What Are the Special Features and Advantages of a Lateral Vacuum Device for an Extruder?

Lateral Forced Vacuum System Diagram: Meizhilong

Traditional vacuum extraction devices are mostly placed above the extruder. The principle is to remove volatiles from the material through negative pressure. However, this method tends to pose a risk of "material overflow" during high-output processing or when processing specific raw materials. "Material overflow" refers to the phenomenon where material is sucked out at the vacuum port, leading to contamination or equipment malfunctions.

The lateral vacuum extraction device effectively avoids this problem.The design places the vacuum inlet on the side, and since the rotation direction of the screw is inward, the raw materials are continuously pressed into the screw channel during rotation, effectively preventing the material from being drawn out. This not only enhances process stability but also avoids the hassle of frequently cleaning the vacuum system. It resolves the quality issue of product discoloration caused by top vacuum backflow, and cleaning the vacuum without stopping the machine will not contaminate the product.

This is a common misconception. Many people believe that vacuuming is "the stronger, the better," but this is not actually the case. In the degassing process, the key is not the degree of vacuum, but a continuous, stable negative pressure environment and a sufficiently large pumping capacity.

An experienced operator stated, "Generally, we aim for negative pressure, but there's no need to pursue an extremely high level of vacuum. The key is to avoid blockages and material overflow, and to ensure stable operation of the vacuum system." In fact, the effectiveness of vacuuming is closely related to screw design, temperature control, and speed coordination.

In addition to the vacuum system itself, the desorption effect is also influenced by the following factors:

1. Temperature control:To release volatile substances from the material, appropriate temperature support is necessary. If the temperature is too low, the volatiles will not be sufficiently released, while too high a temperature may lead to material degradation.

Screw speed:The rotational speed determines the residence time of the material and also affects the devolatilization efficiency.

3. Threaded block design:Different combinations of threaded blocks can affect the distribution and shear state of the material, thereby influencing the release of volatile components.

The emergence of lateral vacuum extraction devices provides a more stable and safe solution for volatilization, especially suitable for process scenarios that are sensitive to volatilization materials or contain a high level of volatile impurities. Although it occupies some space, its advantages are evident from the perspective of practical application.

When selecting a vacuum system, we should comprehensively consider the process requirements, equipment layout, and material characteristics, rather than just looking at the "vacuum degree" indicator. It's not about extracting as vigorously as possible, but about extracting 'correctly'.