Nanofibre nonwovens properties

The mechanical and attritional properties of nanofibre nonwovens are inherently low. This can result in issues during conversion into product, eg, a pleated filter, as the integrity of the nonwoven can be disrupted during manufacture. The in-use mechanical stresses and abrasion conditions should be carefully considered when designing a product. The nanofibres are commonly laid upon a relatively inexpensive nonwoven support layer, eg, a spunbond fabric. 

Compared with microfibres, nonwovens with nanofibres were developed in smart polymer textiles such as shape memory polymer nonwovens, PCM nonwovens and colour change nonwovens. SMP electrospun micro- and nanofibre nonwoven structures have unique properties including quicker response to the external stimuli, larger recovery stress, quicker recovery rate and enhanced functionalities such as antibacterial and water vapour permeability. 

Micro- or nanofibre coatings are applied to the nonwoven substrate surface to create special surface properties (e.g. filter/barrier). 

Nanoscale-fibre nonwovens are a relatively new technology commercially and still have relatively low market penetration compared to macroscale nonwovens. With all nanofibre processes, the mechanical and attritional properties of the nanolayer... 

In the past 10 years, electrospun nanofibrous membranes have been spotlighted as an effective filter media to capture fine particles. In addition to the basic studies of electrospinning process to better understand the membrane construction process, researchers from all over the world focus on the study of the relationships between the structure characteristics of electrospun nanofibrous membranes (fiber diameter, pore size, porosity, surface area, etc.) and filtration performances (filtration efficiency, pressure, air permeability, etc.). In this chapter, recent advances in fabricating nanofibrous filter media via electrospinning process have been reviewed. In particular, filtration performances and relevant mechanical properties are discussed in detail. It is interesting that the electrospun nanofibrous membranes have been able to outperform conventional nonwoven membranes fabricated essentially by using the meltblown or spunbonded process. 

Although a random deposition of electrospun fibres gives a nonwoven fibre sttucture, the web morphology varies depending on the polymer properties and the operating conditions. Usually, the nanofibres are accumulated by a simple physical interaction and the fibres do not bond with each other. However, when the electrospinning distance is very short, the solvent has insufficient... 

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