Nonwoven Fiber Research and Fracture Analysis

Fiber Imaging and Analysis at DSM for Materials Research

"The Phenom is located centrally in the R&D area of DSM, where it is available for all divisions...used for several projects in multiple fields. This has proven to be very successful..."

Excellence in creating innovative products and solutions for customers in Life Sciences and Material Sciences is the key to the success of DSM. One of the key competence centers in R&D at DSM is DSM Ahead, located in Geleen, The Netherlands. The research center supports most of DSM’s business entities, including Engineering Plastics, Dyneema, Resins and Nutritional Products.

Dr Chiche with a Phenom SEM at DSM
Dr. Arnaud Chiche with the Phenom SEM at DSM Ahead

DSM Ahead offers a wide range of expertise, from chemistry to process technology to material sciences and properties. It also closely collaborates with neighboring departments of complementary expertise, such as Colloids & Interfaces and Analytics. 

The Challenge 

One of DSM Ahead’s research topics is nonwovens for filtration. Electrospinning is used to create specific polymer fibers down to below 100 nm in diameter. Fiber size and distribution are key factors for filtration performance, and are best measured using scanning electron microscopy (SEM). DSM has a central microscopy lab where people can bring their samples for high-end imaging and analysis.

The decision was made to purchase a desktop SEM to increase the number of samples screened and allow in-line characterization during processing runs. This speeds up the project work and increases the availability of the high-end SEM at the analytical center for more detailed investigations requiring higher resolution and more advanced sample preparation.

For polyamide nanofibers made by electrospinning for filtration applications, DSM Ahead needed a method to accurately measure fiber diameter using statistically significant data. The process also needed to control morphology, for example round, flat or branched. The Phenom SEM was the answer to this challenge.

Polyamide fibers made by electrospinning from DSM Ahead
SEM image of electrospun polyamide nanofibers

Why the Phenom SEM

There is no dedicated operator of the desktop SEM, which had to be accessible and easy to use by everyone, without extensive training or SEM expertise. The Phenom desktop SEM best fitted this profile. The Phenom is located centrally in the R&D area of DSM, where it is available for all divisions.

The Phenom was bought initially to support the nanofibers project, but today is used for several projects in multiple fields. This has proven to be very successful and the number of users has grown to over 30. Among the users are not only technicians but also project leaders and interns.

SEM image of UHMWPE fibers showing damage
SEM image of UHMWPE showing location of damage and screening for presence of debris 

The Solution

With the growing number of users, the different applications for which the Phenom is used are also growing. Some examples besides nanofibers are:

  • Imaging of drug delivery systems after in vivo studies
  • Reactor powder morphology
  • Abrasion and scratch tests – including level of debris – on coatings, resin and glass
  • Process and application impacts on the morphology of Dyneema yarns and tapes
  • Filler distribution in composite materials
  • Post-mortem fracture analysis to understand the mechanisms involved

Every month DSM organizes a lunchtime meeting where Phenom users can share their experience and discuss issues and results with microscopy experts from the analytical department. Topics discussed include how to handle specific samples or how to gather the best information. In this way participants improve and raise their skills to a higher level.