AEQ-QEG Technico-Commercial meeting November 8, 2017 N990 Thermal Black in Natural Rubber isolation bushings for improved dynamic performance
What is Thermal Carbon Black? A niche product (specialty chemical) Produced by thermal decomposition of the natural gas molecule (CH 4 ) The largest particle size (100-700nm diameter) carbon black The lowest structure carbon black The highest purity carbon black 2
INCREASING STUCTURE OAN (DBP) Absorption (ml/100g) THE CARBON BLACK SPECTRUM 140 120 100 80 60 N650 N550 N539 N660 N774 N762 N326 N330 N339 N343 N121 N220 N110 40 20 0 N990 0 20 40 60 80 100 120 140 160 Nitrogen Surface Area (m 2 /g) DECREASING PARTICLE SIZE
THERMAX vs FURNACE BLACK GRADES Particle size diameter N660 (60nm) 4
THERMAX vs FURNACE BLACK GRADES High Structure Moderate Structure Low Structure N550 N762 N660 N990 5
DYNAMIC APPLICATIONS Tires Motor mounts Air springs V-belts Conveyor belts Blow out preventer Dynamic seals Roll covers Shoe soles Dynamic mechanical goods Bushings Shock absorbers Hoses Bridge bearings Foam, sponge compounds Innertubes Caster wheels Sporting goods Diaphragms Suspension bumpers Body mounts Vibrations isolators Rail pads Vacuum tubing Wiper blades Bladders Mats 6
RUBBER VISCOELASTICITY Rubber exhibits both viscous and elastic properties, allowing for very specialized applications. Perfect spring Rubber Honey 7
HYSTERESIS Energy is lost in the viscoelastic material as heat causes heat buildup and accelerates rubber aging 8
Stress Load (kn) HYSTERESIS Energy is lost in the viscoelastic material as heat causes heat buildup and accelerates rubber aging 4 3.5 3 2.5 2 1.5 1 0.5 0 0 1 2 3 4 5 6 7 Strain Displacement (mm) 9
MEASURED DYNAMIC PROPERTIES WHAT DO THEY MEAN Viscous Response Elastic Response tan δ = G viscous modulus = G elastic modulus G δ G Tan delta is indicative of heat buildup, noise transmission, rolling resistance 10
MEASURED DYNAMIC PROPERTIES WHAT DO THEY MEAN Dynamic stiffness and static stiffness spring ratio = K d K s Surface area Structure Want a low spring ratio low K d and high K s Low dynamic stiffness (K d ) is a predictor of vibration isolation performance. Sufficient static stiffness (K s ) is required to support a load 11 Sunnicliffe, L. (2017). Carbon black reinforcement of rubber for vibration isolation applications. Presented at: Technical Meeting of Rubber Division, ACS.
OBJECTIVES FOR AN IDEAL RUBBER BUSHING 1 Reduce tan delta (heat buildup, noise transmission) 2 Increase static stiffness (mechanical integrity) 3 Increase processability and cost effectiveness The compound must balance the requirements for static stiffness with minimized dynamic stiffness and hysteresis in order to suppress the frequency of resonance 12
TESTING MATERIAL AND FORMULATIONS Objective: Evaluate the replacement of N660 with N990 in natural rubber isolation bushings for use in automobiles Anticipated results: Increased N990 loading to obtain same hardness Decreased tensile strength Increased adhesion between rubber and steel with N990 addition 13
