FIBCs (flexible intermediate bulk containers) are fantastic for transporting and storing large quantities of product safely and efficiently. They are commonly used in numerous industries including but not limited to agriculture, chemical, pharmaceutical, pet food, and metals & mining. In many of these industries, a bag is not enough and needs to be paired with a bag poly liner.

Bulk bags with poly liners are often used for food products and very fine powders. These poly liners are inserted into each bag and work with both duffle top and spout top bags. Often times, liners can also be made with attachment tabs which allow the liners to be sewed, tied or glued to the bag removing the chance of liner discharge. Below are four common types of bag liners:

• Lay-Flat Liners
• Form-Fit Liners
• Baffle Liners
• Aluminum Liners

Let’s examine the similarities and differences between these common types of bag liners and define features as well as common uses. Don’t forget to subscribe to our blog by filling out the “Subscribe to our blog” form to the right!

Lay-Flat Liners

Lay-flat polyethylene liners are the most common type of liners. They are cylindrical in shape, open at the top, and the bottom is often heat sealed. If the liner is heat sealed it must be cut to discharge the product. Lay-Flat liners can come already inserted in the bag or can be purchased by the roll. Some other features of Lay-Flat liners include: 

• Oxygen barrier
• Moisture barrier
• Chemical resistance
• Anti-static properties
• High strength

Form-Fit Liners

Form-fit bulk bag poly liners are specifically designed to take the exact form of the bag including the spout inlet and outlet. Form-fit poly liners improve the bags performance and protect the product packed from contamination during processing, storage, and transportation.

Form-fit liners also allow for a consistent fill and discharge of products because they do not have folds, pleats or other traps to slow down product flow. These liners can either be permanently attached to the bag or easily removed after each use. Some other features of form-fit liners include:

• Oxygen barrier
• Moisture barrier
• Chemical resistance
• Anti-static properties
• High strength

Baffle Liners

The form-fit baffle design can provide superior package performance and, at times, reduce storage and shipping costs. The baffle liner is form fitted to the outer container and makes use of internal baffles to maintain a square shape and prevent the outward push of the product being packed that would normally result in a rounded bag. The square shape of baffle poly liners can also help save space on pallets and in trucks. Some other features of baffle liners include:

• Increased bag stack-ability
• Increased stability
• Can hold up to 30% more product in a given space
• Protection from contamination
• Formed spouts for filling and discharge

Aluminum Foil Liners

Form shaped aluminum liners, also know as foil liners, improve filling, discharging, handling and stability of the outside of the bag. Foil liners offer great moisture, oxygen, and UV protection and are compatible with a wide variety of bags.

FIBC foil liners are made of aluminum-laminated films that protect the quality and the integrity of the product that is packed in the bag. Each foil liner can be manufactured using various aluminum compounds depending on the specific needs of each application. Some other features of foil liners include:

• Preventing product damage and/or contamination
• Available with top and/or bottom spouts for safe filling and discharge
• Protection against moisture and oxygen
• Can be manufactured using different materials to suit specific applications

Which liner is right For my application? 

This is a question that we hear quite often and the answer depends on what you’re packing in the bag. To learn more about bulk bag poly liners, check out our poly liners page by clicking here.

To determine what bag poly liner is right for your specific application, click here to fill out our contact form OR give us a call at 1-888-237-4224 to speak with one of our experts. Our specialists have over 20 years of industry experience and are ready to work with you to create a custom bag solution for your business. 

Thanks for reading!

Thanks for reading our post "A Quick Guide to FIBC Bulk Bag Liners"! We hope you found this post both helpful and informative. 

Finding the right bulk bag polyethylene liner for your product and application can be difficult. Not only is it important to determine the right type of liner of your product and application, it is imperative that you also determine the correct size of liner for the specific bag you are using.

To accurately determine what size polyethylene liner is right for the bag you are using or are interested in, download our FIBC Bulk Bag Liner Estimation Calculator by clicking the button below!