In the manufacturing fields of new energy materials, rubber modification, sealant production, etc., the dispersion uniformity, oxygen content control, and bubble elimination ability of the material mixing process directly determine the performance and qualification rate of the end products.
Analysis of the core technology of vacuum kneading machine
The vacuum kneading machine is a specialized mixing equipment developed for high viscosity and high elastoplastic materials. It is designed and manufactured strictly in accordance with the JB/T6489-2007 national kneading machine industry standard. The core technology revolves around the three core areas of "vacuum environment empowerment+efficient mixing guarantee+precise process control", integrating multiple fields of technology such as mechanical structure, vacuum system, temperature control system, and automation control to achieve fine processing of high viscosity materials.
（1） Core structural technology
The structural design of a vacuum kneading machine directly determines its mixing efficiency and product quality. It mainly consists of six core modules: kneading part, machine base part, hydraulic system, transmission system, vacuum system, and electronic control system. Each module works together to ensure stable and efficient operation of the equipment.
Kneading core components: Adopting a W-shaped sealed cylinder body and dual axis low-speed blade design, the blades are mostly Sigma or Z-shaped, and the two shafts rotate in opposite directions at different speeds (speed ratios are usually 1.5:1 to 2:1). The clearance between the blades and the cylinder wall is precisely controlled at 1-5mm, which can eliminate mixing dead corners and ensure that every material in the cylinder can be fully kneaded and sheared. The parts of the cylinder body and blade that come into contact with the material are made of SUS304 stainless steel. Special materials such as SUS316L or Hastelloy can be used in special scenarios to prevent material contamination, improve equipment wear resistance and corrosion resistance, and adapt to strong corrosion and high wear production scenarios.
Vacuum sealing technology: Adopting a combination sealing structure, the shaft seal uses a PTFE V-ring or packing combination, combined with a vacuum box balance structure, which can ensure the sealing of the cylinder body, maintain a stable vacuum environment, and prevent material leakage or black particle pollution caused by shaft seal wear. This design is particularly important for products with high cleanliness requirements such as sealants and silicone rubber.
Transmission and Hydraulic Technology: The transmission system consists of a motor, a reducer, and gears. The motor speed is transmitted to the reducer through an elastic coupling, which then drives the blades to rotate. It supports variable frequency drive speed regulation and can flexibly adjust the speed according to material characteristics and process requirements, adapting to the mixing needs of different viscosity materials. The hydraulic system is driven by a hydraulic station and controls the oil cylinder to complete actions such as opening the cover and flipping the cylinder. The system is designed with a pressure of usually 7.0 MPa and can achieve various discharge methods such as hydraulic flipping cylinder tilting, ball valve discharge, screw extrusion, etc. It is suitable for the discharge requirements of materials with different viscosities, ensuring clean and residue free discharge.
（2） Vacuum system technology
The vacuum system is the core competitiveness of the vacuum kneading machine, consisting of a vacuum pump, a buffer tank, and a sealing strip. The buffer tank can prevent materials from being sucked into the vacuum pump, ensuring stable operation of the equipment. The equipment can adjust the vacuum degree inside the cylinder to -0.09MPa to above -0.098MPa according to production needs. During the mixing process, it continuously extracts air, moisture, and low molecular weight volatiles from the chamber, solving problems such as residual material bubbles and oxidation deterioration from the root. At the same time, it can also drive the chemical balance to move towards the positive reaction direction, accelerate the reaction process, and improve product performance and purity.
（3） Precise temperature control technology
Adopting a jacket type cylinder design, steam, circulating heat transfer oil (electric heating) or cooling water can be introduced into the interlayer to achieve flexible switching between heating and cooling, adapting to the process requirements of different materials. Equipped with high-precision temperature sensors and intelligent temperature control systems, the temperature control accuracy can reach ± 1 ℃. It can monitor the temperature inside the cylinder in real time and provide feedback adjustment to avoid material degradation caused by local overheating. It can also prevent materials from being fully mixed due to low temperature, especially suitable for temperature sensitive materials and production scenarios that require specific reaction temperatures. For example, in the preparation of BMC bulk molding materials, it is necessary to maintain low temperature to avoid premature curing, and in the production of hot melt adhesives, high-temperature liquefied materials are required for easy mixing.
（4） Automation Control Technology
Equipped with a PLC intelligent control system, it supports both manual and automatic control modes, and can preset process parameters such as mixing time, temperature, speed, vacuum degree, etc., achieving automated operation of the entire process of feeding, mixing, degassing, discharging, and cleaning, reducing manual operation errors, and ensuring the stability of batch product quality. At the same time, it can record various parameters in real-time during the production process, facilitating production traceability and process optimization, reducing labor costs and operational difficulties, and adapting to the needs of large-scale mass production.