How to Choose the Right Box Liner for Your Packaging Setup?

Whether you're packaging powders, produce, or palletized parts, box liners are a crucial yet often overlooked part of efficient packaging. A box liner not only separates your product from the corrugated box — it also protects against leaks, contamination, and moisture, making it essential for industries that deal with bulk goods. 

But not all box liners are the same. 

From liner formats to material thickness, the right choice depends on your product, filling process, and storage conditions. 

What Is a Box Liner? 

A box liner is a flexible LDPE bag placed inside a corrugated carton to create a protective barrier between the contents and the box. These are typically open-top layflat or gusseted bags, sized to fit the interior dimensions of the carton. 

Once inserted, the excess film folds over the box edges and is tucked, heat-sealed, or twist-tied before closing the carton.

Key Factors When Selecting a Box Liner

Product Type  

• Powders and granules may need thicker liners to avoid tearing or puncture. 

• Produce or ice may require FDA-grade material or a thicker gauge to prevent leaks. 

• Oily or greasy materials often call for a higher slip film for easier discharge.

Temperature Requirements

• Cold or frozen products need stronger films (e.g. 2 mil+) that remain flexible at low temps.

  
  

Filling Process

• Manual vs. automated filling impacts how the bag should be sized and whether gussets are needed for volume expansion.

Material Considerations

• Clear vs. tinted 

• Food-safe or anti-static 

• Virgin or reprocessed LDPE 

• Compostable or biodegradable options (upon request)

Key Factors When Selecting a Box Liner

At M Plastics Inc., we custom-manufacture box liners in a variety of formats: 

✅ Layflat open-top liners (most common for general use) 

✅ Side-gusseted liners (allow expansion for bulky or irregular loads) 

✅ Bottom-seal construction for strength and leak resistance 

We also offer perforated roll options and printed liners depending on your packing line requirements. 

Common Industries Using Box Liners 

🍏 Produce and Agriculture 

🧪 Chemical and Pharma 

🧊 Ice and Frozen Foods 

🛠️ Hardware and Industrial Parts 

🍞 Bakery and Grain Storage 

Box liners reduce product loss, improve cleanliness, and extend the lifespan of your boxes during transit and storage.

Final Thoughts: 

The right box liner can streamline your operations, reduce product damage, and ensure compliance with food or safety regulations. At M Plastics, we tailor each liner to your box size, product weight, and production flow — all made in-house from high-quality LDPE film. 

Get in touch today to explore custom box liner options for your workflow — and keep your products covered from the inside out.