Effect of heat-setting on the physical properties of chemically recycled polyester nonwoven fabrics

Chemically recycled polyester fibers consisting of a core and sheath layer were used to produce nonwoven fabrics for ecofriendly automotive interiors. The density and thermal shrinkage of the recycled polyester nonwoven fabrics were higher than in virgin polyester nonwoven fabrics, irrespective of the heat-setting temperature and time, but the air permeability was lower. The wicking property of the recycled polyester nonwoven fabrics decreased significantly above 180℃. The tensile stress and modulus of the recycled polyester nonwoven fabrics increased gradually with increasing heat-setting temperature. However, the strain at maximum stress of the recycled polyester nonwoven fabrics decreased rapidly. The abrasion strength of the recycled polyester nonwoven fabrics improved above a heat-setting temperature of 200℃. The impact strength of the recycled polyester nonwoven fabrics was higher than that of virgin polyester nonwoven fabrics. As the heat-setting temperatures used for the nonwoven fabrics were higher than the melting temperature of chemically recycled and virgin polyester fibers, thermal bonding occurred between fibers. The lightness of the recycled polyester nonwoven fabrics decreased with increased heat-setting temperature and time. The recycled polyester nonwoven fabrics also showed slight yellowing. The thermal bonding between the fibers in the recycled polyester nonwoven fabrics was generated at a lower heat-setting temperature than for virgin polyester nonwoven fabrics, and therefore it is considered that under more relaxed heat treatment conditions, the recycled polyester nonwoven fabrics would show a performance similar to that of the virgin ones.