Selected Processing Aids in EPDM

Content Page

1. Introduction 2

2. Fundamentals of the experiments 2

2.1 Processing Aids 2

2.2 Basic formulations and preparation of compounds 2

2.3 Test equipment, methods and parameters 3

3. Effects of Processing Aids in EPDM 3

3.1 Mooney Viscosity 3

3.2 Injection Moulding (Rheovulka-meter), Transfer Moulding 4

3.3 Extrusion (Torsiograph) 5

4. Effects of Processing Aids on physical properties 6

4.1 Sulphur cured EPDM-Compounds 6

4.2 Peroxide cured EPDM-Compounds 8

5. Summary of all laboratory tests 9

Appendix

Performance of recommendedProcessing Aids under industrial conditions 10

Information for the Rubber Industry

-KONTAKT 37

-KONTAKT 37

EPDM rubber is predominantly used for theproduction of extruded or injection mouldedrubber articles. Excellent processing propertiesare essential for such applications. Experienceis teaching that by far not all EPDM compoundsshow the requested easy processability. Im-proved processing characteristics can be ob-tained by the use of Processing Aids.

The DOG Kontakt 37 will demonstrate theeffects of selected Processing Aids in EPDMcompounds at different procedures. This Kon-takt 37 represents the revised version of DOGKontakt 29 and includes the extended DOGproduct range.

2

1. Introduction

2. Fundamentals of the experiments

2.1 Processing Aids

Zinc soaps of defined unsaturated fatty acids

Zinc free Dispersing

Agents

2.2 Basic formulation and preparation of compounds

■ Dispergum L*■ Dispergum 18■ Dispergum E ■ Dispergum K

■ Dispergum C■ Dispergum T■ Dispergum N■ Dispergum R

■ Deoflow S*■ Deoflow A*■ Deoflow D■ Deoflow 821

Emulsion Plasticizer

Special Lubricant

■ Deosol H*

■ Deogum 80*

Products marked with * are representative for each product group. Their results are published in this Kontakt 37. Other test results are available on demand.

Basic formulation (phr)

EPDM (4% EN) 100.0Carbon Black N 550 100.0Paraffinic Oil 17.0Stearic Acid 1.0Zinc Oxide 5.0

Deovulc EG 281 3.1MBT 0.9Sulphur 1.35

Perkadox 14/40 7.0TAIC (70%) 1.5

In order to assure the same fundamental pre-conditions, all tests have been carried out withthe same basic batch. This batch has been pre-mixed on a W&P internal mixer (1.5 l) without

sulphur, accelerator and peroxide. The addi-tion of these three substances took place onan open mill at 70 °C / 6 min.

1DOG also offers the nitrosamine-free accelerator blends Deovulc BG 187 andDeovulc BG 200, which basically provide similar results.

Table 1

Table 2

Sulphur System Peroxide System

3

Figure 1

Influence of Processing Aids on Mooney Viscosity (ML 1+4, 100 °C)

(x Sulphur / Peroxide System)

2.3 Test equipment, methods and parameters

The addition of Processing Aids decreases the compound viscosity and the torque needed.

Internal mixers: 1. 1.5 l W&P2. 1.3 l Guix

Torsiograph: 20 D extruder with feeding zone, screw diameter 20 mm

Göttfert Rheovulkameter: 180 °C, 60 bar, injection time 50 seconds

Injection Moulding machine: Desma D 962, pressure: 1000 bar Temperature 176 °C,

Vulcameter: Göttfert Elastograph, temperature 180 °C

Vulcanization temperature: 180 °C

Vulcanization time: 2 x t90, 3 x t90 for compression set only

3. Effects of Processing Aids on unvulcanized EPDM compounds

3.1 Mooney Viscosity

Table 3

Control3 phr5 phr

Mo

on

ey V

isco

sity

-KONTAKT 37

4

The Injection Moulding process has beensimulated by injecting accelerated compoundsinto the Spider Mould at 180 °C temperatureand 60 bar pressure / 50 sec.

