Interior box protection for food, industrial, and shipping.
Box liners are pre-formed polyethylene bags designed to fit inside corrugated boxes, providing a moisture barrier and contamination protection layer between the box and its contents. They are essential for food packaging, chemical products, pharmaceuticals, and any application where the product must not contact the corrugated material directly. Corrugated cardboard can transfer dust, fibers, odors, and moisture to unprotected products, which is unacceptable in food and clean-room environments.
Our box liners are sized to common corrugated box dimensions and are designed to fold over the top of the box before closing the flaps, creating a complete interior barrier on all six sides. The liner extends several inches above the box rim so there is adequate material to fold over, ensuring full coverage even when the box is packed to capacity. This overlap is critical — a liner that does not fold over the top leaves the contents exposed to dust and contamination from above.
Available in 1.5 mil for lightweight applications and 2-3 mil for heavier or moisture-sensitive products. The 1.5 mil gauge works well for lightweight dry goods, textiles, and products where the liner is primarily a dust barrier. The 2 mil gauge is the standard for food packaging and general industrial use. The 3 mil gauge is reserved for heavy products, sharp items, or applications where the liner must withstand significant stress during filling and handling.
FDA-grade box liners are available for food contact applications and are required for any food product packed directly into a corrugated box without individual product wrapping. This includes bulk baked goods, fresh produce, candy, snack foods, and any food item that is loaded loose into a lined box. The FDA-grade material meets 21 CFR 177.1520 requirements and is manufactured from 100% virgin LDPE resin.
Box liners also serve a practical function in operations that handle liquids, powders, or granular products. If a bag or container inside the box leaks, the liner contains the spill within the box rather than allowing it to damage other products, pallets, or warehouse floors. Chemical manufacturers and distributors routinely use poly box liners as a secondary containment measure for bottled and bagged products.
Request a free sample of our box liners to evaluate quality, thickness, and fit for your application.
8 standard sizes listed. Custom sizes manufactured to your exact specifications.
Don't see your size? Build custom packaging or request a quote for any dimension.
Flexible Poly Industries stocks box liners for the most common corrugated box sizes for nationwide shipping from our Los Angeles warehouse. Custom sizes are available for any box dimension — tell us your box measurements and we will manufacture liners to fit. We supply food processors, bakeries, manufacturers, and distributors across Southern California and nationwide.
Contact us at (626) 250-2030 for stock availability or custom box liner quotes.
FDA-grade poly liners create a food-safe barrier between edible products and the corrugated box material. Required for any food packed directly into a box without individual wrapping. Common applications include bulk bakery products, fresh produce, candy, snack foods, and deli items.
Barrier between chemical products and box material, providing secondary containment in case of leaks from bottles, bags, or containers inside the box. Chemical manufacturers and distributors use box liners as standard practice for hazardous and non-hazardous liquid and powder products.
Protects box contents from humidity, condensation, rain exposure during loading, and any moisture intrusion that could damage the products inside. Especially important for ocean freight, cold chain logistics, and shipments moving through humid climates where corrugated boxes absorb moisture.
Contamination barrier for sensitive products that must not come into contact with corrugated fibers, dust, or particulates. Medical device manufacturers, pharmaceutical companies, and electronics firms use poly box liners to maintain product cleanliness during storage and transit.
Same-day shipping on stock sizes from our LA warehouse. Rush production available.
Order as little as one case on stock sizes. Minimums vary by product. Contact us for details.
Any width, length, gauge, or gusset. We manufacture to your exact specifications.
Manufactured from virgin resin at our facility. Quality you can trust for every order.
Manufacturer-direct pricing with volume discounts. No middleman, no markup.
Up to 6-color flexographic printing. Add your logo, branding, and compliance text.
Measure the inside dimensions of your box: width, depth, and height. The liner should be slightly larger than the box interior (add 1-2 inches to width and depth) and tall enough to fold over the top flaps (add at least 4-6 inches to the height). This ensures the liner covers all interior surfaces and folds over for complete protection.
Yes. Our LDPE box liners are available in FDA-grade material that meets 21 CFR 177.1520 requirements for direct food contact. The FDA-grade liners are manufactured from 100% virgin resin. Specify food-grade when ordering, as standard industrial-grade liners may not meet food safety requirements.
Yes. If your box dimensions do not match our standard sizes, we manufacture box liners to fit any corrugated box. Provide us with the interior width, depth, and height of your box, and we will produce liners that fit properly with adequate overlap for folding. Custom sizes are available in all gauges and materials.
1.5 mil is suitable for lightweight dry goods and dust protection. 2 mil is the standard for food packaging and most industrial applications. 3 mil is recommended for heavy products, sharp items, chemical containment, or any application where the liner will experience significant stress during filling and handling.
Yes. Poly box liners provide an effective moisture barrier inside the corrugated box, protecting contents from humidity, condensation, and water intrusion. This is especially important for products shipping by ocean freight, through humid climates, or via cold chain logistics where temperature differentials cause condensation.
Yes. A properly fitted box liner acts as secondary containment. If a bottle, bag, or container inside the box leaks, the liner contains the spill within the box rather than allowing it to damage other products, pallets, or warehouse floors. Chemical and pharmaceutical companies commonly use box liners for this purpose.
Yes. We stock box liners sized for the most common corrugated box dimensions in our Los Angeles warehouse for nationwide shipping. Sizes range from small carton liners (15" x 9" x 24") to large box liners (36" x 24" x 48") in 1.5, 2, and 3 mil gauges. Contact us at (626) 250-2030 to check stock availability for your size.
We manufacture box liners to your exact specifications. Any size, gauge, material, or print.