Transfer Molding

Imparting color plays a crucial role in injection molding processes to manufacture products according to the specific vision of the part. There are various processes through which color can be added to the injection molding process and one of the most popular processes is color masterbatch.

A color masterbatch is typically a collection of highly pigmented plastic pellets that cannot undergo injection molding by themselves. These pellets are thus mixed with uncolored plastic pellets so that the color combines with the plastic, thereby creating an overall color that is tailored and unique to the project requirement. In this article, we discuss various parameters and specifications of color masterbatch in detail.

Table of Contents

What is a Color Masterbatch?

The color masterbatch is also referred to as color type or color concentrate. The primary purpose of color masterbatch is to color polymers with specific hues and tones. You should note that a color masterbatch can be engineered to manufacture any type of hue in the color spectrum.

A color masterbatch is a type of pigment blend that is injected and mixed into raw polymers and is employed for coloring thermoplastics during the manufacturing process. A color masterbatch is highly concentrated and its composition can consist of one or more colorants. 

color master batch

The color masterbatch is obtained by distributing pigments and additives into a polymer carrier by heat treatment and a high-shear mixing extruder. This mixture is cooled off, cut, and formed into granules via a pelletiser. The pigments are uniformly loaded in an ultra-constant amount and this is also referred to as the pigment concentration. The range of additives is typically between 40-65 % but in exceptional cases, this range can be altered to be between 15-80 %. 

Color masterbatch is further categorized into the following types:

  • Single Pigment Concentrates (SPC): SPC Masterbatches are also referred to as mono-batches. They primarily consist of a particular pigment. 
  • Customized Color Masterbatches: These types of color masterbatches are mixtures of various powder pigments. They are bespoke formulations that are designed for specialized projects. 
  • Custom Color Masterbatches: They are a mixture of various SPC granules. These color masterbatches are custom and produced precisely as per the requirement of the project and the customer.

Components of Color Masterbatch

A color masterbatch consists of four elements i.e. colorants, carriers, dispersants, and additives. This composition is referred to in the industry as its recipe. Let’s understand these components further: 

color masterbatch components


Colorants are further classified into several categories such as organic dyes, organic pigments, and inorganic pigments. 

You should note that dyes can be used for transparent coloration as they are soluble in plastics whereas pigments remain intact in their original particle form inside the plastic which is why they need to be dispersed within the plastic.

Some of the most commonly used organic pigments are phthalocyanine red, phthalocyanine blue, phthalocyanine green, light fast red, macromolecular red, macromolecular yellow, permanent violet, azo red, etc., and inorganic pigments are cadmium yellow, titanium dioxide, carbon black, iron oxide red, iron oxide yellow, etc. 

The following table enlists some of the properties of the colorants:

color masterbatch colorant properties


A carrier is one of the most essential components of color masterbatches and it serves as the base material to hold and disperse the colorants uniformly throughout the plastic. 

A carrier in a color masterbatch acts as a dispersion medium that ensures that the colorants are uniformly blended with the polymer. In addition, carriers provide compatibility with the polymer which enables easy processing. 

There are several types of carriers and they are chosen as per application and compatibility with the target polymer. Let’s understand the various types of carriers: 

  • Polyethylene Carriers: These types of carriers are widely compatible with a range of polymers such as polyethylene, polypropylene, and more. They are versatile and suitable for various processing methods, such as extrusion, blow, and injection molding.
  • Polypropylene Carriers: These carriers exhibit excellent thermal stability and are thus employed in applications that require high-temperature processing.
  • Polyvinyl Chloride Carriers: These carriers ensure effective dispersion and color retention in polyvinyl chloride applications.
  • Ethylene Vinyl Acetate Carriers: They are primarily employed for soft and flexible applications.


Dispersants in color masterbatches avoid the flocculation of pigments and dyes. They promote uniform dispersion of the colorant. To ensure that there is no agglomerate, the following should be noted: 

  • The melting point of the dispersant is lower than that of the resin
  • It should be compatible with resin
  • The dispersant should have a good affinity with the pigment. 

Some of the most commonly employed dispersants in color masterbatches are polyethylene low-molecular wax and stearate.


The additives in a color masterbatch can permanently modify the properties of the plastic. It is included only when it is required for the project and requested by the customer. Some of the properties that additives can impart are flame-retardant, anti-bacterial, anti-static, anti-oxidation, etc. 

Types of Color Masterbatches

Silk-like Polymer Alloy Masterbatches

Silk-like Polymer Alloy Masterbatches impart silk-like luster through polymer alloy technology and exhibit high color saturation and brilliance.

Frosted Masterbatches

Frosted masterbatches impart a frosted glass-like appearance without processing the mold surface.

Anti-yellowing Masterbatches

Anti-yellowing color masterbatches have a highly dispersed titanium oxide and are excellent in suppressing yellowing caused by titanium.

