Marjo Peeters of Owens Corning (Holland) reviewed the current uses of glass nonwovens. High performance glass fibre with diameters of 6.5 to 23 microns and lengths from 6 to 18mm were wet-laid in very large quantities and bonded with thermoset or thermoplastic resins. This nonwoven was used as a primary backing for tufted carpets where its dimensional stability, heat resistance and wet strength were second to none. Unfortunately, the cheap and effective thermoset bonding systems used for carpet backing out-gassed traces of formaldehyde and this was becoming unacceptable indoors.
Sustaina™ formaldehyde-free glass nonwovens had therefore been developed and these were now being commercialised:
- · Tensile strengths of Sustaina™ were better than the Urea-Formaldehyde bonded glass nonwovens (dry) and the same when wet.
- · Hot-dry strength retention was triple that of UF.
- · Sustaina™ was the only product with a USDA certified-biobased bonding system.
· It cost less than UF or competitive acrylic-based formaldehyde-free systems.
In response to questions, Ms Peeters could not reveal the chemistry used in Sustaina™ but said the USDA certificate was awarded because 49% of the organic component of the nonwoven was bio-based. The resin itself is inherently flame retardant.