Nano Fiber Double Spinning & Yarning System is known as one of the most efficient, convenient methods to produce fibers of a nanometric scale. These nanometric fibers reveal several remarkable characteristics such as a large surface area to the volume ratio, high porosity, flexibility in surface functionality, and superior mechanical performance. Nanofibers are utilized in a wide variety of applications such as filtration and multifunctional membranes, medical usages, and military systems due to their outstanding properties.
Holmarc's Nano Fiber Double Spinning & Yarning System comprises of a bipolar high voltage supply and a set of collectors for different applications. The instrument also equips with a unique rotary collector through which user will be able to spin the fiber into threads and collect it in spools. The diameter of the fiber depends on various parameters but mainly flow rate. In order to make fiber in to yarn, two syringe pumps, one with positively charged spinneret and the other with negatively charged spinneret, are targeted to a funnel shaped collector from where fiber yarns are formed and rolled into spool.
The equipment is controlled by a software compatible with Windows OS. The parameters like solution flow rate, rotating speed of the funnel or mandrel collector, duration of electrospinning, horizontal and vertical speeds of the spool etc can be controller using this software.
I. High Voltage Power Supply
HOLMARC HO-NFES-SYS comes with HMPSKV30 model high voltage power supply. Output voltage and current can be set using front panel knobs and readout from the digital panel meters.
1. -15kV to +15kV Dual HV powersupply, 0.5mA max Current
2. Digital Voltmeter and Current meter
3. Static Removal Device - Shorting Stick
4. Constant current / Constant Voltage mode of operation
5. Built-in ARC & Short Circuit Protection
II. Independently Controlled Dual Channel Syringe Pump
HOLMARC’S HO-SPLF4 model syringe pump provides independent control of two dual channel syringe pumps. The speed and flow rate can be changed on both to achieve custom fabrications of fibers.
The Syringe pump also can be moved to and fro in X axis. The maximum travel distance is 200mm. The movement is controlled via PC.
It can operate with standard off-the-shelf syringes made of plastic, glass or stainless steel. The microprocessor based control circuit can render a flow rate of 0.4 µl/hr to 650 ml/hr (with 5ml Syringe). The syringe diameter, spin duration or the target volume can be set by the user through the ElectroSpinner software interface.
1. To dispense from standard disposable or glass syringes from 2.5 to 60ml
2. Syringe holder made of insulating material to work under high voltage conditions
3. Motor control through microcontroller to control and indicate flow rate
4. Four syringe dispensing system
5. PC based control with documentation of parameters like syringe diameter, flow rate, spray duration etc.
6. Manual height adjustment platform to vary the pump height according to the target height.
III. Metal Funnel Collector
Metal funnel collector is a funnel shaped rotating mandrel where fiber yarns are formed and rolled into spool. A thin film web of nanofiber is first formed on a metal funnel collector and is drawn initially to a 3D cone shape. With the rotation of funnel collector, a twisted nanofiber yarn is drawn from the vertex of the cone.
1. Rotating speed : 300 to 4000 rpm
2. Material : Aluminium
3. Diameter : 100mm
IV. Yarn Spool
Yarn Spool is compact and modular motorized positioner for rolling the nanofiber yarn into spool. Stepper motor is used as electrical actuator. Yarn Spool is XY axis configurable.
1. Material : Acetal resin
2. Rotating speed : 1 to 100 rpm
3. Linear reciprocating movement : 50 mm
V. Rotating Mandrel
Rotating mandrels which comes with the electrospinning unit can be used as a target to get an aligned continuous mesh of nanofiber. It has a speed range of 300rpm to 4000rpm suitable for electrospinning. Grounding of the mandrel to the HV power supply is attained through a carbon brush contact. The rotating mandrel has a speed stability of +/- 1%. Holmarc’s HO-RM-01 is a high speed rotating mandrel assembly which works with Holmarc HO-MN series mandrels of 2mm to 100mm diameter and is of 200mm length. No. of mandrels supplied are 100mm, 75mm, 50mm, 25mm, 15mm, 12mm, 6mm, 4mm, 2mm.
1. Stainless steel drums of different sizes
2. Rotational Speed : 300 - 4000 rpm
3. Grounding facility : Available
4. Actuator : Microprocessor controlled BLDCmotor with hall sensor feedback
5. Speed stability : +/- 1%
6. PC based control with documentation of speed and duration
VI. Y Plate Collector & Stationary Target
This collector can be used as Stationary target or as Y plate collector. The stationary target which acts as a collector of electro spun nanofibers, is made of stainless steel plate such that it can be held vertically on a table top. It also has connector for grounding.
Using a stationary target alone cannot attain a uniform density of fibers, as most of the fiber is collected around the point orthogonal to the syringe needle. Combined with X movement provided on the syringe pump, the Y translation stage on the target keeps the target move through a commanded motion profile. Depending on the motion profile, fibers get collected uniformly on the target. The motion profile can be created using a series of commands available in the software.
1. Plate Dimension 250 x 175 x 3mm
2. Plate Material : Stainless Steel
3. Grounding Facility : Available
4. Programmable Y motion profile to control the nano fiber deposition characteristics
5. PC based motion control with documentation of parameters like speed, traverse, motion profile and duration
The Flat tipped metal needles are provided for the easy flow of the nano fibers. The high voltage is connected to the tip of the needle using metal clips.
VIII. Fume Hood
HOLMARC’s HO-FH-03 model fume hood provides an enclosed atmosphere for electrospinning. An enclosed chamber is necessary to protect the user from pollutant air caused by solvent evaporation during the process. It comes with an exhaust fan attached or optionally with a duct of custom dimension so that it can be connected to an exhaust duct available onsite.
HOLMARC’s Fume Hood also has an option for in-built heater capable to provide a temperature up to 45°C. An independent PID controller ensures precise control of temperature. A common electronic control unit for all the devices in the electrospinning system is integrated within the hood.
The fume Hood has transparent side walls and front door shield made of float glass. This ensures good visibility of the process. High intensity light from the optional halogen lamp illuminates the nanofibers being spun on its way to the target. The table top is made of granite which makes the cleaning process easy.
1. Standalone unit with in-built power supply and wiring for the heater, lighting and exhaust
2. Transparent glass windows on three sides for easily monitoring the electrospinning process
3. Foot print: 1000mm x 800mm x 1672 mm
4. Construction Material: Stainless Steel, Aluminium & Glass
5. Epoxy coated for electrical insulation
6. Ambient to 40°C temperature control
7. Exhaust fan ventilation at the top of the hood which can be connected to an exhaust outlet available at the customer facility.
a. Normal Glass Syringe
b. Teflon Tube
c. Spare Needle
X. UV Curing Lamp (Optional)
A special 10W 254nm UV light can be added on top of the rotating collector drum which helps to cure the spun fibers.
It can be switched on during the operation or when fiber spun is completed on the collector drum.
As the UV light is harmful for our skin and eye, the glass surfaces of the chamber is protected with special coatings to reflect maximum UV.
The controller is also provided with an ON/OFF Switch for the UV Lamp.