Description about Application

White Master Batch(TiO2 Master Batch) is a type of color master batch, it is widely used in plastic products industry, almost covering the whole plastic products industry, such as all kinds of injection products, all kinds of film, sheet, pipe and other building materials industry.

Description of production process

The disadvantages of single stage twin screw extruder with water strand pelletizing process: The traditional production process compounded by a twin screw extruder , then through water cooling strand and cutting into pellets. The biggest disadvantage of single stage twin screw extruder is that the twin screw extruder cannot bear high die pressure, so the strip extruded from the die is not dense, and the process of cooling traction process in the water tank absorbs higher moisture. Extra drying is required. On the other hand, a single-stage twin-screw die head pressure is too high, which leads to a large increase in current, and reduces the output.

In response to the above-mentioned process shortcomings, the company introduced a two-stage extruder + water ring granulation production process, the upper stage uses a twin-screw extruder, the second stage uses a conical twin-screw extruder, and the granulation method is water ring granulation. The double-stage granulation process has the following advantages:

1. The upper stage twin screw extruder L/D=48~52:1 high torque twin screw extruder, long length screw is good for sufficient compounding and dispersion. With natrual venting port or vacuum degassing port to eliminate the volatiles in the melt.

2. The second stage uses a conical twin screw extruder to compact the homogenized melt, cool and deliver to the die for granulation. The conical twin-screw extruder is able to withstand higher die head pressure, resulting in more compacted  pellets and increasing extrusion output. The dense granules can reduce the water absorption at the granulation stage while increasing the surface gloss.

   Adopts water ring granulation method. Water ring granulation can be applied to formulations with large differences in melt characteristics. For example, the masterbatch in different proportions of TiO2 content, CaCO3 powder, and fluorescent whitening agent can be successfully pelletized. On the other hand, the water ring cutting have a shorter residence time in the water, and the moisture content after the dehydrator and the vibrating screen is less than 0.1%, and no additional drying is required.

Twin screw two stage extruder unit model: