A new prototype melt-electrospinning device for the production of biobased thermoplastic sub-microfibers and nanofibers

Abstract

Sub-microfibers and nanofibers have a high surface-to-volume ratio, which makes them suitable for diverse applications including environmental remediation and filtration, energy production and storage, electronic and optical sensors, tissue engineering, and drug delivery. However, the use of such materials is limited by the low throughput of established manufacturing technologies. This short report provides an overview of current production methods for sub-microfibers and nanofibers and then introduces a new melt-electrospinning prototype based on a spinneret with 600 nozzles, thereby providing an important step towards larger-scale production. The prototype features an innovative collector that achieves the optimal spreading of the fiber due to its uneven surface, as well as a polymer inlet that ensures even polymer distribution to all nozzles. We prepared a first generation of biobased fibers with diameters ranging from 1.000 to 7.000 μm using polylactic acid and 6% ( w /w) sodium stearate, but finer fibers could be produced in the future by optimizing the prototype and the composition of the raw materials. Melt electrospinning using the new prototype is a promising method for the production of high-quality sub-microfibers and nanofibers.

The effect of additives and process parameters on the pilot-scale manufacturing of polylactic acid sub-microfibers by melt electrospinning

“…To scale up the melt electrospinning process beyond current state-of-the-art technologies, we used a newly developed prototype pilot-scale setup including a spinneret with 600 nozzles, each 0.3 mm in diameter and spaced at 8 mm intervals. 27 The new device development is based on the concept idea of Christoph Hacker et al., 46,47 whereby a nozzle revision to reduce dwell times, a more efficient heating system, and a new collector design and fiber deposition concept were integrated. 27 A schematic of our pilot-scale melt-electrospinning device is shown in Figure 2.…”

“…27 The new device development is based on the concept idea of Christoph Hacker et al., 46,47 whereby a nozzle revision to reduce dwell times, a more efficient heating system, and a new collector design and fiber deposition concept were integrated. 27 A schematic of our pilot-scale melt-electrospinning device is shown in Figure 2. A constant supply of polymer melt was ensured by a speed-adjustable single-screw extruder with three heating zones based on integrated heating elements and a spinning pump.…”

“…23,24 Until recently, the largest multi-needle configuration was a device with 64 nozzles, 25 but our latest prototype features 600 nozzles and therefore provides the basis for pilot-scale melt electrospinning. 26,27…”

Melt Electrospinning of Nanofibers from Medical‐Grade Poly(ε‐Caprolactone) with a Modified Nozzle

“…Increasing the number of nozzles could increase this output, used in other MES scale‐up studies where 600 nozzles were used. [ 29 ] The current manual assembly of introducing acupuncture needles in the nozzles is not compatible for such scale‐up approaches, however the principles of physically injecting charge at the site of the nozzle could be achieved using similar “sharp‐point” strategies. [ 30 ] While sharp edges in electrohydrodynamic have been adopted especially for SES scale up, [ 22,31 ] the acupuncture needle approach adopted here both introduces a sharp point and limits the fluid flow through the nozzle.…”

Electron-Beam Irradiation of the PLLA/CMS/β-TCP Composite Nanofibers Obtained by Electrospinning

“…Among them, electrospinning has become the most popular technique because of its economic properties, easy-to-control parameters, and versatility for producing nanofibers [15][16][17]. Either polymeric melt or the polymeric solution can be used in the electrospinning technique [18,19]. In early studies, a single polymer was used to produce nanofibers [20].…”