MD-ESP

NANOStruc 2014

International Conference on Structural Nano Composites,20-21 May 2014 in Madrid, Spain

（Email:15001276730@163.com）

Advances in Polymer Melt

Differential Electrospinning

Yinglan Laboratory

Beijing University of Chemical Technology

李好义（Haoyi Li）

2

MD-ESP

1. Research Background

2. Electrospinning

3. New Solution: Melt Differential Electrospinning

4. Recent Results in Pilot Line

5. Applications and Future Prospects

Content

MD-ESP Polymer Nanofiber

comparison between electrospun

fibers and traditional fibers. selectrospun fabirc-oriented . electrospun fabric-

nonwoven.

MD-ESP Applications of Polymer Nanofiber

Air Filtration Water Treatment Lithium Battery

Membrane

Nonwoven with

Special Functionalities Tissue Engineering Catalyst Loading Material

MD-ESP Electrospinning and Nanofiber

Comparison on Existing Preparation

Technology of Polymer Nanofibers

MD-ESP

1 Solvent-free, environmental-friendly, simple.

Polymers such as PP, PE, PPS which can not

find solvent at room temperature is spinnable .

2 No evaporation of solvent, 100% conversion

rate. Productivity of MESP is one order of

magnitude higher than that of SESP at the

same condition.

3 No defects are left because of the evaporation

of solvents, fiber surface is smooth and exhibit

higher mechanical strength.

Comparison between MESP and SESP

Melt Electrospinning Solution Electrospinning

7

MD-ESP

1. Research Background

2. Electrospinning

3. Melt Differential Electrospinning

4. Recent Results in Pilot Line

5. Application and Future Prospects

Report content

MD-ESP

Basic Principle of

Electrspinning

Introduction into Electrospinning

Polymer

Solution/Melt Polarization

of Molecular

Chains

Overcome

Surface

Tension

Solvent

Evaporatin

g, Melt

Solidifying

High-

Voltage

Electric

Field

Collected

Indirectly or

by Electrode

Common View in Academia：

the road to industrialized

production of nanofibers:

electrospinning

MD-ESP Popularity of Electrosinning

2 4 3 3 17 6 12 13 24 28 3289277 320

492770969

14301769

2431

28503041

0

500

1000

1500

2000

2500

3000

35002002

2003

2004

2005

2006

2007

2008

2009

2010

2011

2012

熔体静电纺丝文献数量

溶液静电纺丝文献数量

1

6758

6 51118 17

32

0

15

30

45

60

75

2004

2005

2006

2007

2008

2009

2010

2011

2012

Image on the left is based on SciFinder, showing the number of published papers (until 2012), image on the right is based on Dingxianghua Foundation Searching Platform, showing the number of NSFC programs (until 2012).

The number of published papers on solution electrospinning is

100 times that on melt electrospinning.

number of papers on melt

electrospinning

number of papers on solution

electrospinning

MD-ESP Progress in Solution Electrospinning

Multi-needle Needleless

Participators: DuPont's facility in South Korea; NFTC - Nanofibre Future Technologies Corporation; NanoStatics Corporation & Texas Tech University; Donalson CO; KX Industries; Hills Inc; Rieter; Fanacaran nano-meghyas, Iran; Xiaohong Qin Team, Donghua University; Haoqing Hou team, Jiangxi Xiancai Nanofiber Technology Ltd.

Participator: Czech Elmarco (100 sold out, sales volume billion)

Low productivity

Easy to be blocked

Hard to maintain

No Blockage

Discontinuous solution supply

Limited mechanical strength

of nonwoven

MD-ESP Progress in Melt Electrospinning

In 1981, Larrondo and Manley firstly fabricate PP, PE nanofibers with hundreds of microns in diameter using melt elecrospinning.

In 2001, Reneker and Rangkupan reported the melt electrospinning of PP, PE, PET and PEN in a container in their review.

A large part of research is based on electrospinning device with a single needle as its nozzle.

Syringe-type Electrospinning Device：

Needle Based Melt Electrospinning Device Multi-needle Based Melt Electrospinning Device Manufactured by ITAAachen in Germany

12

MD-ESP

Naoki Shimada et al put a polymer sheet under the adjusted laser beam and melt the polymer sheet along its length, then several Taylor cons will be formed along a single line with interjet distance of 4-6 mm. But this method still faces the issues of high cost and low production and its safety has to be assessed, so mass production of nanofibers by this method still doom.

Schematic of slit-type electrospinning device, Analysis on electric field distribution, Flying jets in experiment

Czech Republic University proposed an idea of cleft-type electrospinning device, melt didn't distributed uniformly along the cleft. Furthermore, the number of Taylor cones were not enough to be applied into mass production.

Needleless electrospinning device：

Progress in melt electrospinning

13

MD-ESP

When free surface electrospinning method was applied to melt electrospinning, problems such as high threshod voltage, easy degradability of melt, poor continuous production are emerging.

