Lead stabilizers, also known as lead salt stabilizers, are compounds primarily composed of mixtures of lead salts. For many years, they have been widely used as cost-effective thermal stabilizers in the PVC industry. These stabilizers play a crucial role in enhancing the heat resistance and durability of PVC products during processing and end-use.
Advantages of Lead Stabilizers
Excellent Thermal Stability: Lead stabilizers provide superior heat resistance, ensuring long-term thermal stability in PVC applications.
Outstanding Electrical Insulation: They maintain excellent electrical insulation properties, making them suitable for electrical-grade PVC products.
Good Weather Resistance: These stabilizers help PVC products withstand environmental factors like UV radiation and moisture.
Cost-Effective: Lead-based stabilizers are economically advantageous compared to many alternative stabilizers.
Disadvantages of Lead Salt Stabilizers
Poor Dispersibility: Lead salts often have low dispersibility, which can affect the uniformity of stabilization.
High Toxicity: Due to the lead content, these stabilizers pose health and environmental risks, requiring careful handling.
Initial Coloring: They tend to cause initial coloration of PVC products, making it difficult to produce transparent or brightly colored items.
Lack of Lubricity: Lead salt stabilizers do not provide lubrication during processing, which can affect product quality.
Sulfur Pollution Prone: They are susceptible to contamination by sulfur compounds, which may degrade product performance.
Common Types of Lead Salt Stabilizers
Tribasic Lead Sulfate (TBLS)
The most commonly used lead stabilizer, often combined with lead bisphosphate. Due to its lack of lubricity, it requires additional lubricants. Mainly applied in rigid, opaque PVC products.Dibasic Lead Phosphite
Offers slightly lower thermal stability than TBLS but superior weather resistance. It is typically used in combination with TBLS at about half the dosage.Dibasic Lead Stearate (DLS)
Known for its lubricity but lower thermal stability than TBLS and dibasic lead phosphite. It is used as a complementary stabilizer, usually dosed between 0.5 to 1.5 parts per hundred resin (phr).Lead Stearate
Functions as both a thermal stabilizer and lubricant, often serving as an auxiliary stabilizer. It is also used for high-temperature lubrication and in combination with TBLS.
Safety and Usage Considerations
Lead salt stabilizers are typically in powder form, which can be easily inhaled or absorbed by the human body, posing risks of lead poisoning. To enhance performance and safety, formulations often combine multiple lead stabilizers to achieve synergistic effects, improving thermal stability. Additionally, internal and external lubricants are incorporated to produce one-pack lead stabilizer systems optimized for PVC extrusion and injection molding processes.
About Shenzhou Lianfu Plastic-Rubber Tech. Co., Ltd.
Unity can turn stone into gold. Founded in 2007 with a registered capital of 20 million yuan, Shenzhou Lianfu Plastic-Rubber Tech. Co., Ltd. spans over 10,000 square meters and boasts an annual sales volume of 30,000 tons of additives. With the second phase of expansion underway, the company will reach an annual production capacity of 70,000 tons of various PVC stabilizers.
Our team is composed of highly skilled professionals, all with at least secondary education and years of experience in the additives industry. Innovation and quality drive our operations. We focus on producing industrial-grade, nationally certified products that deliver optimized performance and peace of mind to our customers.
Our Innovations in Stabilizers
PVC Lead Salt Stabilizers: We are pioneers in producing and labeling lead salt stabilizers and calcium zinc stabilizers without added calcium powder. By optimizing the effective components and formulas, we have fixed the national standard pipe lead salt stabilizer dosage at 1.8 kg per 100 kg resin — the industry’s limit dosage — achieving international competitiveness.
Calcium Zinc Stabilizers: Leading the industry, our calcium zinc stabilizers avoid harmful additives like high oxides (perchlorates, peracetic acid), hydroxides (alkalis), and others that can damage machinery. Through chemical synthesis and process optimization, our stabilizers guarantee product stability, safety, and excellent processing performance comparable to lead salts, earning strong user approval.
