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Specialty Elastomers for Automotive TPO Compounds

Flexible Solutions. Endless Possibilities.

®Trademark of The Dow Chemical Company

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Look to Dow for Innovative TPO Material Solutions for Automotive

Interiors and Exteriors with advanced material science and process technology. INSITE™ Technology is used by Dow to design new molecules and create innovative new specialty olefin products that deliver significant improvements in performance, cost, recyclability, and material usage over the polymers they replace. INFUSE™ Olefin Block Copolymers, which promise to expand the possibilities for olefin-based elastomers, are the most recent example of Dow materials innovation.

Dow is the world leader in specialty elastomer technologies for automotive Thermoplastic Polyolefin (TPO) compounds. Included are specialized solutions for “hard” TPOs used in automotive exterior and interior applications as well as “soft” TPOs for instrument panel (IP) skins and other interior components. Dow materials offer the flexibility you require to meet your specific engineering needs and processing requirements. In many cases, Dow materials and technology can help you identify TPO solutions that deliver

better performance and economics as replacements for PC/ABS, f-PVC, TPVs, leather, fiberglass and other materials. Our product offering continues to expand as we apply our advanced and proprietary polymer and catalyst technologies to identify TPO solutions that enable our customers to meet emerging requirements, differentiate their products, and improve their competitive positions. INSITE™ Technology One important platform for Dow innovation is INSITE™ Technology, which combines metallocene catalysts invented by Dow

Meeting Your Requirements Advanced Dow technology, coupled with our in-depth knowledge of automotive TPO compound requirements, enables Dow to offer a range of solutions based on desired compounding and processing characteristics as well as finished part performance and appearance. Specialty elastomers from Dow are used as copolymers with polypropylene to enhance impact resistance, improve weatherability, minimize weight and contribute to the recyclability of parts. Dow materials also can improve the processability of TPO compounds, enhancing productivity and economy in injection molding, sheet extrusion/thermoforming, and blow molding operations.

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Serving You Globally Global automotive supply chains demand global material solutions. Dow’s worldwide capabilities enable us to meet your current needs and your expanded needs tomorrow. These world-class capabilities include… • Global application and development and technical service resources • Global customer service organization • Global production capabilities and raw material integration Flexible Materials from Dow Here’s an overview of the specialty elastomer materials available to you from Dow for TPO Compounds: ENGAGE™ Polyolefin Elastomers have long been the impact modifiers of choice in hard TPO applications. Today they are contributing to new advances in the performance and processability of both hard and soft TPOs as the use of TPO technology expands across today’s vehicles and the cars of tomorrow. FLEXOMER Very Low Density Polyethylene (VLDPE) Resins are good impact modifiers that also contribute strength, toughness and flexibility in hard and soft TPOs. ™

Dow Innovation Continues Dow continues to develop innovative new solutions that enhance the performance and processability of TPO compounds. VERSIFY™ Plastomers and Elastomers are just one example. These versatile propylene-ethylene copolymers are used as performance or processing modifiers that contribute superior optics, elasticity, flexibility, softness and other haptic properties. Dow‘s ongoing contributions to the expanded use of hard and soft TPOs are reducing vehicle weight, improving vehicle safety, improving durability, reducing glass fogging, and improving the recyclability of materials at the end of vehicle life.

NORDEL™ Hydrocarbon Rubber products are unique EPDM materials that offer enhanced processability and impart low temperature toughness to other polymers.

™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow.

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Applications for TPO Compounds Containing

Dow Specialty Elastomers Processing and Performance Characteristics Specialty elastomers from Dow can meet the full range of processing requirements for automotive TPO compounds. Dow offers several options for compounds used in injection molding of hard TPOs. Included are ENGAGE™, FLEXOMER™ and NORDEL™ grades offering an excellent balance of impact resistance and economy, lower density materials for greater impact strength and low temperature ductility, as well as materials offering maximum impact resistance and higher flow during

processing…the answer for today’s increasingly complex and demanding part designs. For thermoforming and blow molding of hard and soft TPOs, Dow has developed several grades of ENGAGE™ Polyolefin Elastomers that exhibit high melt strength due to the introduction of long chain branching into the polymer structure. In blow molding, high melt strength provides better sag resistance than conventional polyolefin elastomers as well as extensibility

