Box Compression Test (BCT) Factor: The Key to Safe and Durable Packaging

The Box Compression Test (BCT) factor is a useful metric in the packaging industry, used to determine the strength and durability of corrugated cardboard boxes. BCT evaluates how much pressure a box can withstand before deforming or collapsing, which is essential for ensuring that the packaging will protect your products during transportation. Let's take a closer look at what the BCT factor is, why it's important, and how it affects the strength of boxes.

What is the BCT factor?

The BCT factor refers to the weight that a packed corrugated cardboard box can withstand when pressure is applied to its top surface until it crushes. The BCT value results from several factors, including the box design, the type of corrugated cardboard used, and the quality of the material.

Factors affecting the BCT factor:

1. **Material quality**: The strength of the cardboard and the quality of the corrugated material directly affect the BCT. Higher quality materials typically offer better compression resistance.
2. **Box design**: The structure of the box, including its dimensions and flap arrangement, plays a significant role. For example, double-walled boxes have a higher BCT value compared to single-walled boxes.
3. **Corrugation type**: The type of corrugation in the cardboard (e.g., B-flute, C-flute, EB-flute, BC-flute) affects compression strength. Different flutes offer varying degrees of stiffness and cushioning.
4. **Environmental conditions**: Humidity and temperature can influence BCT. Boxes exposed to high levels of moisture may have reduced compression strength.

How to calculate the BCT factor?

Determining the strength of corrugated cardboard packaging is not straightforward. Basic parameters such as the box's perimeter, the thickness of the cardboard, and the ECT (Edge Crush Test) of the cardboard allow for the calculation of the optimal cardboard for the packaging construction using the formula:

BCT = 5.87*square root( (perimeter*cardboard thickness)*ECT

where:

- **BCT** - box strength [kg]
- **perimeter** - box perimeter (2 \times length + 2 \times width) [m]
- **cardboard thickness** - thickness of the corrugated cardboard [mm]
- **ECT** - cardboard strength [kN/m]

It should be noted that the result is indicative, and factors such as air humidity (a 10% increase reduces ECT by up to 50%), the distance to the destination, storage time, whether pallets are stacked, if the goods inside are wet and if they "breathe" (e.g., fresh food products) all impact the packaging's strength.

Generally, it is accepted to multiply the result by 0.60 to ensure that the selected fill and composition of the corrugated cardboard from which the packaging is made are sufficient.

Optimization and innovation in packaging strength

Every packaging can be reinforced using solid cardboard angle boards by gluing them to the inside corners of the packaging. Ordinary angle boards can double the BCT value, meaning that by using such an angle board in packaging placed on the lower layers of a pallet, we can easily stack boxes higher on the pallet or stack pallets in the warehouse, saving space.

Of course, each approach is individual and requires the right strategy. Packaging engineering leads to making smart purchasing decisions and savings. Sometimes a small expense, such as using slightly stronger cardboard, leads to savings in logistics (storage and transport), saving time and money in the event of complaints.

Summary

Focusing on the BCT factor is crucial for us to produce packaging that meets high standards of durability and reliability. Understanding the factors affecting BCT and implementing best practices for its optimization allows CartonBox to ensure that their boxes offer excellent protection, maintain integrity during transportation, and provide cost-effective solutions for customers.