As the performance requirements for rubber products continue to increase, traditional fillers such as carbon black and precipitated silica are gradually showing limitations in certain applications. Functional nano-reinforcing fillers are becoming a research hotspot in the rubber industry due to their unique particle size effects, surface activity, and structural characteristics. Based on the technical characteristics, experimental data, and comparative analysis of PF series products of GreenThinking®PF81 nano-reinforcing filler, this paper systematically discusses its reinforcing effect, processing performance, aging behavior, and application prospects in rubber. It also introduces the professional production base located in Zhaoqing, Guangdong, offering high-quality kaolin-based functional fillers for the rubber industry. As leading Rubber reinforcing filler Manufacturers and Rubber Functional filler Manufacturers China, we are committed to providing the market with the best solutions.
1. Introduction
The application of inorganic fillers in the rubber industry has a long history. Their cost advantages and functional diversity make them an important supplement to traditional fillers like carbon black. In recent years, with the development of surface modification technology and nanomaterial science, the reinforcement, dispersibility, and processing performance of functional nano-fillers in rubber have been significantly improved. Particularly under the industry trend of green environmental protection, energy saving, and emission reduction, developing high-performance, low-energy, and renewable fillers has become an inevitable choice. This is a key strategy for many Rubber reinforcing filler Suppliers looking to innovate.
GreenThinking®PF81 is a nano-scale reinforcing filler launched by Shanghai Powerflex New Material Co., Ltd. that undergoes surface hydroxyl removal activation treatment. It uses high-whiteness natural minerals as raw materials and is processed through strict internal control processes. It has the characteristics of uniform particle size distribution and high chemical purity. Its layered structure, high specific surface area, and hydroxyl-free surface make it exhibit excellent performance in the rubber and plastics industry. As a premium example of Surface treated nano fillers for rubber, PF81 is designed to meet the evolving needs of modern compounders.
2. Product Characteristics of GreenThinking®PF81
2.1 Physical and Chemical Properties
GreenThinking®PF81 is prepared from selected natural mineral raw materials through processes such as crushing, grinding, classification, surface modification, and nano-treatment. Its key physical and chemical indicators are as follows:
- Appearance and Structure: Layered structure, high porosity, lightweight, soft, with a reasonable particle size distribution.
- Surface Characteristics: Through activation treatment that removes hydroxyl groups, the surface is strongly hydrophobic, has good compatibility with the rubber matrix, and is not easy to agglomerate.
- Chemical Composition: SiO₂ content about 55%, Al₂O₃ content about 42%, contains a small amount of TiO₂, loss on ignition <0.3%.
- Key Indicators:
- Whiteness (GE): ≥94%, suitable for light-colored and colored rubber products, making it ideal as White fillers for colored rubber products.
- Median Particle Size: Approximately 800 nm, with most particles distributed in the nanometer scale.
- Oil Absorption Value (ASTM D-281): 60-70 g/100g, indicating good structure and filling capacity.
- Specific Gravity: 2.53, moderate density, conducive to high filling.
- pH Value: 6-7, close to neutral, with no adverse effect on the vulcanization system.
- Moisture Content: <0.3%, good storage stability.
- 325 Mesh Residue: <0.4%, high fineness, good dispersibility.
2.2 Functional Advantages
- High Reinforcement: The reinforcing effect in rubber is slightly better than N660 carbon black and close to N550. It can partially replace carbon black for use in non-black products, offering a viable solution for replacing N550 with functional fillers and helping customers reduce carbon black cost.
- Excellent Processing Performance: Good dispersion in rubber, good fluidity, stable dimensions. It can extend scorch time (TS2) and shorten the vulcanization cycle (TC90), improving production efficiency.
- Improved Product Performance: Enhances wear resistance, oil resistance, and heat aging resistance; low compression set, suitable for dynamic applications such as seals; excellent electrical insulation, suitable for wires and cables.
