There are several key indicators of strength. Edge Crush Test (ECT) measures the corrugated structure’s resistance to compression; compressive strength determines stacking height; and bursting strength measures puncture resistance. These metrics are directly related to the base paper’s grammage, flute type, and moisture content. Confirming these parameters with the manufacturer when ordering is far more reliable than simply looking at thickness.
When choosing, consider three factors: product weight, transport distance, and stacking height. For standard e-commerce boxes, choose C-flute single-wall or double-wall; for mailing boxes, opt for lightweight B-flute or E-flute; for heavy goods or long-distance exports, select reinforced double-wall structures. If unsure, ask the manufacturer to propose a solution based on your product—creating a prototype for testing is more intuitive than guessing parameters.
The number of layers is the second variable. Single-wall consists of two paper liners sandwiching one corrugated layer; it is lightweight and suitable for light goods. Double-wall features two corrugated layers, offering significantly higher strength—a common choice for heavy goods and long-distance transport. Triple-wall has three corrugated layers and is used for heavy-duty applications. Generally, the more layers, the sturdier the box, but the higher the cost.
Corrugated boxes are ubiquitous in e-commerce and logistics, yet most people simply refer to them as “cardboard boxes.” Terms like flute type, single/double-wall, and edge crush strength determine a box’s load-bearing capacity and how to select the right one. This article explains the basics of corrugated boxes so you can choose without guesswork.
Flute type is the first variable. A-flute has a high profile and excellent cushioning, making it suitable for fragile items. C-flute offers balanced performance and is the most common specification. B-flute is thinner with a flat surface and good compressive strength, making it ideal for printing. E-flute is even thinner, often used for small packages and boxes requiring high-quality printing. Select the flute type based on your product and shipping scenario.
First, consider the corrugated structure. Corrugated board is a sandwich structure consisting of an outer liner, a corrugated medium, and an inner liner; the middle corrugated layer is wave-shaped and provides cushioning and compression resistance. Structure determines strength; even among boxes of the same type, different flute profiles result in vastly different load-bearing capacities.
