Masterbatch is a concentrated mixture of pigments, additives, or both dispersed within a carrier resin and added to a base polymer during plastics manufacturing. It is a commonly used method for introducing color and functional additives into molded, extruded, and blow-molded plastic products.
While color may be the most visible part of a finished plastic product, developing the right concentrate involves much more than matching a color standard. The formulation must work with the customer's resin, manufacturing process, processing conditions, performance requirements, and specific needs.
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What Is Masterbatch?
Masterbatch concentrates pigments and/or additives into a compatible carrier resin. During manufacturing, the concentrate is blended with natural resin at a predetermined let-down ratio before the material is processed into the finished product.
In plastics manufacturing, the terms color masterbatch, color concentrate, and pellet color concentrate are often used to describe concentrated color in pellet form.
Masterbatch generally serves one or both of two purposes:
A concentrate that performs well in one resin or process may behave differently in another. This is why masterbatch formulation needs to consider more than the target color alone.
How Is Masterbatch Used?
Before molding or extrusion, masterbatch pellets are metered and blended with the base resin at a predetermined let-down ratio. The appropriate let-down ratio depends on the formulation, resin, color strength, processing conditions, and requirements of the finished product.
Once blended, the material is processed through the manufacturer's existing equipment, where the concentrate distributes throughout the base polymer.
This allows manufacturers to introduce color and functional additives without handling individual pigments or additive components during production.
What Determines the Right Masterbatch Formulation?
Masterbatch development begins with understanding the customer's application and existing production requirements. In most cases, the base resin and manufacturing process have already been selected, and the concentrate is formulated to work within those parameters.
Several factors can influence the formulation, including:
- Base polymer
- Manufacturing process
- Processing temperatures
- Desired color and appearance
- Let-down ratio
- Additive and performance requirements
- Part geometry, wall thickness, and opacity requirements
- Applicable regulatory requirements
- Customer-specific requirements
These factors are interconnected. The resin, processing temperature, wall thickness, additive package, and other production requirements can all influence how a color looks and performs in the finished part.
Regulatory requirements can also influence which raw materials are available for a formulation. In some applications, these requirements may limit the pigments, additives, or carrier systems that can be used while still achieving the desired color or performance.
Pellet Color Concentrates and Liquid Color Systems
Masterbatch is not the only way to introduce color into plastics. Depending on the application and processing equipment, manufacturers may use pellet color concentrates or liquid color systems.
Pellet color concentrates bind pigments and additives within a solid resin carrier, producing pellets that feed alongside the base polymer.
Liquid color disperses pigments and additives through a fluid carrier and introduces the color through liquid metering equipment.
Neither format is automatically the right choice for every application. The customer's resin, processing conditions, equipment configuration, production requirements, and specific needs all help determine the appropriate color delivery system.
Beyond Color: Functional Additive Concentrates
Color is only one role a concentrate can serve. Additive concentrates can be formulated to protect the polymer, modify properties of the finished product, or support processing.
Common technologies include:
- Protection: UV stabilizers, antioxidants, antimicrobials, and flame retardants
- Processing: Processing aids, mold release agents, nucleating agents, and blowing agents
- Surface and appearance: Slip additives, antiblocks, anti-fog additives, matting agents, and optical brighteners
BADGER COLOR USA can supply these technologies as standalone additive concentrates or incorporate additives into a color concentrate when the application requires both color and additional functionality.
Combining technologies within a single concentrate can also simplify material handling when the formulation and application allow it.
Applications Across Plastic Manufacturing
Custom masterbatch formulations are used across a wide range of plastic manufacturing markets and applications, including:
- Packaging
- Consumer products
- Furniture
- Building and construction
- Automotive
- Industrial applications
Requirements can vary considerably from one application to another. Moving from one resin, manufacturing process, or market to another may require adjustments to the concentrate rather than simply using the same formulation under different conditions.
From Color Target to Production
Color matching is one stage of masterbatch development. A color that looks correct in a sample still needs to work with the customer's resin, process, equipment, performance requirements, and production needs.
The concentrate is only one part of achieving consistent results. The customer's resin, processing conditions, equipment, additives, and part design can all influence the appearance and performance of the finished product.
BADGER COLOR USA develops custom pellet color concentrates, liquid color systems, and additive concentrates to work within each customer's material, processing, performance, regulatory, and color requirements.
By considering these requirements throughout development, the goal is to create a formulation that moves from an approved color target to consistent production.
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