Mullen Burst Test Explained: Corrugated Board Puncture Strength

What Is the Mullen Burst Test?

The Mullen Burst Test measures the amount of pressure, in pounds per square inch (psi), required to puncture or rupture the face of corrugated board. A rubber diaphragm is inflated against the board surface until the material fails, and the peak pressure at failure is recorded as the burst strength. This test has been a long-standing industry standard for evaluating how well corrugated board resists forces that push outward against or into the box walls.

Mullen values are commonly printed on the Box Manufacturer’s Certificate (BMC) found on the bottom flap of corrugated boxes. Single-wall board typically carries Mullen ratings from 125 to 350 psi, while double-wall board can reach 400 psi or higher.

When to Specify Mullen-Rated Board

Mullen burst strength is most relevant when your packaging faces puncture risks during handling, transit, or storage. Products with sharp corners, heavy concentrated loads, or irregular shapes can exert outward pressure on box walls, making burst resistance a critical factor. Industries shipping hardware, automotive parts, or dense consumer goods often rely on Mullen-rated specifications.

For applications where warehouse stacking is the primary concern, the Edge Crush Test (ECT) may be a more appropriate metric. Many packaging buyers now use ECT-rated board for cost efficiency, but Mullen remains essential when puncture protection is the priority.

Understanding Mullen Ratings by Board Type

The Item 222 tariff classification historically defined minimum Mullen values for different board constructions. Single-wall 200# board, for instance, requires a minimum burst strength of 200 psi and supports a maximum box weight limit of 65 pounds. The 275# grade supports heavier loads up to 95 pounds. Double-wall constructions rated at 350# or 400# handle the most demanding industrial applications.

These ratings appear on the certificate stamp and help freight carriers, warehouse operators, and buyers verify that boxes meet the required performance thresholds. When you provide a spec sheet for your packaging needs, including the desired Mullen value ensures your boxes arrive with the correct burst resistance.

Mullen Testing at President Container Group

At President Container, our quality assurance processes include verifying Mullen burst values alongside other performance metrics like the Box Compression Test (BCT). We work with you during the prototyping phase to validate that your packaging meets all required strength standards before full production begins.

Our structural design team leverages CAD technology to optimize board selection, balancing burst strength with weight and cost. Combined with our sustainable sourcing practices and FSC/SFI certifications, you receive packaging that performs reliably and responsibly.