The compound containing Deoflow S has

shown the highest increase of injected volume,followed by the compound with Dispergum L.The dosage of 3 phr Deoflow S doubled theinjected volume within 50 sec. Similar effectscan be seen on Transfer Moulding processes.

3.2 Injection Moulding (Rheovulkameter), Transfer Moulding

Figure 2

Increase of injected volume in relation to control compound

(Sulphur System)

Increase of injected volume in relation to control compound

(Peroxide System)

Figure 3

Incr

ease

of

inje

cted

vo

lum

e in

%In

crea

se o

f in

ject

ed v

olu

me

in %

3 phr5 phr

3 phr5 phr

5

3.3 Extrusion (Torsiograph)

Data shown in figure 4 and 5 are obtainedunder constant torque of 70 Nm at a tempera-ture of 120 °C.

The effects of each Processing Aid areshown by the different extrusion speed.

Best results have been achieved with Disper-gum L, Deogum 80 and Deoflow S. Furtherbenefit can be found in a lower energy inputlevel at constant extrusion speed.

Increase of extrusion speed in % (Peroxide System)(Percentage values are based on cm/min)

Figure 5

Figure 4

Incr

ease

of

extr

usi

on

sp

eed

in

%

5 phr

5 phr

Increase of extrusion speed in % (Sulphur System)(Percentage values are based on cm/min)

Incr

ease

of

extr

usi

on

sp

eed

in

%

-KONTAKT 37

6

4.1 Sulphur System

The Influence of processing aids on physicaldata is shown in figures 8 to 13. The Modulus

shows slightly lower values, whilst the TensileStrength is only insignificantly influenced.

4. Effects of Processing Aids on physical properties

Figure 6

Scorch timeat 180 °C (t10)

The Influence of Processing Aids on cure cha-racteristics is illustrated in figure 6 and 7. It

can be seen, that there is no major influenceon scorch and on cure time.

t 10

min

utes

Control

3 phr

5 phr

Figure 7

Optimum cure time at 180 °C (t90)

t 90

min

utes

Control

3 phr

5 phr

Figure 8

Modulus 200%(MPa)

MPa

Control

3 phr

5 phr

Tensile Strength(MPa)

MPa

Control

3 phr

5 phr

Figure 9

7

Figure 10

Elongation at break (%)

Rebound(%)

% %

Control3 phr5 phr

Control3 phr5 phr

Compression Set(72 h/70 °C)

%

Control3 phr5 phr

Figure 11

Figure 12

Compression Set(24 h/100 °C)

%

Control3 phr5 phr

Figure 13

As it is to be expected from the Modulus values the Elongation at break leads to a

higher level, especially by the use of zincsoaps. The Rebound is not influenced.

It can be seen from figure 12, that Deosol Hand Deoflow A keep excellent Compression

Set values, which are near to the level of thecontrol compound or even better.

-KONTAKT 37

8

4.2 Peroxide Systems

Scorch time t10at 180 °C

Figure 14

Control3 phr5 phr

Tensile Strength (MPa)

Figure 16

Control3 phr5 phr

Elongation at break(%)

Figure 17

Control3 phr5 phr

Optimum Cure time t90at 180 °C

Figure 15

Control3 phr5 phr

t 10

min

utes

MPa

%t 9

0m

inut

es

By the use of the peroxide system as listed on page 2 the following cure behavior and

physical properties have been obtained.

Deoflow S and Dispergum L cause a remark-able reduction of the Cure time in combina-

tion with a slighty lower Tensile Strength.

Other data such as Scorch time and Elongation at break remain rather unchanged.

9

Compression Set 72 h/70 °C

Figure 18

Control3 phr5 phr

Compression Set 24 h/100 °C

Figure 19

Control3 phr5 phr

Considering the great variety of applicationsin the rubber industry, a large number of Pro-cessing Aids is available to solve specific pro-blems.

In a first step DOG has carried out compri-sing tests with 14 Processing Aids out of 4 dif-ferent additive groups in order to identify themost effective products for EPDM.

In the following the additives giving bestresults have been subject of further investiga-tion.

