Masterbatch or plastic masterbatch, is a plastic processing aid developed in the 1980s. It is composed of excessive amounts of chemical additives, carrier resins and dispersants. Masterbatch is an aggregate obtained by evenly loading a super-normal amount of pigments (dyes) in resin. Masterbatch refers to the process of plastic processing and molding. For the convenience of operation, the required various additives, fillers and a small amount of carrier resin are first mixed and kneaded, and then measured, mixed, melted, and extruded through equipment such as extruders. The granular materials obtained by processing such as extrusion and pelletizing are called masterbatch. Masterbatch is composed of carrier resin, various fillers and various additives. The limit of additives or filler content in the masterbatch is several to ten times higher than the amount required in actual plastic products. During the molding process, the ratio of the masterbatch to the matrix resin must be adjusted according to the content of the relevant components in the masterbatch and the amount that needs to be added to the actual product. Masterbatch can usually be divided into ordinary filled masterbatch and functional masterbatch, such as color masterbatch, anti-fogging masterbatch, etc.
Masterbatch specifications
Masterbatch is a granular solid composed of particle size 0.1~3mm. 0.1mm (100μm) is a powder composed of fine particles; 1~10μm is a fine powder; 0.1~1μm is an ultra-fine powder; > 3mm particles are broken solid blocks. The smaller the particle size, the denser the resulting mixture. However, the smaller the particle size of the same solid, the easier it is for the particles to adsorb each other and form agglomerates. This agglomeration is not easy to open when mixed with another solid particle, and it is also difficult to disperse in the plastic melt.
Particle size distribution: Masterbatch powders with a wide particle size distribution are more densely packed than those with a narrow particle size distribution. Because small particle sizes can enter the gaps between large particles, but it is difficult to mix two powders with large particle size differences to achieve uniform mixing.
Masterbatch varieties
Filled masterbatch
- Fillers: such as calcium carbonate, talc, etc.;
- Coupling agents: such as carbonate silane, etc.;
- Dispersants: such as polyethylene wax and stearate;
- carrier resin.
Hygroscopic defoaming masterbatch
- Hygroscopic defoaming masterbatch is composed of metal oxide;
- resin;
- additives.
Flame retardant masterbatch
- flame retardant;
- resin;
- additive composition.
Conductive masterbatch
- long copper fiber and resin, coated and pelletized.
Foaming masterbatch
- composite foaming agent;
- lubricant;
- dispersant;
- colorant composition.
Anti-UV masterbatch
- two kinds of composite anti-UV agents;
- carrier;
- dispersant;
- additives.
Weather-resistant masterbatch
- light stabilizer;
- resin;
- additives.
Color Masterbatch
- Pigments: organic pigments, such as phthalocyanine green, etc.; inorganic pigments, such as iron oxide red, titanium white, etc.; dyes, such as reduced peach red, dispersed orange, etc.
- Dispersant;
- Carrier resin.
Classification
Masterbatches can be classified into different types based on their functions and uses, including:
Ordinary filling masterbatch
Abbreviated as filling masterbatch, mainly used to increase the physical properties of plastics, such as strength, hardness, etc.
Functional masterbatch
Such as anti-static masterbatch, cooling masterbatch, light absorbing and heating masterbatch, deodorizing masterbatch, anti UV masterbatch, and far-infrared masterbatch, which endow plastics with special functions such as anti-static, cooling, light absorbing and heating, deodorizing, anti UV, and far-infrared emission.
Antistatic masterbatch is a special type of masterbatch used to reduce the surface resistance of materials and prevent adverse effects caused by static electricity. It is obtained by high-speed mixing and extrusion molding of carriers and anti-static systems, followed by granulation. Anti static masterbatch has good compatibility with resin, which can effectively prevent static electricity accumulation and protect equipment and personnel safety.
Functional masterbatch is a concentrate of various plastic additives. Due to the difficulty in dispersing and low efficiency of directly adding additives, it is often added in the form of masterbatch. The particle size of this type of masterbatch is usually between 0.1 and 3 millimeters, which can reduce the temperature by 30-50 degrees during plastic processing, improve production efficiency and product quality.
Masterbatch processing method
Traditional plastic masterbatch processing methods can be divided into three types according to the process route: two-roller open mixing method, internal mixing method, and extrusion method. Commonly used equipment include double-roller machine, single-screw extruder, twin-screw extruder, and internal mixer. Waiting for mixing equipment. The masterbatch prepared by this method has shortcomings such as uneven distribution of additives in the carrier resin, poor cross-sectional adhesion between the additives and the carrier resin, and complicated production processes.
In response to the above shortcomings, many new processing technologies have been developed. The new masterbatch processing technologies include:
- carrier resin selection and processing technology;
- polymer wrapping technology;
- liquid phase blending method;
- Melt phase blending method;
- Molecular self-assembly technology, etc.