Hard TPO molding for rear bumper fascia

Hard TPOs for rocker panels and side molding

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for high blow-up ratios. In thermoforming, extruded sheet material made with our high melt strength materials is compliant during processing, yet retains shape stability, minimizing sag during preheating. This results in parts with high levels of surface quality and consistency as well as color stability. When combined with high melt strength polypropylene, these elastomers contribute to higher re-crystallization temperatures, allowing parts to be removed from molds more quickly, enhancing productivity.

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Figure 1 compares the melt strength of Dow high melt strength elastomers to ENGAGE™ 8150, a conventional grade. Choosing the Right Material The range of products available from Dow for TPO compounds allows part designers, compounders and processors to specify and select the best options for their particular applications. Dow offers copolymers of ethylene with propylene, butene and octene monomers. The increasing α-olefin chain length from propylene (C3), up to butene (C4) and up to octene (C8) enhances low temperature impact performance as illustrated in Figure 2.

important than others. But in most cases, the best material for a particular application will reflect an optimum balance of several performance properties. When evaluating individual materials it is helpful to understand the general effects of various material properties on TPO compound performance as shown in Table 1 on page 6. Figure 3 on page 6 illustrates a comparison of TPOs based on a homopolymer polypropylene compounded with three general purpose elastomers against multiple performance parameters for an injection molding application.

Preparation of trial compounds for testing and analysis of this kind allows selection of the material offering the optimum balance of performance. In this case, the ethylene octene copolymer (ENGAGE™ 8003) outperforms the ethylene butene elastomer (ENGAGE™7270), particularly in terms of weld line strength, ultimate elongation, and several impact tests. While the FLEXOMER™ elastomer, an ethylene/butene material, exhibits generally lower performance, it may still provide the desired balance of performance and economy in the application.

Figure 1 – Melt Strength of Elastomers

Performance requirements for each specific application will guide elastomer material selection. Depending on the application, certain properties may be judged more

ENGAGE™ 8150

ENR 6386.00

ENGAGE™ 7387

ENR 7086.01

7,000,000 190 °C, 0.1 s-1

Extension Viscosity (Poise)

6,000,000

5,000,000

4,000,000

3,000,000

2,000,000

1,000,000

TPO moldings for front end body panels

0 0.000

0.500

1.000

1.5000

2.000

2.500

3.000

3.500

4.000

4.500

Hencky Strain (cm/cm)

Figure 2 – Low Temperature Ductility of Various Ethylene/ α-olefin Elastomers Propylene

Butene

Octene

Glass Transition Temperature (deg C)

-35

Hard TPOs for bumper fascia

-40

-45

-50

-55

-60

-65 0

5

10

15

Crystallinity (%) ™Trademark of The Dow Chemical Company (“Dow”) or an affiliated company of Dow.

5

20

25

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Initial material selection decisions can be based on processing requirements. Table 2 provides an overview of recommended materials for processes used to produce TPO parts. The table on the back page of this brochure describes the elastomer grades available from Dow for TPO compound applications. Use this information to identify the polymers most suitable for your application. Then, obtain more detailed properties and performance information from Dow by downloading the technical data sheets (TDS) for individual grades of interest to you at www.dowplastics.com.

Figure 3 – Multi-Property Comparison of TPO Performance

Shrinkage (%)

Shore 10D Hardness 1.2 MI-flow rate (g/10min) 1

WL Elong@Yld (%)

Hardness Test HD1D

0.8 0.6 WL Ten@Yield (psi)

HDT D648 0.455MPa 0.4 0.2

FlexMod (PSI)

Dart Impact 23C (% Ductile)

0

Elong@Yld (%)

Also available at www.dowplastics.com are Material Safety Data (MSD) sheets for each specialty elastomer product grade offered by Dow. Our technical team can provide you with the processing guidelines and other information necessary to obtain maximum productivity and economy from Dow materials. To gain access to our full knowledge and information, visit us online or call the number for your area, listed on the back of this brochure.

