Barium sulfate is unfamiliar to most people, and some may even consider it harmful.
In reality, barium sulfate is everywhere in our daily lives. It’s found in household items like refrigerator and air conditioner casings, plastic decorations, packaging bags, and paints.
1. What is barium sulfate, and where does it come from?
In nature, barium sulfate is a natural mineral called barite powder. Pure barite powder is colorless and transparent and is harmless to the body in direct contact. The melting point is as high as 1580℃ and it is insoluble in water. It is corrosion-resistant, non-toxic, and non-magnetic. It can absorb X and Y radiation.
Regarding barium sulfate, we have talked many many topics. Such as its production, characteristics, application, and other top 10 questions. We have talked about Natural Barium Sulfate vs. Precipitated Barium Sulfate Difference. we have written Precipitated Barium Sulfate roles in coating and analyzed degrading barium sulfate in plastics. For further details, please refer to the corresponding content.
China is rich in barite powder resources, especially in Hunan, Guizhou, Guangxi, and other regions. These areas have greater reserves than many overseas locations. It makes China the world’s leading producer of barite powder.
2. Main function
It improves the corrosion resistance of products such as sports shoes. It can add weight and texture to plastic speaker enclosures. It has unparalleled heat resistance and excellent dispersion properties, and significantly reduces production costs.
3. Main feature
When barium sulfate is used as a filler in rubber together with titanium dioxide and pigments, it can reduce the amount of pigments and save about 10% of the cost. About 25% barium sulfate is added to the surface of PP to make it similar to ABS. It can not compromise the properties of PP, providing a glossy and durable surface.
Many manufacturers choose barium sulfate-filled particles for electrical products made of ABS. Because they require high strength and gloss. It not only reduces the cost but does not affect the appearance of the product.
Some manufacturers choose calcium carbonate, but it can produce an opaque effect. Making it difficult to achieve the desired appearance for electrical products. For customers who use ABS as raw material, barium sulfate-filled particles are the first choice.
4. How to achieve high transparency?
Many people wonder how barium sulfate plastic filler pellets can achieve high transparency.
4.1 Relationship between Barium Sulfate and Transparency in Film Products
Adding barium sulfate at high pressure between 150-170 degrees is recommended at 5%-10% for better transparency. At low pressure between 150-200 degrees, it’s suggested to add 15%-20%. The amount added depends on the film’s quality requirements. Barium sulfate’s physical properties peak around 30%-35% addition in film production. Exceeding this point decreases overall performance, affecting film quality.
4.2 Relationship between Barium Sulfate Pellets and Transparency in Film Processing
Nano barium sulfate filler pellets have gained rapid popularity. Adding this material in HDPE, LDPE, and LLDPE film processing:
- Adding up to 20% minimally affects film transparency.
- It enhances production efficiency and reduces costs.
- Improves mechanical strength and decorative appearance, making printing easier.
4.3 High Gloss Characteristics of Barium Sulfate
Using barium sulfate as a filler with titanium dioxide and pigments in plastics reduces pigment usage and costs by approximately 10%. Applying around 25% barium sulfate to PP surfaces makes them resemble ABS without affecting PP’s properties. It can provide a glossy and hard surface. Barium sulfate can fill up to 80% of its weight, effectively dampening noise in drainage pipes, speakers, and curtains. It enhances glossiness, color, scratch resistance, and dimensional stability in household appliance casings.
4.4 Factors Affecting Transparency of Barium Sulfate Pellets
Factors include particle size, impurities, crystal structure, wetting agents, and heat treatment.
- Smaller particle size increases surface area, scattering more light and reducing transparency.
- Impurities like metal ions (iron, copper, manganese), calcium carbonate, and silicates decrease transparency.
- Crystal structure affects transparency; single-crystal structures are more transparent than polycrystalline. Different wetting agents and quantities affect pellet transparency.
- Heat treatment at high temperatures causes surface oxidation, impacting transparency.
