Cold-Pressed Insulation Boards from Recycled Cotton Fibers Using a Water-Borne PVAc-Starch Binder: Processing,...

Area of Science:

• Materials Science
• Sustainable Engineering
• Circular Economy

Background:

• Textile waste poses significant environmental challenges.
• Recycled materials offer potential for sustainable product development.
• Development of formaldehyde-free binders is crucial for greener manufacturing.

Purpose of the Study:

• To valorize post-consumer and post-industrial recycled cotton fibers into insulation composites.
• To investigate the use of a water-borne polyvinyl acetate (PVAc) and modified cornstarch hybrid binder.
• To evaluate the effect of density on the microstructure and properties of the insulation boards.

Main Methods:

• Low-temperature cold-pressing process for composite fabrication.
• Systematic adjustment of recycled cotton fiber and binder weight fractions to control density (300–340 kg·m^-3).
• Microstructural analysis, thermal conductivity, compressive strength, internal bond strength, and water absorption testing.

Main Results:

• Achieved low thermal conductivity (0.0710–0.0739 W·m^-1·K^-1).
• Compressive strength ranged from 46–162 kPa, and internal bond strength from 2–6 kPa.
• Increasing density reduced water absorption by ~18% and improved binder distribution.

Conclusions:

• Recycled cotton fibers are a viable feedstock for high-performance insulation composites.
• The PVAc-starch binder system enables formaldehyde-free, low-temperature processing.
• This method supports circular economy principles by valorizing textile waste into sustainable building materials.