- Environmentally Friendly and Safe: Non-toxic and odorless, meeting environmental requirements, suitable for high-end fields such as food contact and medical applications, serving as Non toxic fillers for food grade rubber.
3. Experimental Data and Performance Analysis
To verify the application effect of GreenThinking®PF81 in rubber, we conducted comparative experiments in an EPDM peroxide curing system and made a parallel comparison with other PF series products (PF82, PF87, PF88, PF91, PF93).
3.1 Experimental Formula
The experiment uses a typical EPDM peroxide curing formula, as detailed in Table 1.
Table 1. Experimental Formula
| Raw Material | Amount (phr) |
| EPDM 5601 | 115 |
| CZ500R100 | – |
| Filler (PF Series) | 40 |
| Paraffinic Oil | 60 |
| 30# Oil | 50 |
| STA (Stearic Acid) | 1 |
| MA-L221L-241 | – |
| DCP-40C (Peroxide) | 6 |
| PL400/70 | 2 |
| S-80 (Sulfur) | 0.3 |
| GE (Other Additives) | 0.3 |
| Total | 316.3 |
3.2 Curing Characteristics
The curing characteristics were tested under the conditions of 180°C × 5 min, and the results are as follows:
Table 2. Curing Characteristics Data
| Item | PF81 | PF82 | PF87 | PF88 | PF91 | PF93 |
| ML (dN.m) | 0.85 | 0.90 | 0.88 | 0.88 | 0.87 | 0.92 |
| MH (dN.m) | 8.33 | 7.64 | 7.70 | 8.14 | 8.40 | 8.35 |
| TS2 (m:s) | 0:48 | 0:48 | 0:45 | 0:45 | 0:52 | 0:55 |
| TC90 (m:s) | 3:25 | 3:16 | 3:06 | 3:09 | 3:25 | 3:32 |
Analysis:
- PF81 has a low ML, indicating moderate viscosity during mixing and good processing fluidity.
- The high MH value indicates a high cross-linking density and a significant reinforcing effect.
- TC90 is 3 minutes and 25 seconds, which is in the mid-to-upper range, but the overall performance is excellent.
3.3 Physical and Mechanical Properties
The test specimens were prepared under the conditions of 175°C × 6 min, and the test results are as follows:
Table 3. Physical and Mechanical Properties Data
| Item | PF81 | PF82 | PF87 | PF88 | PF91 | PF93 |
| Hardness (Shore A) | 65 | 65 | 66 | 67 | 64 | 66 |
| Tensile Strength (MPa) | 13.63 | 13.55 | 12.36 | 13.38 | 13.84 | 13.99 |
| Elongation at Break (%) | 442 | 541 | 505 | 509 | 471 | 504 |
| 100% Modulus (MPa) | 3.12 | 3.01 | 3.04 | 3.34 | 2.71 | 3.34 |
| Specific Gravity (g/cm³) | 1.185 | 1.188 | 1.185 | 1.184 | 1.198 | 1.196 |
| Compression Set (%, 150°C×22h) | 21.9 | 34.4 | 40.6 | 31.3 | 27.7 | 21.8 |
Analysis:
- The tensile strength of PF81 reaches 13.63 MPa, which is at a high level among all samples, indicating its significant reinforcing effect.
- The elongation at break is 442%, balancing strength and elasticity.
- The compression set is only 21.9%, much lower than other products, indicating that PF81 has excellent long-term elastic retention in dynamic sealing applications. This makes it ideal for producing High air tightness rubber compounds.
3.4 Hot Air Aging Performance
Aging conditions: 150°C × 22h, the test results are as follows:
Table 4. Hot Air Aging Performance Data
| Item | PF81 | PF82 | PF87 | PF88 | PF91 | PF93 |
| Hardness Change (Shore A) | +5 | +6 | +6 | +6 | +8 | +7 |
| Tensile Strength Change Rate (%) | +4.5 | -4.2 | +3.6 | +3.4 | -0.4 | -3.1 |
| Elongation at Break Change Rate (%) | -3.4 | -18.7 | -13.3 | -10.2 | -12.1 | -23.4 |
Analysis:
- The tensile strength of PF81 increased by 4.5% after aging, indicating that it forms a more stable cross-linked network in the peroxide curing system and has outstanding thermal oxidative aging resistance.
