Innovative Application of Double Screw Extruder in Color Masterbatch Modification Processing

The color masterbatch is a highly concentrated and efficient color formulation that is produced by uniformly mixing excessive amounts of pigment with a resin using a double screw extruder to create a polymer composite. It is undeniable that the double screw extruder is the choice for processing masterbatch particles.

Optimization of various properties of the double screw extruder

The double screw extruder has a higher feeding capacity and can accommodate more material, resulting in a significant increase in the filling rate of the material within the screw.

The thickness of the material layer can be represented by h. The thicker the material layer, the higher the filling rate, the greater the production. The letter v represents the screw speed. When the screw speed is constant, the shear rate r decreases as h increases, thereby reducing the shear rate of the screw on the material. During the process of the material being pushed forward by the screw, the closer it gets to the outer circle, the higher the linear velocity, and the stronger the shear force, and the higher the material filling rate. Only when the material is close to the small circle, will the shear rate decrease. At the same time, because the material filling rate is higher, the chance of metal friction between the screw and the barrel is reduced.

This has resulted in lower energy consumption, higher product quality, longer equipment lifespan, and better stability.

Optimization of screw surface lubricity for the double screw extruder

During the process of material extrusion, if there is a high demand for residual impurities (such as films, XLPE cables), the screw needs to be removed and the surface needs to be cleaned after a period of use to prevent material carbonization and adhesion on the screw surface. This is especially necessary for color masterbatch processing where materials of different colors need to be quickly replaced.

In response to this type of demand, a formula has been designed to spray the screw surface with a wear-resistant and lubricating layer: the surface hardness of the component reaches HV3500, the color is black-gray, the coating thickness is 4.0-6.0 (μm), the operating temperature is 900°C, and the friction coefficient is 0.3. The increased surface hardness also maintains good coating toughness, adhesion, and lubricity.

Optimization design and processing technology progress for the barrel of the double screw extruder

For many years, the barrel of the double screw extruder has mainly consisted of C-type liner structures and integral liner structures, which can adapt to various polymer formulas. In color masterbatch processing, the seams inside the barrel can cause cross-contamination between different colors due to the need to frequently switch materials.

Effective energy consumption reduction for the double screw extruder

A brand-new barrel cooling and heating structure is used, and the barrel adopts a new radial cooling waterway design and imported heating elements. This not only improves temperature control efficiency but also reduces the temperature difference distribution and thermal deformation of the barrel, avoiding the production of local shear heat and hardware wear, and improving the lifespan of equipment and parts.