01 Jun Multi-nozzle electrospinning machines
Electrospinning is a versatile and cost-effective process for the fabrication of nano or micro-scale fibrous structures. Until recently, electrospinning has been extensively studied within academia for a wide variety of applications, including regenerative medicine and tissue engineering scaffolds, controlled drug delivery devices, cosmetics, air filters and liquid separation membranes, composite reinforcement veils, battery and fuel cell membranes, and many more. However, due to perceived difficulties in scaling up the electrospinning process for many of these applications, the industrial uptake has mostly been limited to air filtration, which often has relatively low demands in terms of materials consistency and process control. This situation is now beginning to change, with the introduction of multi-nozzle electrospinning machines, which maintain the benefits of the needle-based electrospinning process whilst enabling industrially relevant volumes to be manufactured.
The needle-based electrospinning process has several advantages over other alternatives, free-surface electrospinning technique, also referred to as needle-less electrospinning. In particular, spinning from capillary needles, or nozzles, means that a wider variety of polymers can be processed in a well-controlled manner, including those that require volatile organic solvents, which during needle-less electrospinning undergo uncontrolled evaporation from free-surfaces leading to inconsistent fiber size and morphology over time. Additionally, needle-based electrospinning is more versatile in terms of the microstructures that can be created (fibers, particles, multi-component core-shell structures, etc) and the format of the products that can be fabricated (membranes, tubes, complex 3-D structures, etc). Therefore, for many applications there are numerous reasons to scale-up the needle-based electrospinning process by the development of multi-nozzle electrospinning machines.
Typically, electrospinning of polymer solutions using single-needle lab-scale electrospinning apparatus is capable of processing between 0.1 – 10ml/h of solution, depending on the properties of the solution. To achieve higher throughputs, arrays of individual needles can be configured within multi-nozzle spinning heads to create multiple spinning jets with the same level of process control as for single-needle electrospinning. Such multi-nozzle arrays must be carefully designed to minimize the affects of electrostatic interactions between neighboring needles and spinning jets and to ensure even distribution and flow of solution to each nozzle. In order to electrospin from multiple needles it is also necessary for multi-nozzle electrospinning machines to be capable of generating a stronger electrostatic field than is usually necessary for single-needle electrospinning. This is often achieved using both a positive HV power supply connected to the spinning head as well as a negative HV power supply connected to the collecting surface. When spinning from several multi-nozzle spinning heads, it may also be necessary to increase the power of the HV supplies from those used in smaller apparatus.
A common concern about the use of multi-nozzle electrospinning machines for manufacturing is that the spinning heads are complicated and time-consuming to assemble and needles can become blocked as a result of solvent evaporation from the Taylor cones. Although there is a potential for this to happen, through optimization of the solution formulation and considered design of the spinning head itself, these concerns can be largely alleviated. In fact, multi-nozzle electrospinning heads developed by Bioinicia, who supply premium-quality lab to industrial-scale electrospinning equipment, enable simple and quick assembly and replacement of individual needles and even the use of disposable, single-use needles with Luer lock adapters.
In addition to increasing the production rate for electrospun materials, the use of a multi-nozzle electrospinning machine also enables fibers to be deposited over a wider area with a more uniform deposition, which is important for many applications where product consistency is critical.
Bioinicia are specialists in the electrospinning and electrospraying processes (EHD) and world-leading providers of premium-quality, climate-controlled electrospinning and electrospraying equipment. Offering Contract Research and Development services and Contract Manufacturing of electrospun and electrosprayed materials under GMP certification means that we can assist you at any stage in your product development, including for pharmaceutical and medical applications.
Simply leverage our expertise in multi nozzle electrospinning machines and the electrospinning/electrospraying processes, from laboratory research to industrial manufacture, and advance the development of your future generation of products to the next level.
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