As a society, we deal with colored plastics on a daily basis. On the production side, it’s more difficult than it might seem to obtain the material to have the right vibrancy and color.
A plastic can be colored using either raw pigment or a masterbatch.
Dry powders known as raw pigments are combined with water to produce a consistency akin to that of paint or dye (dependent on the requirement).
However, masterbatches are more sophisticated.
The alternatives to using masterbatches are purchasing a finished product or compounding on-site from raw components. Masterbatches require more storage space and take longer to produce than pure pigments. The carrier and the additive are exposed to higher heat, which is another drawback.
What is Masterbatch?
Masterbatches are plastic pellets that contain a high proportion of additives and/or pigments compared to the final application.
These are added to the raw polymer during later process steps like injection molding, film or fiber manufacturing in order to color it or precisely adjust its properties.
The use of a masterbatch enhances process dependability compared to pastes, powders, or liquid additives due to the accurately calculated pigment share in each pellet.
The masterbatch also has the added benefit of being very simple to process because it eliminates the need to handle vast quantities of powder. Its use is advantageous in terms of workplace pollution and environmental effects.
To impart plastic attributes that would not otherwise be present, an additive masterbatch is used. These characteristics can include flexibility, flame resistance, and anti-static.
A highly concentrated chemical called a color masterbatch is used to tint plastics. Pigments or additives are mixed with a carrier substance to create a color masterbatch.
The final plastic product acquires the desired color or qualities by combining the plastic with either a colorant or an additive masterbatch.
Uses of Masterbatch
The issues caused by additive or colorant clumping or insufficient dispersion are lessened by the use of masterbatches. The concentration of masterbatch additives is larger than that of the finished polymer, yet they are evenly dispersed throughout the host resin.
Their use is similar to that of ferroalloys, which are used to add alloying elements to steels, in some ways.
With high “let-down ratios,” the masterbatches can be quite concentrated (in relation to the desired composition); for instance, one 25 kilogram bag can be used for one tonne of natural polymer. When opposed to raw additives, masterbatches are relatively diluted, which makes it possible to dose expensive components more precisely.
Dust problems that would otherwise be connected to fine-grained solid additives are minimized by the compact form of the grains in solid masterbatches. Since there is no solvent present in solid masterbatches, they have a longer shelf life because the solvent does not deteriorate with time.
The masterbatch normally makes up 40–65% of the addition, though under extreme conditions, the range might be as large as 15%–80%.
The normal ratio of masterbatch to base resin is 1 to 5%. It is possible to employ many masterbatches (colors and additives) at once. The carrier can also serve as a processing aid or plasticizer (which is typical in liquid masterbatches).
Typically, the host polymer and the masterbatch are delivered to the machines as pre-mixed granules. The machine’s screw and extrusion part is where the final mixing happens.
The foundation material and masterbatch can thus be separated, which may have negative effects. In addition, the masterbatch can be dispensed directly into the machine’s screw, either as a liquid masterbatch or as a free-flowing solid, respectively, using a peristaltic pump.
Liquid masterbatches allow for quick color changes between machine runs and extremely accurate dosing.
Benefits of Masterbatch
- Masterbatch has the capacity to increase production while taking volume into account. Furthermore, it has the ability to down-gauge due to the improved film physical properties.
- By requiring less energy to run the machine due to the high CaCO3 specific heat of the component, masterbatch aids manufacturers in reducing material costs.
- Additionally, masterbatch aids in the enhancement of a number of physical characteristics of the plastic, including higher toughness, flexural stiffness, adhesion, and printability.
- Through greater dispersion, the use of an additive masterbatch also enhances product uniformity and process stability. Less components may need to be rejected due to inconsistent hue or other crucial characteristics that have a detrimental influence on quality if masterbatches are used for more uniform dispersion.
- In their pure state, many additives are dangerous or bothersome substances. Masterbatches include the ingredient in a liquid or polymer resin. This encapsulation lessens, or in most cases completely eliminates, the additive’s potential for harm. Additionally, it eliminates the numerous risks associated with handling powders. Due to these qualities, less engineering controls and less personal protective equipment are necessary (PPE).
- Masterbatch additives are not only cleaner, but they are also safer to handle. No powdered colorant or other additives can waft, spill, or statically adhere to surfaces. The end effect is a more hygienic production area, less cross-contamination, and perhaps quicker changes between goods.
- The additive gains advantages from the masterbatch’s incorporation of the additive. During storage, the masterbatch can aid in shielding the additive from humidity, temperature, and UV exposure. This may lower the cost of materials lost to degradation by greatly extending the additive’s shelf life.
Why Choose Masterbatch?
Overall, it is easy to understand why many firms prefer masterbatch to raw pigment powders.
It is obvious that masterbatch is the most dependable and effective way to color your plastic products, offering benefits such as simpler storage and handling, fewer product waste, and a more consistent product.
The Walton Group is a significant producer and supplier of additive and color masterbatches. Contact us to see how we can support your company.