Eastman Cyphrex™ microfibers designed for wet laid nonwoven & paper

processing

Co-Authors

John Allen, Ph.D (Right)

Senior Research Associate,

Microfiber Applications Development

Keh Dema (Left)

Technology Associate,

Microfiber Applications Development

Topics

Background on microfibers• Characteristics of Cyphrex™ microfibers

• Differences between Cyphrex™ microfibers and most known synthetic fibers

Formation

Strength

Permeability

Attributes of Cyphrex™ microfibers in wet laid nonwovens• Incline wire paper machine (Incline Wire)

• Fourdrinier paper machine (Fourdrinier)

• Compare samples from incline wire and Fourdrinier

Potential applications

Conclusion

Background

Current

non-fibrillated synthetic

fibers for wet laid

minimal wet strength without

bonding agents

minimal dry strength without

bonding agents

cannot be dispersed above 1%

consistency without significant

chemistry

Cyphrex™ can be

conveyed on the wet end of the

machine without bonding agents

dried with enough bond strength to

prepare a roll good

dispersed from 1 to 3.2% consistency

similar to wood pulp

Cyphrex™ microfibers

potential to change everything…

Wet-lap pulp

Media

Wet-laid nonwoven processing

Microfiber precursor

Fiber

processing

Eastman Cyphrex™

microfiber slurry

Eastman CyphrexTM microfibers

50 microns

Novel flat PET microfiber characteristics

1. This novel flat fiber has a ribbon-like cross

section

2. Dimension

- 2.5 microns nominal thickness

- 18 microns nominal width

- 1.5 mm length

3. Supplied as a wet pulp at 50% solids

4. Forms highly uniform wet laid nonwoven papers

- flat microfibers oriented parallel to media

surface

- high inter-fiber surface for bonding

- high sheet surface smoothness

Cyphrex™ microfibers behave differently…

1. Disperses easily in water with minimal shear energy

2. Compatible with traditional paper mill dispersion equipment

3. Accessible dispersion consistencies range up to 3.2%

4. Processes well at desired headbox consistencies for a wide range of forming

equipment – including incline wire, rotoformer, and Fourdrinier

5. Inherent wet green strength allows for producing of 100% PET sheet

6. Enables preparation of synthetic roll good without binder or wet end additives

7. Compatible with typical wet-strength agents – which have also been shown to

significantly improve dry strength as well

8. Blends easily with other fibers – most notably, cellulose, synthetics, and glass

Uniformity attained with 15 gsm novel flat PET

microfiber sheet

Photograph of handsheet

SEM top

view

SEM cross

section

Pulp and paper formation measurement (80 gsm handsheets)

0

0.2

0.4

0.6

0.8

1

Re

lati

ve

Fo

rma

tio

n (

M/K

In

de

x)

NBSK (SR50) 2.5 µ round fiber 4.5 µ round fiber flat PET fiber

NBSK = Northern bleached softwood Kraft wood pulp

Typical strengths of 100% flat PET media(produced on incline wire)

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4

8

12

16

20

0 20 40 60 80 100

Te

ns

ile

, lb

f/in

Basis Weight, gsm

MD Tensile CD Tensile

Effect of wet strength agent on 100% flat PET

media (produced on incline wire)

20

30

40

50

60

70

80

90

20 30 40 50 60 70 80 90 100

Mu

lle

n B

urs

t, p

si

Basis Weight, gsm

without wet strength agent with wet strength agent

Paper properties differ based on machine

configuration (100% flat PET microfibers)

0

4

8

12

16

20

0 25 50 75 100 125

Ten

sil

e, l

bf/

in

Basis Weight, gsm

MD Fourdrinier MD Incline Wire

Blends of novel flat PET microfibers with

cellulose fibers (produced on Fourdrinier)

0

5

10

15

20

25

20 40 60 80 100

MD

Te

ns

ile

, lb

f/in

Basis Weight (gsm)

25% Flat PET 50% Flat PET 100% flat PET

Novel flat PET microfiber improves tear strength(60 gsm media blends with cellulose on Fourdrinier)

0

20

40

60

80

100

120

140

0 20 40 60 80 100 120

MD

Elm

en

do

rf T

ea

r, g

ram

s

%Flat PET microfiber

Novel flat PET microfiber improves permeability(60 gsm media blends with cellulose on Fourdrinier)

0

2

4

6

8

10

12

20 30 40 50 60 70 80 90

Pe

rme

ab

ilit

y, F

3/F

2/m

in

Basis Weight, gsm

100% flat PET flat PET fiber / cellulose blend 100% cellulose

Choice of bonding agent can influence strength (80 gsm flat PET fiber sheets with 10% added binder)

0

5

10

15

20

25

30

35

40

45

MD

Te

ns

ile

, lb

f/in

no binder or calender

acrylic latex

polyurethane dispersion

polyester dispersion

Potential applications

Our fibers enable papermakers to produce high-

performing, high-strength synthetic nonwovens

on standard papermaking equipment.

• High strength paper – packaging, etc.

• Wall cover

Other applications

• Filtration – RO and FO membrane support

• Battery separator – Lithium ion, Lead acid,

etc

Conclusion

Cyphrex™ Flat PET microfibers:

1. Process at consistency similar to wood pulp

2. Can be processed on the flat Fourdrinier, Incline Wire, or Rotoformer

3. Produce highly uniform sheets with high green strength

4. Blend well with other synthetic fibers as well as wood pulp at any ratio

- Preliminary studies suggest that paper made with this synthetic fiber are easily

printable without exotic pretreatment

- The unique properties that this fiber imparts to substrates can create

opportunities for many applications

Next step

Contact us for further discovery, sampling, or development conversations.

Email: pdulick@eastman.com

Phone number:

1-800-Eastman or 1-423-229-3910

Visit website:

http://www.eastmancyphrex.com