Thermal ConductivityGraphite Solutions for Polymers

• Highest purity with synthetic graphite

• Consistent quality• Regulatory compliance• High performance

Graphite GraphiteTIMREX® TIMREX® C-THERM™

Contact us for further information on our products.www.imerys-graphite-and-carbon.com

Polymers

INNOVATIONS TO POWER EVERYDAY LIFE

W/m

.K

0

80

60

120

100

20

40

Castaluminum

PA6 PA6+50%alumina

PA6+50%boron nitride

PA6+50%graphite

Stainlesssteel

1.60.22 4.5

15 15

96

Graphite Solutions for Thermally Conductive Compounds

The use of polymers to achieve thermal conductivity offers substantial advantages compared to standard metal-based technologies in terms of:• Weight reduction; • Design flexibility; • Corrosion resistance; • Manufacturing cost reduction.

Since polymers are inherently thermally insulating (<0.5 W/m.K), conductive fillers have to be added in order to provide the requested thermal conductivity. Graphite-based fillers are known to be the most effective conductive additives for poly-mers, combining the best features in terms of performance and price.

In-plane thermal conductivity of polyamide plastic compounds in comparison to steel and aluminum.

Graphite thermally conductive compounds may be found in automotive headlamps. LED lamps need to dissipate thermal energy in order to reduce the operating tempera-ture that is known to reduce the lamp lifetime. Along with the LED heat sink, many other components of the lighting unit and housing structure are made of plastics, and increasing their thermal conductivity can further decrease the operating temperature.

Beside LED lamps, a world of specific applications requiring thermal conductivity can be found in the automotive sector, as well as in other sectors such as household ap-pliances. Metal replacement is an increasing trend, and Graphite is the most efficient and affordable additive, allowing to manage thermal conductivity to the desired level.

Thermal conductivity of a generic graphite loaded compound.

METAL REPLACEMENT

AUTOMOTIVE HEADLAMP

BEYOND LED LAMPS

W/m

.K

0

8

6

14

12

10

2

4

In plane

Through plane

Graphite content (%v/v)

0 20 30 4010 50

LIGHTING UNITBMC, PC-HT, PEI, PES, PSU

HOUSINGGF reinforced PP, PBT. PSU or PES

W/m

.K

0

86

2018

1214

10

16

24

80x150

KS44

Graphite content (%w/w)

0 20 30 40 60 705010 80

In plane

Through plane

PPh

In some cases the high thermal conductivity of metals can be unnecessary, meaning that a different level of thermal conductivity is required for each specific application. If we have to cool down a heating element, and we may use the LED lamp example again, most of the heat transfer is usually convection limited (air cooling).

Thermal dissipation of LED lamp, air convection is the limiting step.

The question is related to how much conductivity can be reached with graphite filled plastics. Imerys Graphite & Carbon’s expertise and field applications demonstrate that compounds with graphite additions can increase thermal conductivity well above 10W/mK in the in plane component. As a reference, stainless steel has a thermal conductivity of 15 W/mK.

Different requirements must be taken into account for different applications. This influ-ences the selection of additives that are used in the compound.

Heat fluxes in heat sink and pipe applications: heat sink needs high in plane thermal conductivity while pipe applica-tions need high through plane thermal conductivity.

Graphite is known to be a flaky material giving anisotropic thermal conductivity. Depend-ing on the application requirement, a specific graphite grade can be chosen, increasing the thermal conductivity in the desired direction.

IMERYS Graphite & Carbon has the expertise to give you advice on the best grade according to both your thermal conductivity and mechanical properties requirements.

Thermal conductivity of polypropylene compounds loaded with two graphite grades. Different graphites give different anisotropy.

Air convection

Heat source

Heat sink

REQUIRED THERMAL CONDUCTIVITY

REACHING 10W/MK WITH GRAPHITE

SPECIFIC APPLICATIONS

in plane

through plane

in plane

through plane

in plane

through plane

in plane

through plane

NATURAL OR SYNTHETIC?

INTRODUCING C-THERM GRAPHITES

Graphite is a fascinating material and it can be of natural origin or synthetic. Imerys Graphite & Carbon is able to provide both materials depending on the customer’s request. Synthetic graphite is known to be very pure, without any microcrystalline silica content, a contami-nant that can be detrimental for health. Pure graphite is also important for applications that are exposed to severe environmental conditions (such as high tempera-ture, fuel or chemical contact, etc.), or for drinking water applications. In those applications, contamination (tran-sition metal ions) can catalyze polymer degradation, or migrate to surface, thus contaminating other materials.

Imerys Graphite & Carbon’s TIMREX® C-THERM® graphites are special solutions with an extremely High Aspect Ratio.

Mechanical properties of glass fiber reinforced aliphatic polyketones compounds containing graphite.

When compared with standard graphites, TIMREX® C-THERM® can be used at lower loading to reach similar thermal conductivity (injection molding), both in through plane and in plane applications.

