The main advantage of color masterbatch and additive masterbatch is the ability to economically color raw polymers, making them an essential material in the plastic and polymer industry.
What Is Masterbatch? | Masterbatch Definition
Masterbatch, also known as plastic color concentrate, is a formulation used for plastic coloring and performance enhancement.
In this process, pigments, colorants, and polymer additives are uniformly dispersed in a polymer carrier, then extruded and converted into masterbatch granules.
These granules are added to polymer resin during injection molding, extrusion, film, or fiber production at a specific ratio to ensure uniform color dispersion. The typical addition rate ranges from 1% to 4%.
Masterbatches contain color pigments as well as thermal stabilizers and UV stabilizers concentrated in a polymer carrier. When added at low dosages, they enhance color consistency, heat resistance, and UV stability of the final plastic product.
The additive loading in masterbatch can reach up to 70% by weight, while the usual application rate is 1% to 5%. Custom masterbatch manufacturing allows production tailored to specific requirements such as color shade, thermal performance, and UV resistance.
General-Purpose Masterbatches and Limitations
Some general-purpose masterbatches are designed to color a wide range of plastic resins, but using a single solution has limitations.
Final color may vary depending on the natural color and transparency of the polymer, and masterbatch–polymer incompatibility can negatively affect mechanical properties or even cause product failure.
Difference Between Masterbatch and Pre-Colored Resin
Color masterbatch is a highly concentrated product added to raw polymer during processing, whereas pre-colored plastic resin is fully compounded with pigments and ready for use.
From an economic perspective, using masterbatch is more cost-effective, allows the purchase of natural resin, prevents color aging, and preserves polymer properties by minimizing thermal exposure.
Color Matching Process (Masterbatch Color Matching)
The process begins with defining the final color. Masterbatch color matching is performed based on Pantone, RAL, or Munsell standards, or according to a customer-provided sample.
Color matching is carried out using the same polymer material supplied by the customer. Initially, computer-based color analysis is performed, followed by visual and instrumental evaluation.
Spectral data, laboratory samples, and technical documentation are provided. Once approved, the color chip and pricing are submitted for final confirmation. The entire color matching process typically takes about one week.
Placing an Order (Masterbatch Order Process)
After color approval, the order is placed and color masterbatch production begins based on the approved formulation.
Each production batch generally takes 1 to 2 weeks, with a minimum order quantity of 25 kg per color.
Masterbatch Production
Masterbatch consists of polymer granules containing a high concentration of plastic additives, more than what is required in the final product. These granules are blended with raw polymer during injection molding, extrusion, film, or fiber manufacturing to impart color or modify specific properties.
Compared to powder pigments, pastes, or liquid additives, plastic masterbatch provides superior processing stability due to precise and consistent pigment dosing.
Additionally, reduced handling of powders keeps the production environment clean and safe.
Masterbatch Applications
In general, plastic masterbatches are classified into three main categories:
1. Color Masterbatch
Used for plastic coloring, delivering uniform and long-lasting color in the final product.
2. Additive Masterbatch
Designed to enhance physical and chemical properties such as UV resistance, antistatic behavior, flame retardancy, and anti-blocking.
3. Filler Masterbatch
Contains fillers such as calcium carbonate (CaCO₃) and is commonly used for cost reduction and improvement of certain mechanical properties.
Production Goal
The primary goal of masterbatch manufacturing is achieving uniform and ideal dispersion of additives within the polymer matrix.
Depending on the raw material, masterbatches with additive loadings ranging from 20% to 90% are available.
Production Process
A premix consisting of polymer, pigments, and dispersing additives is fed into a single-screw or twin-screw extruder.
The extruder performs homogenization, wetting, and uniform dispersion of pigments within the polymer matrix. In most cases, strand pelletizing systems are used for granule formation.
Quality Control (QC)
Masterbatch quality control varies based on the final application and includes injection molding tests, evaluation of color strength, and pigment dispersion.
Each production batch is assigned a unique batch number to ensure full traceability. No product leaves the facility without passing all required quality inspections.
Buying Masterbatch
Choosing the right masterbatch supplier and product plays a critical role in the quality of the final plastic product.
High-quality plastic masterbatch ensures production stability, reduces waste, and improves overall product competitiveness.
Investing in standardized and compatible masterbatch solutions is a strategic decision for plastic manufacturers.