liner is an inner bag, typically made from polyethylene (PE) or other plastics, inserted into the FIBC to provide an additional protective barrier. When handling sensitive products—such as fine powders, hygroscopic materials, or food ingredients—a liner is essential to maintain product quality and safety.
Liners help prevent product leakage, protect against moisture ingress, and reduce odour transfer in both directions. They are especially important for products that are prone to absorbing moisture from the environment, or that could be contaminated by dust or other external agents. By using a liner, you extend the range of products that can be safely transported in FIBCs and reduce the risk of costly product loss or quality issues.
Types of Liners: Matching Design to Application
There are several common liner types, each designed to suit different applications and filling methods. Tubular liners are the most straightforward option, offering a simple, cost-effective solution for basic protection. These liners are essentially open-ended tubes that fit inside the FIBC and are suitable for many dry bulk products.
Form-fit liners are manufactured to match the precise internal dimensions of the FIBC, ensuring optimal space utilisation and making filling and discharge more efficient. Shaped liners, which may include gussets or custom contours, can further improve fit and performance. For specialised needs, options such as aluminium-laminated liners provide enhanced barrier properties, while antistatic liners are available for products that require static control during handling.
Material and Thickness: Balancing Protection and Efficiency
The choice of liner material and thickness directly affects its barrier properties and suitability for your application. Most FIBC liners are made from low-density polyethylene (LDPE) or linear low-density polyethylene (LLDPE), materials known for their flexibility and moisture resistance. Thickness typically ranges from 50 to 150 microns, with thicker liners offering greater strength and improved barrier performance.
For products with higher protection requirements—such as food, pharmaceuticals, or chemicals—multi-layer or co-extruded films can be used. These advanced liners combine different materials to provide superior resistance to moisture, oxygen, and other contaminants. Selecting the right material and thickness is a balance between ensuring adequate product protection and maintaining cost-effectiveness and ease of handling.
Installation Methods and FIBC Compatibility
How a liner is installed in the FIBC impacts its effectiveness and the ease of your filling and discharge processes. Liners can be loosely inserted for easy replacement, or they can be fixed in place by gluing or sewing to prevent shifting during handling. The choice of installation method depends on your product characteristics, filling equipment, and discharge requirements.
Proper installation ensures the liner stays in place throughout filling, transport, and emptying, minimising the risk of liner collapse or product loss. TRI offers a range of liner installation options and provides guidance to ensure compatibility with your existing equipment and processes. Our technical team can help you select the best liner and installation method for your specific needs.
Compliance, Quality, and Customisation
When selecting a liner, it is important to consider regulatory compliance and quality standards, especially for food, pharmaceutical, or hazardous products. Liners can be manufactured from food-grade materials or produced in cleanroom environments to meet stringent industry requirements.
Customisation is another key advantage of working with an experienced supplier like TRI. We can tailor liner dimensions, materials, and features to your product and process, ensuring optimal protection and operational efficiency. Whether you need printed liners for traceability or special closures for tamper evidence, TRI can deliver a solution that meets your specifications.
Key takeaways
- Liners provide essential protection against moisture, contamination, and odour in FIBCs.
- Tubular, form-fit, and specialty liners are available to match different product and process needs.
- Material choice and thickness impact barrier properties, strength, and cost.
- Correct liner installation is critical for maintaining product integrity during handling.
- Regulatory compliance and customisation options ensure liners meet your industry standards.
- TRI offers expert advice and a wide range of liner solutions tailored to your requirements.