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In the plastics industry, optimizing raw material costs while maintaining product performance is a critical competitive factor. Recently, virgin resin prices increased by 30–70% across different polymer grades during recent market fluctuations. Under such pressure, manufacturers have sought technical solutions that balance cost efficiency and material performance. One of the most widely adopted solutions is filler masterbatch.

However, filler masterbatch is not simply a low-cost additive. Its effective use requires a clear understanding of its composition, its impact on mechanical properties, and its compatibility with various processing technologies. This article provides a structured and technical overview of filler masterbatch and its role in plastic production.

1. What is filler masterbatch?

1.1. Definition of Filler Masterbatch

Filler masterbatch is a pelletized additive produced by compounding mineral filler—most commonly calcium carbonate (CaCO₃)—with a carrier resin and dispersion additives.

A typical filler masterbatch formulation includes:

• 60% - 85% calcium carbonate (CaCO₃)
• Carrier resin (PE or PP)
• Dispersion and thermal stabilizing additives

Filler masterbatch is not used independently. Instead, it is blended with virgin resin at controlled ratios during processing methods such as injection molding, blown film extrusion, and profile extrusion.

According to MarketsandMarkets, the global calcium carbonate market reached USD 48.5 billion in 2022 and is projected to reach USD 64.9 billion by 2027. This growth reflects the increasing demand for mineral fillers across industries, including plastics manufacturing.

The production of filler masterbatch includes 4 steps:

Step 1: CaCO3, additives and plastic resin are mixed together by high-speed mixer. 

Step 2: The mixture above is completely melted at high temperature.

Step 3: That mixture is then cooled and put into a screw extruder, pushed forward and pressed into the mold. 

Step 4: The output of the extruder is cut into similar small pieces. They are filler masterbatch applied into plastic manufacture.

1.2. The Role of Filler Masterbatch in Plastic Systems

Filler masterbatch serves two primary functions in polymer formulations:

Cost Optimization: Calcium carbonate typically costs 2–4 times less than virgin resin, depending on market conditions. By replacing 20% of virgin resin with filler masterbatch, manufacturers can reduce total raw material costs by approximately 8–15%, depending on the application.

Adjustment of Mechanical Properties: Due to its high modulus, CaCO₃ increases the stiffness of the polymer matrix when properly dispersed. This may result in:

• A 10–25% increase in modulus
• Reduced shrinkage in injection molding
• Improved opacity in film and packaging applications

However, excessive filler loading—typically above 30–40%—may reduce tensile strength and elongation if not properly formulated.

1.3. Difference Between Filler Masterbatch, Compound, and Virgin Resin

Filler masterbatch is often confused with compounded plastic materials. However, these materials differ significantly in function and usage. Filler masterbatch provides flexibility, allowing manufacturers to adjust filler loading according to product requirements. Compounds, in contrast, are pre-formulated materials designed for direct processing.

Criteria	Filler Masterbatch	Compound	Virgin Resin
Function	Additive for blending	Finished material	Base polymer
Usage Ratio	5%–40%	100%	100%
Formulation Flexibility	Adjustable	Fixed formulation	No additive

 

Related: Top 3 suppliers for you to buy plastic filler calcium carbonate

2. Why choose filler masterbatch?

First of all, primary plastic is made up of high molecular polymers, which are constituted of monomers. To create primary plastic, humans combine natural components including cellulose, rubber,... or Ethin, Benzol, Ethene gas, and most importantly - kerosene together. 

Read more: What is plastic? Everything you need to know about plastic

Thus, using 100% primary plastic in plastic manufacture has the following disadvantages:

• Firstly, primary plastic is non eco-friendly. It takes hundreds of years for products made of primary plastic to be completely decomposed under natural conditions.

• Secondly, kerosene - the main component of primary plastic largely depends on foreign suppliers, which ends up with a relatively high price of finished products. Besides, due to the instability of kerosene supply, primary plastic is easily influenced by negative effects of foreign market.

• Thirdly, kerosene is a non-renewable resource, thus contributing to the unsustainable and unstable development of firms which takes kerosene as the main input material. 

With a view to providing customers with an appropriate solution to address the root of the production expense problem, filler masterbatch was born. 