- The elongation at break only decreased by 3.4%, maintaining good flexibility.
3.5 Experimental Conclusion
Based on the above data, PF81 excels in initial performance, aging performance, compression set, and other aspects. It is particularly suitable for dynamic sealing products with strict requirements for compression set. Its short TC90 time is beneficial for improving production efficiency. In the peroxide-cured EPDM system, PF81 offers the highest cost-performance ratio, solidifying its status as a premier High performance rubber fillers.
4. PF Series Product Selection Guide
According to the PPT information in Appendix 3, the GreenThinking®PF series includes PF81, PF82, PF87, PF91, PF93, etc.( if need more data report , contact us to get more details for visit our website find download section ) For different rubber systems and performance requirements, the following selections are recommended:
Table 5. PF Series Product Selection Guide
| Product | Applicable System | Characteristics |
| PF81 | Peroxide Curing System | High reinforcement, low compression set, excellent overall performance. |
| PF82 | Sulfur Curing System | Good processing performance, good dispersibility, suitable for general-purpose rubber. |
| PF87 | Non-polar Rubber (EPDM, NR, etc.) | Reinforcement close to N550, excellent heat aging resistance. |
| PF91 | Polar Rubber (NBR, HNBR, etc.) | Good compatibility with polar matrix, improved wear resistance, making it ideal as Reinforcing agents for NBR seals. |
| PF93 | High Filling System | High filling rate, maintains good physical properties, low compression set, a perfect example of a High filling low hardness rubber filler. |
In addition, PF95, PF94, etc., are reserved products and can be customized according to customer needs.
5. Industry Applications and Typical Cases
The GreenThinking®PF series is widely used in the following fields:
- Automotive Rubber Products: Sealing strips, oil seals, shock-absorbing parts, hoses, etc. PF81, with its low compression set, is particularly suitable for high-temperature dynamic seals around the engine, making it a preferred choice among Fillers for automotive sealing strips.
- Industrial Rubber Products: Belts, rollers, sheets, gaskets, etc. The PF series can improve wear resistance and oil resistance, extending service life.
- Wires and Cables: Insulation layer, sheath material. The high insulation and low water absorption of the PF series make it an excellent cable filling material.
- Light-colored and Colored Products: Sports shoe materials, medical supplies, food contact products. The high whiteness and non-toxic, odorless characteristics of the PF series meet high-end requirements, serving as excellent White fillers for colored rubber products.
Typical Application Cases:
- A well-known automotive seal supplier used PF81 to replace part of the carbon black in an EPDM peroxide formula. This not only reduced costs but also improved the compression set of the product, passing the 150°C × 70h aging test, demonstrating how to reduce carbon black cost effectively.
- An industrial hose manufacturer introduced PF91 into an NBR oil-resistant formula. The oil resistance volume change rate of the hose was reduced by 15%, and the tensile strength was increased by 10%.
6. Introduction to the Zhaoqing, Guangdong Factory
To meet the market demand for high-quality functional fillers, we have established a professional production base in Zhaoqing City, Guangdong Province, specializing in providing modified kaolin series products for the rubber industry. As a leading Rubber reinforcing filler Factory, our facility is designed to deliver consistent quality and supply.
6.1 Factory Overview
The factory covers an area of approximately 30,000 square meters and has modern standard workshops, an R&D center, and a quality testing center. The production capacity is sufficient to meet the bulk needs of domestic and international customers.