Another highlight regarding the mechanical properties of TIMREX® C-THERM® graph-ites is related to its good performance when combined with fiber reinforced plastics.

In plane thermal conductivity of C-THERM011 and natural graphite 80x150 in polypropylene. High thermal conductivity at low loading can be achieved with C-THERM additives.

The main advantages of this product range are:• Weight saving due to the lower loading needed to achieve compound thermal

conductivity target;• Higher mechanical properties in fiber reinforced materials.

MP a

0

80

60

100

120

20

40

PP44 (21%)C-THERM001 (9%)

Tensile strenght

%

0.0

2.0

1.5

2.5

0.5

1.0

PP44 (21%)C-THERM001 (9%)

Elongation at breakM

P a

0

5000

3000

7000

1000090008000

6000

4000

10002000

PP44 (21%)C-THERM001 (9%)

Tensile modulus

kJ/m

2

0.0

30

20

35

25

15

5

10

PP44 (21%)C-THERM001 (9%)

Impact strength (Charpy unnotched)

W/m

.K

0

86

2018

1214

10

16

24

80x150

C-THERM011

Graphite content (%w/w)

0 20 30 40 60 705010 80

PPh

Elecotron microscope image of C-THERM.

GRADE GRAPHITE TYPE PARTICLE SIZE (approx)

ASH(max %)

BET(m2/g)

SCOTT DENSITY(g/cm3)

KS44 Primary Synthetic Graphite d90<44 µm 0.1 9 0.19

SFG44 Primary Synthetic Graphite d90<44 µm 0.1 5 0.19

M100 Natural Graphite <150 µm 4 <1 0.48

80x150 Natural Graphite 100-180 µm 4 <1 0.62

50x80 Natural Graphite 180-300 µm 4 <1 0.59

20x50 Natural Graphite 300-850 µm 4 <1 0.57

C-THERM 001 Graphite nanoplatelet - 0.3 25 0.19*

C-THERM 011 Graphite nanoplatelet - 2.5 25 0.19*

*Tap Density, DIN ISO 787-11

Graphite Solutions for Polymers

TIMREX®

GraphiteTIMREX® C-THERMTM

Graphite R&D Laboratories• Product Development• Application Development• Scientific Support to Customers

Added Value Processes• Size Reduction• Surface Modification• Shape Modification• Purification• Exfoliation• Mixing• Sieving• Milling

C

U S T O M I Z AT I O N

I N N OVAT I V E S U STA I N A BLE SOLUT ION

S

S E C U R I TY O F S U P P LY

GRAPHITE BASED SOLUTIONS PORTFOLIO FOR THERMAL CONDUCTIVITY

Imerys Graphite & Carbon’s goal is to satisfy the requirements of thermal conductiv-ity in a large variety of applications.We can supply a wide range of graphite solutions for thermal management. We offer technical support for in plane and through plane thermal management of polymer components, orientation on carbon additive loading, as well as advice on the effect of various processing techniques.For further information, product selection and sampling, feel free to contact us, or visit our website: www.imerys-graphite-and-carbon.com.

SYNERGIES

Applications

www.imerys-graphite-and-carbon.com

Long termavailability

ResponsibleActor

FinancialStrength

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Since1908

6Industrial Sites

Committed toGrowth

Passion forInnovation

40Countries

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Centers

Reliable PartnerCommitted toGrowth

500EmployeesWorldwide

INNOVATIONS TO POWER EVERYDAY LIFE

About Imerys Graphite & CarbonImerys Graphite & Carbon, member of Imerys Group, is the reference for innovative capability in the field of carbon powder-based solutions: natural graphite and synthetic graphite powders, conductive carbon blacks, as well as silicon-carbon composites and water dispersions.

High standards in terms of employees’ health and safe-ty, social behaviour and environmental responsibility are core values of the company, which is capturing opportu-nities by developing new products and applications, in-vesting in assets & people, and growing its commercial presence worldwide.

Seoul, South Korea

Tokyo, Japan

Kawasaki, Japan

Willebroek, BelgiumLac-des-Îles (QC),Canada

Terrebonne (QC), Canada

Bodio, Switzerland

Shanghai, China

Otjiwarongo, Namibia

Kitakyushu, Japan

Headquarters Sales offices R&D Laboratories Industrial sites

Bironico, Switzerland

FINANCIAL STRENGTH RELIABLE PARTNER RESPONSIBLE GROWTH

Profitable company, part of Imerys, the world leader in mineral-based specialty solutions for industry, listed on the Paris stock exchange

IMERYS Group 2016

Workforce16,000

Revenue4.1 Bn

Operating margin14 %

Innovation strategy Focused on the market and

Customers’ needs

Security of supply6 Industrial Sites

Our driving forceCustomer

Satisfaction

Commitment toGreen technology and

Sustainable development

Reduction ofCO2 Footprint

Engagement with Local

Communities

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