What’s a Flat Crush Test?
Industrial Packaging is always looking for ways to ensure our materials are up to the task. Enter the Flat Crush Test – an important testing system we use to assess the strength and structural integrity of cardboard and other corrugated materials.
Imagine pressing down on a cardboard tube until it starts to give way. That’s essentially what we’re doing with the Flat Crush Test. We measure how well materials resist compression forces that are applied perpendicular to their surface. This test is particularly important for cores – the cylindrical structures made of paperboard that form the backbone of many packaging solutions.
Why Crush Testing Matters
You might wonder why we’re so keen on putting our materials through such a demanding test. Well, there are several good reasons:
- It ensures our packaging can withstand the pressures of storage and shipping.
- We can verify that our materials meet required strength standards.
- It helps us detect any weaknesses before they become real-world problems.
- It’s a key part of our quality control, ensuring consistent performance across all our materials.
A Brief History of Crush Testing
While we use modern, high-tech equipment today, the concept of testing material strength isn’t new. The Industrial Revolution in the 1800s sparked a keen interest in material testing among engineers. However, the Flat Crush Test as we know it today came into its own in the early 20th century. As cardboard boxes began to replace wooden crates for shipping, the need for standardised strength testing became apparent. While an exact invention date for the Flat Crush Test is unknown, it emerged to become one of the popular standardised testing protocols alongside other tests such as the Edge Crush Test and the Ring Crush Test, which all help to evaluate the structural characteristics of corrugated materials
How We Perform the Flat Crush Test
Our testing process is precise and methodical:
- We start by preparing a sample, cutting it to a specific length (100 mm for cores with a diameter ≤ 300 mm).
- The sample is conditioned under controlled temperature and humidity.
- We place the sample between two parallel flat plates in our compression testing machine.
- A compressive force is applied at a constant rate (typically 50-65 mm/min).
- We record the force required to cause the first signs of flattening.
- Finally, we calculate the flat crush resistance in kilonewtons per metre (kN/m).
What the Results Tell Us
The outcome of the Flat Crush Test gives us valuable insights into our materials’ performance. If a sample meets or exceeds the specified requirements, we know it’s suitable for its intended use, whether that’s packaging, transportation, or structural support.
If a sample doesn’t meet the mark, we take action. First-up, we launch a thorough investigation, reviewing everything from our production process to material quality. Our goal is always to identify the root cause and implement improvements. When we address the issue that caused the test fail, we integrate any learnings into our production process. Finally, we re-test thoroughly to ensure the necessary performance is consistently achieved.
For us, the Flat Crush Test is more than just a quality check – it’s a commitment to excellence. By ensuring our materials can stand up to specified levels of pressure, we’re making sure your products are protected, from your facility through to your customers’ hands.
So, the next time you receive a package in perfect condition, you’ll know that somewhere along the line, a piece of cardboard bravely withstood the Flat Crush Test – and came out on top!