The pile yarn recovery behavior is a key parameter that can significantly influence the durability, appearance retention, and mechanical performance of machine-made carpets. Conventional evaluation methods are primarily based on measuring thickness loss and pile recovery, and they are not capable of directly measuring the pile yarn recovery force.

In the present study, a lever-based testing device was designed and fabricated to directly measure the time-dependent recovery force of the pile yarn in machine-made carpets. Experimental validation was conducted on a machine-made carpet with acrylic pile yarn under different compressive loads. The results obtained from the developed device revealed a direct and nearly linear correlation between the applied compressive load (within the range corresponding to human foot pressure) and the pile recovery force. Specifically, as the compressive force increased, the pile recovery force increased proportionally.

The ratio of the recovery force to the applied compressive force was defined as the Pile Recovery Force Index (PRF). The PRF remained approximately 7% throughout the entire loading range, indicating a proportional elastic response of the carpet pile and confirming both the mechanical reliability and sensitivity of the developed device.

Another important outcome of this study was the validation and estimation of the carpet pile recovery force using the proposed device. The results demonstrated that an increase in pile recovery force was accompanied by a decrease in carpet thickness loss (TL%). Therefore, the developed device can serve as a practical tool for evaluating the instantaneous resilience of carpets under foot traffic as well as for quality control of machine-made floor coverings in laboratory and industrial applications.