LABORATORY TESTING Dynamic and static testing Tokai Chita Lab Dynamic testing - ESI Lab Adhesion testing - RDAbbott Tensile strength Resilience Rheometry Dynamic and Static moduli Dynamic and Static Moduli Heat buildup upon compression cycles Rubber hysteresis Rubber Pull Test (ASTM D429 Method B) 14
FORMULATIONS Compound # 1 2 3 4 5 6 7 8 9 Carbon black loading in phr A-0 B-9.65 C-19.3 D-28.95 E-38.5 F-48.25 G-57.9 H-67.55 I-77.2 N660 40 35 30 25 20 15 10 5 0 N990 0 9.65 19.3 28.95 38.6 48.25 57.9 67.55 77.2 Total carbon black loading 40 44.65 49.3 53.95 58.6 63.25 67.9 72.55 77.2 Additional Materials: Natural rubber (100phr), Aromatic process oil (5phr) Antioxidant (1phr), Zinc oxide (5phr) Stearic acid (3phr), Accelerator (0.75phr) Sulfur (2.25phr) 15
HARDNESS MAINTAINED WITH ADDED N990 LOADING Compound # 1 2 3 4 5 6 7 8 9 Carbon black loading in phr A-0 B-9.65 C-19.3 D-28.95 E-38.5 F-48.25 G-57.9 H-67.55 I-77.2 N660 40 35 30 25 20 15 10 5 0 N990 0 9.65 19.3 28.95 38.6 48.25 57.9 67.55 77.2 Total carbon black loading 40 44.65 49.3 53.95 58.6 63.25 67.9 72.55 77.2 Hardness 57 57 57 58 57 58 59 58 58 Hardness after aging 62 62 62 62 63 63 64 63 63 16
Strength (Mpa) TENSILE STRENGTH BEFORE AND AFTER AGING Tensile strength decreases with increasing N990 loading. Effects are less pronounced after aging. This is to be expected when replacing a furnace black with thermal black. 30.0 25.0 20.0 15.0 10.0 5.0 0.0 0 9.65 19.3 28.95 38.6 48.25 57.9 67.55 77.2 N990 loading (phr) Before aging After aging at 100 C for 3 days 17
Tensile Stress (Mpa) Tensile Stress (Mpa) Tensile Stress (Mpa) TENSILE STRESS BEFORE AND AFTER AGING Tensile stress is relatively unaffected by N990 loading. 100% Elongation 200% Elongation 300% Elongation 12.0 12.0 12.0 10.0 10.0 10.0 8.0 8.0 8.0 6.0 6.0 6.0 4.0 4.0 4.0 2.0 2.0 2.0 0.0 0.0 0.0 N990 loading (phr) N990 loading (phr) N990 loading (phr) Before Aging After Aging 18
0 9.65 19.3 28.95 38.6 48.25 57.9 67.55 77.2 0 9.65 19.3 28.95 38.6 48.25 57.9 67.55 77.2 Tensile Stress (Mpa) Tensile Stress (Mpa) Tensile Stress (Mpa) TENSILE STRESS BEFORE AND AFTER AGING Tensile stress is relatively unaffected by N990 loading. 100% Elongation 200% Elongation 300% Elongation 0.9 2.5 3.5 12.0 10.0 8.0 0.8 0.7 0.6 0.5 12.0 10.0 8.0 2.0 1.5 12.0 10.0 8.0 3.0 2.5 2.0 6.0 4.0 2.0 0.4 0.3 0.2 0.1 6.0 4.0 2.0 1.0 0.5 6.0 4.0 2.0 1.5 1.0 0.5 0.0 0.0 0.0 0.0 0.0 0.0 N990 loading (phr) N990 loading (phr) N990 loading (phr) Before Aging After Aging Change 19
Rebound resilience (%) REBOUND RESILIENCE Rebound resilience increases with N990 loading. 72.5 72.0 71.5 71.0 70.5 70.0 69.5 69.0 68.5 68.0 67.5 67.0 0 9.65 19.3 28.95 38.6 48.25 57.9 67.55 77.2 20 N990 loading (phr)
Compression set (%) COMPRESSION SET Slight decrease in compression set at elevated temperatures. Compression set does not increase with additional filler loading. 60.0 55.0 50.0 45.0 40.0 35.0 30.0 25.0 20.0 0 10 20 30 40 50 60 70 80 N990 loading (phr) 70 1day 100 1day 21
