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Dow Elastomers

Fewer Gels Mean

More Peace of Mind

Gels Cannot Hide from This

State-of-the-Art Technology

Consistency. Reliability. Quality. These are the char-

acteristics customers want in the products delivered

by The Dow Chemical Company (Dow). They are also

the drivers behind the new gel detection process for

NORDEL Hydrocarbon Rubber.

Gels reduce productivity and can result in an end product

far below consumer standards. This often means waste,product delivery delays, and reduced profits. Dows

new state-of-the-art equipment is designed to detect

gels more accurately and, therefore, improve the quality

of NORDEL IP products that are delivered to processing

sites around the world.

Traditional detection methods have typically been

incapable of reliably identifying the gel content of the

whole product. In an effort to improve customer service,

and maintain consistency with our company-wide

Six Sigma(1) goal of virtually zero defects, Dow has

significantly improved its gel detection process for

ethylene propylene diene terpolymers (EPDM).Leveraging technology used successfully within Dow

for plastic resins, we invested in machine vision equip-

ment to measure gel content. We also changed the

sample collection process, as well as how gel content

is reported on the Certificate of Analysis (COA).

We are very excited about these changes and pleased

to share the benefits with NORDEL Hydrocarbon

Rubber customers.

Pioneering Chemistry and Processes

Yield Unmatched Quality

The distinct catalyst and process technology

pioneered by Dow for EPDM production are funda-

mentally low gel processes. Consequently, gels are

rare events which require frequent testing and statisti-

cally large enough samples to predict processing and

end-use performance with accuracy.

The new gel detection technology includes a processof frequent sampling of the production line and evalu-

ating the gel content directly to ensure high quality

production. Sample frequency is sufficient to ensure

that every batch produced is analyzed for gels. In some

cases, multiple samples are taken to ensure statistically

significant characterization.

Improving the sampling process is just the beginning.

The way gels are measured has also been greatly

improved. To determine the total gel level, state-of-the-

art cameras are used to scan the sample. Each gel is

measured and digitized to determine its actual size.

Gels typically appear as an array of distorted shapes.The methodology of characterizing them in Dows

new process is to convert the non-uniform surface area

into an equivalently sized circle. The diameter of this

circle is called the equivalent circular diameter (ECD).

Based on the ECD, the volume of each gel is estimated

using simple geometry, then added together and

reported as a total gel volume. The result is a much

more accurate picture of the total gel content of the

entire production lot.

State-of-the-art equipment helps ensure quality by systematically inspecting for gels in the naturally clean NORDEL products.

(1)

A quality discipline throughout Dow that focuses on product and service excellenceTrademark of The Dow Chemical Company (Dow) or an affiliated company of Dow

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NOTE: While this state-of-the-art technology helps

ensure quality by systematically inspecting for gels in

NORDELHydrocarbon Rubber, its important to keep in

mind that gels can also be commonly formed in the

shipping, handling, and/or final processing of EPDM.

As a result, customers may wish to review their own

operations to help maintain the low gel levels in the

products as manufactured and shipped.

A New Industry Standard

NORDEL Hydrocarbon Rubber expands the range of

possibilities beyond traditional EPDM products. Dows

continued innovation and newly defined gel volume

standards are setting the pace for high-quality hydrocar-

bon rubber products. Contact your Dow representative

for more information.

If the total gel content of a test sample is too high,

Dow has the ability to react quickly, diverting product

from the prime designation, so customers consistently

receive only top quality product.

More Accurate Results

In addition to detecting and totaling the actual sizes

of each gel, the new method has the capability of

detecting very small gels, which are also factoredinto the total gel area.

Using the volume of measured gels and the dimensions

of the test strip (length, width, thickness), an actual

volume of gels is calculated and reported as parts per

million by volume (ppmv). Table 1 shows test results

using the old and new methods.

Note that it is possible for two or more samples to

have the same gel count while having very different

gel volumes.

