What is nonwoven fabric?
Nonwovens, as the name implies, are fabric-like materials composed of fibers that are bound together without weaving or knitting. You’re likely familiar with these kinds of materials in the form of common consumer goods such as craft felt, but the COVID-19 pandemic has put another nonwoven material in the spotlight: meltblown synthetic fibers used in face mask filters.
The entangled structure of meltblown fibers makes them ideally suited to capture air droplets that are responsible for the spread of airborne diseases such as the coronavirus. As the need for protective equipment continues to grow, manufacturers are scrambling to scale up production while maintaining the high product quality needed to keep us safe. As a result, the price of raw materials used in the production of face masks has increased dramatically since the COVID-19 pandemic took hold.
Nonwoven fabric analysis
A critical aspect of meltblown fiber production is quality control, as maintaining consistent fiber diameter is essential for an effective product. Manufacturers need on-site QC that allows them to quickly and accurately analyze their samples without disrupting production.
Nonwoven fabric and fibers imaged with a scanning electron microscope.
Scanning electron microscopy (SEM) is an imaging technique that is ideal for analyzing nonwoven fibers. Nonconductive materials such as nonwovens can be notoriously difficult to image with an SEM due to the buildup of charge on the surface. This can be counteracted by using a lower vacuum inside the SEM chamber. As a result, nonwovens can be placed directly into the microscope and imaged without any sample preparation. With so many SEMs to choose from, it may be difficult for an industrial lab to pick the most suitable instrument for their particular needs. Fortunately, the versatility of a desktop SEM enables users to image a wide variety of materials, which is why we offer desktop SEMs tailored to specific applications.
Desktop SEM for nonwoven analysis
While most benchtop SEMs do not exceed the capabilities of larger, floor-models, they are often easier to use and can be readily integrated into any analytical lab. This is particularly beneficial to QC and other industrial labs where space and time are limited.
The Thermo Scientific Phenom Pro Desktop SEM is a high-resolution instrument that can generate nanometer-resolution images of nonwoven materials. The true power of the Phenom Pro SEM, however, comes from integrated Automated Image Mapping and Thermo Scientific Fibermetric Software. This software suite allows even novice users to semi-automatically measure the diameter distribution of thousands of fibers within a few minutes.
Meltblown filter material analysis performed automatically with the Phenom Pro Desktop SEM and Fibermetric Software.
The image above shows a customer’s analysis of a meltblown nonwoven material. The red circles indicate the distance across which the fiber diameter was measured by Fibermetric Software. A histogram of fiber diameter allowed the customer to easily verify that the fibers were in the expected range of 1-3 µm. As a result, the Phenom Pro Desktop SEM with Fibermetric Software helped the customer to dramatically decrease their time to data. Not only that, but the easy-to-use semi-automated data collection also means that anyone in the lab can obtain high quality, reliable results.
To learn more, please visit our Phenom Pro Desktop SEM product page.
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