Masterbatch Manufacturing Process
What is masterbatch?
Masterbatch is a granular material created by blending different additives, fillers, and a small quantity of carrier resin in the plastic processing and molding procedures to enhance operational convenience. This involves the measurement, mixing, melting, extrusion, granulation, and other processes facilitated by extruders and additional equipment. The resulting product is known as masterbatch and is comprised of carrier resin, assorted fillers, and various additives. The concentration of additives or fillers in masterbatch can be several times to more than ten times higher than that in the final plastic products.
The development of various color masterbatch processing equipment and production processes arose based on the fundamental theory of pigment dispersion. These innovations aim to address issues related to wetting, dispersion, and dispersion stability of pigments. The overarching objectives are to achieve high quality, increased output, reduced energy consumption, and lower costs. In essence, there are numerous processing technologies available, with dry production technology and wet production technology being the primary methods.
Two Main Masterbatch Manufacturing Processes
The dry production method involves the application of additives to treat the pigment surface, utilizing the viscosity of resin melt for shearing, dispersing, and stabilizing the pigment. Currently, common processing technologies include high-speed mixers, twin-screw extruders, and internal mixers.
On the other hand, the wet production process employs mediums such as solvents and water, along with mechanical force, to disperse the pigment finely and wet the surface. Leveraging the lipophilic characteristics of pigments, this process involves transforming the pigments into the dispersant phase and stabilizing them through phase transformation technology.
Methods for the Masterbatch Manufacturing Process
Ink Method: In the ink method, which aligns with its name, the production process for Color Masterbatch involves applying a low molecular protective layer onto the pigment surface through three-roll grinding. Following this, the finely ground color slurry is combined with the carrier resin, plasticized using a two-roll plasticizer (also known as a two-roll open mixer), and ultimately granulated through a single-screw or twin-screw extruder.
Washing Method: Alternatively, the washing method entails grinding the pigment, water, and dispersant to reduce pigment particles to less than 1 μm. The pigment is then transferred into the oil phase through a phase transfer method, followed by drying to obtain the color masterbatch. This process necessitates organic solvents and corresponding solvent recovery devices for phase conversion.
Kneading Method: The kneading method involves mixing the pigment with an oily carrier, where the pigment is washed from the aqueous phase into the oil phase through kneading. Simultaneously, the pigment's surface is coated by the oily carrier to disperse and stabilize the pigment, preventing condensation.
Metal Soap Method: In the metal soap method, the pigment's particle size reaches 1 μm after grinding. At a specific temperature, a soap solution is added to ensure the even wetting of the surface layer of each pigment particle by the soap solution, forming a layer of saponification solution. When the metal salt solution is introduced, it reacts with the saponification layer on the pigment surface, creating a protective layer of metal soap (such as magnesium stearate). This safeguards the ground pigment particles from flocculation, maintaining a certain level of fineness.
Masterbatch Manufacturing Process Flow
The manufacturing process for masterbatch adheres to stringent standards, predominantly employing the wet process. This involves the creation of masterbatch through water phase grinding, phase transformation, water washing, drying, and granulation to ensure the highest product quality.
During the pigment grinding phase, various tests are conducted, including the measurement of sanding slurry fineness, assessment of sanding slurry diffusion performance, determination of sanding slurry solid content, and evaluation of color slurry fineness.
Masterbatch, an essential colorant in plastic products, undergoes a meticulous manufacturing process. The masterbatch granulator operates on the principle of enhancing the versatility of masterbatch applications in plastic products through the intricate structure within the plastic. This modification strengthens the gravitational interaction between molecules, resulting in robust and durable plastics. The masterbatch production process strictly adheres to the wet process, and the screw of the masterbatch granulator follows the building block principle.
Optimization and rational configuration of the masterbatch granulator are carried out based on the material system and process formula requirements. Parameters such as the length-diameter ratio, machine structure, screw arrangement, screen change structure, exhaust quantity and position, feeding mode, etc., are adjusted to meet processing needs.
Steps of Masterbatch Manufacturing Process
Step 1: Weighing - Toner, carrier, lubricant, dispersant, and other additives should be accurately weighed based on the required process weight. Higher accuracy is preferable.
Step 2: Mixing - Add the weighed additives into the high-speed mixer following the process flow.
Step 3: Extruder - Set the extruder according to the masterbatch carrier temperature. Start it after a specific holding time, gradually increasing from slow to fast.
Step 4: Bracing - Once the die is discharged, move the strip to the pelletizer at a consistent speed, passing through the dryer or suction dryer midway.
Step 5: Cutting and Pulling - As the strip reaches the pelletizer's feed inlet, slowly increase the pelletizer's speed.
Step 6: Packaging - Packaging the product according to customer requirements.
Step 7: Subsequent Adjustment - After the entire equipment set operates normally for a week, sequentially adjust the speed to reach the normal production speed.
Additionally, during the pigment grinding process, perform various tests such as measuring the fineness of sanding slurry, assessing the diffusion performance of sanding slurry, determining the solid content of sanding slurry, and measuring the fineness of color slurry.
Masterbatch Production Process
Polyethylene with a melt index of 50 exhibits high fluidity, making it ideal for manufacturing various functional masterbatches, including those for filling, antioxidants, longevity, flame retardants, and antibacterial purposes. It is well-suited for the production of items such as plastic flowers, grass, simulated turf, plants, plastic dipping powder, powder coating, injection molding of small objects, plastic-modified substrates, surface coating, and sole foaming.
This high-pressure polyethylene (LDPE) with a melt index of 50 is pure, ash-free, and not recycled, ensuring a consistent and reliable supply. Whether you are involved in masterbatch production or engaged in injection molding and coating processes, it offers excellent cost performance.