In the area of plastics processing and polymer modification, laboratory double-snail squeezers have become indispensable equipment in research and development. Its high portability, precise control capabilities and multifunctional applications have resulted in the extensive use of double-snail squeezers in laboratories. The design and optimization of the screws is a key factor in maximizing the performance of the lab double-heavy. This paper will explore in depth how to enhance the performance of the double-heavy extruder through screw design to help laboratories achieve efficient and stable processing。
1. Basic structure and working principles of double-snail squeezers
The laboratory double screw squeezer is usually transported and processed by two relatively rotating screws. The advantage of a double screw squeezer compared to a single screw squeezer lies in its ability to provide a better mix of materials, a more even flow of melts and greater processing efficiency. Double-heavy structures are usually modular and can meet different processing needs by replacing different screw elements。
The design of the screws is usually divided into multiple functional segments, such as feed, solid transport, melting, mixing, exhaust, etc., each of which is designed to directly affect the overall performance of the extruder。
Thermal smelt double-snail out
2. Design of the feed section screw
The feed section is a critical part of the laboratory double-snail squeezer, which is responsible for the smooth transport of materials to subsequent processing areas. For the screw design of the feed segment, the most important is to ensure the smooth addition of materials. The main conductor commonly used here is a screwdriver that can accommodate more materials and increase their delivery capacity by increasing the snail volume。
In practical applications, the addition section screw design needs to meet different material requirements. For example, for low-condensity powders and fibre-based materials, the larger conductor screw elements with a greater depth of snails can ensure that these materials are delivered smoothly without congestion or carding. In addition, experimental data show that large-guided screwd components can increase the delivery efficiency of feed segments, usually increasing material delivery capacity by 20-30 per cent。
3. Solid transmission segment screw design
The main task of the solid transport segment is to carry the imported solid material along the screw, while promoting downstream melting and plasticization by crushing or increasing the abundance of the material. In this segment, the screws are designed to gradually compress the material by combining a large directional straight threading element with a small direction straight threading element。
Experimental data show that the use of screws designed to transition from a large to a small course can effectively pressure the material. For the transport of particulate matter, the design allows for greater compression efficiency, allowing the material to reach a higher filling density during the transport, thereby accelerating the melting process。
4. Melting and plastic section screw design
The melting and plasticization segment is one of the most critical parts of the double-snail squeezer, whose main task is to transform solid materials into a flat melt by mechanical cutting and external heating. The screw design of the melting segment requires effective conversion of mechanical energy into thermal energy and ensures that the material is melted equally。
In order to achieve an efficient melting effect, the melting segment often uses a combination of condensed blocks, reverse screw elements and asymmetrically large spiral screw elements. The synergy of these elements increases the shearing power and the melting speed of the material. The data show a 40-50 per cent improvement in melting efficiency compared to traditional designs in laboratory double-snail extruders using this design。
In addition, the use of reverse screw elements reduces the risk of thermal degradation of polymers by keeping the melt under appropriate pressure and avoiding excessive temperature increases。
5. Snail design for vent areas
The vents ejected gas, moisture and other impurities in the material mainly through high temperature and pressure. This paragraph is a key step in ensuring the purity and quality of the final product. By reducing the abundance of materials and increasing the area of free surfaces, moisture, air and volatile substances can be effectively removed. In order to achieve this objective, the vents often use a combination of large-conductor screw elements and sealed components。
Large conductor screw elements can thin the melting layer and provide sufficient time and space to emit the gas. According to experimental data, vent design can effectively reduce the content of moisture and volatilizers in materials, usually reducing moisture and volatile compositions by 10-20 per cent, thus ensuring product quality。
6. Splint design of mixed segments: improving material homogeneity
The mixed segment of the lab double screw squeezer is a critical area for ensuring the equitable distribution of materials. The screw design of the mixed segment can significantly increase the mixing strength and dispersive effect of the material by using combinations of rodents, turbo-mixing and reverse screw elements. Based on laboratory data, the particle size of the material can be reduced effectively, usually within a range of 30-40 per cent, using the design of turbo-mixed components and multiple-capture blocks. This is essential for the homogeneity of polymers。
7. Impact of screw design on the performance of double-helicopter crowding in laboratories
Experimental data show that the screw design has a significant impact on the processing performance of the lab double-heavy squeezer. Rational screw design increases the delivery efficiency of materials, melting evenly, mixing and exhausting. Unsuited design may result in overloading of equipment, increased temperature and uneven melting, affecting the quality of the final product。
For example, some experiments have shown that optimized double screw design can reduce melting time by more than 40 per cent and increase material delivery capacity by 10-20 per cent. At the same time, reasonable exhaust design can effectively reduce the moisture content of materials and reduce the risks posed by bubbles。