Under the old system, all products would have passed

gel count standards and been shipped as prime prod-

uct. However, only products B, C and D would beacceptable by the new, more stringent gel volume

standards. Product A, despite having the same gel

count as B and C, would be unacceptable and there-

fore not sold as NORDEL Hydrocarbon Rubber because

of the high gel volume.

For additional information regarding NORDEL Hydrocarbon Rubber, contact your Dow Technical Service & Development professional,

your Dow Elastomers seller, or call the Dow Customer Information Group (CIG) at 1-800-441-4369. Find out more about Dow Elastomers and

Dow products for EPDM applications at www.dowelastomers.com.

NOTICE: If products are described as experimental or developmental: (1) product specifications may not be fully determined; (2) analysis of hazards and cautionin handling and use are required; (3) there is greater potential for Dow to change specifications and/or discontinue production; and (4) although Dow may from time

to time provide samples of such products, Dow is not obligated to supply or otherwise commercialize such products for any use or application whatsoever.

The information herein is supplied upon condition that the persons receiving same will make their own determination as to its suitability for their purposes prior to

use. In no event will Dow be responsible for damages of any nature whatsoever resulting from the use of or reliance upon the information herein or the product to

which that information refers. Nothing contained herein is to be construed as a recommendation to use any product, process, equipment, or formulation in conflict

with any patent, and Dow makes no representation or warranty, express or implied, that the use thereof will not infringe any patent. NO REPRESENTATIONS OR

WARRANTIES, EITHER EXPRESS OR IMPLIED, OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE OR ANY OTHER NATURE ARE MADE HEREUNDER

WITH RESPECT TO INFORMATION OR THE PRODUCT TO WHICH INFORMATION REFERS.

(1) Specific COA content may vary slightly by geographic region.

Figure 1: Sample Certificate of Analysis (COA) (1) with the new

gel volume maximum showing the batch was less than 12 ppmv.

Form No. 265-12101-1009X SMGSMG 11805

Trademark of The Dow Chemical Company (Dow) or an affiliated company of DowPrinted in United States. Intended for use within North America.

Table 1: Comparison of Gel Detection Results

Old New

Product Large Medium Small Total Gel ppmv

Count

A 1 2 3 6 13.4

B 0 3 3 6 6.2

C 0 0 6 6 3.3

D 0 0 0 0 0

Certificate 4437914 The Dow Chemical Company Page 1

Date: 11.06.2009 Certificate of Analysis Shipped: 11.06.2009

File CopyDOW EUROPE GMBH Fax: COA ARCHIVEROTTERDAM HAVENROTTERDAM ZH 3012 CA THE NETHERLANDS

Cust P.O.: 030/50/40107738 Dlvy Note: 70076967 10Order No.: 17122777

Material: NORDEL* IP 4760P Hydrocarbon Rubber25 KG Bag40 Bags on a Pallet Spec: 00146120-S

Cust Mtl:

Batch: XE2901A3NB

Dlvy Qty:BG 640Vehicle: CLHU 466963-4

Ship from: THE DOW CHEMICAL COMPANY PLAQUEMINE LA UNITED STATES

Results LimitsFeature Units XE2901A3NB Minimum Maximum Method-----------------------------------------------------------------------------Mooney Viscosity unit 59 55 65 ASTM D1646

ML1+4 @ 125degCEthylene % wt 67,7 65,5 69,5 ASTM D3900ENB % wt 5,0 4,5 5,3 ASTM D6047Volatiles, Total % wt 0,2 ---- 0,4 ASTM D3030Contamination count 0 ---- 15 PQ-E-030

Specks/300gGel Conc. (200) Passes DOWM 102370

< than 12 ppmv, per 5.0 m2

Yellowness Index - 3 ---- 7 ASTM E313

Quality Systems Specialist

For inquiries please contact Customer Service or local sales.English: 800-232-2436 French: 800-565-1255

* Trademark of The Dow Chemical Company