Low shrinkage Pigments Masterbatches

Low-shrinkage pigments exhibit excellent color stability and high dispersion. This type of color masterbatches avoids plastic warping or distortion in molded parts.

Black and White Color Masterbatch

Black and white color masterbatches are common color masterbatches that have a high functional value. 

A white masterbatch is often used to create plastic parts with coating and laminations whereas a black masterbatch is employed to manufacture black-colored products. You should note that black color masterbatch can also be designed for a wide range of color depth and crystallization.

Color Masterbatch Ratio

The primary goal of determining the color masterbatch ratio or proportion is to achieve a uniform coloring effect with no streaks, spots, or defects. Let’s understand the various ratios:

1:100 Ratio

The 1:100 ratio is the most cost-effective ratio of color masterbatches however; it is not recommended to use this particular ratio as uneven pigment dispersion is likely to occur.

1:50 Ratio

1:50 color masterbatch ratios are employed for general coloring requirements. They are mostly used for Polyethylene and Polypropylene color masterbatches.

1:20 Ratio

The 1:20 color masterbatch is employed for advanced plastic parts and can be used for a variety of processes such as injection molding, blow molding, and other processes, etc.

1:20 and above Ratio

This particular ratio is typically employed for coloring high-grade cosmetic containers. It is also mostly used in small injection molding machines.

Causes for Incorrect Color Development

If the color hasn’t developed as per the ratio i.e. if it’s too light or dark, then the following needs to be considered: 

  • Either the measurement is inaccurate or the pigment may be less or more indicating that the color masterbatch has not been tested carefully. 
  • The next error could be that the resin type is incompatible with the color master batch. 
  • It is also possible that the carrier of the color master batch is incorrectly selected. 

Color Master-batch Applications

Color Master-batch is employed in various industries such as the electronics, automotive, agriculture, construction, packaging, and textile industries. Let’s take a look at some instances: 

  • In the electronics industry, color masterbatches are implemented to impart color to color wires and lighting fixtures.  
  • Color masterbatches are extensively applied in the automotive industry to color interior and exterior car components. 
  • They are also extensively applied in the consumer industry to color various products such as bottles, toys, and furniture. 
color masterbatch applications
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Color Masterbatch Advantages, Challenges, and Precautions

Why should you choose the Color Masterbatch?

color masterbatch advantages

Higher Accuracy in Aesthetic Appearances

Since the additive ingredients are pre-determined, the chances of variance during the manufacturing process are minimal thus, color masterbatches enable higher accuracy in aesthetic appearances. They help in delivering accurate transparency and opacity consistently in the products.

Excellent Color Consistency

You should note that since the binding agents in masterbatch are matched with target polymers, the melting processes are improved which helps color masterbatch to deliver excellent color consistency, especially during large production runs. 

Easy Additives Incorporation

Color masterbatch reduces the complexity of mixing pellet-to-pellet and it eliminates the requirement of a special dosing device in case of minute quantities.

Increased Additive Stability and Shelf-Life

Color masterbatch increases the stability and shelf-life of additives. It helps to protect additives from various environmental factors such as exposure to humidity, temperature, and UV during storage.

Safe Hazardous Materials Handling

Many additives can be hazardous in their raw formulations. In the case of masterbatches, the additives are encapsulated in a polymer resin or a liquid form thereby, reducing its unsafe nature. This not only helps to reduce its hazardous effects but also helps to reduce the requirements for personal protective equipment and technical controls.

Cleaner Production

Masterbatch additives are not only safer to handle but they also enable cleaner production. During processing, pigments, unlike color masterbatch, can become airborne, which results in contamination. In the case of color masterbatch, no powdered additives or color pigments attach to surfaces which reduces cross-contamination, and thereby, cleaner production areas. 

Facilitate a Cost-effective Process

Purchasing colored raw polymers is relatively more expensive than uncolored polymers. In addition, they can be stocked for use with various types of color masterbatch.

Color Masterbatch Challenges and Precautions

Color masterbatch is relatively simple however; some precautions must be noted. These are enlisted below: 

  • Typically, there are various temperature zones around the mixing cavity of an injection molding machine or extruder. You should note that the temperature near the blanking port should be slightly higher to enable the color masterbatch to melt as quickly as possible after it enters the mixing chamber. 
  • The back pressure applied to the injection molding machine must be appropriate as it improves the mixing effect of the screw which further facilitates pigment dispersion.
  • The temperature of the die head of the extruder must be increased to increase the product brightness. 
Contact Us

Color Master Batching requires skilled expertise to produce high-quality parts. It is crucial to understand the various aspects of the technique so that the specific requirements of your project are met. 


While we are more focused on injection molding and tooling, we also cater to various services such as prototyping, retail assembly, and more. You can connect with us for any query, and our team of experts will connect with you.