Pineapple leaf fiber-based nonwovens as sustainable thermal insulation liner for distribution packaging

Pineapple leaf fiber (PALF)-based nonwovens were developed as a bio-based thermal insulation liner in fresh produce packaging. Effects of key parameters-fiber composition and bonding methods- were systematically investigated in relation to their physical properties and thermal insulation performance. PALF was blended with low-melt polyester (LM) fibers at varying ratios (90/10, 80/20, and 70/30) and fabricated to PALF/LM nonwovens via two bonding methods: thermal bonding and needle punching. PALF/LM nonwovens exhibited thermal conductivities ranging from 0.035 to 0.052 W/m·K, confirming their suitability as insulation materials. Needle-punched nonwovens displayed more compact structure, resulting in slightly reduced air permeability (1584–2436 vs. 1948–2658 L·m⁻²·s⁻¹), and thermal insulation compared to the thermal-bonded nonwovens, but demonstrated superior mechanical strength and dimensional stability. Increasing LM fiber content slightly improved insulation performance. Among all samples, the 80/20 needle-punched PALF/LM nonwoven exhibited an optimal balance of thermal insulation, dimensional stability, compactness, and mechanical strength. When used as an insulation liner in a prototype box, it achieved an R-value of 0.275 m²·°C/W and maintained an internal temperature below 5°C for 25.1 h—comparable to commercial expanded polystyrene foam box (R = 0.335 m²·°C/W, 30.0 h) and significantly outperforming standard cardboard box (R = 0.154 m²·°C/W, 14.5 h). The prototype box exhibited increased volume utilization (78.38%) compared to that of foam box (50.70%), offering higher packing efficiency. This study demonstrates the potential of PALF/LM nonwoven liners as eco-friendly and high-performance alternative to conventional foam-based packaging for fresh produce.