Green and sustainable kapok fibre as novel core materials for vacuum insulations panels

Vacuum insulation panel (VIP) is a new type of thermal insulation material with ultra-low thermal conductivity. Most of the VIP core materials are petroleum based, which helps achieve good thermal insulation performance and long service life. However, high cost and poor sustainability are not conducive to the long-term development of this industry. In this study, a new strategy is developed to prepare VIP core materials by using light, ecofriendly, and renewable kapok fibres. The results show that the wet forming process of the kapok fibre core material can maintain their hollow structure of the fibre and the porosity of VIP core could reach above 94%. The prepared kapok fibre VIPs have excellent thermal insulation performance and the thermal conductivity was as lower as 6.12 mW/(m center dot K) at an internal pressure of 0.05 Pa. Furthermore, these VIPs have outstanding stable thermal performance, and thermal conductivity increased only by 9-13% when the ambient temperature increased from 15 to 55 degrees C. The VIP density is lower than 105 kg/m(3) due to the special thin-walled and large cavity structure of kapok fibres. It was confirmed that kapok fibres are a potential alternative to fume silica for super novel VIPs that are green, renewable, and eco-friendly with sustainable performance.

Automated summary

A new strategy was developed to prepare vacuum insulation panel (VIP) core materials using light, ecofriendly, and renewable kapok fibres. The kapok fibre VIPs showed excellent thermal insulation performance, with a thermal conductivity as low as 6.12 mW/(m center dot K) at an internal pressure of 0.05 Pa. These VIPs also demonstrated outstanding thermal performance stability, with only a 9-13% increase in thermal conductivity when the ambient temperature increased from 15 to 55 degrees C. The low density of the VIPs, below 105 kg/m(3), was attributed to the special thin-walled and large cavity structure of kapok fibres. Therefore, kapok fibres are a potential alternative to fume silica for sustainable, green, renewable, and eco-friendly VIPs.