Related: Top 3 industries that benefit most from filler masterbatch

3. How it benefits plastic products?

So, how exactly plastic firms benefit from filler masterbatch? 

• Product’s cost decrease: One of the main components of filler masterbatch is CaCO3, which is famous for its rich and high-quality reserve worldwide. This will definitely reduce production cost, stabilize the amount of input materials and significantly improve product’s competitiveness. 
• Physical properties enhancement: Rigidity and plasticity increase, shrinkage decrease.

• Flexible applications: Thanks to the suitable toughness and stable chemical properties, filler masterbatch can be easily cut into small pieces or crushed into powder. It can also be mixed with other plastic resin to create new products with more functionalities. 
• Forming enhancement: Filler masterbatch plays a vital role in adequate heat distribution in blow film or raffia, thus getting rid of bubbles on plastic surface situations. 

4. What are filler masterbatch's applications in the plastic industry?

Thanks to its outstanding advantages regarding functionality and price, filler masterbatch has been widely applied into many industries. 

4.1. Injection molding

Injection molding is a common technology based on two main phases: extruding melted plastic mixture and pressing it into the mold for forming. This method is used to create many plastic products including rice cooker lid, toilet lid, buckets, baskets, boxes, toothbrush, plastic toys,...

With filler masterbatch, the injection molding products have these following advantages:

• Manufacturing lead time decrease due to the good thermal conductivity of CaCO3. 
• Input material expenses reduce thanks to the reasonable price of CaCO3, which is significantly more economical than primary plastic. 
• Energy saving due to the decrease of manufacturing lead time. 
• Stability increase during the product forming process. 
• Carbon footprint decrease thanks to the replacement of primary plastic with CaCO3.
• Product’s physical properties increase (flexibility, rigidity,...)
• Product’s tear resistance increase regardless of its thickness. 
• Product’s printability increase. 

4.2. Extrusion

One of the most popular plastic manufacturing methods is extrusion. After being mixed together, input materials go into the extruder through the hopper. This combination is then melted under extremely high temperature and extruded by a mould clamping cylinder in the form of fibers. The cross section of these depends on the form of the mould clamping cylinder (commonly square or round). 

Filler masterbatch has been applied in extrusion

The plastic fibers are then cooled by water or fan on the assembly line and cut into small pieces for packaging.  

Extrusion is a common method to produce plastic products such as PVC pipes, straws, gutters,... thanks to its simple technology.  

The application of filler masterbatch into extrusion helps: 

• Reduce production cost thanks to the reasonable price of CaCO3 compared to primary plastic, thus decreasing product’s price and driving competitiveness. 
• Enhance rigidity and Cải thiện độ cứng và khả năng chịu lực cho thành phẩm.

4.3. Blown film

Blown film is a common plastic manufacturing technology, especially in producing packaging (thin-film packaging, biodegradable packaging, paper packaging, packaging roll film, waste packaging,...). To create packaging film, materials mixture enters the extruder through the hopper. After being melted, it goes through an annular slit die and is formed as a thin tube. The tube is then cooled by the air ring and continues moving upwards until it passes through nip rolls, where it is flattened. This lay-flat tube is then taken back down via more rollers. The edges of the lay-flat are slit off to produce two flat film sheets and wound up onto reels.

Filler masterbatch is used in blown film to improve the rigidity, control heat, enhance the turbidity and most importantly, cut production expense. 

5. EuroPlas filler masterbatch 

EUROPLAS is one of Vietnam’s leading masterbatch manufacturers, providing advanced material solutions to the global plastics industry. With 18 years of experience in production and export, EUROPLAS supplies products to over 95 countries, serving a wide range of sectors including packaging, household goods, and industrial applications.

Our most popular products including:

• PP filler masterbatch: the combination of PP resin, high-quality CaCO3 and additives. 
• PE filler masterbatch: is produced with PE resin, high-quality CaCO3 and additives. 
• PS filler masterbatch: the mixture of PS resin, CaCO3 and other additives. 
• BiOMates: includes bio plastic, CaCO3 and other additives. 

For further information and samples, please contact us HERE!