Deoflow S has proven in all tests carried outto have the best overall results for sulphurand peroxide cured EPDM compounds.

Deoflow A is the recommended ProcessingAid for articles (sulphur and peroxide cured)requiring a low Compression Set.

Deogum 80 is providing good general resultsand also prevents in some cases mould foulingin peroxide cured compounds.

Also the other Processing Aids of the DOGproduct range show positive results for EPDMprocessing and can be used on specificdemands in adequate dosage.

Practice is teaching that the use of Proces-sing Aids provides a positive influence inbatch to batch uniformity.

5. Summary of all laboratory tests

%

%

Figure 18 and 19 are clearly showing that forapplications where the Compression Set is of

high importance, Deoflow A and Deosol Hgive the best results.

-KONTAKT 37

10

The recommended products Deoflow S andDeoflow A have been tested on a Desma D962injection moulding machine with a sulphurcured EPDM compound. The laboratory resultsachieved in 3.2 have been confirmed.

Mixing Conditions

Test formulation Injection Moulding MachineType Desma D 962Mould temperature 176 °CPressure 1000 bar

Control

Deoflow A

Deoflow S

Appendix

Performance of recommended Processing Aids under industrial conditions

Recipe 1 2 3

EPDM (4% EN) 100.0Carbon Black N 990 30.0Carbon Black N 550 90.0Paraffinic Oil 80.0Stearic Acid 1.0Zinc Oxide 8.0Sulphur 1.35Deovulc EG 28 3.1MBT 0.9Deoflow A – 5.0 –Deoflow S – – 5.0

Mixer 1.3 l GuixMethode upside downMixing time 3 minutesRotor Speed 77 rpm

Impressum:Editor: DOG DEUTSCHE OELFABRIK Gesellschaft

für chemische Erzeugnisse mbH & Co KGD-20457 Hamburg, Ellerholzdamm 50 Tel. +49 (0)40/31 18 05-0Fax +49 (0)40/31 18 05-88E-Mail: info@dog-chemie.deInternet: www.dog-chemie.de

Authors: Henry AhrensDr. Bernd BornemannJoachim DiederichsenArnulf HaverlandManfred Heide

Production: EHRENBERG WERBUNG Tel. +49 (0)40/27 09 45-0, Fax +49 (0)40/27 50 44

Use of text and pictures – even in extracts – is subjectto approval of the editor and is illegal to copyright.This also applies to copies, translations, micro recor-ding, saving on data carrier and/or commercial use ofaddresses and names especially sales to third parties.

11

Add Efficiency to your compounds

More detailed information and physical data of all products can be found on our Internet Homepage

DOG – Product Range

Dispergum 24 and 36 – Peptizing Agents

Homogenizer – Homogenizing and Tackifying Resins

Deotack – Synthetic Resins

Deosol H – Emulsion based Dispersing Agent and Lubricant

Dispergum – Zinc Soaps

Deogum 80 – Special Lubricant

Deoflow – Zinc free Dispersing A

Deolink TESPT – Silane Preparations

Deolink Vinyl – on an EVA / Wax carrier

Sulphur Factice

Sulphur Chloride Factice

Peroxide Factice

Special Factice

Deovulc EG + BG – Accelerator Blends

Deovulc M + CLD – Sulphur Donors

Deosulf – Sulphur Preparations

Deostab – Vulcanization Stabilizer

Deomag – Inorganic pH - Stabilizer

Controzon – Selected n / iso – Paraffins

Deosec R and RG – Dispersions of Calcium Oxide

www.dog-chemie.de

ProcessingAids

Cross-linkedNative Oils

VulcanizationChemicals

AntiozonantWaxes

Desiccants

Activatorsfor Filler

DOG DEUTSCHE OELFABRIK Gesellschaft für chemische Erzeugnisse mbH & Co KG

Ellerholzdamm 50 • D -20457 Hamburg • Postbox 11 19 29 • D -20419 Hamburg

Tel. +49(0)40 /31 18 05 0 • Fax +49(0)40 /31 18 05 88 • e- Mail: info@dog-chemie.de • Internet: www.dog-chemie.de

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