NCIDQ IDFX Practice Exam

What characteristic of foam cushions is measured by the indentation load deflection (ILD)?

1. Durability

2. Density

3. Firmness

4. Support ratio

The correct answer is: Firmness

The indentation load deflection (ILD) is a critical measurement used to determine the firmness of foam cushions. This assessment involves applying a specific weight to a foam sample and measuring the amount of deflection (compression) that occurs. A higher ILD value indicates a firmer foam that provides more resistance to compression, while a lower ILD value reflects a softer foam that compresses more easily under weight. This characteristic is essential for selecting foam in various applications, particularly in furniture and bedding, as it directly influences comfort and support. Understanding ILD helps designers and consumers make informed choices based on desired comfort levels and ergonomic support needs. While other characteristics such as durability, density, and support ratio are essential in evaluating foam, they do not directly equate to the firmness measurement specifically defined by ILD.