6.2 Advanced Production Equipment
The factory has introduced international advanced wet grinding, classification, surface modification, and drying complete sets of equipment, achieving full automation control from raw materials to finished products. Key equipment includes:
- High-precision air classifier
- Continuous surface modifier
- Spray drying tower
- Laser particle size analyzer
- Specific surface area analyzer
- Full set of physical property testing instruments such as whiteness meter and pH meter
6.3 Strict Quality Control
We have established a whole-process quality control system from raw material procurement to finished product shipment. Each batch of products undergoes multiple testing procedures such as particle size, whiteness, oil absorption value, pH, moisture, and sieve residue to ensure product stability and consistency. The company has passed the ISO 9001 quality management system certification, and its products comply with environmental regulations such as RoHS and REACH.
6.4 R&D and Technical Support
The factory has an R&D center equipped with a professional technical team that can customize product development according to customer needs. We maintain close cooperation with many universities and scientific research institutions to continuously promote technological innovation in kaolin functional fillers.
6.5 Corporate Vision
We always adhere to the corporate spirit of “Enterprising, Efficient, Win-Win” and are committed to becoming the most trusted functional material service provider in the rubber industry. Customers from home and abroad are welcome to visit the factory for discussions and cooperation, jointly promoting the green and sustainable development of the rubber industry.
7. Conclusion
GreenThinking®PF81 and its series of products, with their excellent reinforcing properties, processing adaptability, environmental characteristics, and stable product quality, are becoming indispensable functional fillers in the rubber industry. Experimental data confirm that PF81 has high cost performance in peroxide curing systems, especially suitable for products with strict requirements for compression set and aging resistance. Combined with the strong manufacturing capabilities of the Zhaoqing, Guangdong production base, we will continue to provide customers with high-performance, high-stability products and solutions, helping the rubber industry move to a higher level. By offering a cost effective rubber filler, we support our clients in optimizing their formulations and reducing overall costs, including through the partial replacement of precipitated silica.
FAQs
1. How can GreenThinking® PF81 help me reduce carbon black cost in my rubber compounds?
GreenThinking® PF81 is designed as a high-performance functional filler that can partially replace more expensive reinforcing fillers like carbon black (e.g., N550, N660) and precipitated silica. Our experimental data shows its reinforcing effect is close to N550. By using PF81 as a cost effective rubber filler, you can significantly lower your raw material costs without sacrificing, and in some cases even improving, the final mechanical properties of your product.
2. Is GreenThinking® PF81 suitable for producing food-grade or medical rubber products?
Yes, it is. GreenThinking® PF81 is produced from high-purity natural minerals and is non-toxic and odorless. It meets stringent environmental and safety requirements, making it an ideal choice as Non toxic fillers for food grade rubber. Its high chemical stability and purity ensure it is safe for applications requiring indirect or direct contact with food and medical materials.
3. Which PF series product is best for improving the performance of NBR oil seals?
For polar rubber like NBR (Nitrile Butadiene Rubber), which is commonly used in oil seals, we recommend GreenThinking® PF91. It is specifically engineered for polar systems, offering excellent compatibility with the NBR matrix. This results in improved abrasion resistance, enhanced oil resistance, and better overall durability, making it one of the most effective Reinforcing agents for NBR seals.
4. Can these fillers be used to achieve high hardness with low compound density?
Absolutely. Products like GreenThinking® PF93 are specifically designed as High filling low hardness rubber fillers. They allow for a high loading level in the compound, which can increase hardness and modulus while maintaining good processability and without a disproportionate increase in compound weight or cost. This is particularly useful for optimizing the performance-to-cost ratio of various industrial rubber goods.
Contact Us
For more information about GreenThinking®PF81 and our other high-performance fillers, or to discuss how we can help optimize your rubber compounds, please contact us:
Shanghai Powerflex New Material Co., Ltd.
(A Sanezen Company)
Website: www.sanezenrubber.com
WhatsApp: +86 136 7164 1995
Commercial Address:
Room 1606, Boda Commercial Building, No. 11 Puhuitang Road, Xuhui District, Shanghai, China 200030
Tel: 021 6487 9251
Mobile: 136 7164 1995
Email: yorichen@sanezen.com
Factory Address:
Zhaoqing City, Guangdong Province
Rubber Solution Provider
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