NEEDLE or Capillary to

NEEDLELESSS NOZZLE

Method

MD-ESP

High dielectric properties

of polymer melts；

High viscosity；

Safety issues associated

with high voltage；

Hard to control micro-flow rate precisely during mass production

Solution Electrospinning

0.8-4Pa.s 40-200Pa.s

10-6-10-2S/cm

10-11-10-13S/cm

Less than 20kv,

40-100kv,

0.1-1g/h*needle

0.01-10g/h*needle

Technical Difficulties in Melt Electrospinning

Melt Electrospinning

MD-ESP

Realize the mass-production of polymer superfine fibers

16

MD-ESP

1. Research Background

2. Electrospinning

3. New solution: Melt Differential Electrospinning

4. Recent Results in Pilot Line

5. Application and Future Prospects

Report Content

MD-ESP

Miniature extruder

Schematic of Melt Differential Electrospinning

Melt Differential Electrospinning

TPU

Connical surface of nozzle

multiple taylor cones

collector

MD-ESP Designing

Split-flow and Multi-flow of Melt Differential Technique (The Idea of Calculus)

Solution: Peculiar Structure of Spinning Die Head Assembly

First Split-flow on the runner of Injection Moulding Machine

Second Split-flow on Inner Connical Surface

of the Nozzle

Hot air has a Thinning Effect on the Melt

+ Assisted by Hot Air

Smallest Inter-jet Distance Can Reach 1.1 mm

MD-ESP

High voltage is applied to nozzle, which makes heating of polymer melts complicated and restricts the research on industrialization.

Japan academic magzine Molding Processing highlights the importance of electrode inversion in their overview on electrospinning.

Designing

MD-ESP

PP Processing Using MD-ESP

Experimental Prototype of MD-ESP

Designing

MD-ESP Experimental

Inter-jet distance --productivity

MD-ESP Experimental

Interpjet distance --productivity

Li H, Chen H, Zhong X, et al. Journal of Applied Polymer Science, 2014, 131(15).

MD-ESP Experimental

Hot air assistance--finner fiber

Without hot air: 5.6 μm

Hot air assisted: 1.4μm Hot air assisted: 2.4μm

MD-ESP Experimental

Hyperbranched polyester as viscosity-reducing modifiers：

Absence of hyperbranched resin PP 5-6μm

Presence of hyperbranched resin PP 1-2μm

MD-ESP Experimental

Stearic acid viscosity-reducing modifiers：

Presence of 8% Stearic acid PP 1.65μm

Zhiyuan C, He J, Fengwen Z, et al Journal of

the Serbian Chemical Society, 2013 (00): 150-

150.

26

MD-ESP

1. Research Background

2. Electrospinning

3. New solution: Melt Differential Electrospinning

4. Results in Pilot Line

5. Application and Future Prospects

Report Content

MD-ESP

Basic Features: 32 Melt-differential Nozzles are integrated; Breadth: 0.8 m, output：300- 600g/h; Average Fiber Diameter: 500-800nm; Nonwoven Thickness: 10-1000μm (controllable)

Operating Speed: 1-10 m/min; Continuous Supply of the Melt; Electrospinning of Polymer blending; Modularly extendable

Pilot Prototype of MD-ESP

MD-ESP Pilot Prototype of MD-ESP in Operation

MD-ESP

Pilot Prototype of MD-ESP in Running Microphotograph of MD-ESP Fibers SEM Images of MD-ESP Fibers: D=645nm

Electrospinning Process of Nanospiders

Microphotograph of S-ESP Fibers by Reneker

SEM Images of Respirator by 3M

MD-ESP

S-ESP

Spinning Effects of MD-ESP

30

MD-ESP

1. Research Background

2. Electrospinning

3. New solution: Melt Differential Electrospinning

4. Recent Results in Pilot Line

5. Application and Future Prospects

Report Content

M-ESP

PM2.5 Shelter Easy for rechange; Low pressure drop; Efficient isolation of outdoor tiny particles; Highly recycable.

Applications

High efficient PP oil sorbent Reused for over a hundred times.High oil sorption capacity (129 g/g, 6 to 7 times that of traditional melt blown fabirc); Reused for over a hundred times.

MD-ESP

Lithium Battery Membrane PP superfine fibrous membrane; Membrane thickness: 20-60μm; Melting point: 160℃; Porosity > 80%.

Thermal Insulation Material Dust absorption and thermal insulation; Acid and alkali resistant; Ventilated and and hydrophobic; Soft and light.

Medical Dressing Bio-compatible material like PlA and PCL; No toxic solvent residue; soft and comfortable; recycable and bio-degradable.

Filtration membrane for water treatment Operating

Temperature: 5-80 ℃;

Filtration Efficiency

for 0.3μm particles:

99.9%;

Acid and Alkali

Resistant(ph:1-14),Ethanol Resistant.

Potencial applications

J Appl Polym Sci, Vol.125，2012 J Mater Sci, Vol. 46, 2011

Polym Engine Sci, Vol.50, 2010

J Non-Newtonian Fluid Mech,Vol.202, 2013 J Appl Polym Sci, Vol.131, 2014

MD-ESP Published Papers

J Appl Polym Sci, Vol.131，2014 Desalination, Vol.344，2014

J Appl Polym Sci, Vol.114，2009

MD-ESP

Multi-layer nowoven mebrane combining s-ESP and m-ESP

What we are doing

3D-Printing using m-ESP head.

3D multi-level structure built using m-ESPUN fiber(micro scale) twined by s-ESPUN

MD-ESP

Thanks for Your Participation！

Questions or Suggestions are

welcome!

（Email:15001276730@163.com）