Torque (lb f ) RHEOMETRY VULCANIZATION PROPERTIES Slight change in rubber vulcanization characteristics, increased Mooney scorch with increasing N990 10.0 9.0 8.0 7.0 6.0 5.0 4.0 3.0 2.0 1.0 0.0 3 5 7 9 11 13 15 Time (min) A-0 B-9.65 C-19.3 D-28.95 E-38.6 F-48.25 G-57.9 H-67.55 I-77.2 N990 loading 0 phr 77 phr 22
Mooney scorch (min) Mooney viscosity MOONEY VISCOSITY AND MOONEY SCORCH Mooney scorch increases with N990, Mooney viscosity unaffected up to 70phr N990 loading. This allows for high filler loading without a decrease in processing abilities. 32.0 31.0 30.0 29.0 28.0 27.0 26.0 25.0 24.0 23.0 22.0 0 10 20 30 40 50 60 70 80 N990 loading (phr) Viscosity Scorch 23
tan delta 1% DYNAMIC STRAIN Tan delta decreases with increasing N990 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0 10 20 30 40 50 60 70 80 90 100 Frequency (Hz) Increasing N990 loading A-0 B-9.65 C-19.3 D-28.95 E-38.6 F-48.25 G-57.9 H-67.55 I-77.2 N990 loading 0 phr 77 phr 24
tan delta 2% DYNAMIC STRAIN Tan delta decreases with increasing N990 0.12 0.11 0.1 0.09 0.08 0.07 0.06 0.05 0 10 20 30 40 50 60 70 80 90 100 Frequency (Hz) Increasing N990 loading A-0 B-9.65 C-19.3 D-28.95 E-38.6 F-48.25 G-57.9 H-67.55 I-77.2 N990 loading 0 phr 77 phr 25
tan delta 5% DYNAMIC STRAIN Tan delta decreases with increasing N990 0.12 0.11 0.1 0.09 0.08 0.07 Increasing N990 loading 0.06 0.05 0 10 20 30 40 50 60 70 80 90 100 Frequency (Hz) A-0 B-9.65 C-19.3 D-28.95 E-38.6 F-48.25 G-57.9 H-67.55 I-77.2 N990 loading 0 phr 77 phr 26
tan delta 10% DYNAMIC STRAIN Tan delta decreases with increasing N990 0.12 0.11 0.1 0.09 0.08 0.07 Increased Increasing N990 loading 0.06 0.05 0 10 20 30 40 50 60 70 80 90 100 Frequency (Hz) A-0 B-9.65 C-19.3 D-28.95 E-38.6 F-48.25 G-57.9 H-67.55 I-77.2 N990 loading 0 phr 77 phr 27
Temperature change ( C) NORMALIZED HEAT BUILD-UP No correlation 0.3 0.25 0.2 0.15 0.1 0.05 0-0.05-0.1-0.15-0.2 0 7.5 15 22.5 30 37.5 45 52.5 Time (minutes) A-0 B-9.65 C-19.3 D-28.95 E-38.6 G-57.9 H-67.55 I-77.2 N990 loading 0 phr 77 phr 28
Dynamic Stiffness K d (N/mm) NORMALIZED DYNAMIC RATE FALLOFF DURING HEAT BUILD-UP Dynamic stiffness (K d ) decreases with N990 loading 1 0.95 0.9 0.85 0.8 0.75 0 2000 4000 6000 8000 10000 12000 14000 Cycles A-0 B-9.65 C-19.3 D-28.95 E-38.6 F-48.25 G-57.9 H-67.55 I-77.2 N990 loading 0 phr 77 phr 29
Dynamic to Static Spring Ratio SPRING RATIO 2.2 2 1.8 1.6 1.4 1.2 K d K s Decrease spring ratio with increased N990 loading. A lower spring ratio indicates improved dynamic properties 1 0 9.65 19.3 28.95 38.6 48.25 57.9 67.55 77.2 N990 Loading (phr) 0.2% ds (Chita lab) 1% ds 2% ds 5%ds 10%ds 30
Maximum load (lbf) PEEL ADHESION All samples failed in the rubber substrate, not by the adhesion of rubber to metal. 180 160 140 120 100 80 60 40 20 0 0 9.65 19.3 28.95 38.6 48.25 57.9 67.55 77.2 N990 loading (phr) 31
OVERALL BENEFITS OF USING N990 Good static properties Higher rebound resilience Better dynamic properties Lower tan delta Lower dynamic to static spring ratio Lower dynamic stiffness Better adhesion Potential Cost savings Higher filler loading of N990 at same hardness value vs smaller particle size carbon blacks 32
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GLOBAL ADVANTAGE 34