Dart Impact OC (% Ductile)

Ten@Yield (psi)

Dart Ductile/Brittle Transition

Izod Impact OC

Ult. Elong (%) Gloss 60deg FLEXOMER™ 1085NT

WL Izod Impact R.T. (J) 30% ENGAGE™ 7270

30% ENGAGE™ 8003

Table 1 – Elastomer Effects on TPO Compound Performance TPO Performance Low Temperature Flexural Impact Modulus

Elastomer Properties

Heat Distortion Temperature

Decreasing Comonomer Chain Length Decreasing Elastomer Crystallinity (Lower Density) Decreasing Melt Index (Increasing Molecular Weight) Decreasing Elastomer Content Decreasing Molecular Weight Distribution Decreasing Branching Key:

Increased Effect

Minimal Effect

Decreased Effect

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TPO Injection Molding Flow TPO Shrinkage

TPO Thermoform/ Blow Molding Melt Strength

Gloss

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Soft TPOs to simulate leather on interior door panels

Hard and soft TPOs for instrument panel components, plus soft touch controls

Hard TPOs for interior roof pillar moldings

Soft TPO skin for simulated leather console covering

Table 2 – Processing Performance INJECTION MOLDING Good (Cost Effective Impact Resistance)

Better (Lower Density)

ENGAGE™ 8003 ENGAGE 7270/7277 FLEXOMER™ DFDB-1085 NT FLEXOMER DFDA-1095 NT NORDEL™ IP 3720P NORDEL IP 3745P

ENGAGE 8100/8107 ENGAGE 8150/8157 ENGAGE 8200/8207

Best (Max. Impact Resistance)

(Higher Flow)

ENGAGE 8180 ENGAGE 8842 ENGAGE 7467

ENGAGE 8137 ENGAGE 8400/8407 ENGAGE 7447

EXTRUSION/ THERMOFORMING (High Melt Strength and High Recrystallization Temp.)

BLOWMOLDING (High Melt Strength and Extensibility)

ENGAGE ENR 6386.00 ENGAGE ENR 7086.01 ENGAGE 7387 FLEXOMER DFDB-1088 NT FLEXOMER DFDA-1098 NT

ENGAGE ENR 6386.00 ENGAGE ENR 7086.01 ENGAGE 7387 FLEXOMER DFDB-1088 NT FLEXOMER DFDA-1098 NT

Hard TPOs for knee bolsters

PERFORMANCE/ PROCESSING MODIFICATION (Enhanced Softness, Haptic Properties) VERSIFY™ 2300

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Specialty Elastomers for Automotive TPO Compounds

Properties of Dow Specialty Elastomers for TPO Compounds† Grade

Comonomer (with Ethylene)

Density g/cm3 (ASTM D792)

Octene Octene Octene Octene Octene Octene Octene Octene Propylene Butene Butene Butene Butene Butene Butene Butene Butene Butene Propylene†† Propylene†† Propylene

0.885 0.870 0.864 0.868 0.863 0.870 0.870 0.857 0.875 0.901 0.880 0.870 0.865 0.862 0.884 0.884 0.886 0.886 0.87 0.87 0.866

ENGAGE™ 8003 ENGAGE 8100/8107 ENGAGE 8137 ENGAGE 8150/8157 ENGAGE 8180 ENGAGE 8200/8207 ENGAGE 8400/8407 ENGAGE 8842 ENGAGE ENR 6386.00 ENGAGE ENR 7086.01 ENGAGE 7270/7277 ENGAGE 7387 ENGAGE 7447 ENGAGE 7467 FLEXOMER™ DFDB-1085 NT FLEXOMER DFDB-1088 NT FLEXOMER DFDA-1095 NT FLEXOMER DFDA-1098 NT NORDEL™ IP 3720P NORDEL IP 3745P VERSIFY™ 2300

Melt Index dg/min (ASTM D-1238 190°C, 2.16 kg) 1.0 1.0 13 0.5 0.5 5.0 30 1.0